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Delogu, Ilenia. "Virus chikungunya et traitement antiviral." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX20668/document.
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Les Alphavirus sont des virus à ARN enveloppés, d’un diamètre de 70 nm, à structure icosaédrique à symétrie de type T=4 (Choi et al. 1991; Cheng et al. 1995; Garoff et al. 2004). Ces virus, dont la répartition est mondiale, sont capables d’infecter une grande variétés d’animaux vertébrés (mammifères, oiseaux, poissons). Ces virus sont des arbovirus, c’est-à_dire des virus transmis par des arthropodes. Dans le cas des Alphavirus, la vectorisation est faite par des moustiques appartenant à plusieurs espèces. A ce jour, 29 espèces d’Alphavirus ont été identifiés, dont au moins 6 sont pathogènes pour l’Homme. Chez l’Homme, certains Alphavirus sont responsables d'encéphalites, d'arthrites, de fièvres, d'éruptions cutanées et peuvent être fatals (Thiruvengadam et al. 1965; Pialoux et al. 2006).Le premier Alphavirus isolé fut l'Encephalite Equine de l'Ouest (WEEV), en 1930 (Meyer et al. 1931). Les virus de l'encéphalite de l'Est (VEEV) et le virus de l'Encephalite Equine du Vénézuéla (VEEV) furent isolés respectivement en 1933 et 1938 (Gibbs EP. 1976 ; Beck et al. 1938 ; Kubes et al. 1939). Le Virus Sindbis isolé en Egypte en 1952 (Taylor et al. 1955), fut le premier Alphavirus responsables d’arthrites à être isolé. La mise en évidence de l'existence du CHIKV se fera 1952 en Tanzanie (Robinson 1955) (Lumsden 1955). Suivent alors les découvertes de l'ensemble des autres Alphavirus. Le South Elephent Seal virus (SESV), identifié en 2000 sur l'île australienne de Macquarie, est à l’heure actuelle le dernier Alphavirus découvert. La phylogénétique des souches de Chikungunya permet d’identifier des clades différents pour les souches d’Afrique de l’Est, de l’Ouest ou d’Asie, et l’analyse phylogénétique est très proche du O’Nyong-Nyong (Powers et al. 2000), Le séquençage de différents isolats de l’épidémie de 2005, a permis de mettre en évidence chez certains d’entre eux une mutation dans la glycoprotéine de l'enveloppe plus précisément dans E1, (Schuffenecker et al. 2006). Cette mutation entraine la substitution d'une arginine en position 226 au lieu de la valine (A226V), est un élément clé pour déterminer le choix d'un nouveau vecteur pour la transmission ou Aedes albopictus (qui le transmet sur l'île de La Réunion) par rapport au vecteur Aedes aegypti (Tsetsarkin et al. 2007). Cette mutation a ensuite été également trouvée en Inde en 2007. (Arankalle et al. 2007; Kumar et al. 2008; Santhosh et al. 2008).Le tableau clinique classique débute souvent par l’apparition brutale d’une forte fièvre (40°C) pendant 3 / 10 jours accompagnée de frissons intermittents (Deller et al.1967). La fièvre est, dans certains cas, bi-phasique, c’est-à-dire qu’elle diminue durant un ou deux jours, avant de remonter brutalement. Elle est généralement suivie d’érythèmes, de courbatures douloureuses ou myalgies et douleurs musculaires (Ozden et al. 2007) en particulier celles impliquant la douleur au niveau des extrémités (poignés, phalanges et chevilles) (Robinson 1955; Jadhav et al. 1965; Thiruvengadam et al. 1965). Egalement migraine, éruptions cutanées maculo-papuleuses parfois prurigineuses. L'éruption touchant le thorax et le visage les mains et les pieds, chez les enfants ont été observées des éruptions de type bulleux accompagné par un détachement cutané (Talarmin et al. 2007). L'évolution de la maladie régresse progressivement. Il n’y a aucun traitement antiviral efficace contre le CHIKV. Le traitement est donc essentiellement symptomatique et composé d'antalgiques non salicylés, de paracétamol et d'anti-inflammatoires non stéroïdiens. Ce travail se compose de deux parties : 1 partie sur l’étude phylogénétique du CHIKV et 1 partie sur l'étude des molécules antivirales. [...]The Alphavirus RNA viruses are enveloped with a diameter of 70 nm, icosahedral structure with symmetry of type T = 4 (Choi et al. 1991; Cheng et al. 1995; Garoff et al. 2004). These viruses, whose distribution is worldwide, can infect a wide variety of vertebrates (mammals, birds, fish). These viruses are arboviruses, is à_dire viruses transmitted by arthropods. In the case of Alphavirus, the vectorization is done by mosquitoes from several species.To date, 29 species of Alphavirus have been identified, including at least six are pathogenic for humans. In humans, some are responsible for Alphavirus encephalitis, arthritis, fever, rash and can be fatal (Thiruvengadam et al. 1965; Pialoux et al. 2006).The first was isolated Alphavirus Equine Encephalitis West (Weeve) in 1930 (Meyer et al. 1931). The encephalitis virus Eastern (VEEV) and virus Venezuelan equine encephalitis (VEEV) were isolated respectively in 1933 and 1938 (Gibbs EP. 1976; Beck et al. 1938; Kubes et al. 1939 ). Sindbis virus isolated in Egypt in 1952 (Taylor et al. 1955), was the first Alphavirus responsible for arthritis to be isolated. The demonstration of the existence of CHIKV in Tanzania will be 1952 (Robinson 1955) (Lumsden 1955). Then follow the discoveries of all other Alphavirus. The South Elephent Seal virus (SESV), identified in 2000 on the Australian island of Macquarie is now the last Alphavirus discovered. The phylogenetic strains of Chikungunya can identify different clades for strains of East African, Western or Asian, and phylogenetic analysis is very close O'Nyong-Nyong (Powers and al. 2000), The sequencing of different isolates of the epidemic of 2005, helped to highlight some of them a mutation in the envelope glycoprotein more specifically in E1 (Schuffenecker et al. 2006). This mutation causes the substitution of an arginine at position 226 instead of valine (A226V), is a key element in determining the choice of a new vector for the transmission or Aedes albopictus (which transmits on the island of La meeting) with respect to the vector Aedes aegypti (Tsetsarkin et al. 2007). This mutation was later also found in India in 2007. (Arankalle et al. 2007; Kumar et al. 2008; Santhosh et al. 2008).The classic presentation often begins with sudden onset of high fever (40°C) for 3 / 10 days intermittent chills (Deller and al.1967). Fever is, in some cases, bi-phasic, that is to say, it decreases during a day or two before rising sharply. It is usually followed by erythema, pain or stiffness of muscle pain and muscle aches (Ozden et al. 2007) especially those involving pain in the extremities (wrists, ankles and knuckles) (Robinson 1955; Jadhav et al. 1965; Thiruvengadam et al. 1965). Also headache, rash maculopapular itchy sometimes. The rash affecting the chest and face hands and feet, children were seen eruptions like bullous skin accompanied by a detachment (Talarmin et al. 2007). The evolution of the disease regresses gradually. There is no antiviral therapy effective against CHIKV. Treatment is essentially symptomatic and consists of non-analgesic salicylates, paracetamol and anti-inflammatory drugs. This work consists of two parts: one part on the phylogenetic study of CHIKV and one part of the study of antiviral molecules. [...]
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Koga, Rosemary de Carvalho Rocha. "ASPECTOS CLÍNICOS E SOROLÓGICOS DE INDIVÍDUOS COM SINAIS E SINTOMAS DE FEBRE CHIKUNGUNYA." Pontifícia Universidade Católica de Goiás, 2017. http://tede2.pucgoias.edu.br:8080/handle/tede/3664.
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Introduction: Chikungunya fever (FCHIK) is a disease of abrupt onset, transmitted by arthropod mosquitoes intermediate hosts of the Chikungunya virus (CHIKV). The illness has a significant impact on the quality of life of the affected person. Since a disease causes intense and prolonged symptoms of polyarthralgia and myalgia, it requires health care, during a recovery, more than other arboviruses. The objective of this study was to study clinicians and clinicians suggestive of FCHIK, residing in the States of Amapá and Goiás, aiming to correlate the results of laboratory tests with the presented symptomatology. Materials and methods: The study was carried out at the Center for Immunological Studies and Research of the Pontifical Catholic University of Goiás, Goiânia, and in Emergency Care Units in the cities of Macapá, Oiapoque and Santana-AP. The study population consisted of 80 individuals with suspected FCHIK and for investigators of inflammatory markers, the control group consisted of 20 blood samples from healthy donors from Goiana Central de Serologia e Imunohematologia. Viral RNA extraction was performed, followed by RNA detection by Real-Time Polymerase Chain Reaction. In addition to ELISA for detection of IgM and IgG against Chikungunya virus. Participants symptoms were correlated with serology and Creactive protein (CRP), which was evaluated in healthy subjects and in people with FCHIK. Results: No data presented for detection of viral RNA by RT-qPCR for CHIKV, but three samples were positive in this technique for zika virus and one for dengue subtype 1 (DENV1). In an enzyme-linked immunosorbent assay, 26 samples were positive for IgG and 3 for IgM. Regarding the stage of the disease, 10 were in the acute phase, 04 in the subacute phase and 12 in the chronic phase. Correlated the results of the serology with a symptomatology it was observed that the acute phase, all have fever, 90% headache, 70% arthralgia and 60% edema. (100%), myalgia and edema (75%). (100%), arthralgia (92%) and myalgia (75%). When comparing participants with negative serology, n = 54, the most prevalent symptoms were rash, headache, fever, and arthralgia. The CRP levels in individuals infected with more than four symptoms were higher when compared with healthy individuals. Conclusion: The study focused on people with a clinical picture characteristic of FCHIK. The most common symptom in the three phases presented for arthralgia, followed by edema and myalgia, a fever was frequent only in the acute phase. All participants were negative in the evaluation of viral RNA by RT-qPCR for CHIKV, for the virus has a short duration in the body, and this methodology is limited to the time of symptom onset and sample collection, DENV and ZIKV. IG G. Those with negative serology for CHIKV, despite taking into account the joints, symptoms common to other arboviruses. CRP levels have been shown to be high relative to healthy subjects.
Introdução: A Febre Chikungunya (FCHIK) é uma doença de início abrupto, transmitida por mosquitos artrópodes hospedeiros intermediários do vírus Chikungunya (CHIKV). A enfermidade representa um significativo impacto na qualidade de vida da pessoa afetada. Uma vez que a doença causa sintomas intensos e prolongados de poliartralgia e mialgia, requerendo atenção de saúde, durante a recuperação, mais do que outras arboviroses. Objetivou-se estudar aspectos clínicos e sorológicos de indivíduos apresentando quadro clínico sugestivo de FCHIK, residentes nos Estados de Amapá e Goiás, visando correlacionar os resultados de testes laboratoriais com a sintomatologia apresentada. Materiais e métodos: O estudo foi realizado no Núcleo de Estudos e Pesquisa Imunológica da Pontifícia Universidade Católica de Goiás, em Goiânia, e em Unidades de Pronto Atendimento de Saúde das cidades de Macapá, Oiapoque e Santana-AP. A população de estudo foi constituída de 80 indivíduos com suspeita de FCHIK e para comparar os marcadores inflamatórios, o grupo controle foi constituído de 20 amostras de sangue de doadores saudáveis da Central Goiana de Sorologia e Imunohematologia. Foi realizada a extração do RNA viral, seguido de detecção do RNA por meio de Reação em Cadeia de Polimerase em Tempo Real. Além de ELISA para detecção de IgM e IgG específicos para o CHIKV. Os sintomas dos participantes foram correlacionados com o resultado da sorologia e da proteína C reativa (PCR), que foi avaliada em indivíduos saudáveis e em pessoas com FCHIK. Resultados: Nenhuma amostra apresentou limiar de detecção do RNA viral por RT-qPCR para CHIKV, porém três amostras foram positivas nessa técnica para vírus zika (ZIKV) e uma para dengue subtipo 1 (DENV1). Em ensaio imunoenzimático, 26 amostras foram positivas para IgG e 3 dessas para IgM. Em relação ao estágio da doença, 10 encontravam-se em fase aguda, 04 em fase subaguda e 12 em fase crônica. Correlacionados os resultados da sorologia com a sintomatologia observou-se que os de fase aguda, todos tiveram febre, 90% cefaleia, 70% artralgia e 60% edema. Enquanto que, os de fase subaguda tiveram: artralgia e cefaleia (100%), mialgia e edema (75%). Os de fase crônica tiveram edema (100%), artralgia (92%) e mialgia (75%). Quando comparados os participantes com sorologia negativa, n=54, os sintomas mais apresentados foram exantema, cefaleia, febre e artralgia. Os níveis de PCR nos indivíduos infectados e que apresentavam mais de quatro sintomas foram maiores quando comparados com indivíduos saudáveis. Conclusão: O estudo focou em pessoas com quadro clínico característico para FCHIK. O sintoma mais comum nas três fases apresentadas foi a artralgia, seguido de edema e mialgia, a febre foi frequente somente na fase aguda. Todos os participantes foram negativos na avaliação do RNA viral por RT-qPCR para CHIKV, pois o vírus tem uma curta duração no organismo, e esta metodologia é limitada ao tempo de início dos sintomas e coleta de amostra, ainda assim foi encontrado RNA viral do DENV e ZIKV. Alguns participantes foram positivos para sorologia IgG. Aqueles com sorologia negativa para CHIKV, apesar de terem dor nas articulações, tinham sintomas comuns a outras arboviroses. Os níveis de PCR demonstraram-se elevados em relação aos indivíduos saudáveis.
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Hiroki, Carlos Hiroji. "Papel das Neutrophil Extracellular Traps no controle da infecção por Chikungunya." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/17/17147/tde-01022019-105719/.
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O Chikungunya é um vírus reemergente que causa uma doença caracterizada por uma artralgia incapacitante que afeta milhares de pessoas. A resposta inata contra este vírus é bem descrita pela participação de macrófagos, células dendríticas e células NK, porém há poucos trabalhos que demonstram o papel dos neutrófilos nesta infecção. As Neutrophil Extracellular Traps (NETs) constituem uma rede de DNA complexada a enzimas antimicrobianas que foram descritas por combaterem diversos patógenos. Porém, não há trabalhos que demonstram sua importância em infecção por Chikungunya. Nosso objetivo foi investigar se há produção de NETs na infecção por Chikungunya, descrever seus mecanismos e demonstrar sua importância in vitro e in vivo. Observamos que neutrófilos murinos e humanos incubados com Chikungunya são capazes de produzir NETs via Toll-Like 7 e produção de espécies reativas de oxigênio. Estas NETs foram capazes de capturar o vírus e impedir sua infecção in vitro. Mais além, animais infectados com Chikungunya e tratados com rhDNAse apresentam maior carga viral e são mais suscetíveis à infecção, demonstrando sua importância in vivo. Por fim, pacientes diagnosticados em fase aguda de infecção por Chikungunya possuem elevados níveis de NETs correlacionados com uma alta carga viral.Chikungunya is a reemerging virus which causes a disease characterized by an incapacitanting arthralgia and affects thousands of people. Innate response against this virus is well described by participation of macrophages, dendritic cells and NK cells, however few works demonstrate the roe of neutrophils in this infection. Neutrophils Extracellular Traps are a web of DNA complexed with antimicrobial enzymes which were described for fighting against many pathogens. However, there are no works which demonstrate its relevance in Chikungunya infection. Our objective was to evaluate if there is release of NETs in Chikungunya infection, describe its mechanisms and demonstrate its relevance in vitro and in vivo. We observed that mouse and human neutrophils incubated with Chikungunya are able to produce NETs via Toll-Like 7 and reactive oxygen species production. These NETs were able to capture the virus and inhibit its infection in vitro. Moreover, animals infected with Chikungunya virus and treated with rhDNAse demonstrated higher viral load and are more susceptible to the infection, showing its importance in vivo. Lastly, patients diagnosed during acute infection of Chikungunya infection have high levels of NETs correlated with a high viral load.
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MARQUES, Nuno Miguel da Silva. "Dengue e chikungunya: arboviroses emergentes em Angola." Doctoral thesis, Instituto de Higiene e Medicina Tropical, 2017. http://hdl.handle.net/10362/57140.
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Nas últimas décadas tem-se assistido a uma redução do número de casos de malária em muitos países da África Subsariana. No entanto, o sobrediagnóstico de malária em zonas endémicas é frequente.
É desconhecida a relevância clínica das arboviroses no diagnóstico diferencial da malária em Angola. Historicamente a principal arbovirose descrita em Angola tem sido a febre amarela. No entanto, existiu evidência de circulação de outros arbovírus como o vírus
chikungunya durante o período colonial. Após a independência do país, que ocorreu em 1975, foram registados em vários países casos esporádicos de dengue importados de Angola. Deste modo, até 2012, o desconhecimento sobre a prevalência de arboviroses, como dengue e chikungunya era uma realidade.
Foi realizado um estudo observacional e transversal com o objectivo de identificar a presença do vírus dengue e do vírus chikungunya. Incluíram-se doentes com síndroma febril (temperatura corporal ≥37,5ºC à admissão e/ou história de febre) e com clínica
compatível com malária. Foram aplicados testes de diagnóstico rápido (TDR) [SD BIOLINE®], que são ensaios imunocromatográficos para detecção de: Ag NS1 e anticorpos IgG / IgM contra o vírus dengue; Ig M contra o vírus chikungunya; Ag HRPII- P.f e pLDH-P.v de Plasmodium spp. Foram ainda colhidas amostras para realização de técnicas de biologia molecular (PCR ou RT-PCR) para Plasmodium spp., dengue e
chikungunya.
O estudo decorreu em duas fases, a primeira, de Fevereiro a Abril de 2012, na província do Huambo e a segunda, de Maio a Junho de 2015, na província de Benguela, tendo sido incluídos um total de 542 doentes. Na primeira fase incluíram 242 doentes, maioritariamente do sexo feminino (59,9%). A média de idades foi de 16 anos. A clínica
mais frequente foi a respiratória, nomeadamente tosse (60,7%) e corrimento nasal (48,3%) seguida das queixas álgicas, cefaleias (40,1%), dores abdominais (36,4%), artralgias (33,9%) e mialgias (30,6%). As taxas de positividade do TDR foram as seguintes: malária (2,1%), chikungunya (1,7%) e dengue (0,8%). Verificou-se um caso
de positividade concomitante para dengue (Ag NS1+) e chikungunya. Na segunda fase foram incluídos 300 doentes, também maioritariamente do sexo feminino (61%). A média de idades foi de 19 anos. A clínica mais frequente foi a álgica, cefaleias (53%), mialgias
(45%), artralgias (43,3%), dores abdominais (38,3%) seguida da respiratória, tosse (26,3%) e corrimento nasal (16,3%). As taxas de positividade do TDR foram as seguintes: malária (36,7%), chikungunya (18,3%) e dengue (3,3%). Verificaram-se 28 casos de positividade concomitante para malária e chikungunya e 4 para malária e dengue (1 com Ag NS1+ e 3 com IgM+). Nesta segunda fase foi ainda identificada por RT-PCR uma sequência genómica do vírus chikungunya que revelou uma elevada identidade com uma estirpe circulante nos Camarões em 2006.
