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Schauren, Juliana da Silveira. "Estudo dos polimorfismos CCR2-64I, CCR5-59353, CCR5-59356, CCR5-59402 e CCR5-59653 em pacientes com lúpus eritematoso sistêmico do sul do Brasil." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/78127.
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O Lúpus Eritematoso Sistêmico (LES) é uma doença autoimune inflamatória crônica que possui uma etiopatogênese complexa. Diversos fatores participam da patogênese da doença, dentre eles alterações no balanço de citocinas e quimiocinas. As quimiocinas e seus receptores são fundamentais na regulação da migração de leucócitos durante a inflamação e acredita-se que elas possam ter um papel importante na patogênese de doenças autoimunes, inclusive no LES. Diversos estudos abordaram o papel de quimiocinas e seus receptores no LES, porém, principalmente se tratando dos receptores de quimiocinas CCR5 e CCR2, não existe um consenso. Devido à falta de consenso em relação ao papel dos receptores de quimiocinas na patogênese do LES e considerando a necessidade de mais estudos nesta área, o presente trabalho tem por objetivo investigar o possível papel de polimorfismos na região promotora do CCR5 no desenvolvimento do LES, comparando as frequências dos genótipos e haplótipos entre pacientes e controles, e analisar o possível envolvimento destes polimorfismos nas manifestações clínicas/laboratoriais da doença. O estudo incluiu 382 pacientes com LES (289 Euro-descendentes e 93 Afro-descendentes) e 375 controles (243 Euro-descendentes e 132 Afro-descendentes) genotipados para os polimorfismos CCR2-64I G>A (rs1799864), CCR5-59353 C>T (rs1799988), CCR5-59356 C>T (rs41469351), CCR5-59402 A>G (rs1800023) e CCR5-59653 C>T (rs1800024) através de PCR-RFLP e sequenciamento, respectivamente. Dados prévios de nosso grupo em relação ao CCR5delta32 foram incluídos no estudo para a inferência dos haplótipos e como um possível fator de confusão na regressão binária logística. Os resultados obtidos indicam que, em pacientes Euro-descendentes, as frequências reduzidas o polimorfismo CCR5delta32 e o haplótipo HHG*2 observadas em pacientes quando comparados com controles foram associadas com a doença (p=0,001; OR 3,5; 95%CI 1,6-7,5 e 2,0% vs. 7,2%; presidual=2,9E-5; respectivamente). Em pacientes Afrodescendentes, as frequências dos haplótipos HHA/HHB, HHC e HHG*2 foram diferentes em pacientes e controles (10% vs. 20,5%, presidual = 0,003; 29,4% vs. 17,4%; presidual=0,003 e 3,9% vs. 0,8%; presidual=0,023; respectivamente). Em relação às manifestações clínicas da doença, a presença do CCR5delta32 foi confirmada como um fator de susceptibilidade para nefrite classe IV em pacientes Afro-descendentes e no grupo de pacientes como um todo (pcorrigido=0,012; OR 3,0; 95%CI 3,0-333,3 e pcorrigido=0,0006; OR 6,8; 95%CI 1,9-2,48; respectivamente). Em conclusão, o presente estudo indica que polimorfismos na região promotora do CCR5 podem atuar como modificadores no LES. Os resultados observados reforçam o papel do polimorfismo CCR5delta32 como um fator de proteção para o desenvolvimento do LES em Euro-descendentes e como um fator de susceptibilidade à nefrite classe IV em pacientes Afro-descendentes. Além disto, também foram descritos a redução da frequência dos haplótipos HHA/HHB e o aumento da frequência dos haplótipos HHC e HHG*2 em pacientes Afro-descendentes, que possivelmente podem estar associados com uma maior expressão do CCR5 em subtipos específicos celulares e com uma menor expressão deste receptor de maneira geral.Systemic Lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease, characterized by a complex etiopathogenesis. Many factors are known to participate in the pathogenesis of SLE, including alterations in the cytokines or chemokines balance. Chemokines and their receptors are central players in the regulation of leucocytes chemotaxis in inflammation and they are thought to have an important role in the pathogenesis of autoimmune diseases, including SLE. Several studies have addressed the role of chemokines and their receptors in SLE, however there is no consensus regarding their involvement on the pathogenesis of the disease. Given the lack of consensus considering the role of chemokine receptors in SLE pathogenesis and the need for more studies in this area, the present work aims to investigate a possible role of the CCR5 promoter region polymorphisms in the development of SLE comparing the frequencies of the genotypes and haplotypes with