Este estudo foi pioneiro na investigação recente de arbovírus em Angola, documentando a sua circulação, assim como também possibilitou, pela primeira vez, a aplicação em larga escala de TDR para dengue e chikungunya neste país.In recent decades, there has been a reduction in the number of malaria cases in many sub- Saharan African countries. However, the overdiagnosis of malaria in endemic areas is frequent. The clinical relevance of arboviruses in the differential diagnosis of malaria in Angola is unknown. Historically the main arbovirosis described in Angola has been Yellow Fever. However, there was evidence of circulation of other arboviruses such as the Chikungunya virus during the colonial period. After the country's independence, which occurred in 1975, sporadic dengue cases imported from Angola were registered in several countries. Thus, until 2012, the lack of knowledge about the prevalence of arboviruses, such as Dengue and Chikungunya, was a reality. An observational and cross - sectional study was carried out to identify the presence of Dengue virus and Chikungunya virus. Patients with febrile syndrome (body temperature at admission ≥37.5 ° C and / or history of fever) and clinically compatible with malaria were included. Rapid diagnostic tests (TDR) [SD BIOLINE®], which are immunochromatographic assays for the detection of: Ag NS1 and IgG / IgM antibodies against Dengue virus have been applied; Ig M against the Chikungunya virus; Ag HRPII- P.f and pLDH-P.v from Plasmodium spp. Biological samples were also collected for molecular biology techniques (PCR or RT-PCR) for Plasmodium spp., Dengue and Chikungunya. The study was conducted in two phases, the first from February to April 2012 in Huambo province and the second from May to June 2015 in Benguela province, with a total of 542 patients. In the first phase 242 patients were included, mostly female (59.9%). The average age was 16 years. The most common symptoms were respiratory such as cough (60.7%) and nasal discharge (48.3%) followed by painful complaints, headache (40.1%), abdominal pain (36.4%), arthralgia (33 , 9%) and myalgias (30.6%). The rates of positive TDR were as follows: malaria (2.1%), Chikungunya (1.7%) and Dengue (0.8%). There was a case of concomitant positivity for Dengue (Ag NS1 +) and Chikungunya. In the second phase 300 patients were included, also mostly female (61%). The average age was 19 years. The most frequent clinic complaints were headaches (53%), myalgias (45%), arthralgia (43.3%), abdominal pains (38.3%) followed by cough (26.3%) and runny nose (16.3%). The rates of positive TDR were as follows: malaria (36.7%), Chikungunya (18.3%) and Dengue fever (3.3%). There were 28 cases of concomitant positivity for malaria and Chikungunya and 4 cases for malaria and Dengue (1 with Ag NS1 + and 3 with IgM +). In this second phase a Chikungunya genomic sequence was also identified by RT-PCR which revealed a high identity with a circulating strain in Cameroon in 2006. This study was relevant for the recent investigation of arbovirus in Angola, documenting its circulation, as well as for allowing for the first time the large-scale application of TDR to Dengue and Chikungunya in this country.
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Thiberville, Simon-Djamel. "Investigations épidémiologiques, cliniques et thérapeutiques du chikungunya." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM5016.
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Le virus chikungunya est un arbovirus, transmis par les moustiques du genre Aedes, qui provoque des arthralgies invalidantes et parfois des rhumatismes chroniques. Dans une première partie nous avons décrit les aspects ambulatoires cliniques, biologiques et virologiques du chikungunya (CHIK) de la phase aiguë jusqu'au 300ème jour lors de l’épidémie de la Réunion en 2006. Des scores d’aide au diagnostic ont été élaboré et une étude de la diversité virale intra-hôte a été réalisée. Pour compléter nos premiers résultats nous avons étudié une épidémie survenue en République du Congo en 2011. La description clinique était similaire à celle identifiée lors de l’épidémie de la Réunion. L’évaluation du score clinique ne permettait pas de le proposer comme outil diagnostique à l’échelle individuelle mais apparaissait comme un bon marqueur pour le suivi de la courbe épidémique. Une étude de séroprévalence et une analyse phylogénétique complètent ce travail. Le dernier travail porte sur l’utilisation de la chloroquine à la phase aiguë du CHIK lors d’une prise prophylactique chez le singe et lors d’un essai clinique chez l’homme. Le principal effet de ce type de traitement semble lié son action immuno-modulatrice ; en prise préventive il provoque une exacerbation de la symptomatologie aiguë tandis qu’en prise à la phase précoce de la maladie il augmente le risque d’évolution vers des arthralgies chroniques. En conclusion nous avons réalisé une description des formes ambulatoires du CHIK, identifié des facteurs de risques de formes chroniques, proposé des scores d’aide au diagnostic et argumenté la contre-indication de l’utilisation de la chloroquine à la phase aiguë du CHIKChikungunya virus (CHIKV) is an arthropod-borne virus transmitted by Aedes mosquitoes that cause debilitating arthralgia and possible chronic rheumatism. In the first part we describe the clinical, biological and virological presentation of outpatients with chikungunya disease (CHIK) from the acute stage to the chronic stage at day 300, during the outbreak in the Reunion Island in 2006. We elaborated scores for CHIK diagnosis and we also analysed the intra-host genetic diversity.To complete our first results, we investigated a CHIKV outbreak, which occurred in the Republic of Congo in 2011. The clinical presentation was similar to the first description of the Reunion island outbreak. We assessed the clinical score which appeared to be unusable at the individual level but was still relevant to follow the epidemic curve. This work was completed by seroprevalence and phylogenetic analyses.The last study presented in this thesis focused on the use of chloroquine during the acute stage of CHIK in a non-human primate (NHP) model (prophylactic use) and during a clinical trial (therapeutic use). The main effect of chloroquine treatment at the acute stage of CHIK appeared to be related to its immuno-modulatory action; in prophylactic taking, chloroquine exacerbated acute symptoms while treatment during the early stages of the disease increased the risk of acquiring chronic arthralgia.In conclusion, we provide a detailed description of CHIK outpatients and identify risk factors for the chronic stage of the disease. We propose tentative diagnostic scores and we firmly establish that the use of chloroquine at the acute phase of CHIK is contraindicated
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Enguehard, Margot. "Interaction between chikungunya and dengue viruses during co-infection in Aedes mosquito cells and in Aedes aegypti mosquito." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1161/document.
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Au cours des dernières années, de nombreuses épidémies ont emergé ou ré émergé, et sont causées par des arbovirus (arthropod-borne viruses), des virus transmis à des vertébrés par des insectes piqueurs vecteurs. Avec l'augmentation de la densité humaine dans certaines zones géographiques et le réchauffement climatique qui contribuent à l'expansion géographique des vecteurs, les maladies induites par ces virus (arboviroses) ont un impact de plus en plus important sur la santé humaine et l'économie mondiale. Il est donc déterminant d'augmenter nos connaissances sur les systèmes mis en jeux pour garantir la sécurité sanitaire des populations exposées. Les enjeux actuels reposent aussi bien sur la compréhension des virus que sur la compréhension de l'alternance d'hôtes, directement responsables de l'émergence et la dissémination des agents infectieux. Les moustiques sont des vecteurs majeurs des arbovirus comme la dengue (genre Flavivirus) et le Chikungunya (genre Alphavirus). Transmis par les mêmes moustiques Aedes aegypti et Aedes albopictus, le virus de la Dengue (DENV) est responsable de la plus importante arbovirose en zone tropicale, et le virus Chikungunya (CHIKV) est responsable dans le monde entier de centaines de milliers de cas d'infection, et les épidémies récentes ont touché les pays européens. Ainsi, il a été observé que le moustique Ae. albopictus pouvait porter simultanément CHIKV et DENV, et des cas de co-infections humaines ont été observés en Afrique. Toutefois, bien qu'en théorie les deux virus soient capables d'infecter les mêmes cellules chez l'insecte ou l'homme, il n'y a aucune étude détaillée sur les interactions au niveau cellulaire entre CHIKV et DENV lors de la co-infection d'une cellule. C'est pourquoi il est indispensable d'accroitre nos connaissances sur l'interférence éventuelle entre les virus Chikungunya et Dengue pour l'utilisation de voies cellulaires communes chez les insectes vecteurs et l'hôte humain lors de co-infectionEmergence and geographical extension of dengue (DENV), Zika (ZIKV) and chikungunya (CHIKV) viruses increase simultaneous outbreak in an increasing number of countries. To date, no vaccine or cure have yet been developed against these diseases those cause a tremendous impact on human health and in the economy worldwide. During recent simultaneous outbreaks, up to 12% of patients have been diagnosed to be co-infected by CHIKV and DENV. In addition, it was shown that the mosquitoes Aedes albopictus could carry and transmit simultaneously CHIKV and DENV. However, the pathology, as well as the epidemiology of a pathogen, relies on the interactions between several infectious agents present within an organism or a community in the environment. It is crucial to consider to which extent a host infected by a first microorganism is modified and whether its reaction to the infection by a second microorganism is consequently altered. However, there is no extensive report of Alphavirus-Flavivirus or Flavivirus- Flavivirus interactions. Our global objective is to characterize these co-infections in both mosquitoes and humans, at the cell and molecular level. To this aim, we started this project by performing sequential co- infection in different cell lines from Aedes albopictus and Aedes aegypti. We found that the permissiveness and production of DENV is enhanced in presence of CHIKV. On the contrary, there is no effect of DENV pre-infection on subsequent CHIKV co-infection. We generalized the synergistic phenomena and we showed that CHIKV pre-infection also increased the infection by DENV-1, DENV-3 and DENV-4, but also by two others re-emerging Flaviviruses, the Yellow Fever Virus (YFV), and the Zika Virus (ZIKV). Remarkably, we succeeded to establish a mosquito model of co-infection of Aedes aegypti mosquito after by different two feedings at 4 days interval. Using this sequential co-infection, we were able to show that a pre-infection of Aedes aegypti by CHIKV increase the level of DENV-2 RNA in salivary glands compare to mono-infected mosquitos. This phenotype is reminiscent of the phenotype we observed in vitro during successive infections. Altogether, our study paves the way to the characterization of molecular interaction between Flaviviruses and Alphaviruses in mosquito in vitro and in vivo. This study can be crucial for a better understanding of disease and epidemiology during simultaneous outbreaks
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VENTORIM, D. P. "DIVERSIDADE Genética de Chikungunya no Estado do Espírito Santo." Universidade Federal do Espírito Santo, 2018. http://repositorio.ufes.br/handle/10/7120.
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Previous issue date: 2018-03-05A febre chikungunya é uma arbovirose altamente debilitante, causada pelo vírus chikungunya, o qual é transmitido pela picada de mosquitos do gênero Aedes. Em 2014 foram registrados os primeiros casos da doença no Brasil, sendo constatada a presença dos genótipos asiático e Leste/Centro/Sul africano do vírus. No final de 2015, pela primeira vez, foram reportados casos no Espírito Santo (ES) e entre 2016-2017 o estado enfrentou um surto da doença. Diante disso, nós, juntamente à Secretaria Estadual de Saúde/ES e ao Laboratório Central/ES objetivamos identificar qual linhagem do vírus circula no ES; analisar características genéticas virais nas amostras estudadas e levantar dados epidemiológicos sobre a doença no estado. As amostras do estudo foram provenientes do Laboratório Central/ES e referentes ao período de março/2016 - dezembro/2017. O diagnóstico viral foi realizado por sorologia ou por técnicas moleculares. Vinte e sete amostras (diagnosticadas molecularmente) foram utilizadas na amplificação parcial e sequenciamento de dois genes codificantes de proteínas do envelope viral, E1 e E2. Seis dessas amostras foram utilizadas nas análises filogenéticas. Os resultados epidemiológicos demonstraram que no período do estudo foram reportados 2.021 casos suspeitos da febre chikungunya, sendo 412 (20,38%) confirmados. Além disso, a distribuição geográfica desses casos constatou que Vitória e Vila Velha representaram mais de 50% de todos os casos do estado. Os achados mostraram que a frequência da infecção pelo vírus chikungunya, em relação ao número de amostras referenciadas ao Laboratório Central/ES, pode ser considerada baixa. No entanto, constatou-se que a doença apresenta relevância epidemiológica e grande distribuição no estado. Os resultados filogenéticos evidenciaram que o vírus circulante pertence à linhagem Leste/Centro/Sul africana, a qual também foi constatada em diversos surtos na Europa, África e Ásia. Além disso, a caracterização molecular dos fragmentos das proteínas E1 e E2 não mostraram a presença das mutações adaptativas E1-K211E; E1-A226V; E2-L210Q e E2-I211T. Esse resultado permite sugerir que o vírus circulante no ES apresenta um potencial de disseminação menor em comparação aos vírus circulantes em grandes epidemias mundiais recentes. Devido à falta de uma vacina e à dificuldade no controle populacional do mosquito vetor, estudos sobre a diversidade genética como este tornam-se alternativas viáveis em busca de melhor entendimento e controle da febre chikungunya no Brasil e, especificamente, no ES.
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Dagley, Ashley L. "Amelioration of Chikungunya through Inhibition of the Inflammatory Response." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4996.
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Chikungunya (CHIK) is an emerging viral disease, which causes significant morbidity and mortality throughout tropical/subtropical areas of the world, including a recent outbreak in the Americas. Disease typically includes fever, rash, and arthritis. Joint involvement is generally self-limiting, but infection with Chikungunya virus (CHIKV) can lead to chronic debilitating arthritis that can last for months to years. With no vaccine and no licensed treatment, suitable animal models of CHIKV are needed to test intervention strategies. We developed a model of CHIK in DBA1/J mice that develop joint swelling, increase in inflammatory cytokines and splenomegaly in mice, which include important symptoms of disease seen in infected humans. We used this model to test the hypothesis that treatment with immune-modulatory compounds would ameliorate disease. GP1681, which suppresses TNF-α, IL-1β, and IL-6, exacerbated CHIK as indicated by increased footpad swelling and viral load. Prophylactic treatment with mDEF201, an adenovirus-vectored interferon, reduced disease, including joint swelling, virus titers at the site of virus challenge and inflammatory cytokines (IL-6, MCP-1, MIP-1α, and RANTES), although efficacy waned as treatment initiation was extended beyond virus challenge. Methotrexate treatment was also effective at ameliorating joint swelling and other disease parameters. Actemra (ACT), an anti-IL-6 antibody, reduced IL-6 levels to baseline, although the resulting improvement in footpad swelling was not significant. Combination therapy with methotrexate and ACT resulted in reduced footpad swelling. Based on our results, immune modulators have potential for the treatment of CHIKV and some of the compounds tested might have potential for clinical developmental.
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Yapa, Badal Madiththegedara Chamini Randika Wimalasiri. "Chikungunya virus transmission dynamics and immune responses in mosquitoes." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/206132/1/Badal%20Madiththegedara%20Chamini%20Randika%20Yapa%20Thesis.pdf.
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Chikungunya is a mosquito-borne viral disease that has become a public health threat in tropical and sub-tropical regions of the world. The research presented here documents the epidemiology of the disease in the Asia-Pacific region. It then examines the effect of ambient temperature on the ability of two mosquito species in Australia to transmit the virus. Finally, it investigates how gene expression in mosquitoes infected with chikungunya virus might vary depending on ambient temperature. The findings presented in the thesis increase our understanding of this neglected tropical disease and may contribute to better managing the risk of future outbreaks.
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Vega, Rua Anubis. "Émergence du virus chikungunya en Amérique et en Europe." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066197/document.
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Le virus chikungunya (CHIKV), transmis par les moustiques Aedes aegypti et Aedes albopictus, constitue un problème majeur de santé publique. Depuis 2004, des épidémies de CHIKV ont été rapportées en Afrique, en Asie, dans les îles de l'Océan Indien, et en Europe. Seule l'Amérique semblait épargnée malgré la présence de fortes densités de moustiques vecteurs et de multiples importations du virus dans le continent par des voyageurs de retour de pays où le virus circulait. Nous avons abordé dans cette thèse le risque d'émergence du CHIKV en Amérique à partir d'une évaluation de la compétence vectorielle de 35 populations d'Ae. aegypti et Ae. albopictus locaux avec différentes souches de CHIKV. Ces populations sont compétentes vis-à-vis du CHIKV avec un rôle des glandes salivaires comme "filtre" de la transmission. De plus, le génotypage des Ae. albopictus d'Amérique par microsatellites a permis d'identifier un cluster génétique de populations se caractérisant par une faible transmission des souches de CHIKV de génotype Est-Centre-Sud-africain. En octobre 2013, des souches asiatiques de CHIKV ont été signalées dans la Caraïbe. Nous avons alors évalué la réceptivité de 11 populations d'Ae. aegypti et Ae. albopictus d'Amérique vis-à-vis de CHIKV de génotype asiatique et avons mis en évidence que les deux espèces étaient compétents pour assurer la diffusion du virus sur le continent. On note aussi qu'Ae. albopictus peut faciliter la propagation du CHIKV vers l'Europe. Néanmoins, la compétence vectorielle d'Ae. albopictus de France vis-à-vis de CHIKV asiatique est affectée négativement par des températures plus basses que celles habituellement observées dans les pays tropicauxChikungunya virus (CHIKV), transmitted mainly by the mosquitoes Aedes aegypti and Aedes albopictus, is a major public health problem. Since 2004, CHIKV epidemics have been reported in Africa, Asia, the Indian Ocean Islands, and Europe. Only the Americas seemed spared despite high densities of mosquitoes and multiple introductions of the virus to the continent by travelers returning from countries where CHIKV was circulating. We have assessed the risk of CHIKV emergence in the Americas by evaluating the vector competence of 35 local populations of Ae. aegypti and Ae. albopictus infected with different strains of CHIKV. These populations were shown to be susceptible to CHIKV infection, highlighting the predominant role of salivary glands as a "filter" of transmission. Genotyping of Ae. albopictus from the Americas using microsatellites allowed the identification of a genetic cluster of populations characterized by a low transmission of CHIKV strains of the East-Central-South-African genotype. In October 2013, Asian strains of CHIKV began circulating in the Caribbean. Thus, we evaluated the susceptibility of 11 populations of Ae. aegypti and Ae. albopictus to the Asian CHIKV genotype and showed that the two species were sufficiently competent to ensure dissemination of the virus throughout the continent. Furthermore, we showed that Ae. albopictus was likely to facilitate the spread of CHIKV to Europe. However, the vector competence of French Ae. albopictus to the Asian CHIKV genotype was negatively affected by temperatures lower than those usually found in tropical countries
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Vega, Rua Anubis. "Émergence du virus chikungunya en Amérique et en Europe." Electronic Thesis or Diss., Paris 6, 2015. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2015PA066197.pdf.
Full textAbstract:
Le virus chikungunya (CHIKV), transmis par les moustiques Aedes aegypti et Aedes albopictus, constitue un problème majeur de santé publique. Depuis 2004, des épidémies de CHIKV ont été rapportées en Afrique, en Asie, dans les îles de l'Océan Indien, et en Europe. Seule l'Amérique semblait épargnée malgré la présence de fortes densités de moustiques vecteurs et de multiples importations du virus dans le continent par des voyageurs de retour de pays où le virus circulait. Nous avons abordé dans cette thèse le risque d'émergence du CHIKV en Amérique à partir d'une évaluation de la compétence vectorielle de 35 populations d'Ae. aegypti et Ae. albopictus locaux avec différentes souches de CHIKV. Ces populations sont compétentes vis-à-vis du CHIKV avec un rôle des glandes salivaires comme "filtre" de la transmission. De plus, le génotypage des Ae. albopictus d'Amérique par microsatellites a permis d'identifier un cluster génétique de populations se caractérisant par une faible transmission des souches de CHIKV de génotype Est-Centre-Sud-africain. En octobre 2013, des souches asiatiques de CHIKV ont été signalées dans la Caraïbe. Nous avons alors évalué la réceptivité de 11 populations d'Ae. aegypti et Ae. albopictus d'Amérique vis-à-vis de CHIKV de génotype asiatique et avons mis en évidence que les deux espèces étaient compétents pour assurer la diffusion du virus sur le continent. On note aussi qu'Ae. albopictus peut faciliter la propagation du CHIKV vers l'Europe. Néanmoins, la compétence vectorielle d'Ae. albopictus de France vis-à-vis de CHIKV asiatique est affectée négativement par des températures plus basses que celles habituellement observées dans les pays tropicauxChikungunya virus (CHIKV), transmitted mainly by the mosquitoes Aedes aegypti and Aedes albopictus, is a major public health problem. Since 2004, CHIKV epidemics have been reported in Africa, Asia, the Indian Ocean Islands, and Europe. Only the Americas seemed spared despite high densities of mosquitoes and multiple introductions of the virus to the continent by travelers returning from countries where CHIKV was circulating. We have assessed the risk of CHIKV emergence in the Americas by evaluating the vector competence of 35 local populations of Ae. aegypti and Ae. albopictus infected with different strains of CHIKV. These populations were shown to be susceptible to CHIKV infection, highlighting the predominant role of salivary glands as a "filter" of transmission. Genotyping of Ae. albopictus from the Americas using microsatellites allowed the identification of a genetic cluster of populations characterized by a low transmission of CHIKV strains of the East-Central-South-African genotype. In October 2013, Asian strains of CHIKV began circulating in the Caribbean. Thus, we evaluated the susceptibility of 11 populations of Ae. aegypti and Ae. albopictus to the Asian CHIKV genotype and showed that the two species were sufficiently competent to ensure dissemination of the virus throughout the continent. Furthermore, we showed that Ae. albopictus was likely to facilitate the spread of CHIKV to Europe. However, the vector competence of French Ae. albopictus to the Asian CHIKV genotype was negatively affected by temperatures lower than those usually found in tropical countries
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Punelle, Clément Pasquier Christophe. "Implication de la faune domestique et sauvage dans l'épidémie de Chikungunya dans les îles de l'Océan Indien." [S.l.] : [s.n.], 2008. http://oatao.univ-toulouse.fr/2166/1/celdran_2166.pdf.
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Pinto, Tatiana Priscilla Coelho. "Expressão e purificação da proteína E3 do vírus chikungunya (CHIKV)." Master's thesis, Expressão e purificação da proteína E3 do vírus chikungunya (CHIKV), 2013. http://hdl.handle.net/10362/10528.
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RESUMO: O vírus chikungunya (CHIKV) é um vírus de RNA, com invólucro, da família Togaviridae, transmitido por mosquitos Aedes spp. Distribuído por largas regiões de África e Ásia, causa grandes epidemias de artrite grave. A semelhança de sintomas com outras doenças como a dengue e a malária e a persistência de IgM específicas, dificultam o diagnóstico da infeção por CHIKV. A deteção no sangue de E3, uma glicoproteína viral secretada, a incluir num ensaio imunoenzimático poderá melhorar o diagnóstico nos países onde as técnicas de biologia molecular são de difícil acesso. Para testar a utilidade de E3 num ensaio de diagnóstico, esta deverá ser expressa em quantidade, purificada e usada para produção de anticorpos específicos.
Para expressar E3 numa forma solúvel, suscetível de ser purificada num único passo cromatográfico sem proteases, recorreu-se à estratégia da fusão com o domínio de ligação à quitina (CBD)-inteína (IMPACT™ System, NEB). A sequência codificadora de E3 foi amplificada a partir de RNA viral, clonada em pTYB21 e expressa em E. coli como uma proteína de fusão insolúvel de 64 kDa. A expressão a 12ºC induzida por IPTG 0,1 mM aumentou a solubilidade de CBD-inteína-E3. A aplicação de lisados celulares em colunas de quitina originou a retenção de CBD-inteína-E3 na matriz. Porém, a autoclivagem da inteína na coluna, induzida com reagentes tiol, foi pouco eficiente e mesmo a proteína E3 separada não eluiu da coluna. E3 foi ainda expressa em E. coli com uma cauda de seis histidinas (E3[His]6) por clonagem no vetor pET28b(+). Lisados celulares aplicados em colunas de níquel permitiram a eluição de uma proteína de 9 kDa, compatível com a massa molecular estimada para E3[His]6, ainda que com outros contaminantes proteicos. A identidade da proteína de 9 kDa será confirmada pela indução de anticorpos com esta preparação e reatividade daqueles com células infetadas com CHIKV.----------------ABSTRACT: Chikungunya virus (CHIKV) is an enveloped, positive strand RNA virus belonging to the family Togaviridae. Transmitted by Aedes spp mosquitoes, CHIKV causes large epidemics of severe arthritogenic disease in Africa and Asia and represents a serious threat in countries where vectors are present. Symptoms similarity with other diseases, e.g. dengue and malaria, along with CHIKV IgM persistence turns accurate CHIKV diagnosis a difficult task in low-income countries. Detection of E3, a small secreted viral glycoprotein, to be included in an immunoenzymatic test was envisaged as a possible improvement in CHIKV diagnosis. To test the diagnostic value of E3, recombinant E3 should be expressed and purified to generate antibodies.
In order to express CHIKV E3 in a soluble form amenable to purification by a single step affinity chromatography, the chitin binding domain (CBD)-intein fusion strategy without proteases (IMPACT™ System, NEB) was employed. The E3 coding sequence was amplified from viral RNA, cloned in pTYB21 and expressed in E. coli ER2566 as an insoluble 64 kDa CBD-intein-E3 fusion protein. Solubility was partially achieved by lowering the expression temperature to 12ºC and the inducer (IPTG) concentration to 0.1 mM. Clarified cell lysate loaded onto a chitin column allowed ligation of the fusion protein but the intein-mediated cleavage efficiency was low and E3 failed to elute from the column as demonstrated by SDS-PAGE. E3 was further expressed with a six histidine tag, E3[His]6, employing the pET System (Novagen). E3[His]6 was expressed in E. coli Rosetta (30ºC, 0.4 mM IPTG) as a 9 kDa protein. Soluble cell extracts in 20-40 mM imidazole, applied onto a nickel column and eluted with 500 mM imidazole yielded a protein preparation enriched in the 9kDa protein. The 9 kDa will be used as antigen to generate antibodies that upon reaction with CHIKV infected cells will confirm its identity.
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VELEZ, André Filipe Marques. "Produção de virus like particles (VLPs) do vírus chikungunya (CHIKV)." Master's thesis, Instituto de Higiene e Medicina Tropical, 2012. http://hdl.handle.net/10362/19201.
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O vírus Chikungunya (CHIKV) é um alfavírus, transmitido por mosquitos, que causa infecção aguda no Homem caracterizada por febre, mialgia e poliartrite dolorosa e incapacitante que pode durar meses ou anos. Descrito pela primeira vez na Tanzânia em 1952, tornou-se endémico em África, Índia e sudeste Asiático. Desde 2005, os surtos no oceano Índico e no continente Asiático têm atingido
proporções e virulência atípicas, com muitos milhares de indivíduos infectados e mortalidade associada. A mobilidade de indivíduos infectados e a alteração dos padrões de distribuição e abundância dos vectores devido a alterações climáticas, tornaram o CHIKV uma ameaça global sem estratégias de controlo eficazes. Uma abordagem para o controlo da transmissão será o
desenvolvimento de uma vacina eficaz. As virus-like particles (VLPs) são uma classe segura e eficaz
de vacinas que simulam a estrutura nativa das partículas virais. Neste trabalho pretendemos obter um vector de expressão recombinante, capaz de induzir a síntese de VLPs de CHIKV quando transfectado em culturas celulares, como fonte da sequência codificante da poliproteína estrutural para clonagem em baculovírus e produção de VLPs em células de insecto. A ORF estrutural de CHIKV foi
amplificada por RT-PCR como um fragmento SacI-NotI e clonada no vector de expressão pLEXm a jusante do promotor forte da beta actina de galinha. Obtiveram-se vários clones com o tamanho
correcto do inserto, os quais foram usados para transfectar células HEK 293T usando polietilenimina
como agente de fusão. A análise por imunofluorescência indirecta (IF) e Western blotting (WB) de células transfectadas, usando um soro policlonal anti-CHIKV, demonstrou que cinco vectores recombinantes expressavam antigénios virais. Um clone apresentou níveis elevados de fluorescência apenas quando da permeabilização celular e induz, muito provavelmente, a síntese de uma glicoproteína E2 truncada (26 kDa) que não é transportada até à membrana citoplasmática. Três clones
deram origem a intensidades de fluorescência relativamente fracas que poderão estar correlacionadas com menor taxa de tradução e/ou processsamento incompleto. As células transfectadas com pLCHIKS67 revelaram fluorescência e padrão proteico em WB semelhante aos de células infectadas com CHIKV. Ainda, o seu sobrenandante de cultura quando precipitado com PEG 8000 revelou (WB)
uma composição de antigénios virais idêntica ao precipitado correspondente de células infectadas com CHIKV. A análise por microscopia electrónica de transmissão de células infectadas com CHIKV e de células transfectadas com pLCHIKS67 demonstrou a presença de VLPs nestas últimas, com dimensões e morfologia idênticas às partículas virais, e ainda um extenso rearranjo de membranas
intracelulares, observado igualmente nas células infectadas, o qual deverá estar associado à tradução, processamento e transporte das proteínas estruturais. De acordo com os resultados obtidos, pLCHIKS67 será uma boa fonte da sequência nucleotídica da poliproteína estrutural para usar na geração de baculovírus produtores de VPLs de CHIKV.Chikungunya vírus (CHIKV) is a mosquito-transmitted alphavirus that causes an acute infection in humans, characterized by fever, myalgia and painful invalidating poly-arthralgia that may last for months. CHIKV was first reported in Tanzania in 1952 and became endemic in Africa, India and South-East Asia. Since 2005, outbreaks in the Indian Ocean and Asian continent reached an atypical magnitude and virulence, with many thousands of people infected and associated fatalities. Travelling and changing patterns of vector distribution and abundance due to climatic changes, make CHIKV a global threat without effective control strategies. One approach to reduce the CHIKV burden is the development of a vaccine. Virus-like particles are a safe and highly effective class of recombinant vaccines that mimic the overall structure of virus particles. Accordingly, we aimed to obtain a recombinant vector, able to induce CHIKV VLPs upon cell transfection, as a source of CHIKV structural genes to construct a recombinant baculovirus for VLP production in insect cells. CHIKV structural ORF was amplified by RT-PCR as a SacI-NotI fragment, and cloned into the mammalian expression vector pLEXm downstream from the strong chick beta actin promoter. Several clones with the correct insert size were obtained and transfected into HEK 293T cells using polyethylenimine as the transfection reagent. Five recombinant vectors were shown to express CHIKV proteins by immunofluorescence (IF) and Western blotting (WB) with a polyclonal serum against CHIKV. One clone, with high levels of IF labelling, demonstrated a truncated viral polyprotein of 26 kDa on WB while three others, with a lower IF signal, originated low levels of viral envelope glycoproteins correctly processed. Cells transfected with clone pLCHIKS67 showed IF staining and viral glycoprotein WB pattern similar with those of cells infected with CHIKV. Precipitation with PEG 8000 of clarified cell culture medium from pLCHIKS67 transfected cells and from CHIKV infected cells generated pellets with an identical content of viral glycoproteins on WB, strongly indicating that pLCHIKS67 transfected cells express CHIKV structural proteins that are assembled into VLPs. Transmission electron microscopy of transfected cells demonstrated cytoplasmic membrane rearrangements similar to the vesicle arrays observed in CHIKV infected cells and confirmed the assembly of VLPs with size and morphology similar to the virus particles produced in infected cells. Therefore, pLCHIKS67 will be used as a source of CHIKV structural genes for construction of recombinant baculoviruses and VLP production in insect cells, well-known for allowing high yields of recombinant protein expression.
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Silva, Filho Edson Meneses da. "Neuromodula??o para o tratamento das artralgias decorrentes da chikungunya." PROGRAMA DE P?S-GRADUA??O EM CI?NCIAS DA REABILITA??O, 2017. https://repositorio.ufrn.br/jspui/handle/123456789/24763.
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O v?rus da Chikungunya (CHIK) ? uma epidemia no Brasil com 170.000 casos no primeiro semestre de 2016. Mais de 60% dos pacientes apresentam rea??o e remiss?o de artralgia cr?nica com dor debilitante que dura anos. N?o existem agentes terap?uticos espec?ficos para tratar e reabilitar pessoas infectadas com CHIK. Dor persistente pode levar ? incapacita??o exigindo tratamento farmacol?gico de longo prazo. Os avan?os nos tratamentos n?o farmacol?gicos s?o necess?rios para promover o al?vio da dor sem efeitos colaterais e restaurar a funcionalidade. Aqui, n?s demonstramos que a Estimula??o Transcraniana com Corrente Cont?nua (ETCC) sobre o c?rtex motor prim?rio reduz significativamente a dor na fase cr?nica da CHIK. Nossos achados sugerem que a ETCC pode ser uma terapia eficaz, barata e implant?vel em ?reas que n?o possuem recursos e que apresentam um grande n?mero de pacientes com dor cr?nica persistente gerada pela CHIK.
The Chikungunya (CHIK) virus is epidemic in Brazil, with 170,000 cases in the first half of 2016. More than 60% of patients present relapsing and remitting chronic arthralgia with debilitating pain lasting years. There are no specific therapeutic agents to treat and rehabilitee infected persons with CHIK. Persistent pain can lead to incapacitation, requiring long-term pharmacological treatment. Advances in non-pharmacological treatments are necessary to promote pain relief without side effects and to restore functionality. Here, we demonstrate that the transcranial direct current stimulation (tDCS) across the primary motor cortex significantly reduces pain in the chronic phase of CHIK. Our findings suggest tDCS could be an effective, inexpensive and deployable therapy to areas lacking resources with a great number of patients with chronic CHIK persistent pain.
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Bouraï, Mehdi. "Caractérisation d'un interactome virus-hôte : l'exemple du virus du Chikungunya." Paris 7, 2011. http://www.theses.fr/2011PA077183.
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Récemment, la levée de nombreux verrous technologiques a permis le développement de la « génomique fonctionnelle », désignant l'approche systémique appliquée à la biologie moléculaire et cellulaire. Les virus, parasites intracellulaires obligatoires, interagissent avec de nombreux composants de la cellule afin de se répliquer. Mieux définir les interactions entre les protéines virales et cellulaires permet de mieux comprendre le cycle de réplication et la pathogenèse virale, et ouvre la voie à de nouvelles approches thérapeutiques innovantes. Au cours de mon travail de thèse, j'ai cherché à définir la carte d'interaction, ou interactome, du virus du chikungunya (CHIKV), virus dont les interactions avec la cellule à l'échelle moléculaire restent encore mal connues. J'ai pour cela utilisé des approches par double-hybride à haut débit en levure (HT-Y2H) et de validations en cellules de mammifère (notamment la technique de protein complémentation assay ou PCA). Nous avons criblé toutes les protéines matures du CHIKV contre 3 banques différentes d'ADNc humains, et une banque normalisée de 12. 000 ORFs (open reading frame) humaines entières. Nous avons ainsi mis en évidence 22 interactions dont la plupart impliquent la protéine non structurale 2 (nsP2) du CHIKV. Parmi les interacteurs cellulaires mis en évidence, nous avons pu montrer le rôle important joué par hnRNP-K (heterogeneous nuclear ribonucleoprotein K) et l'ubiquiline 4 dans la réplication du virus in vitro. Par ailleurs, nous avons démontré l'implication de la protéine TTC7B (tétratricopeptide 7B) dans l'activité d'inhibition transcriptionnelle induite par la protéine nsP2 du CHIKV. Les techniques utilisées au laboratoire m'ont également permis de participer à la caractérisation de trois interactions virus-hôte identifiées par un autre étudiant en thèse du laboratoire et jouant un rôle dans la réplication du virus de la rougeole (VR) et du virus parainfluenza humain (hPIV3). J'ai notamment pu cartographier avec précision des domaines peptidiques impliqués dans ces interactions, grâce à une technique adaptée du Y2H. Ce travail m'a donc permis d'appréhender les techniques actuelles permettant de définir les interactomes virus-hôte, et de proposer ainsi une carte d'interactions virus-hôte pour le CHIKV, mais aussi d'apporter des éléments de réponses quant aux mécanismes viraux impliquées dans le cycle réplicatif et la pathogenèse de ce virusThe lifting of many technological barriers in recent years has allowed the development of « functional genomics », an innovative systemic approach to molecular and cell biology. Viruses, being intracellular parasites, interact with several components of the cell to replicate. Thus, defining and improving our knowledge of the interactions between viral and cellular proteins ensures a better understanding of the viral replication cycle and pathogenesis and opens the pathway to new therapeutic approaches. In my thesis, I defined the interaction map, or interactome, of the chikungunya virus (CHIKV), a virus whose interactions with the cell at the molecular level have been poorly understood. For this, I performed high throughput two-hybrid approaches in yeast (HT-Y2H) and validations in mammalian cells (including protein complementation assay technique or PCA). We screened all the CHIKV mature proteins across three different human cDNA libraries and a normalized 12,000 human full-length open reading frames (ORF) library. We identified 22 interactions, the majority of which involve non-structural protein 2 (nsP2) of CHIKV. Among the identified cellular interactors, we showed the important role of hnRNP-K (heterogeneous nuclear ribonucleoprotein K) and ubiquilin 4 in virus replication in vitro. Furthermore, we demonstrated the involvement of the TTC7B protein (tétratricopeptide 7B) in the transcriptional inhibition activity induced by the nsP2 protein of CHIKV. Such techniques conducted in the laboratory also allowed me to participate in thé charaterization of three virus-host interactions identified by a fellow PhD student and contribute to researching the replication of measles virus (MV) and type 3 human parainfluenza virus (hPIV3). In particular, I was able to accurately map the peptide domains involved in these interactions, using a technique adapted from Y2H. This work has allowed me to not only understand the current techniques for defining virus-host interactomes and consequently produce a map of virus-host interactions for CHIKV, but also to shed some light on the viral mechanisms involved in the replication cycle and the pathogenesis of this virus
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Mohamed, Ali Souand. "Le virus Chikungunya : mécanismes évolutifs et outils de génétique inverse." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0665/document.