ethnically matched controls and analyze if there is a possible involvement of the polymorphisms in the clinical outcome of the disease. This study included 388 SLE patients (289 classified as Europeanderived and 93 as African-derived) and 375 controls (243 European-derived and 132 African-derived) genotyped for the CCR2-64I G>A (rs1799864), CCR5-59353 C>T (rs1799988), CCR5-59356 C>T (rs41469351), CCR5-59402 A>G (rs1800023) and CCR5-59653 C>T (rs1800024) polymorphisms though PCRRFLP and direct sequencing, respectively. Previous data from CCR5delta32 were included in the study to infer the haplotypes and also as a possible confounding factor in the binary logistic regression. Our results indicated that, in Europeanderived patients, CCR5delta32 and the HHG*2 haplotype reduced frequencies in patients when compared to controls were associated with the disease (p=0.001; OR 3.5; 95%CI 1.6-7.5 and 2.0%, vs. 7.2% residual p= 2.9E-5, respectively). In African-derived patients, the HHA/HHB, HHC and HHG*2 haplotype frequencies differed between patients and controls (10% vs. 20.5%, residual p= 0.003; 29.4% vs. 17.4%, residual p=0.003 and 3.9% vs. 0.8%, residual p=0.023; respectively). Considering the clinical manifestations of the disease, CCR5delta32 presence was confirmed as a susceptibility factor to class IV nephritis in the African-derived group and when patients were considered together (pcorrected=0.012; OR 3.0; 95%CI 3.0-333.3 and pcorrected= 0.0006; OR 6.8; 95%CI 1.9-2.48, respectively). In conclusion, this study indicates that CCR5 promoter polymorphisms are important disease modifiers in SLE. Present data reinforces CCR5delta32 polymorphism as a protective factor for the development of the disease in European-derived patients and as a susceptibility factor for class IV nephritis in African-derived patients. Furthermore, we also describe a reduced frequency of HHA/HHB and an enhanced frequency of HHC and HHG*2 haplotypes in our African-derived patients, which potentially could reflect in a higher expression of CCR5 in specific cell subsets and in a lower expression of CCR5 overall.
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Sax, Michael John. "The CCL5-CCR5 Axis in Breast Cancer." Thesis, Griffith University, 2015. http://hdl.handle.net/10072/365646.
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Cancer is one of the leading underlying causes of death worldwide. Despite decades of research, cancer is predicted to be the leading cause of death by the year 2020. Anti angiogenic therapies that target the key signalling molecule, vascular endothelial growth factor (VEGF) have shown promise in the treatment of some solid tumours, resulting in increased progression-free survival times in patients. However, there are several significant problems with current anti-angiogenic therapies, such as the phenomenon of resistance. Tumours can be divided into those that are intrinsically nonresponsive to therapy, and those that do respond. However, for those tumours that do respond to therapy, an initial positive response (tumour regression) is followed by tumour re-vascularisation and rapid relapse. Secondly, anti-angiogenic therapies target normal physiological processes, including vascular homeostasis, wound healing and the immune system, leading to a range of potentially negative side effects, including death. Thus unravelling the biology of angiogenesis and developing new drug targets is a priority of current research. The C-C chemokine receptor 5 (CCR5) has been the subject of extensive research in the last few years. This is primarily because of its association with the pathology of disease, viral infection, and the immune response. However, while the main ligand for CCR5, C C chemokine ligand 5 (CCL5) is known to be upregulated in malignant breast cancer, little has been done to unravel the CCL5-CCR5 axis in breast cancer and its potential role as a driver of malignancy. Furthermore, while experimental evidence, including data from CCR5 knockout mouse, suggests a role for CCL5-CCR5 in neovascularisation, little has been done to study the potential role of CCL5-CCR5 in tumour angiogenesis, as well as implications CCL5-CCR5 signalling may have on clinical course in breast cancer.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Medical Science
Griffith Health
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Sato, Wakiro. "Human Th17 Cells Are Identified as Bearing CCR2+CCR5- Phenotype." Kyoto University, 2008. http://hdl.handle.net/2433/124335.