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L’émergence de certains arbovirus pathogènes pose un problème majeur en termes de santé public. Le virus Chikungunya (CHIKV) est un exemple de virus émergent car il s’est récemment adapté à un nouveau vecteur et cause des épidémies explosives. Cette émergence est en partie la conséquence de phénomènes liés à la grande plasticité génomique du CHIKV. Mieux comprendre les mécanismes d’adaptation des arbovirus pourrait permettre de mieux contrôler ces pathogènes viraux. La première partie de cette thèse porte sur l’étude des mutations associées à l’évolution à long terme du CHIKV sur différentes lignées de mammifères et de moustiques. Les résultats montrent des profils d’évolution distincts sur cellules de mammifères ou de moustiques, illustrant les difficultés liées à l’alternance d’hôte au cours du cycle naturel du CHIKV. La deuxième partie porte sur l’étude chez le CHIKV de la recombinaison génétique, un mécanisme fondamental pour l’évolution des virus à ARN. Les résultats montrent une absence de recombinaison homologue entre virus non défectifs, mais ces expériences ont permis de mettre en évidence la présence de virus délétés qui semblent aider par trans-complémentation la réplication d’un virus atténué. La dernière partie de cette thèse porte sur l’étude de méthodes de génétique inverse qui permettent de générer des virus et d’étudier les mutations associées à l’émergence de certains arbovirus. En utilisant le CHIKV comme modèle, nous avons étudié l’impact qu’ont certaines méthodes sur le génotype et le phénotype du virus in-cellulo et in-vivo chez le moustique. Les résultats montrent une stabilité du phénotype alors que le génotype viral dépend de la méthode utiliséeEmergence of some pathogenic arboviruses is a major public health concern. The Chikungunya virus (CHIKV) is a typical example of re-emerging pathogen since it recently caused large outbreaks in human population, adapted to a new vector and spread to new areas. This emergence is the consequence of phenomena related to the high genomic plasticity of CHIKV. Understanding the mechanisms of adaptation of arboviruses could help to better control these viral pathogens. The first part of this thesis presents a study of the mutations associated with long-term replication of CHIKV in mammalian and mosquito cells. Our results revealed different evolutionary patterns in mammalian and mosquito cells highlighting the difficulties encountered by arboviruses related to host alternation during their natural cycle. The second part of this thesis deals with the homologous recombination, an important process that play a role in the evolution of RNA viruses. Working with the CHIKV, we did not detect any recombination events between attenuated infectious viruses. However, we detected viruses harboring large genomic deletion that could help an attenuated virus by trans-complementation. The last part of this thesis focused on reverse genetic methods that give the possibility to rescue viruses and can be used to study mutations associated with emergence phenomena. Using the CHIKV as a model, we compared the genotype and the phenotype of viruses generated using different reverse genetic methods in cellulo and in vivo using Aedes mosquitos. Our results showed that the choice of the method influenced the genetic diversity of viral populations but whatever the method used, the phenotype was similar
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Cresson, Marie. "Study of chikungunya virus entry and host response to infection." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1050.
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Les alphavirus sont un groupe de virus enveloppés à ARN simple brin positif retrouvés sur la totalité du globe et responsables de nombreuses maladies humaines et animales. Durant la dernière décennie, une réémergence du virus du chikungunya (CHIKV) a été observée causant de nombreuses épidémies sur tous les continents. Malgré les nombreuses études, les mécanismes moléculaires de réplication du CHIKV et les interactions hôte-virus restent peu caractérisées. L’objectif de mon travail était de mieux comprendre et caractériser l’entrée du virus du chikungunya et les facteurs de l’hôte impliqués dans la réplication chez les mammifères. Plusieurs approches distinctes ont été utilisées dans ce projet. Dans un premier temps, nous avons mis en avant une diminution de l’infection du CHIKV après un traitement avec du fer sous forme de citrate d’ammonium ferrique et nous avons étudié le rôle potentiel dans l’entrée virale de NRAMP2 et TFRC, deux protéines impliquées dans le transport cellulaire du fer et connus comme récepteurs d’entrée de plusieurs virus. D’autre part, nous nous sommes intéressés à deux autres protéines, CD46 et TM9SF2, identifiés à travers un criblage par ARNi réalisé en collaboration, dans le but de déterminer si elles sont utilisées comme facteurs d’entrée par le virus du chikungunya. Dans un dernier axe, nous avons mis en place et réaliser un criblage perte de fonction sur le génome entier en utilisant la technologie CRISPR/Cas9 afin d’identifier des facteurs de l’hôte importants pour l’entrée du CHIKV, sa réplication ou la mort viro-induite. Bien qu’il soit apparu que l’approche utilisée pour le criblage devrait être optimisée, nous avons pu identifier des candidats potentiellement nécessaires pour l’infection par le CHIKV. Ces candidats sont testés individuellement afin de confirmer leur implication dans la biologie du virusAlphaviruses are a group of enveloped, positive-sense RNA viruses which are distributed almost worldwide and are responsible for a considerable number of human and animal diseases. Among these viruses, the Chikungunya virus (CHIKV) has recently re-emerged and caused several outbreaks on all continents in the past decade. Despite many studies, molecular mechanisms of chikungunya virus replication and virus-host interactions remain poorly understood. The aim of my project was to better understand and characterize the CHIKV entry and the host factors involved during replication steps in mammals. Several different approaches have been used in this work. As a first step, we have demonstrated a decrease of CHIKV infection after iron treatment in form of ferric ammonium citrate and we have studied the potential role in viral entry of NRAMP2 and TFRC, two proteins involved in iron transport and known receptors for other viruses. On the other hand, we have also focused on two proteins, CD46 and TM9SF2, identified through an RNAi screen in collaboration, in order to determine if they are required as entry factors for chikungunya virus. In a last axis, we have set up and carried out a genome-wide loss of function screen with the CRISPR/Cas9 technology in order to identify host factors important for chikungunya virus entry, replication or virus-induced cell death. Although it appears that screen conditions should be optimized, we have identified potential candidates required for CHIKV infection and we are currently testing them
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White, Timothy William. "Identifying drivers of Chikungunya virus transmission in the Asia-Pacific." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/225936/1/Timothy_White_Thesis.pdf.
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This research project investigates the climate drivers and transmission potential of the mosquito-borne chikungunya virus (CHIKV) in the Asia-Pacific region. The thesis utilises statistical and mathematical modelling to gain epidemiological insight into CHIKV transmission and understand the weather patterns that can influence transmission in Australia and Singapore. By further understanding lessons of the past, this project can assist in future public health preparedness plans and improve predictions of virus transmission using climate forecasts.
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Soumahoro, Agbo Man-Koumba. "Epidémie de Chikungunya à l'île de La Réunion : aspects médicaux et économiques." Paris 6, 2010. http://www.theses.fr/2010PA066244.
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La survenue d'une épidémie de Chikungunya à La Réunion en 2005-2006 a constitué une opportunité pour approfondir les connaissances sur cette arbovirose. Après avoir montré que les régions à risque d'épidémies dans le monde s'étendent largement au delà des zones endémiques, nous avons 1) évalué les manifestations tardives le l'infection et ses conséquences sur la qualité de vie et la consommation de soins et 2) estimé le coût de la maladie au cours de cette épidémie. Une enquête exposés-non exposés a comparé 199 personnes séropositives à 199 personnes séronégatives pour le Chikungunya. Elles ont été appariées sur le sexe, l'âge et la zone de résidence. Dix-sept mois après l'infection, l'analyse a montré que les personnes ayant un antécédent de Chikungunya se plaignaient plus souvent de douleurs articulaires et musculaires, d'asthénie, de dépression et de chutes de cheveux. Cependant, ces manifestations ne semblaient pas avoir de conséquences sur la consommation d'analgésiques ni sur la fréquence des consultations médicales et des hospitalisations. L'impact sur la qualité de vie a montré une diminution modérée du score de santé physique chez les sujets exposés, comparativement aux non-exposés. Le poids économique de cette épidémie a été estimé par une étude de type coût de la maladie. Selon la perspective de l'Assurance Maladie, ce coût a été estimé à 29,8 millions d'euros. Le coût par cas ambulatoire était de 90 € et celui de chaque cas hospitalisé de 2013 €.
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Solignat, Maxime. "Cycle de réplication du virus Chikungunya chez l'homme et l'Aedes : tropisme cellulaire et mécanisme d'entrée." Montpellier 1, 2009. http://www.theses.fr/2009MON1T007.
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Le virus du Chykungunya (CHIKV) est un Arbovirus transmis par les moustiques, et plus particulièrement les moustiques du genre Aedes. Cet alphavirus du groupe des Semliki Forest a été identifié comme l'agent pathogène responsable de l'épidémie en 2005 et 2006 sur le territoire de La Réunion ainsi que dans l'Océan Indien. Alors que cette maladie était généralement considérée comme généralement non fatale, 256 décès ont été directement attribués au virus lors de l'épidémie à La Réunion. Bien qu'isolé en 1952, le CHIKV reste mal connu et les modifications brutales de la physiopathologie de l'infection par ce virus à La réunion sont inexpliquées à ce jour. Aucun traitement n'est disponible à l'heure actuelle. Chez les virus enveloppés, il existe différentes voies d'entrée possible dans la cellule hôte, qui sont autant de cibles pour inhiber le cycle réplicatif de ces virus. L'objectif principal de ma thèse a consisté à caractériser le mécanisme d'entrée de ce virus dans les cellules humaine [i. E. Humaines] et dans les cellules des vecteurs de la famille Aedes. Nous avons pu décrire pour la première fois le mécanisme d'entrée du CHIKV dans ces cellules cibles et pour différents isolats viraux. Ainsi, nous avons mis en évidence le rôle de l'endocytose dépendante des puits recouverts de clathrine et des endosomes dans ce mécanisme d'entrée; enfin, nous avons étudié l'influence des interactions cellulaires et moléculaires entre le CHIKV et l'endosymbionte Wolbachia sur la réplication virale. Cette bactérie intracellulaire obligatoire qui est présente dans les populations naturelles d'Aedes albopictus pourrait être impliquée dans le cycle de transmission et la pathogenèse virale du CHIKV comme il est déjà démontré pour d'autres systèmes virus-arthropodes-WolbachiaChikungunya virus (CHIKV) is a mosquitoe transmitted Arbovirus and more particulary by the Aedes mosquitoe genus. This Alphavirus which belongs to the Semliki Forest group was identified like the responsible [i. E. Responsable] agent for the epidemic disease in 2005 and 2006 on the territory of La Reunion and in the Indian Ocean. Whereas this disease was generally regarded as nonfatal, 256 deaths were directly allotted to the virus at the time of the epidemic episode in La Reunion. Although it was isolated in 1952, the CHIKV remains poorly understood and the brutal modifications of the physiopathology of the infection by this virus in La Reunion are unexplained to date. No treatment is available at the present time. Among envelopped viruses, there are various entry pathways in the host cell which are as many targets to inhibit the replicative cycle of these viruses. The main aim of my thesis consisted in characterizing the entry mechanism of CHIKV in human cells and in mosquitoe cells of the Aedes family. Thus, we described for the first time the entry mechanism of CHIKV in these target [i. E. Targets] cells and this, for various viral isolates. More particularly, we highlighted the role of the clathrin mediated endocytic pathway and the endosomes vesicles in these mechanism [i. E. Mechanismes]. Finally, we studied the influence of cellular and molecular interactions between the CHIKV and the endosymbiotic bacteria Wolbachia on viral replication. This obligatory intracellular bacteria which is present in the natural populations of Aedes albopictus could be implied in the transmission cycle and the viral pathogenesis of the CHIKV as it is already shown for other virus-arthropods-Wolbachia systems
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Fernandes, Alana Batista, and 92-98197-7160. "Clonagem e expressão da proteína do capsídeo do vírus Chikungunya para produção de antígeno recombinante: Produção de antígeno recombinante através de gene sintético do vírus Chikungunya." Universidade Federal do Amazonas, 2016. http://tede.ufam.edu.br/handle/tede/5951.
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CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico
The Chikungunya virus (CHIKV) is an RNA virus (family Togaviridae, genus Alphavirus) transmitted to humans through the bite of female mosquitoes Aedes aegypti and Aedes albopictus. The clinical onset in CHIKV infection is most often characterized by fever and joint pain, and so far there is no specific antiviral therapy or vaccine for the treatment of the infection. The diagnosis of CHIKV infection is based on clinical and laboratory findings, with the latter being performed by virus isolation, reverse transcription-polymerase chain reaction (RT-PCR), serology, and rapid tests: To produce a recombinant antigen through the cloning and expression of the capsid protein (C) of CHIKV in order to detect anti-CHIKV antibodies in human serum samples by immunoenzymatic assay. A synthetic gene (gBlock), specifically designed for this study, corresponding to the protein C (400 base pair) of Chikungunya virus, was amplified by polymerase chain reaction (PCR) and then cloned into pGEM-T Easy system-Escherichia coli. The transformant clones were sequenced, and recombinant products were digested using the restriction endonucleases EcoRI and BamHI, and then subcloned and expressed in the vector pET-23a+ Escherichia coli BL21 (DE3). The recombinant protein C expression and the molecular weight were determined by SDS-PAGE and Dot Blot and purified by affinity chromatography using nickel column. A immunoenzymatic assay was performed using the recombinant antigen to detect IgM and IgG antibodies in sera from patients with CHIKV infection confirmed by the National Reference Laboratory of the Ministry of Health, as well as sera from patients tested positive for Mayaro virus, Dengue virus and Cytomegalovirus infection. The derived recombinant protein showed size and antigenicity compatible with the native protein C from the CHIKV; a concentration of 0.342 ng/mL of recombinant protein C was obtained using the pET-23a+ E. coli BL21 (DE3); the affinity chromatography using nickel column was effective to obtain the soluble protein C, confirmed by the Bradford method; the immunoenzymatic assay using the recombinant antigen showed cross-reactivity to others Alphavirus pathogens. The results indicate that the expression system pET-23a+ E. coli BL21 (DE3) was effective to produce the recombinant protein C of CHIKV, however the antigen was not sensitive enough to detect only the CHIKV infection.
O vírus Chikungunya (CHIKV) é um vírus de RNA (família Togaviridae, gênero Alphavirus), transmitido aos seres humanos através da picada de mosquitos fêmeas de Aedes aegypti e Aedes albopictus. O início das manifestações clínicas da infecção por CHIKV na maioria das vezes é caracterizada por febre e dor nas articulações, e até agora não existe uma terapia antiviral específico ou vacina para o tratamento da infecção. O diagnóstico da infecção CHIKV é baseado em achados clínicos e laboratoriais, com o último sendo realizada por isolamento do vírus, transcrição reversa-polimerase reação em cadeia (RT-PCR), sorologia e testes rápidos. Para produzir um antígeno recombinante através da clonagem e expressão da proteína do capsídeo (C) de CHIKV de modo a detectar anticorpos anti-CHIKV em amostras de soro humano, por ensaio imunoenzimático. Um gene sintético (gBlock), especificamente concebidos para esse estudo, correspondente à proteína C do capsídeo (400 pares de bases) do vírus Chikungunya, foi amplificado por reação em cadeia da polimerase (PCR) e, em seguida, clonado em pGEM-T Easy sistema de Escherichia coli. Os clones transformantes foram sequenciados, e os produtos recombinantes foram digeridos com as endonucleases de restrição EcoRI e BamHI, e depois subclonado e expresso no vector pET-23a+ e Escherichia coli BL21 (DE3). A expressão da proteína C recombinante e o peso molecular foram determinados por SDS-PAGE e Dot Blot e purificado por cromatografia de afinidade utilizando uma coluna de níquel. Um ensaio imunoenzimático foi realizada utilizando o antígeno recombinante para detecção de anticorpos IgM e IgG em soros de pacientes com infecção CHIKV confirmados pelo laboratório nacional de referência do Ministério da Saúde, bem como soros de pacientes positivos para o vírus Mayaro, vírus da dengue e citomegalovírus infecção. O derivado da proteína recombinante mostrou tamanho e antigenicidade compatível com a proteína C nativa do CHIKV; uma concentração de 0,342 ng / mL de proteína C recombinante foi obtido utilizando o pET-23a+ de E. coli BL21 (DE3); a cromatografia de afinidade utilizando uma coluna de níquel foi eficaz para obter a proteína C solúvel, confirmada pelo método de Bradford; o ensaio imunoenzimático utilizando o antígeno recombinante mostrou reatividade cruzada com outros agentes patogénicos de Aphavírus. Os resultados indicam que o sistema de expressão pET-23a+ de E. coli BL21 (DE3) foi eficaz para produzir a proteína C recombinante de CHIKV, no entanto, o antígeno não foi suficientemente sensível para detectar apenas a infecção CHIKV.
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Alva-Urcia, Carlos, Miguel Angel Aguilar-Luis, Carlos Palomares-Reyes, Wilmer Silva-Caso, Luis Suarez-Ognio, Pablo Weilg, Carlos Manrique, Fernando Vasquez-Achaya, Valle Luis J. del, and Valle-Mendoza Juana del. "Emerging and reemerging arboviruses: A new threat in Eastern Peru." Public Library of Science (PLoS), 2017. http://hdl.handle.net/10757/622421.
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Background
Arboviral diseases are one of the most common causes of acute febrile illness (AFI) and a significant health problem in South America. In Peru, laboratory etiologic identification of these infections occurs in less than 50% of cases, leading to underdiagnoses of important emerging arboviruses.
Aim
To assess the prevalence of the Dengue (DENV), Oropouche (OROV), Chikungunya (CHIKV), Mayaro (MAYV) and Zika (ZIKV) viruses in patients with acute febrile illness from Puerto Maldonado (Peru).
Methodology
Serum samples were obtained from patients with AFI during January 2016 to March 2016. A total of 139 specimens were analyzed for the presence of DENV, OROV, CHIKV, MAYV, and ZIKV using polymerase chain reaction (PCR).
Results
CHIKV in 9.4% and OROV in 8.6% were the most prevalent arboviruses, followed by DENV and ZIKV, with a prevalence of 6.5% and 5%, respectively. Among all patients, the most common symptoms accompanying fever were headaches 79.9%, muscle pain 65.5% and joint pain 63.3%.
Conclusions
During this short 3-month period, 4 arboviruses were detected by PCR, CHIKV and OROV being the most common arboviruses in Puerto Maldonado (Peru). Thus, it is crucial to include OROV detection in the national health surveillance. Furthermore, the etiologic clinical diagnosis of arboviral infections is not possible due to the low specificity of symptoms; therefore an increase of cases confirmed by molecular diagnostic methods will enhance arboviral surveillance in Peru.
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Rozen-Gagnon, Kathryn. "Chikungunya virus nonstructural proteins regulate replication fidelity and pathogenicity in vivo." Paris 7, 2014. http://www.theses.fr/2014PA077199.
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Le virus Chikungunya (CHIKV) est un arbovirus ré-émergent mais aussi l'alphavirus le plus responsable de maladie humaine. La réplication de CHIKV est assujettie d'erreurs ; c'est une caractéristique de tous les virus à ARN, qui présentent les taux de mutation les plus élevés de la nature. Par conséquent, un seul virus génère des millions de descendance virale qui portent de mutations distinctes dans leurs génomes. Ces populations peuvent être décrites comme une quasi-espèce, car la population agira comme (quasi) une unité d'évolution unique (espèces). La diversité de la population virale a des implications importantes dans la biologie du virus à ARN et son évolution, et il a été prouvé que les taux de mutation virale ont été optimisées au fil du temps. Les taux de mutation doivent être suffisamment élevés pour générer de nouveaux variants, ce qui permet une adaptabilité rapide dans des environnements changeants. Toutefois, si les taux de mutation sont trop élevés, l'intégrité du génome est perdue. La découverte récente de variants de fidélité a souligné l'importance du maintien d'un taux de mutation idéal. Les variants de fidélité sont des virus qui présentent des taux de mutation modifiés, entraînant une restriction (antimutateur) ou une expansion (mutateur) des quasi-espèces virales. En général, ces variants contiennent des mutations dans l'ARN polymérase ARN-dépendante (RdRp) qui modifient la fidélité intrinsèque. Mais, on ne sait pas comment la diversité affecte le fitness et le phénotype des arbovirus. Nous avons retrouvé des variants mutateurs de CHIKV avec des fréquences de mutation plus élevés que le virus sauvage et les caractérises in vitro et in vivoArboviruses cycle through both vertebrates and invertebrates, which requires them to adapt to disparate hosts while maintaining genetic integrity during genome replication. To study the genetic mechanisms and determinants of these processes, we use chikungunya virus (CHIKV), a re-emerging human pathogen transmitted by the Aedes mosquito. We isolated novel mutators with decreased replication fidelity and higher mutation frequencies, allowing us to examine the fitness of error-prone arbovirus variants. Although CHIKV mutators displayed no major replication defects in mammalian cell culture, they were attenuated in vivo. Unexpectedly, mutator phenotypes were suppressed in mosquito cells and the variants exhibited significant defects in RNA synthesis. Consequently, these replication defects resulted in strong selection for reversion during inection of mosquitoes. Since residue 483 is conserved among alphaviruses, we examined the analogous mutations in Sindbis virus (SINV), which also reduced polymerase fidelity and generated replication defects in mosquito cells. However, replication defects were mosquito cell-specific and were not observed in Drosophila S2 cells, allowing us to evaluate the potential attenuation of mutators in insect models where pressure for reversion was absent. Indeed, the SINV mutator variant was attenuated in fruit flies. These findings confirm that residue 483 is a determinant regulating alphavirus polymerase fidelity and demonstrate proof of principle that arboviruses can be attenuated in mammalian and insect hosts by reducing fidelity
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Andersson, Klara. "Characterization of nsP-specific nanobodies targeting Chikungunya and Semliki Forest Virus." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-414971.
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Viral infections are constantly increasing and impose a large threat to the public health. Alphaviruses are responsible for several animal and human diseases and have a large medical importance with few treatments available today. Alphaviruses are small, spherical single stranded RNA viruses, and are most often transmitted by mosquito vectors. Alphaviruses contains a domain of nonstructural proteins that compose the replication machinery. The domain is crucial for viral replication to occur and is therefore an interesting target for antiviral therapy. With the focus on Chikungunya and Semliki Forest Virus this work investigates the events in the cells on molecular level during infections. To do this a panel of Camelid derived single domain antibodies are developed to target the nonstructural proteins of Chikungunya and Semliki Forest Virus. Binding of the produced nanobodies to the viral proteins was investigated by biochemical methods including immunoprecipitations, western blot, and ELISA. Cell lines that express nsP-specific nanobodies in the cytosol were employed for infection- and plaque assays with Semliki Forest Virus in order to determine the antiviral potential of the new nanobodies. Three of the nanobodies proved to bind two different nonstructural proteins of the viruses, providing opportunities for further investigations and a possible use of these nanobodies to identify viral vulnerabilities that could be exploited for antiviral intervention.
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Krystosik, Amy Robyn. "CHIKUNGUNYA, DENGUE, AND ZIKA IN CALI, COLOMBIA: EPIDEMIOLOGICAL AND GEOSPATIAL ANALYSES." Kent State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1481111225042036.
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Patramool, Sirilaksana. "Interactions virus (dengue)-vecteurs (aedes) et mise en évidence d'une méthode d'isolement des virus de la dengue et du chikungunya." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20139.
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La dengue et le chikungunya sont deux arboviroses émergentes qui sont transmises à l'homme par la piqûre de moustiques du genre Aedes. Il n'existe ni vaccin ni traitements commercialisés pour ces arboviroses. Il apparaît donc nécessaire de développer de nouvelles stratégies pour isoler les virus circulants et bloquer leur transmission. La compréhension des mécanismes mis en jeu dans les cellules des vecteurs Aedes lors d'une infection par le virus de la dengue (DENV) sont encore très peu étudiés, notamment pour les sérotypes 1 et 3. Par des analyses protéomiques de l'infection d'une lignée cellulaire du moustique Aedes albopictus par ces séroytypes, nous avons démontré qu'en réponse à l'infection, les cellules de moustiques utilisent les mécanismes antioxydants combinés à la production d'énergie pour faire face au virus. Les résultats de notre étude devraient permettre de mieux comprendre l'interaction DENV-vecteur Aedes au niveau cellulaire dans le but de concevoir des stratégies efficaces pour le contrôle du DENV. Nous avons également regroupé dans une revue les connaissances acquises sur les études protéomiques des principaux compartiments des arthropodes vecteurs de maladies humaines. Dans un second volet, nous avons mis en évidence une méthode rapide d'isolement et de concentration des DENV et du chikungunya. Cette technique d'isolement basée sur la capture de virus sur des billes magnétiques enrobées de polymères anioniques permet d'obtenir des particules virales infectieuses. Cette méthode combinée à des approches classiques de détection de virus pourrait non seulement permettre l'identification des échantillons infectés ayant une faible charge virale, mais aussi l'isolement simultanée de particules infectieuses de dengue et de chikungunya à partir d'un seul échantillonDengue (DENV) and Chikungunya (CHIKV) viruses are two emerging arboviruses that are transmitted to humans by the bite of Aedes sp. mosquito vectors. Neither vaccines, nor medical treatments, are commercially available for these infections. It is, therefore, necessary to elaborate novel strategies to isolate the circulating viruses and block their transmission.Our understanding of the molecular mechanisms involved, during the infection of the Aedes vector by dengue virus (DENV), especially serotypes 1 and 3, remains very scant. We, therefore, performed a proteomics analysis of an Aedes albopictus cell line, infected by these two DENV serotypes, and showed that the cells use both anti-oxidant and energy-production mechanisms in the fight against the virus. These results should help to improve our knowledge of the interaction of the DENV virus and the Aedes mosquito vector, at the cellular level, with the aim of designing efficient strategies for the control of this virus. We have, in addition, developed a rapid and sensitive isolation technique, based on viral particle adsorption to magnetic beads coated with an anionic polymer. The use of this technique is of great interest, as it permits the rapid and simultaneous detection and isolation of CHIKV and DENV from samples with reduced viral loads
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Zouache, Karima. "Interactions multipartites entre communautés symbiotiques, pathogènes et vecteurs : le système vectoriel bactéries, endosymbiotiques, virus chikungunya, moustiques aedes." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10183.
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Aedes albopictus et Aedes aegypti sont des moustiques vecteurs d’arbovirus tels que le virus de la dengue et le virus du chikungunya. En plus des virus transmis, les moustiques hébergent également des bactéries dont certaines affectent la biologie des hôtes. Par exemple, la bactérie Wolbachia infecte naturellement Aedes albopictus. Comme chez la plupart des insectes, cette bactérie est un parasite qui manipule la reproduction du moustique et peut également interagir avec certains pathogènes, modifiant ainsi la transmission du pathogène par le moustique hôte. Hors Wolbachia, peu d’études ont été consacrées à l’étude des populations bactériennes hébergées par les moustiques du genre Aedes et aux interactions entre ces populations bactériennes et les arbovirus transmis. Dans ce contexte, le travail de cette thèse a consisté à caractériser la diversité des communautés bactériennes des moustiques du genre Aedes et à explorer l’interférence possible entre le compartiment bactérien et le virus chikungunya. L’utilisation de techniques telles que les isolements bactériens, l’amplification par PCR, la DGGE et l’hybridation in situ ont permis de détecter et localiser certaines bactéries présentes chez des populations naturelles et de laboratoires d’Aedes. Ces populations appartiennent aux Alpha, Beta et Gammaprotéobactéries ainsi qu’aux Firmicutes. L’étude de la dynamique des communautés bactériennes symbiotiques et de l’infection par le virus chikungunya chez Aedes albopictus par PCR quantitative et puces taxonomiques a révélé l’existence d’interactions entre les différents partenaires de ce système vectorielAedes albopictus and Aedes aegypti transmit a large number of arboviruses, including dengue and chikungunya. In addition to viruses, mosquitoes harbour other symbionts that are able to affect its biology. For instance, the bacterium Wolbachia infects naturally Aedes albopictus. As for many insects, this bacterium is an obligate parasite that manipulates the host reproduction and can also interact with pathogens, modifying the transmission of the pathogens by the mosquitoes. Except Wolbachia, little is known about the bacteria associated with Aedes mosquitoes. First, we detected and localized bacteria in field-caught and laboratory populations of Aedes, using culture and non-culture methods including PCR, DGGE and in situ hybridization. The bacterial populations belonged to Alpha, Beta and Gammaproteobacteria as well as to Firmicutes. Then, the effects of chikungunya infection on Wolbachia and total bacterial community were measured using quantitative PCR and taxonomic microarrays. Results showed interactions between the different partners in this vectorial system
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Pham, Thi Kim Lien. "Epidemiology and dynamic of dengue and chikungunya in several provinces in Vietnam." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS095/document.
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La dengue et le chikungunya sont des maladies transmises par Aedes aegypti et Aedes albopictus pouvant causer des pathologies sévères et des atteintes incapacitantes chroniques. Ce sont aussi les maladies qui se diffusent le plus rapidement, en partie à cause du changement climatique. Le Vietnam est une zone d’hyperendémicité pour la dengue et à risque pour le chikungunya comme le Cambodge voisin qui est atteint par les deux maladies.et représente une source de diffusion. L’objectif de cette thèse est d’évaluer le statut de ces deux maladies et la présence du chikungunya, d’évaluer l’efficacité du système de surveillance et d’évaluer la diversité des populations de moustiques vecteurs et leurs rôles respectifs dans la transmission. Une première partie de la thèse est dévolue à une revue bibliographique. La seconde partie comprend trois chapitres associés à trois publications. Le premier chapitre est consacré à une étude de la surveillance à l’hôpital général de la province sud de Dong Thap. Une cohorte de 131 patents avec une fièvre aigue a été étudiée pour tester la présence de dengue et de chikungunya. 101 patients sur 131 ont été positifs pour la dengue et les quatre sérotypes ont été détectés avec une prédominance de DENV1 et DENV4. Aucun cas de chikungunya n’a été détecté. Une variation d’efficacité dans la détection sérologique de la dengue a été observée avec un passage de 29% lors de l’admission à 53% sept jours après admission. Il y a donc clairement un risque de sous-estimation de la dengue alors que le chikungunya, n’est pas du tout testé. Des changements dans la procédure de détection et de surveillance sont proposés pour améliorer l’efficacité de la surveillance et surveiller l’émergence du chikungunya. Le deuxième chapitre est consacré à l’étude du rôle respectif d’A. aegypti et A. albopictus dans l’épidémie de Dengue de 2011 à Hanoi. Seuls DENV1 et DENV2 ont été détectés chez les 140 patients étudiés. Une corrélation positive a été observée entre la densité de population d’A. aegypti et le nombre de cas humains et la durée des épidémies. Ceci n’a pas été observé chez A. albopictus. Trois lots d’A. aegypti se sont révélés positifs pour la dengue, deux pour DENV1 et un pour DENV2. Cette étude montre clairement le rôle d’A. aegypti dans l’épidémie de 2011 à Hanoi. Le dernier chapitre est consacré à une analyse transversale sur 5 provinces frontalières du Laos et du Cambodge. 558 sérums collectés chez des patients admis pour fièvre aigue et de symptômes compatibles avec la dengue et chikungunya entre 2012 et 2014 dans des centres de médecine préventive. Les quatre sérotypes ont été détectés mais pas tous dans la même province. Seulement deux sérotypes ont été détectés au maximum dans une même province. Le chikungunya n’a pas été détecté. Un total de 1104 moustiques adultes a été prélevé dans les mêmes zones à l’intérieur et à l’extérieur des habitations. La densité de population de moustiques et les indices entomologiques ont été évalués suite à la capture de larves. Des densités très différentes ont été observées et la densité la plus importante a été obtenue dans la province de Long An, voisine du Cambodge. Le virus de la dengue a été détecté principalement chez A. albopictus. Le virus du chikungunya a également été détecté chez A. albopictus. L’analyse phylogénétique des moustiques collectés a montré une grande diversité génétique avec des génotypes décrits sur d’autres continents. Cette partie de la thèse met en évidence le rôle différentiel d’A. aegypti et A. albopictus, le rôle croissant de ce dernier et le transport anthropique des moustiques sur de grandes distances. Ce travail souligne le besoin de nouvelles approches de surveillance, au niveau clinique et au niveau entomologique, pour s’attaquer de façon efficace au risque épidémique de dengue et de chikungunyaDengue and chikungunya are both transmitted by Aedes aegypti and Aedes albopictus and can cause potentially severe and or debilitating chronic disease. They are the fastest spreading diseases, in part because of the climate change. Vietnam is a hyperendemicity country for dengue and is at risk to be like neighboring Cambodia affected both by dengue and chikungunya and be an overlapping area of distribution for both viruses. The aim of this PhD work was therefore to assess the status of single and dual infections all over the country, investigate the presence of chikungunya, assess the efficiency of the surveillance procedures routinely established and assess the diversity of mosquito populations and their potential respective role. A first part of the PhD dissertation is devoted to a bibliographic review. The second part comprises three chapters associated to three different publications. The first chapter is devoted to a surveillance study in the general hospital if the Southern Province of Dong Thap. A cohort of 131 patients with acute fever symptoms was investigated for the presence of dengue and chikungunya. 101 patients out of 131 were confirmed with dengue. All four dengue serotypes were detected with a predominance of DENV2 and DENV4. No chikungunya infection was detected although reported in neighboring Cambodia. A differential efficiency of serological dengue detection was observed. Efficiency was 29% upon admission and 53% after seven days on the same patients. There is thus a clear risk of dengue being underestimated while chikungunya is not systematically detected. Changes in detection and surveillance procedures are therefore proposed to increase the efficiency of dengue detection and continue the monitoring the emergence of CHIKV. The second Chapter is dedicated to the respective role of A. aegypti and A. albopictus in the 2011 outbreak in the Northern capital city of Hanoi. Only DENV-1 and DENV-2 serotypes were detected from the 140 patients hospitalized. A positive correlation was found between the population density of A. aegypti and the number of human cases and duration of outbreaks. This was not observed for A. albopictus. Three pools of A. aegypti were positive with dengue virus, two with DENV-1 and one with DENV-2. This work indicate clearly the role of A. aegypti in the 2011 Hanoi epidemics. The last chapter of the PhD is devoted to a crosscutting country wide survey in five provinces border with Lao PDR and Cambodia. In this work, a total of 558 serum samples were collected from patients admitted in the 2012-2014 period in five provincial preventive medicine centers with acute fever and symptoms compatible to DENV-CHIKV infection. All four dengue serotypes were found altogether but not in the same province. Only two serotypes were found at the maximum in a single province. No CHIKV was detected. A total of 1104 adult mosquitoes were collected inside and outside houses at the same place. Mosquito population density and vector indexes were assessed following capture of larvae. Differing densities of mosquito populations were found with the highest one being in the Long An province border with Cambodia. Dengue viruses were detected mostly in A. albopictus. CHIKV was also detected in A. albopictus mosquitoes. The phylogenetic analysis of the collected mosquitoes showed a large diversity of genotypes, all of them having been described in other parts of the world. This part of the PhD work underline the dual role of A. aegypti and A. albopictus, the increasing role of the latter and the high level of man-related very long distance mobility of mosquitoes. This work underlines the need of novel approaches for surveillance both at the clinical and at the entomological level to efficiently tackle the risk of dengue and chikungunya outbreaks
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Uhrlaub, Jennifer L., Vesna Pulko, Victor R. DeFilippis, Rebecca Broeckel, Daniel N. Streblow, Gary D. Coleman, Byung S. Park, et al. "Dysregulated TGF-β Production Underlies the Age-Related Vulnerability to Chikungunya Virus." PUBLIC LIBRARY SCIENCE, 2016. http://hdl.handle.net/10150/622415.
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Chikungunya virus (CHIKV) is a re-emerging global pathogen with pandemic potential, which causes fever, rash and debilitating arthralgia. Older adults over 65 years are particularly susceptible to severe and chronic CHIKV disease (CHIKVD), accounting for >90% of all CHIKV-related deaths. There are currently no approved vaccines or antiviral treatments available to limit chronic CHIKVD. Here we show that in old mice excessive, dysregulated TGF beta production during acute infection leads to a reduced immune response and subsequent chronic disease. Humans suffering from CHIKV infection also exhibited high TGF beta levels and a pronounced age-related defect in neutralizing anti-CHIKV antibody production. In vivo reduction of TGF beta levels minimized acute joint swelling, restored neutralizing antibody production and diminished chronic joint pathology in old mice. This study identifies increased and dysregulated TGF beta secretion as one key mechanism contributing to the age-related loss of protective anti-CHIKV-immunity leading to chronic CHIKVD.