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John, Bangan. "Association Among CCR5 Genotypes, CCR5 Expression, And In Vitro HIV Infection." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1365888090.
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Sohy, Denis. "Etude de la dimérisation des récepteurs aux chimiokines CCR2, CCR5 et CXCR4." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210282.
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La dimérisation des récepteurs couplés aux protéines G est un nouveau concept apparu dans la littérature au cours des quelques années qui ont précédé le début de notre travail. Bien qu’il soit clairement établi que les récepteurs sont capables de former des homo et des hétérodimères, les conséquences fonctionnelles de telles interactions demeurent souvent peu claires. Dans une étude précédente, le laboratoire d’accueil a montré que les récepteurs aux chimiokines CCR2 et CCR5 forment des homo et des hétérodimères de manière constitutive et identifié une coopérativité négative de liaison de nature allostérique entre les deux sites de liaison de CCR2 et CCR5 dans des cellules co-exprimant les deux récepteurs. Dans ce travail, nous avons étendu cette étude au récepteur CXCR4, structurellement plus éloigné que CCR2 et CCR5 entre eux. Nous montrons par une méthode biophysique se basant sur le transfert d’énergie de bioluminescence (le BRET) que CCR2, CCR5 et CXCR4 forment des homodimères et des hétérodimères de manière constitutive. De plus nous démontrons une coopérativité négative de liaison de nature allostérique des deux sites de liaisons pour les hétérodimères CCR2/CXCR4 et CCR5/CXCR4. lorsque CXCR4 est co-exprimé avec CCR2 ou CCR5, la chimiokine spécifique de CXCR4 (SDF-1α) inhibe la liaison du traceur spécifique de CCR2 (MCP-1) ou du traceur spécifique de CCR5 (MIP-1β), et vice-versa. La nature allostérique de ces interactions est démontrée par des expériences mesurant la dissociation de traceurs en présence ou non de compétiteurs. La coopérativité négative de liaison de nature allostérique des deux sites de liaisons est montrée également dans des cellules primaires, excluant tout effet indésirable dû à la surexpression de récepteurs. Nous montrons également que l’antagoniste spécifique de CXCR4 (AMD3100) inhibe la liaison du traceur spécifique de CCR2 (MCP-1) ou du traceur spécifique de CCR5 (MIP-1β), et vice-versa (TAK-779 vs SDF-1α), uniquement quand CXCR4 est co-exprimé respectivement avec CCR2 ou CCR5. Il s’agit là de la première preuve montrant que les interactions allostériques au sein d’hétérodimères de récepteurs aux chimiokines impliquent aussi des antagonistes, et qu’un antagoniste de récepteur aux chimiokines influence la réponse fonctionnelle d’un autre récepteur aux chimiokines auquel il ne se lie pas. De tels effets fonctionnels ont été montré dans des expériences de mobilisation de Ca++, de chimiotactisme sur lymphoblastes et dans des expériences d’air pouch in vivo.Doctorat en Sciences biomédicales et pharmaceutiques
info:eu-repo/semantics/nonPublished
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Longden, James. "Quantitative approaches to the study of the trafficking of CCR1 and CCR5." Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437076.
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Zambra, Francis Maria Báo. "Influência dos genes CCR2 e CCR5 em hiperplasia e câncer de próstata." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/69706.
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A hiperplasia prostática benigna (HPB) e o câncer de próstata (CaP) são duas condições crônicas muito comuns em homens com idade avançada e têm sido relacionadas a processos inflamatórios. As quimiocinas são reconhecidas como mediadores críticos da resposta inflamatória por regular a migração das células imunológicas através da ativação de receptores de quimiocinas na superfície destas células. As quimiocinas estão relacionadas à patogênese tumoral, embora não seja claro de que modo afetam a progressão tumoral humana. O objetivo desse estudo foi investigar a associação de dois polimorfismos de receptores de quimiocinas, CCR2-64I e CCR5-delta32, com HPB e CaP. Neste trabalho foram genotipadas 385 amostras de DNA genômico de homens do sul do Brasil, predominantemente euro-descendentes, incluindo 130 casos de HPB, 136 casos de CaP e 119 indivíduos controle saudáveis. Para o polimorfismo CCR2-64I a genotipagem foi realizada por PCR-RFLP e para o CCR5-delta32 foi por PCR convencional. As frequências alélicas do CCR2-64I foram 14,0%; 15,8% e 11,1% nos grupos controle, HPB e CaP, respectivamente; enquanto as do CCR5-delta32 foram 5,1%; 7,1% e 6,2%, respectivamente. A mediana referente aos níveis de PSA foi de 0,79; 1,45 e 6,91 ng/mL nos grupos controle, HPB e CaP, respectivamente; diferindo significativamente entre estes (todos p<0,001). A mediana do volume da próstata foi 20,00 cm3 no grupo controle, portanto, menor que dos grupos HPB (35,35 cm3) e CaP (35,80 cm3) (ambos p<0,001); no entanto, não foi observada diferença entre pacientes com HPB e CaP (p=0,172). Algo interessante observado foi CCR2-64I como um fator protetor para CaP quando comparado com HPB (OR=0,550; IC95%=0,311–0,975), mas não quando comparado com o grupo controle (p=0,448). Não foi observada associação do CCR2-64I com os estados clinicopatológicos do CaP (estadiamento tumoral e escore de Gleason) (todos p≥0,308). Não foi observada associação significativa da variante CCR5-delta32 com HPB ou CaP (todos p≥0,072), ou com os estados clinicopatológicos do CaP (todos p≥0,253). Assim, nossos dados sugerem a influência da variante CCR2-64I, observada como fator protetor para CaP quando comparada com HPB, no desenvolvimento do câncer de próstata.Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are two chronic conditions very common in aged men and have been related to inflammatory process. Chemokines are recognized as critical mediators of inflammatory responses by regulating the migration of immune cells through the activation of chemokine receptors on the surface of these cells. Chemokines are implicated in tumor pathogenesis, although it is not clear how it affects human tumor progression. The aim of this study was to investigate the association of two chemokine receptor gene polymorphisms, CCR2-64I and CCR5-delta32, with BPH and PCa. In this study were genotyped 385 genomic DNA samples from southernmost Brazilian men, predominantly euro-descendants, including 130 BPH, 136 PCa and 119 healthy control subjects. To CCR2-64I polymorphism the genotyping was performed by PCR-RFLP and to CCR5-delta32 by conventional PCR. The allele frequencies of CCR2-64I were 14.0%, 15.8% and 11.1% in control, BPH and PCa, respectively; while of CCR5-delta32 were 5.1%, 7.1% and 6.2%, respectively. Median of serum PSA levels were 0.79, 1.45 and 6.91 ng/mL in control, BPH and PCa group, respectively (all p<0.001). The prostate volume median was 20.00 cm3 in the control group, thus, lower than BPH (35.35 cm3) and PCa (35.80 cm3) group (both p<0.001), nevertheless no difference was observed between BPH and PCa patients (p=0.172). Interestingly, CCR2-64I was detected as a protective factor to PCa when compared with BPH (OR=0.550; 95%CI=0.311–0.975), but not when compared with control group (p=0.448). No significant associations of the CCR2-64I were observed with PCa clinicopathologic states (tumor stage and Gleason score) (all p≥0.308). No significant associations of the CCR5-delta32 variant were observed with BPH or PCa (all p≥0.072), or with PCa clinicopathologic status (all p≥0.253). Thus, our data suggest a influence of the CCR2-64I variant, that was observed as a protective factor in PCa when compared with BPH, in prostate cancer development.