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Gérardin, Patrick. "Impact en population de l'épidémie de Chikungunya à l'Ile de La Réunion." Paris 6, 2013. http://www.theses.fr/2013PA066042.
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Le Chikungunya est une maladie infectieuse émergente due à un alphavirus (CHIKV) transmis par les moustiques Aedes. En 2004-2007, plusieurs épidémies de grande envergure ont touché la zone Océan Indien. Nos objectifs étaient d'évaluer l'impact de l'épidémie en population générale à l'île de La Réunion (séroprévalence post-épidémique 38,2%, 300. 000 personnes infectées) en termes de morbidité perçue, de qualité de vie, d'identifier les facteurs pronostiques des douleurs musculosquelettiques (DMS) du rhumatisme chikungunya, enfin de déterminer le pronostic neurocognitif des enfants infectés à la naissance par transmission verticale du virus. Pour mesurer l'impact en population de l'épidémie, nous avons mené deux enquêtes téléphoniques sur deux échantillons aléatoires de la population de l'enquête de séroprévalence. Le CHIKV était impliqué dans un tiers des DMS, 10% des troubles neurologiques légers, 7,5% des troubles neurosensoriels, en moyenne dix huit mois après la fin de l'épidémie. La qualité de vie était peu altérée. Les facteurs prédictifs de DMS chroniques étaient un âge supérieur ou égal à 45 ans, des douleurs intenses à la phase aigue de la maladie, enfin une forte réponse humorale contre le CHIKV à sa phase de plateau (titres d'IgG spécifiques élevés). Pour mesurer le pronostic neurocognitif d'une infection materno-fœtale, nous avons suivi pendant deux ans une cohorte d'enfants infectés et non infectés. Plus de la moitié des enfants infectés avaient un retard pyschomoteur, lequel était corrélé à la gravité de la présentation initiale. Nos résultats originaux ouvrent des perspectives intéressantes pour mieux comprendre cette nouvelle maladie infectieuse chroniqueChikungunya is an emerging infectious disease caused by an alphavirus (CHIKV) transmitted by Aedes mosquitoes (Ae albopictus, Ae aegypti). In years 2004-2007, several large scale outbreaks have hit the Indian Ocean area. Our objectives were to assess the burden of the epidemic in the Reunion island community (post-epidemic seroprevalence rate: 38. 2%, 300,000 persons infected) in terms of perceived morbidity, health-related quality of life (QoL), to identify the prognostic factors for musculoskeletal pain of chikungunya rheumatism (RMSP), and finally to determine the neurocognitive outcome of children infected at birth due to the vertical transmission of the virus. In the aim to measure the populational impact of the epidemic, we conducted two telephonic surveys using two random samples of the population of a seroprevalence survey. CHIKV was involved in a third of RMSP, 10% of light cerebral disorders, 7. 5% of sensorineural impairments, on average eighteen months after the end of the outbreak. The Qol was slightly altered in CHIKV-infected subjects. Predictors of chronic RMSP were age greater or equal than 45 years, severe initial rheumatic involvement at the acute phase of infection, and finally a strong humoral response against the CHIKV at plateau phase (high specific IgG titres). To measure the neurocognitive outcome of perinatal infection, we followed-up during two years a cohort of infected and uninfected children. More than half of infected children had a psychomotor delay, which correlated with the severity of the initial presentation. Our original findings open very interesting perspectives for the understanding of this new chronic infectious disease
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Voss, James. "Chikungunya envelope glycoprotein structure at neutral PH determined by X-ray crystallography." Paris 7, 2011. http://www.theses.fr/2011PA077021.
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Le virus de Chikungunya (CHIKV) est un alphavirus émergent, transmis par les moustiques, qui a provoqué des épidémies de maladies débilitantes chez homme pendant les dernières cinq années. L'invasion de CHIKV dans les cellules sensibles est médiée par deux glycoprotéines virales, E1 et E2, qui portent respectivement les boucles de fusion à la membrane et les déterminants antigéniques principaux, et forment une couche protéinique icosaédrique à la surface du virion. La glycoprotéine E2, provenant du clivage par la furine du précurseur p62 (en E3 et E2), est responsable de la liaison au récepteur, tandis que E1 est impliqué dans la fusion membranaire. Dans le cadre d'un effort multidisciplinaire pour comprendre la biologie de CHIKV, nous avons déterminé les structures cristallines de l'hétérodimère précurseur immature (p62-E1; 2. 17 A de résolution) et du complexe mature (E3-E2-E1; 2. 6 A de résolution). Les structures atomiques nous ont permis de faire la synthèse d'une multitude de données génétiques, biochimiques, immunologiques et de microscopie électronique accumulées pendant plusieurs années sur les arbovirus en général. Cette analyse donne une image détaillée de l'architecture fonctionnelle de la couche de surface (25 MDa) des alphavirus. Les structures des complexes matures et immatures de CHIKV a aussi permis de décrire les causes et les mécanismes du changement de conformation des protéines d'enveloppe du virion lors du passage de celui-ci dans l'endosome à pH acide et précédant la fusion membranaireChikungunya is an emerging mosquito-bome alphavirus that has caused widespread outbreaks of debilitating human disease in the past five years. CHIKV invasion of susceptible cells is mediated by two viral glycoproteins, E1 and E2, which carry the main antigenic determinants and form an icosahedral shell at the virion surface. Glycoprotein E2, derived from furin cleavage of the p62 precursor to E3 and E2 is responsible for receptor binding and is the major viral antigen. The E1 protein is responsible for inducing the fusion of viral and cellular membranes in the target cell endosome which is required for release of the viral nucleocapsid into the cytoplasm to initiale infection of a cell. While the structure of E1 has been determined, the structure of E2"has remained elusive over the years. This thesis reports the atomic structures of the mature (E3/E2/E1) and immature (P62/E1) envelope glycoprotein complexes from Chikungunya virus determined by X-ray crystallography using a recombinant protein construct. This construct contained the covalently linked ectodomains of p62 and E1. Diffracting crystals of the purified complexes were obtained at neutral pH when the linker joining the ectodomains was cleaved. The glycoprotein structures were fit into reconstructions of the alphavirus virion obtained from cryo-electron microscopy (cryoEM). This analysis resulted in an inferred atomic model of the entire 25MDa surface of the highly conserved alphavirus virion and allowed for the synthesis of a wealth of genetic, biochemical, immunological and electron microscopy data accumulated over the years on alphaviruses in general
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Wauquier, Nadia. "Exploration des réponses immunitaires induites par les virus Ebola, Chikungunya et Dengue." Paris 6, 2010. http://www.theses.fr/2010PA066548.
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L’espèce Zaïre du virus Ebola (ZEBOV) est très pathogène pour l’homme. Il se manifeste sous la forme de flambées épidémiques de fièvre hémorragique aigue et associe des taux de mortalité de 70 à 90%. Au contraire, les virus Chikungunya (CHIKV) et Dengue (DENV) sont moins pathogènes. Ils sont associés à des faibles taux de mortalité malgré les dizaines de millions de personnes infectées chaque année. Bien que décrites dans les modèles d’infection expérimentale, les réponses immunitaires induites par ZEBOV ou le CHIKV ont été très peu étudiées chez l’homme. L’immunité contre les infections à DENV a été plu étudiée excepté dans le cadre des épidémies africaines. Au cours de ce travail de thèse, nous avons choisi d’explorer les réponses immunitaires induites par ces virus, chez des patients en phase aigüe d’infection. Nous avons montré qu’une infection létale à ZEBOV se distingue par (1) une réponse innée altérée caractérisée par l’absence d’IFN-α et un emballement de la réponse inflammatoire systémique et par (2) une réponse adaptative cellulaire et humorale inexistante résultant probablement de l’apoptose des lymphocytes T et B. Les infections par le CHIKV ou le DENV induisent au contraire une réponse innée cytokinique et cellulaire bien orchestrée qui activerait des réponses lymphocytaires T. L’étude approfondie des réponses induites par ces trois infections virales fournit des éléments de compréhension quant aux différences de pathogénicité et de symptômes associés à ces pathologies virales. Mieux comprendre les mécanismes à l’origine des dérèglements de la réponse immunitaire pourrait permettre de découvrir de nouvelles stratégies thérapeutiques
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Reynolds, Erin Michelle. "Can a low-cost educational intervention result in a change in chikungunya knowledge and prevention practices? Developing and testing an intervention to prevent chikungunya in rural Tamil Nadu, India." Thesis, The University of Iowa, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3680068.
Full textAbstract:
CHIK is a viral infection transmitted by the Aedes aegypti mosquito which causes an illness with symptoms of severe joint pain, high fever, and rash. The joint pain can continue for months, causing disability and economic strain on families. This study included implementation of a baseline needs assessment, and development, implementation, and evaluation of an experimental community-based educational intervention in rural Tamil Nadu, India. A total of 184 households, across 12 purposively sampled villages (six intervention and six control), participated in the needs assessment between August and December 2010. The experimental community-based educational intervention was implemented between December 2010 and August 2011, in the six intervention villages. A total of 180 households, from the same 12 villages, participated in the post-intervention evaluation. A randomized block design with repetition was used to test whether there was a change in CHIK knowledge scores from baseline to post-intervention in the treatment group. A model including respondent variables, household larval status, household container larval status, recent experience with CHIK, numbers of livestock, socioeconomic position (SEP) variables, and water variables were used to predict CHIK knowledge scores in rural Tamil Nadu. Respondent age, measures of luxury amenities and water source were statistically significant predictors of knowledge in this model. The CHIK knowledge score increased from 9.0 to 9.4 in the intervention group (p=0.6457) and from 8.5 to 9.2 in the control group (p=0.393), showing that the educational intervention did not increase CHIK knowledge in the intervention group. Although this low-cost intervention, utilized in a resource poor area of Tamil Nadu, India did not result in an increase of CHIK knowledge, the process of developing the educational intervention may provide a template for future interventions. Future studies should investigate methods of sustainability in the use of educational messages.
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Reynolds, Erin Michelle. "Can a low-cost educational intervention result in a change in Chikungunya knowledge and prevention practices? Developing and testing an intervention to prevent Chikungunya in rural Tamil Nadu, India." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/1496.
Full textAbstract:
CHIK is a viral infection transmitted by the Aedes aegypti mosquito which causes an illness with symptoms of severe joint pain, high fever, and rash. The joint pain can continue for months, causing disability and economic strain on families. This study included implementation of a baseline needs assessment, and development, implementation, and evaluation of an experimental community-based educational intervention in rural Tamil Nadu, India. A total of 184 households, across 12 purposively sampled villages (six intervention and six control), participated in the needs assessment between August and December 2010. The experimental community-based educational intervention was implemented between December 2010 and August 2011, in the six intervention villages. A total of 180 households, from the same 12 villages, participated in the post-intervention evaluation. A randomized block design with repetition was used to test whether there was a change in CHIK knowledge scores from baseline to post-intervention in the treatment group. A model including respondent variables, household larval status, household container larval status, recent experience with CHIK, numbers of livestock, socioeconomic position (SEP) variables, and water variables were used to predict CHIK knowledge scores in rural Tamil Nadu. Respondent age, measures of luxury amenities and water source were statistically significant predictors of knowledge in this model. The CHIK knowledge score increased from 9.0 to 9.4 in the intervention group (p=0.6457) and from 8.5 to 9.2 in the control group (p=0.393), showing that the educational intervention did not increase CHIK knowledge in the intervention group. Although this low-cost intervention, utilized in a resource poor area of Tamil Nadu, India did not result in an increase of CHIK knowledge, the process of developing the educational intervention may provide a template for future interventions. Future studies should investigate methods of sustainability in the use of educational messages.
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Tantaléan, Yépez Derek, José Sánchez-Carbonel, Urizar Gabriela Ulloa, Luis Miguel Angel Aguilar, Morales Diego Espinoza, Wilmer Silva-Caso, Maria J. Pons, and Valle Mendoza Juana Del. "Arboviruses emerging in Peru: need for early detection of febrile syndrome during El Niño episodes." Elsevier B.V, 2016. http://hdl.handle.net/10757/615645.
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The presence of El Niño Southern Oscillation (ENSO) implies the presence of fluctuating rains in coastal areas and these changes influence the occurrence of febrile syndromes outbreaks. In Peru, Aedes aegypti is the vector responsible for various viruses such as the dengue, Zika, chikungunya, which is distributed in 18 Peruvian departments. These viruses cause similar clinical characteristics in the host and for this reason rapid, sensitive and specific diagnostic tests are needed so that the patient can receive timely treatment.Revisión por pares
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Guerrero, Israel. "A Comparison of Chikungunya Virus Infection, Dissemination, and Cytokine Induction in Human and Murine Macrophages and Characterization of RAG2-/-γc-/- Mice as an Animal Model to Study Neurotropic Chikungunya Disease." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8430.
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Chikungunya virus (CHIKV) is classified as an alphavirus in the Togaviridae family. This virus is known to rely on Aedes arthropod vectors for its dissemination. Human infection is characterized by rash, high fever, and severe chronic polyarthritis that can last for years. Recently, efforts in developing animal models have been made in an attempt to better understand CHIKV pathogenesis. CHIKV infection starts with a 7 to 10 day long febrile acute phase, in which most of the symptoms occur (rash, fever, and incapacitating pain in joints and muscle). Once the immune system clears most of the viral infection, a chronic phase starts in as many as 70% of the infected patients. Long term virus-related polyarthralgia is the hallmark of the CHIKV chronic phase. It is believed that CHIKV-infected macrophages infiltrate the joints during the acute phase, and CHIKV infects joint tissue and persists in it. Research into the effects of CHIKV infection in human and murine macrophages revealed that CHIKV-infected human macrophages produce high amounts of virions as well as induce the production of pro-inflammatory cytokines and monocyte recruiting chemokines. This contrasts with murine macrophage infection where low quantities of the virus were detected as well as lower production of pro-inflammatory cytokines. This may contribute to the lack of polyarthritis in murine animal models. Current literature suggests that CHIKV’s viral proteins bind and interact with human host cell machinery promoting viral replication more efficiently in humans than in mice. CHIKV-related neuropathology is not the most common outcome of the disease. However, recent outbreaks suggest that this pathology is becoming more prevalent, affecting as many as 30% of confirmed patients. The role of adaptive and innate immunity in CHIKV disease amelioration has been extensively, yet separately, explored. A RAG2-/-γc-/- Balb/c mouse model was used to study the role of these immune pathways and their associated immune cells in CHIKV infection. The mice in this study developed local arthritis at the site of inoculation as well as showed signs of viral invasion in the brain. This study added to the hypothesis that both innate and adaptive immune responses are necessary to ameliorate the disease and that the lack of adequately matured lymphocytes and STAT6-activation deficient macrophages may result in more severe pathologies.
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Moulay, Djamila. "Modélisation et analyse mathématique de systèmes dynamiques en épidémiologie.Application au cas du Chikungunya." Phd thesis, Université du Havre, 2011. http://tel.archives-ouvertes.fr/tel-00633827.
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Ces dernières années plusieurs maladies infectieuses sont apparues ou ré-apparues. Ce phénomène n'est pas nouveaux et de nombreux facteurs, tels que les changements climatiques, l'intensification des échanges et des voyages, favorisent l'extension, le maintien ou l'émergence de nombreuses maladies infectieuses. L'étude de ces maladies dites (ré-)émergentes est relativement récente (années 1990, concept introduit par S. Morse). Dans cette thèse nous nous intéressons au cas d'une maladie tropical : le Chikungunya. Cette maladie due à un arbovirus (\textit{arthropod-borne virus}) est une maladie vectorielle transmise par les moustiques du genre \textit{Aedes}. Depuis une cinquantaine d'années, plusieurs épidémies ont été recensées, notamment en Afrique et en Asie et plus récemment sur l'île de la Réunion (2005-2006) et en Italie (2007). À l'heure actuelle, il n'est malheureusement pas possible de prédire l'émergence de nouveaux évènements, ceux-ci pouvant être plus ou moins localisés géographiquement, sporadiques ou épidémiques. La modélisation mathématique de ces maladies se révèle donc un atout considérable dans la tentative de compréhension de leur évolution. Ces modèles aident ainsi la prise de décisions et orientent les différentes actions. Dans ce travail nous présentons dans un premiers temps, les caractéristiques biologiques du vecteur et le mode transmission de la maladie à la population humaine. Nous formulons et étudions plusieurs modèles (EDO, Contrôle, EDR) décrivant la dynamique de croissance des différents stades d'évolution du vecteur (œuf/larve/nymphe/adulte) en utilisant des modèles structurés par classes. Cette dynamique est alors couplée à un modèle de transmission de la maladie, décrit par des modèles de type SI-SIR. Différentes stratégies de contrôle, intégrant les techniques de luttes contre la maladie et la prolifération de la population de moustique sont également étudiées. La formulation d'un modèle de type métapopulationnel, décrivant les déplacements humains et vecteurs ainsi qu'une modélisation de l'environnement de l'Île de la Réunion, nous permettent de valider nos modèles grâce à une comparaison aux données de seroprévalence enregistrées et estimées par l'INVS (Institut de Veille Sanitaire).
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Fumagalli, Marcílio Jorge. "Desenvolvimento de métodos sorológicos para diagnóstico de infecções pelos vírus Chikungunya e Mayaro." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/17/17147/tde-15102018-115825/.