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Fish, Richard James. "RANTES derivatives and CCR5." Thesis, University of York, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369362.
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Simonis, Christopher. "Molekulare Klonierung, stabile Transfektion und funktionelle Expression der murinen Chemokinrezeptoren Ccr2 und Ccr5." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-99950.
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Manin, Graziele Zenaro. "Identificação dos componentes do Sistema Imune que participam na resistência de camundongos em modelo de infecção letal por Legionella longbeachae." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/17/17147/tde-21052014-153321/.
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A doença dos legionários consiste em uma broncopneumonia severa e atípica, que acomete de 2 a 7% das pessoas infectadas com Legionella spp e que apresenta taxa de mortalidade que varia de 5 a 30%, sendo considerada uma importante causa de morbidade e mortalidade mundial. A patologia causada pela espécie L. pneumophila tem sido amplamente estudada em modelos experimentais e suas características clínicas foram extensivamente descritas. No entanto, este modelo não representa adequadamente a doença que acomete seres humanos, pois L. pneumophila não é letal aos camundongos como é para humanos. Recentemente, uma nova espécie de bactéria do gênero Legionella, denominada Legionella longbeachae, foi descrita como importante agente de doença dos legionários em países do hemisfério sul. A pneumonia induzida por L. longbeachae em humanos não difere da induzida por L. pneumophila. No entanto, L. longbeachae é letal para camundongos em doses baixas, o que torna esse modelo murino de doença dos legionários mais fidedigno ao que ocorre com humanos. Com a acentuada mudança dos hábitos de nossa sociedade, há o aumento do número de pessoas com fatores que predispõe a doença, como idade elevada ou tratamento imunossupressor. Assim, entender melhor a relação patógeno-hospedeiro no curso da doença dos legionários por meio da utilização de um modelo experimental adequado é importante para a descoberta de novos meios de combater este patógeno. Neste trabalho, geramos uma cepa de L. longbeachae mutante para rpsL, que se torna resistente à estreptomicina. Essa cepa pode ser utilizada para infecções in vivo nas quais a quantificação da CFU foi estimada em placas contendo antibiótico, o que culmina em maior eficiência experimental e menor quantidade de contaminações. Essa cepa foi utilizada em experimentos in vivo para avaliar os componentes do sistema imune que operam na resistência diante de uma dose letal bacteriana administrada pela via intranasal. Demonstramos que camundongos deficientes para as citocinas IFN ou TNF e para o receptor de quimiocinas CCR2 são mais susceptíveis à infecção do que os camundongos selvagens. No entanto, camundongos deficientes para o receptor de quimiocinas CCR5, para o receptor de IL-17, para a citocina IL-6 ou para o receptor citoplasmático NOD2 são mais resistentes à infecção quando comparados com animais selvagens. A descoberta destas moléculas em um modelo de infecção letal in vivo ressalta a importância de alguns componentes da imunidade para a resistência durante a doença dos legionários experimental e possíveis alvos terapêuticos para essa doença.Legionnaires disease is a severe and atypical bronchopneumonia, which affects 2-7% people infected with Legionella spp and has a mortality rate of 5 to 30%, therefore it is considered an important cause of mortality and morbidity worldwide. Disease caused by Legionella pneumophila has been largely studied in experimental models and its clinical characteristics was extensively described. However this model does not adequately represent the disease that affects humans, because L. pneumophila is not lethal to mice, as it is to humans. Recently, a new species of bacterium from Legionella genus, called Legionella longbeachae, was described as an important agent of Legionnaires disease in the southern hemisphere. The pneumonia induced by L. longbeachae in humans is not different from pneumonia induced by L. pneumophila. However, a low dose of L. longbeachae is lethal to mice, which makes this murine infection model of Legionnaires disease more reliable than that which occurs in humans. Because our society is changing, there is an increase in the number of persons with predisposing factors, like higher age or immunosuppressive treatment. So, a better understanding of host-pathogen relationship by using a suitable experimental model is important to find new ways to fight this pathogen. Here, we generated a strain of rpsL mutant L. longbeachae, which becomes resistant to streptomycin. This strain could be used in in vivo infections, when CFU quantification was estimated in plates with antibiotic, culminating in greater experimental efficiency and lower contamination. This strain was used in in vivo experiments to evaluate components of the immune system that participates in resistance against lethal dose of bacteria administered intranasally. We showed that Tnf-/-, Ifn-/- or Ccr2-/- mice are more susceptible to infection than wild type mice. However Ccr5-/-, Il17r-/-, Il6-/- or Nod2-/- mice are more resistant to infection than wild type animals. The discovery of these molecules in a lethal infection model in vivo highlights the importance of some components of immunity to resistance during experimental Legionnaires disease and potential therapeutic targets to disease.
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Arnatt, Christopher Kent. "DEVELOPMENT OF ANTAGONISTS TARGETING CHEMOKINE RECEPTOR CCR5 AND THE CHEMOKINE RECEPTOR CCR5 – MU OPIOID RECEPTOR HETERODIMER." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/517.
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The chemokine receptor CCR5 (CCR5) plays an integral role within the inflammatory network of cells. Importantly, CCR5 is a mediator in several disease states and can be targeted using small molecule antagonists. Within this work, CCR5’s role in prostate cancer and HIV/AIDS has been exploited in order to develop potential therapeutics and probes. First, a series of novel compounds was designed by using pharmacophore-based drug design based upon known CCR5 antagonists and molecular modeling studies of the CCR5 receptor’s three-dimensional conformation. Once synthesized, these compounds were tested for their CCR5 antagonism and their anti-proliferative effects in several prostate cancer cell lines. The data from both the calcium mobilization studies and the anti-proliferation studies suggests that the compounds synthesized have activity as CCR5 antagonists and as anti-proliferative agents in certain prostate cancer cell lines. In addition, a bivalent ligand containing both a mu opioid receptor (MOR) and a CCR5 antagonist pharmacophore was designed and synthesized in order to study the pharmacological profile of the putative CCR5-MOR heterodimer and its relation with NeuroAIDS. The structural-activity relationship between the bivalent ligand and the heterodimer was studied with radio-ligand binding assays, functional assays, HIV-1 fusion assays, cell fusion assays, and in silico molecular dynamics. The subsequent bivalent ligand was proven to be a potent inhibitor in both an artificial cell fusion assay mimicking HIV invasion and a native HIV-1 invasion assay using live virus. In all, two novel sets of compounds were synthesized that targeted either CCR5 or the CCR5-MOR heterodimer. For the CCR5 antagonists, as leads for prostate cancer therapeutics, further work needs to be done to ascertain and develop their structure-activity-relationship. This library of novel compounds was shown as promising leads as CCR5 and anti-prostate cancer agents. The bivalent ligand targeting the CCR5-MOR heterodimer proved to be a potent and tissue-specific inhibitor for neuroAIDS where the known treatment, maraviroc, is less efficacious and fails to inhibit virus entry in the presence of morphine. Both projects illustrate the roles that CCR5 plays in these two unique diseases.
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Leach, Katie. "Pharmacological analysis of the CC chemokine receptors, CCR4 and CCR5 signalling properties and receptor-drug interactions." Thesis, University of Reading, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427859.
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José, de Pessoa Saldanha Carlos. "Avaliação da mutação ccr532 do receptor da quimiocina como marcador genético-histórico na população de Triunfo Pernambuco." Universidade Federal de Pernambuco, 2008. https://repositorio.ufpe.br/handle/123456789/6316.