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Devido a existência de 2 alphavírus artritogênicos no Brasil, os vírus Mayaro (MAYV) e Chikungunya (CHIKV) tornou-se importante desenvolver testes diagnósticos eficazes para discriminar suas infecções. No presente trabalho, desenvolvemos ELISAs indiretos para diagnóstico de CHIKV e MAYV utilizando proteínas de envelope viral E2 recombinantes, produzidas em Escherichia coli, as rE2-CHIKV e rE2-MAYV ELISAs. As proteínas E2 recombinantes tiveram suas antigenicidades verificadas nos ensaios utilizando anticorpos policlonais oriundos de camundongos hiperimunizados com CHIKV, MAYV e outros alphavírus. O rE2-CHIKV ELISA detectou anticorpos murinos de forma homotípica e não produziu reações cruzadas evidenciáveis utilizando anticorpos murinos específicos contra outros Alphavírus. O rE2-MAYV ELISA detectou anticorpos murinos homotípicos e também, reagiu cruzadamente com anticorpos murinos anti-CHIKV, mas não para outros Alphavírus. Esses ELISAs, também, foram usados na detecção de anticorpos em soros de pacientes com suspeita de infecção arboviral. Pelo o rE2-CHIKV ELISA, testaram-se 59 soros, resultando em 26 amostras IgG positivas. Resultados desse ELISA, quando comparados aos obtidos por teste de neutralização, demonstraram sensibilidade de 89,66% e especificidade de 100%. Soros humanos IgG positivos foram detectados em altas diluições pelo rE2-CHIKV ELISA. Quanto a detecção de IgM, o rE2- CHIKV ELISA apresentou moderada concordância com outros ensaios sorológicos. Com rE2- MAYV ELISA, testaram-se 68 soros resultando em 23 amostras IgG positivas, das quais 11 também mostraram-se positivas em teste de neutralização, demonstrando sensibilidade de 100% e especificidade de 78,95%. Portanto, os rE2-CHIKV e rE2 MAYV ELISAs, particularmente para detecção de IgG, mostraram-se adequadamente sensíveis e específicos para serem validados em estudos com maiores números de amostras e serem aplicados ao diagnóstico de pacientes infectados com CHIKV e MAYV.Due the existence of 2 arthritogenic alphaviruses in Brasil, the viruses Mayaro (MAYV) and Chikungunya (CHIKV), it became important the development of efficient diagnose tests to discriminate their infections. In the present work, we developed indirect ELISAs for CHIKV and MAYV diagnosis using viral recombinant envelope proteins E2, produced in Escherichia coli, the rE2-CHIKV and rE2-MAYV. The recombinant E2 proteins had their antigenicity confirmed in the assay by using polyclonal antibodies produced in hyperimmunized mice with CHIKV, MAYV and other alphaviruses. The rE2-CHIKV ELISA detected homotypic murine antibodies and did not produced detectable cross-reactivity signal when using murine antibodies from other alphaviruses. The rE2-MAYV ELISA detected homotypic antibodies and also cross-reacted with murine anti-CHIKV antibodies, but not to other alphaviruses. These ELISAs were also tested for the detection of human antibodies, using patient sera suspected of arboviral infection. For rE2- CHIKV ELISA, it were tested 59 sera, resulting in 26 positive IgG samples. These ELISA results, when compared to those of a neutralizing assay, demonstrated a sensibility of 89.66% and specificity of 100%. The IgG positive human sera were detected in high dilutions by rE2-CHIKV ELISA. Regarding the detection of IgM, the rE2-CHIKV ELISA showed a moderate samples detection agreement when compared to other serologic assays. For rE2-MAYV ELISA, it were tested 68 sera, resulting in 23 positive IgG samples, of which 11 demonstrated to be positive by the neutralization assay, demonstrating a sensibility of 100% and specificity of 78.95%. Therefore, the rE2-CHIKV and rE2-MAYV ELISAs, especially for IgG detection, demonstrated to be properly sensitive and specific to be validated in studies using a greater number of samples, and also to be applied in the diagnosis of infected CHIKV and MAYV patients.
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Moizeis, Raíza Nara Cunha. "Avaliação do perfil da resposta imune inata em pacientes infectados pelo vírus Chikungunya." PROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIAS BIOLÓGICAS, 2018. https://repositorio.ufrn.br/jspui/handle/123456789/25525.
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A infecção pelo vírus Chikungunya causa alta morbidade devido principalmente a artralgia e artrite geradas. A inflamação induzida nas articulações pela infecção viral envolve a imunidade inata e adaptativa. Entretanto, os mecanismos imunológicos envolvidos na proteção ou patogênese não estão ainda, totalmente, elucidados. Dessa forma o objetivo do presente estudo foi avaliar as expressões de receptores da imunidade inata e citocinas induzidas por sua ativação em pacientes infectados pelo vírus Chikungunya. Neste estudo, foi avaliado a expressão de RNAm por PCR em tempo real dos receptores tipo Toll (TLR3, TLR7, TLR8, TLR9), RLR (MDA5 e RIG-1), Moléculas adaptadoras (TRIF e MyD88) e citocinas (IFNα, IFNβ, IFNγ, IL-6, IL-12 e TNFα) em sangue total de pacientes na fase aguda da infecção por Chikungunya (N=28) e em indivíduos saudáveis, não infectados (N=9) utilizados como grupo controle. Os pacientes infectados pelo CHIKV apresentaram aumento da expressão de RNAm de TLR3, em relação aos indivíduos saudáveis. Não foi observada diferença significativa da expressão de TLR7, TLR9, MDA5 e RIG-1 nos pacientes infectados pelo CHIKV, sendo observada, no entanto, uma redução da expressão de RNAm de TLR8, quando comparado aos indivíduos saudáveis. Nossos resultados indicam que a infecção pelo CHIKV em pacientes na fase aguda induz elevada produção de IFN-α, IFN-γ e IL-6, moléculas da imunidade inata, com ação antiviral provavelmente, devido ao reconhecimento do vírus por TLR3 e em menor proporção por MDA5 e RIG-1, além de mecanismos que, possivelmente, envolvam a colaboração de TLR9. Ainda, foram constatadas correlações positivas entre as expressões de RNAm de TLR3, TLR7, TLR9, MDA5 e RIG-1 com expressão IFN-α. De maneira interessante, também foram observadas correlações positivas entre as expressões de RNAm de TLR3 com IFN-α, IFN-γ e IL-12, e entre a expressão de RNAm de MDA5 com IFN-α, IFN-β, IFN-γ e IL-6, IL-12 e TNF-α.
Chikungunya virus infection cause high morbidity mainly due to arthalgia and arthritis generated. An inflammation induced in the joints by viral infection involve innate and adaptive immunity. However, the immunological mechanisms involved in protection or pathogenesis have not yet been completely elucidated. Thus the aim of the present study was to evaluate the expression of innate immunity receptors and cytokines induced by their activation in patients infected with the Chikungunya virus. In this study the expression of mRNA by real-time PCR of Toll receptors (TLR3, TLR7, TLR8, TLR9), RLR (MDA5 and RIG-1), adaptive molecules (TRIF and MyD88) and cytokines (IFN-α, IFN-β, IFN-γ, IL-6, IL-12 and TNF-α) in whole blood of patients in the acute phase of the Chikungunya infection (N=28). Uninfected cases (N=9) were used as negative controls. Pacients infected with CHIKV are older than TLR3 mRNA expression in relation to healthy languages. Influences of the expression of TLR7, TLR9, MDA5 and RIG-1 in CHIKV infected patients in the past have not been confirmed but have been shown to decrease TLR8 mRNA expression when they were found in the healthy populations. Factors related to CHIKV infection in pacients in the suck phase, infection with IFN-α, IFN-γ and IL-6, infections of innate immunity with antiviral action, recognition of the virus by TLR3 and to a lesser extent by MDA5 and RIG-1, in addition to mechanisms that possibly involve TLR9 collaboration. Furthermore, positive correlations were found between the mRNA expression of TLR3, TLR7, TLR9, MDA5 and RIG-1 with IFN-α expression. Interestingly, positive correlations between TLR3 mRNA expression with IFN-α, IFN-γ and IL-12 were also observed, and between MDA5 mRNA expression with IFN-α, IFN-γ and IL-12 were also observed, and between MDA5 mRNA expression with IFN-α, IFN-β, IFN-γ and IL-6, IL-12 and TNF-α.
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Bourjot, Mélanie. "Recherche d'inhibiteurs de la réplication du virus Chikungunya issus de la biodiversité tropicale." Paris, Muséum national d'histoire naturelle, 2012. http://www.theses.fr/2012MNHN0015.
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Dans le cadre d’un projet visant à découvrir des inhibiteurs de la réplication du virus chikungunya (CHIKV), un criblage a été mené sur 685 plantes malgaches. Deux espèces ont ainsi été sélectionnées : Flacourtia ramontchi (Salicaceae) et Anacolosa pervilleana (Olacaceae). Le fractionnement bioguidé de la première a conduit à l’isolement de onze molécules dont dix appartiennent à la série des glucosides phénoliques et six sont nouvelles, tandis que l’étude d’Anacolosa pervilleana a mené à la caractérisation de sept molécules dont quatre acides polyacétyléniques, deux terpènes et un glucoside cyanogénique. Malheureusement, ces molécules n’ont pas montré d’activité sur la réplication du CHIKV. Suite à la découverte par sérendipité d’un diterpène à squelette daphnane et motif orthhoester (DDO) à puissante activité anti-CHIKV, nous avons entrepris l’étude phytochimique de deux espèces de Trigonostemon (Euphorbiaceae) : T. Cherrieri et T. Howii. L’étude phytochimique de l’extrait AcOEt des feuilles de T. Cherrieri a conduit à l’isolement de huit daphnanes de type orthoester, dont deux nouveaux. Ces molécules ont montré une activité puissante et sélective sur la réplication du CHIKV, suggérant la découverte du premier squelette « hit » sur le CHIKV. L’étude de l’extrait AcOEt d’écorces de T. Howii a permis l’isolement de sept composés dont un nouveau tigliane, quatre coumarines et deux phénylpropanoïdes. Le composé de type tigliane a montré une activité modérée sur le CHIKV. Ce résultat nous a mené à investir biologiquement d’autres diterpènes de type tigliane parmi lesquels le phorbol 12-myristate 13-acétate a montré l’activité la plus puissante jamais découverte jusqu’à présentIn order to discover inhibitors of viral replication of chikungunya (CHIKV), a screening was performed on 685 malagasy plants. Two species were selected: Flacourtia ramontchi (Salicaceae) and Anacolosa pervilleana (Olacaceae). The bioguided fractionation of the first species led to the isolation of eleven molecules of which ten were phenolic glycosides and six were new, while the study of Anacolosa pervilleana led to the characterization of seven molecules amongst which four polyacetylenic acids, two terpenoids and one cyanogenic glycoside. Unfortunately, these molecules have not shown any activity on CHIKV replication. Since a potent anti-CHIKV activity of a daphnane diterpenoid orthoester (DDO) isolated from a Trigonostemon species was discovered by serendipity, we have engaged chemical investigations of two species of Trigonostemon (Euphorbiaceae) : T. Cherrieri and T. Howii. The study of the EtOAc extract obtained from T. Cherrieri leaves led to the isolation of eight DDOs amongst which two were new. These molecules showed potent and selective antiviral activity on CHIKV replication. The study of the EtOAc bark extract of T. Howii allowed isolating seven compounds amongst which one new tigliane, four coumarins and two phenylpropanoids. The tigliane-type compound showed a moderate activity on CHIKV. This result led us to biologically investigate other tigliane diterpenoids amongst which phorbol 12-myristate 13-acetate had shown the most powerful anti-CHIKV activity ever found to date
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Lacroix, Renaud. "Etude de terrain d'Aedes albopictus vecteur du Chikungunya sur l'Ile de la Réunion." Versailles-St Quentin en Yvelines, 2009. http://www.theses.fr/2009VERS0053.
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La récente épidémie de Chikungunya a confirmé le potentiel d’Aedes albopictus comme vecteur. Dans l’optique d’utiliser la Technique de l’Insecte Stérile (TIS), des expériences de marquage-lâcher-recapture à l’île de la Réunion ont été réalisées. Un piège BG-Sentinel utilisant des souris pour appât a permis de capturer mâles et femelles. Les résultats ont permis d’établir qu’Ae. Albopictus a une dispersion limitée à 50 m, une activité plus importante en saison humide et une survie similaire pour les deux sexes mais plus élevée en saison humide, s’accouple avant le repas de sang en saison sèche et est inféodé à la végétation. Nous concluons que la TIS devra avoir des lieux de lâchers proches, une fréquence de lâchers peu élevée, et adapter aux saisons le nombre de mâles relâchés et les lieux de lâchers. Beaucoup reste à apprendre avant l’application de la TIS, des expériences avec des mâles stériles seront nécessaires afin d’optimiser le contrôle des populationsThe recent epidemics of Chikungunya confirmed the potential of Ae. Albopictus as a vector. For implementation of Sterile Insect Technique (SIT), Mark-Release-Recapture (MLR) experiments were conducted in La Réunion Island. A mouse baited BG-Sentinel trap shown to be efficient at trapping both males and females. Results indicates that Ae. Albopictus has a limited dispersal range, higher activity during wet season, similar survival for both sexes but higher during wet season, mates before bloodmeal during dry season and preferred heavily shaded vegetated areas. We conclude that SIT should settle close release points, a low frequency of releases, adapt to season number released and places of releases. There is still a lot of work to be done before application of SIT, experiments with sterile males will be necessary for optimisation of vector population control
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Arias, Goeta Camilo. "Evolution et adaptation du virus chikungunya vis-à-vis des ses hôtes vecteurs." Paris 6, 2012. http://www.theses.fr/2012PA066691.
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Les arbovirus se caractérisent par un taux de mutation élevé mais leur cycle de transmission nécessitant à la fois une réplication chez un vertébré et un invertébré tend à limiter leur évolution. Un changement d’hôtes peut favoriser l’émergence de nouveaux variants. Ainsi, lors de l’émergence du virus chikungunya (CHIKV) dans l’Océan Indien en 2004, un nouveau variant épidémique portant un changement d’acide aminé dans la glycoprotéine E1, a été associé à une meilleure transmission par le vecteur secondaire, Aedes albopictus. Nous avons montré que lorsque le variant d’origine et le variant épidémique sont proposés à proportions égales dans un même repas sanguin, le variant épidémique était préférentiellement transmis chez Ae. Albopictus. En revanche, lorsque les deux variants ont été inoculés par voie intrathoracique, permettant de court-circuiter la barrière intestinale, ce variant n’était plus sélectionné chez Ae. Albopictus. Ceci met en évidence le rôle clé de cette barrière dans la sélection du variant épidémique. D’autres mutations pourraient être favorisées par le changement d’hôtes. Nous avons donc évalué si l’alternance d’hôtes pouvait limiter l’évolution du CHIKV compromettant sa fitness. Le variant épidémique du CHIKV a été passé en série ou en alternance sur des cellules de mammifère et de moustique. Après 30 passages, les souches virales ont été caractérisées génétiquement et phénotypiquement. Dans ces conditions expérimentales l’alternance d’hôtes ne limite pas l’évolution du CHIKV. Par contre, nous avons identifié de nouvelles substitutions d’acides aminés dans la glycoprotéine E2 qui pourraient moduler la compétence vectorielle du moustiqueArboviruses are characterized by high rates of mutation. However, it has been assumed that their evolution is constrained by requirement for alternate replication in vertebrate and invertebrate hosts. Host change would favor the emergence of new viral variants pre-existing in the viral population. Indeed, during the 2004 outbreak of chikungunya virus (CHIKV) in the Indian Ocean, a newly emerged epidemic variant harboring a single amino-acid substitution in the E1 glycoprotein was highly transmitted by an unusual mosquito vector, Aedes albopictus. We showed that when the original and the newly emerged epidemic variants were provided at equal titers in blood-meals, the epidemic variant was preferentially transmitted by Ae. Albopictus. Interestingly, when inoculating both variants into mosquitoes bypassing the midgut barrier, the epidemic variant was no longer selected in Ae. Albopictus. Our findings suggest that the midgut barrier plays a key role in the selection of the epidemic variant. Subsequent adaptive mutations in the CHIKV genome are likely to emerge questioning on the evolution of CHIKV. We evaluated if host alternation can limit CHIKV evolution and results in fitness trade-offs. To test this hypothesis, the newly emerging variant of CHIKV was serially or alternately passaged in mammalian or mosquito cells. After 30 passages, obtained CHIKV strains were genetically and phenotypically characterized. Our results were not in line with the general assumption stating that host alternation constrains CHIKV evolution. However, our experimental approach suggested that new amino-acid substitutions in the E2 glycoprotein could modulate the vector competence in mosquitoes
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Schilte, Clémentine. "Rôle de l’interféron de type I dans la physiopathologie du virus du Chikungunya." Paris 6, 2010. http://www.theses.fr/2010PA066090.
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Le virus du Chikungunya est la cause d’une épidémie qui a commencé à la Réunion et continue d’être un problème de santé publique majeur. Ce virus transmis aux hommes par des moustiques, induit chez les patients de la fièvre, des arthralgies et des myalgies. Lors d’une épidémie précédente, une étude clinique avait démontré que la charge virale disparaissait chez les patients avant l’apparition des premiers anticorps, laissant supposer un rôle majeur de la réponse immune innée. Nous avons donc étudié le rôle de l’interféron de type I (IFN) lors de l’infection par le virus du Chikungunya. Alors que les souris de type sauvage (WT) éliminent le virus rapidement après son inoculation, les souris déficientes pour le récepteur de l’interféron de type I (IFNAR) meurent dans les trois jours suivant l’infection. Dans les deux types de souris, les fibroblastes sont la cible cellulaire principale du virus. L’utilisation de souris chimériques m’a permis de conclure qu’in vivo les cellules hématopoïétiques et non-hématopoïétiques participent ensemble à la production d’interféron de type I. En outre, j’ai découvert que l’expression du récepteur aux interférons était requise en périphérie et non sur les cellules hématopoïétiques afin d’éliminer le virus. Du fait de la pathologie sévère observée chez les nouveaux-nés, j’ai également caractérisé un modèle animal utilisant des souriceaux. J’ai démontré que les souris de type sauvage âgées de moins de 10 jours étaient susceptibles à l’infection et développent une paralysie des membres postérieurs ainsi qu’une pathologie musculaire.
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Godaert-Simon, Lidvine. "Aspects épidémiologiques et cliniques d'une infection par le virus du Chikungunya chez les sujets âgés de 65 ans et plus. : Etude sur les spécificités d'une atteinte par arbovirose dans une population âgée." Thesis, Antilles, 2017. http://www.theses.fr/2017ANTI0253/document.
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L’infection par le virus du Chikungunya est devenu en quelques années un problème de santé publique. D’abord limitée dans les régions tropicales et subtropicales, la diffusion mondiale du vecteur de l’infection couplée à la migration humaine et aux adaptations du virus contribue à la survenue de phénomènes épidémiques fréquents et touchant de nombreux territoires jusqu’aux pays tempérés. Dans les prochaines décades, la population des 65 ans ou plus sera probablement largement impactée lors des épidémies. Les conséquences de la maladie dans cette population est méconnu du fait de l’absence de données d’observation disponibles. Or, les spécificités de cette population sont connues (risque de comorbidité associée, immunosenescence, modifications physiologiques affectant le système rénal, cardiaque, pulmonaire…) et influencent fortement son mode de réponse et sa capacité à supporter un épisode infectieux. A travers l’observation et le suivi de la cohorte ChikOld constituée de 687 sujets âgés de 65 ans ou plus ayant contracté ou non la maladie en 2014, nous avons mis en évidence que les outils d’aide au diagnostic élaborés dans une population d’adultes jeunes avaient des performances médiocres dans la population âgée. Nous avons également pu mettre en évidence que les tableaux cliniques habituellement décrits de la maladie ne sont pas ceux observés le plus fréquemment dans une population de sujets de 65 ans ou plus. Ces observations ont abouti à l’élaboration un outil d’aide au diagnostic (score) spécifique à cette population. De nombreuses questions subsistent concernant cette infection, notamment sur les conséquences à moyen et long terme, sachant les conséquences en phase aiguë et l’existence de formes chroniques. Une étude préliminaire que nous avons conduit suggère l’absence de surmortalité à moyen terme (un an) et la majoration de la dépendance dans les suites d’une infection par le virus du Chikungunya. D’autres travaux seront nécessaires pour caractériser la forme habituelle de la maladie chez les sujets âgés ainsi que pour mieux appréhender les conséquences à moyen et long terme concernant la mortalité et la dépendanceChikungunya virus infection is an emergent arthropod-borne alpha-virus transmitted by mosquito bites, and causes fever with debilitating arthritic illness. Chikungunya virus infection is still considered as an emerging public health problem in both tropical and temperate regions. The presence of favourable conditions in temperate regions has enabled propagation of the vector, leading to the emergence of the first autochthonous cases of CHIKV in Europe and the USA. Older people may be particularly concerned about infection during an outbreak. CVhikungunya virus infection prevalence rates are not fully known, and vary from 18% to 48% The use of predictive scores would thus be very helpful in this situation. We have showed that predictive scores developed in young population have poor diagnostic performances in elderly population. In fact, the populations described in observational studies of chikungunya virus infection were predominantly young subjects. Clinical and epidemiological data in older subjects (aged 65 and over) are sparse. The mortality and morbidity related to infection in elderly people is poorly documented. We showed that the usual clinical expression of CHIKV infection is different in elderly subjects (absence of fever, arthralgia or both). We have developed and validated a new Chikungunya virus infection screening score specifically for use in the aged population.Some questions remain, in particular concerning mid- or long-term consequences of infection in elderly people. In a preliminary study, we have showed that the mid-term mortality rate of aged people infected by Chikungunya was lower than that of uninfected aged people.We need to continue our work on this thematic to explore more precisely the consequences of chikungunya virus infection in elderly people (mid- and long-term mortality, loss of autonomy, chronic form…)
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Boussier, Jeremy. "Chikungunya Virus Superinfection Exclusion and Defective Viral Genomes : Insights into Alphavirus Regulation of Genetic Diversity." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC181/document.
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Les arbovirus (dont le virus chikungunya, CHIKV) sont responsables de millions d'infections chaque année ; aucun vaccin n'est encore approuvé, et les traitements disponibles restent limités. De part leur circulation constante entre le moustique et l'humain, leur adaptation rapide à différents hôtes est un facteur clé pour leur pathogenèse. Le taux d'erreur particulièrement élevé de leur polymérase ARN permet une rapide diversification génique qui conduit à la génération d'un nuages de mutants, appelée quasi espèce. Les quasi espèces contiennent non seulement des génomes mutés, mais aussi des ARN recombinés à partir de deux génomes d'origine différente, ainsi que des génomes avec de grandes délétions, incapables de se répliquer sans l'aide d'un autre virion qui doit infection la même cellule, nommés génomes viraux défectifs (GVD). Une régulation étroite de la taille du nuage de mutants est clé pour une pathogenèse efficace : si trop petit, le potentiel adaptatif du virus sera impacté ; au contraire, une quasi-espèce trop grande peut mener à l'accumulation rapide de mutations délétères pour le virus. Alors que la régulation du paysage mutationnel est atteinte grâce à un taux d'erreur de la polymérase viral finement contrôlé, la recombinaison et la réplication des génomes défectifs sont influencés par le potentiel de co-infection des cellules cibles. Dans ce contexte, l'exclusion de la surinfection (ESI), un processus par lequel l'infection par un premier virus inhibe l'infection par un second virus, peut influer le dynamique de la quasi-espèce. Bien que décrite dans la plupart des familles virales, les mécanismes à l'origine de l'ESI restent mal caractérisés. Dans ce travail, je montre que CHIKV exclut une infection future par CHIKV, mais aussi par le virus Sindbis et le virus de la grippe A, mais non par le virus du Nil occidental. Je démontre que l'exclusion de CHIKV se situe au niveau de la pénétration du génome viral dans le cytoplasme, puis de sa réplication, mais n'influence ni l'attachement du virion ni la traduction de son génome. Je montre également que l'ESI est indépendant de l'action des interférons de type I, et qu'elle n'est médiée ni par la transcription cellulaire, ni par un facteur soluble. De plus, l'exclusion n'est pas due à une unique protéine virale, suggérant un potentiel rôle de la réponse cellulaire à l'infection.Déterminer l'influence des pressions immunologiques dans l'établissement de la quasi-espèce peut aider à une meilleure compréhension de l'interaction entre évolution virale et réponse immunitaire. Bien que la caractérisation non biaisée des mutations ponctuelles fût le fruit de nombreux travaux, les GVD restent peu caractérisées, en particulier chez les alphavirus. Dans la deuxième partie de ce travail, je développe des outils bio-informatiques pour isoler rapidement les GVD de données de séquençage à haut débit, et analyse les avantages et les inconvénients d'un ajout d'une étape de pré-amplification pour détecter et quantifier les GVD. À l'aide de ces outils, je fournis ensuite la première description complète des GVD produits par des passages séquentiels de CHIKV en culture cellulaire. En particulier, je montre que le type de GVD générés est très dépendants du type cellulaire, avec des motifs de séquences et des cadres de lecture ouverts différents lorsque les cellules hôtes sont des cellules de mammifère ou d'insecte. Ces résultats soulignent le role de l'environnement cellulaire dans le modelage de la quasi-espèce, et des GVD en particulier. Des travaux futurs aideront à dévoiler les mécanismes sous-jacents à cette interaction et pourraient permettre la conception de nouvelles stratégies thérapeutiques ciblant les dynamiques des quasi-espècesArboviruses such as chikungunya virus (CHIKV) are responsible for millions of yearly infections, with no approved vaccines and limited treatments. Because they circulate between mosquitoes and humans, their fast adaptation potential to different hosts is key to pathogenesis. To achieve genome diversification, they rely on the error-prone nature of their self-encoded RNA-dependent RNA polymerase, which quickly generates a cloud of mutants, termed quasispecies. Quasispecies contain not only mutated genomes, but also shuffled genomes of different parental origin (through a process known as recombination), as well as genomes with large deletions, unable to replicate without the co-infection with a full-length helper genome, and thus termed defective viral genomes (DVGs). A tight regulation of the mutant cloud size is key to pathogenesis: if too small, it will limit the adaptation potential of the virus, whilst too big a quasispecies may lead to the fast accumulation of deleterious mutations. While regulation of the mutational landscape is achieved through the finely tuned error rate of the viral polymerase, recombination and DVG replication are influenced by the co-infection potential of the target cells.In this context, superinfection exclusion (SIE), a process by which infection by a first virus prevents infection by a second, closely related virus, can regulate quasispecies dynamics. While described in most viral families, mechanisms underlying SIE remain poorly characterised. Here, I show that CHIKV infection excludes subsequent infection by CHIKV, Sindbis virus and influenza A virus, but not West Nile virus. I demonstrate that CHIKV exclusion occurs at two steps, impacting independently viral penetration and replication, but does not directly influence binding, nor viral protein translation. I further show that SIE is interferon independent, and does not rely on host cell transcription nor on soluble cellular factors. Moreover, exclusion is not mediated by the action of a single CHIKV protein, suggesting that a cellular response may be at play. Assessing how different immunological pressures can shape quasispecies landscape may prove useful to a more thorough understanding of the interplay between viral evolution and the immune response. Although the unbiased study of point mutations has received much attention, less is known about the characteristics of DVGs, especially in alphaviruses. In the second part of this work, I develop bioinformatics tools to quickly isolate DVGs from next-generation sequencing data, and assess the advantages and drawbacks of pre-amplification steps to detect and quantify DVGs. Using these tools, I provide the first unbiased description of the DVG landscape generated through serial passaging of CHIKV in cell culture. In particular, I show that the DVG landscape is highly dependent on the cell type, with sequence patterns and open reading frames differing between DVGs generated in mammalian and insect cells. These results highlight the role of the cellular environment in shaping quasispecies, and DVGs in particular. Future work will help uncover the mechanisms underlying this crosstalk and may prove useful for the design of treatments targeting quasispecies dynamics
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Raquin, Vincent. "Immunité innée et multi-infections chez le moustique (Diptera, Culicidae) : étude fonctionnelle des interactions Wolbachia-arbovirus-Aedes albopictus." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10341.
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On assiste actuellement à l'émergence et la ré-émergence mondiale d'arboviroses comme le chikungunya, la dengue ou la fièvre de la vallée du Rift. Ces maladies, responsables d'environ 30 000 décès par an, sont dues à des virus principalement transmis à l'homme par des moustiques vecteurs. En l'absence de vaccins efficaces et face aux limites de l'utilisation d'insecticides, nocifs pour les écosystèmes et entrainant des résistances chez les vecteurs, il est nécessaire de développer des moyens alternatifs de lutte. La découverte récente du potentiel antiviral de certaines bactéries symbiotiques du moustique, comme le genre Wolbachia, représente un outil de lutte biologique prometteur face aux arboviroses. Ce projet de thèse porte sur la relation tripartite moustique-bactéries endosymbiotiques-arbovirus, en prenant pour modèle le moustique-tigre, Aedes albopictus. Cette espèce originaire d'Asie envahit progressivement l'Europe. Elle transmet notamment le virus de la dengue et du chikungunya, et est naturellement infectée par Wolbachia. Les résultats obtenus ont permis d'observer un phénotype antiviral chez les moustiques infectés par Wolbachia, contrairement aux moustiques aposymbiotiques. L'utilisation d'une méthode de transcriptomique haut-débit (RNAseq) a permis de déterminer certains mécanismes cellulaires et moléculaires majeurs du moustique spécifiquement impliqués dans l'interaction avec les arbovirus, Wolbachia, et les deux partenaires simultanément. Le développement d'une lignée cellulaire d'Ae. albopictus stablement infectée par Wolbachia a permis de mettre en évidence le rôle central de l'autophagie dans l'interaction Wolbachia-arbovirus chez Ae. AlbopictusArthropod-borne virus (arbovirus) are important cause of human diseases worldwide, leading to nearly 30.000 deaths every year. Many arboviruses like dengue virus (DENV), chikungunya virus (CHIKV) or Rift valley Fever virus (RVFV) are transmitted by mosquitoes, and global changes like climate warming or international trade increase vectors geographic range, thus facilitating the emergence of arbovirosis. Very few vaccines are currently available, and the use of insecticides remains the only way to prevent arbovirosis but cause adverse effects on ecosystems, and lead to resistance phenotypes in vector populations. Recent work showed that mosquito bacterial flora, especially bacteria from the genus Wolbachia, can modulate viral infection, a phenotype called microbial interference. These results provide a promising tool to limit transmission of arboviruses, but little is known about mosquito-Wolbachia-arbovirus interaction especially at the cellular level. We characterized for the first time this multipartite interaction in Aedes albopictus, an important mosquito vector of DENV and CHIKV, which is naturally infected by Wolbachia. Results showed an antiviral phenotype in Wolbachia-infected mosquitoes, compared to aposymbiotic insects. We used RNAseq to decipher the major mosquito pathways implemented during mono-infection by virus, bacteria or during bi-infection. Moreover, we developed an Ae. albopictus cell line stably infected by Wolbachia to go further in mechanical aspects, and showed that autophagy is a major pathway involved in Wolbachia-arbovirus interaction in Ae. albopictus
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Sánchez-Carbonel, José, Derek Tantaléan-Yépez, Miguel Angel Aguilar-Luis, Wilmer Silva-Caso, Pablo Weilg, Fernando Vásquez-Achaya, Luis Costa, Johanna Martins-Luna, Isabel Sandoval, and Valle-Mendoza Juana del. "Identification of infection by Chikungunya, Zika, and Dengue in an area of the Peruvian coast. Molecular diagnosis and clinical characteristics." BioMed Central Ltd, 2018. http://hdl.handle.net/10757/623066.
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Objective: To assess the presence of Dengue, Chikungunya, and Zika in serum samples of patients with acute febrile illness in Piura, Peru and describe the most common clinical features. Results: Dengue was the most common arbovirus detected in 170/496 (34.3%), followed by Zika in 39/496 (7.9%) and Chikungunya in 23/496 (4.6%). Among the 170 samples positive for Dengue, serotype 2 was the most predominant type present in 97/170 (57.1%) of samples, followed by the serotype 3 in 9/170 (5.3%). Headaches, muscle pain, and joint pain were the most common symptoms associated with fever in patients with Dengue and Zika. No symptoms predominance was observed in patients with Chikungunya.Dengue is considered the most frequent arbovirus in Peru and the number of cases has increased dramatically in the last 5 years. However, it is not the only arbovirus that circulates along the northern coast of Peru. It has also been determined the presence of Zika and Chikungunya in our population, which may suggest the circulation of other arboviruses that have not been detected.
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Pinto, Jose Reginaldo. "Investigação epidemiológica da infecção pelo vírus chikungunya e sua relção com a doença renal crônica e outras cormobidades." Universidade de Fortaleza, 2018. http://dspace.unifor.br/handle/tede/108414.
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Previous issue date: 2018-12-07The northeastern region of Brazil has faced the largest outbreak of the Chikungunya virus (CHIKV) in its history in the last two years. There are still few studies on kidney involvement in CHIKV infection. The present study analyzes the clinical and epidemiological characteristics of CHIKV in the State of Ceará, Brazil, outlining the profile of the reported cases, investigating the risk factors for death. This is a cross-sectional study including all registered cases of CHIKV in the State of Ceará in 2016-2017, based on the official data of the Health Secretariat of the State of Ceará (SESA-CE). There were 182,731 cases in 2016 and 2017, with a mean age of 32.4 ± 14.6 years and a predominance of females (62%). The clinical picture was characterized by fever (88.6%), headache (72.9%), severe arthralgia (69.5%) and myalgia (65.6%). Among comorbidities, there was a predominance of systemic arterial hypertension (6.9%) and diabetes mellitus (2.9%). CKD was reported in 691 cases (0.3%). Only 3.3% of patients needed hospitalization and only 0.1% died due to infection. The majority of the patients who died were the elderly, the male and the less educated. Independent risk factors for death were: advanced age (OR 7.35, p<0.0001), male gender (OR 2.05, p<0.0001), leukopenia (OR 3.18, p<0.0001), vomiting (OR 2.19, p<0.0001), and comorbidities like hypertension (OR 3.74, p<0.0001), diabetes (OR 3.29, p<0.0001), and chronic kidney disease (OR 3.14, p<0.0001). They also had a significantly higher frequency of diabetes mellitus, hematological disorders, Liver diseases, hypertension, peptic ulcer diseases and autoimmune diseases. Mortality was significantly higher among CKD patients comparing with patients without CKD (3.0% vs. 0.2%, p<0.0001). CHIKV infection may manifest as a serious disease, especially during epidemic periods. Advanced age and low schooling were associated with a higher mortality risk. Leukopenia and vomiting were signs of severity that should be valued by the health team, as well as the presence of comorbidities, especially hypertension, diabetes and kidney disease.
A região nordeste do Brasil tem enfrentado nos últimos dois anos o maior surto de infecção pelo vírus Chikungunya (CHIKV) em sua história. Ainda existem poucos estudos sobre o envolvimento renal na infecção pelo CHIKV. O presente estudo analisa as características clínicas e epidemiológicas do CHIKV no Estado do Ceará, Brasil, delineando o perfil dos casos notificados, investigando os fatores de risco para óbito. Trata-se de um estudo transversal incluindo todos os casos registrados do CHIKV no Estado do Ceará em 2016-2017, com base nos dados oficiais da Secretaria da Saúde do Estado do Ceará (SESA-CE). Foram registrados 182.731 casos em 2016 e 2017, com média de idade de 32,4 ± 14,6 anos e predomínio do sexo feminino (62%). O quadro clínico foi caracterizado por febre (88,6%), cefaleia (72,9%), artralgia grave (69,5%) e mialgia (65,6%). Entre as comorbidades, houve predomínio de hipertensão arterial sistêmica (6,9%) e diabetes mellitus (2,9%). A DRC foi relatada em 691 casos (0,3%). Apenas 3,3% dos pacientes necessitaram de internação e apenas 0,1% foram a óbito devido à infecção. O grupo de pacientes que foi a óbito era em sua maioria composto por idosos, do sexo masculino e com menor escolaridade. Os fatores de risco independentes para óbito foram: idade avançada (OR: 7,35, p<0,0001), sexo masculino (OR 2,05, p<0,0001), leucopenia (OR: 3,18, p<0,0001), vômitos (OR: 2,19, p<0,0001) e comorbidades como hipertensão (OR: 3,74, p<0,0001), diabetes (OR: 3,29, p<0,0001) e doença renal crônica (OR: 3,14, p<0,0001). Eles também tiveram uma frequência significativamente maior de diabetes, distúrbios hematológicos, hepatopatias, hipertensão, úlcera péptica e doenças auto-imunes. A mortalidade foi significativamente maior entre pacientes com DRC em comparação com pacientes sem DRC (3,0% vs. 0,2%, p <0,0001). A infecção pelo CHIKV pode se manifestar como doença grave, especialmente durante períodos epidêmicos. Idade avançada e baixa escolaridade foram associados a maior risco de mortalidade. Leucopenia e vômitos foram sinais de gravidade que devem ser valorizados pela equipe de saúde, assim como a presença de comorbidades, especialmente hipertensão, diabetes e doença renal.
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Del, Valle-Mendoza Juana, Fernando Vasquez-Achaya, Miguel Angel Aguilar-luis, Johanna Martins-Luna, Jorge Bazán-Mayra, Victor Zavaleta-Gavidia, Wilmer Silva-Caso, et al. "Unidentified dengue serotypes in DENV positive samples and detection of other pathogens responsible for an acute febrile illness outbreak 2016 in Cajamarca, Peru." BioMed Central Ltd, 2020. http://hdl.handle.net/10757/655508.
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Objective: To describe the prevalence of dengue virus serotypes, as well as other viral and bacterial pathogens that cause acute febrile illness during an outbreak in Cajamarca in 2016. Results: Dengue virus (DENV) was the most frequent etiologic agent detected in 25.8% of samples (32/124), followed by Rickettsia spp. in 8.1% (10/124), Zika virus in 4.8% (6/124), Chikungunya virus 2.4% (3/124) and Bartonella bacilliformis 1.6% (2/124) cases. No positive cases were detected of Oropouche virus and Leptospira spp. DENV serotypes identification was only achieved in 23% of the total positive for DENV, two samples for DENV-2 and four samples for DENV-4. During the 2016 outbreak in Cajamarca-Peru, it was observed that in a large percentage of positive samples for DENV, the infecting serotype could not be determined by conventional detection assays. This represents a problem for the national surveillance system and for public health due to its epidemiological and clinical implications. Other viral and bacterial pathogens responsible for acute febrile syndrome were less frequently identified.Revisión por pares