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Previous issue date: 2008O gene ccr5 codifica o receptor b-quimiocina 5 (CCR5), uma proteína transmembrânica que age como principal co-receptor para os vírus HIV-1, Variola major e para a bactéria Yersinia pestis, nos macrófagos e monócitos humanos. Uma deleção de 32 pares de bases neste gene dá origem ao alelo mutante ccr532 cuja presença, em homozigose, tem sido relatada em indivíduos resistentes à AIDS. A mutação ccr532 tem uma origem recente e se deu na Europa, e atinge suas maiores freqüências nas populações do norte (16% na Finlândia). Ocorrências isoladas foram descritas no resto do globo, entretanto resultariam de fluxo gênico recente para essas populações. Segundo informação verbal popular, Triunfo não se constitui numa cidade atrativa para imigrações e apresentaria certo grau de consangüinidade entre os seus 14 mil habitantes, por isso esta população tornou-se objeto de estudos das freqüências dos alelos ccr5 e ccr532 para que se pudesse determinar se essas freqüências divergem ou não das encontradas nos demais Estados Nordestinos. Foram analisados 345 indivíduos não aparentados desta população, e após extração por mini salting-out o DNA genômico foi amplificado por PCR e a partir da eletroforese por PAGE a 5% suas bandas foram visualizadas por impregnação com AgNO3. As freqüências genotípicas observadas foram 89,28% (ccr5/ccr5), 10,72% (ccr5/$32) e 0,0% ($32/$32). As freqüências alélicas foram 94,64% para o ccr5 e 5,36% para o ccr5Q32. A população encontrase em equilíbrio de Hardy-Weinberg (p= 0,61). A freqüência um pouco elevada do ccr532 encontrada na população de Triunfo pode ser resultado da ocorrência de efeito fundador nessa cidade, ou de um processo de deriva genética
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Ahmed, Tasrif. "Discovery of a Novel CCR5 Antagonist as an Effective Therapeutic Agent for Prostate Cancer." VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/2215.
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Previously, the CCR5 receptor was found to be a good target for treating prostate cancer (PCa). Dr. Yan Zhang’s laboratory designed several CCR5 antagonists, which were screened for their inhibitory effect on the growth and invasion of the M12, DU145 and PC-3 PCa cell lines. Primary in vitro screening showed one compound (Drug 17) significantly inhibited the proliferation of PCa cells at 1μM concentration, with a half-maximal inhibitory concentration of 237.68 nM. Further in vitro assays including a proliferation, cytotoxicity and invasion assay confirmed the inhibitory effect of drug 17. The physiological effect of drug 17 was tested by the Ware laboratory in vivo by subcutaneous injection of M12 cells into male, athymic nude mice. Tumor growth was slowed in mice receiving injections of drug 17 compared to sham injected controls. Thus, in vitro and in vivo assays suggest drug 17 might be an effective therapy to block PCa progression.
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Barmania, Fatima. "Analysis of CCR5 diversity in the South African population." Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/31127.
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Infection with the human immunodeficiency virus (HIV) constitutes a global pandemic, and South Africa forms part of the region known to house over two-thirds of HIV infected individuals worldwide. In the early stages of infection, the C-C chemokine receptor type five (CCR5) is the major HIV-1 co-receptor. The importance of this receptor in HIV infection and disease progression was recognised with the discovery of the CCR5 delta 32 (Δ32) allele. Individuals homozygous for this mutation lack functional CCR5 receptors. Consequently, they are almost completely resistant to HIV infection, while the absence of CCR5 has minimal effects on health. Heterozygous individuals display decreased cell surface CCR5 which slows disease progression. Phenotypic expression of CCR5 is heterogeneous and its relation to genetic mutations in the CCR5 gene is not currently known for the South African population. This together with the effect of CCR5 expression on HIV infection provided the rationale for investigating both the phenotypic and genotypic distribution of CCR5. The aim of this study was therefore 1) to investigate CCR5 phenotypic expression on cluster differentiation four (CD4) T-lymphocytes in a group of South African individuals and 2) to analyse the genetic variation in a South African cohort. Flow cytometric methods were used to measure the phenotypic distribution of CCR5 in 245 individuals by assessing both the percentage of CD4+CCR5+ T-cells and CCR5 density. Sixty five individuals, mostly found within the lower CCR5 receptor density range were selected for DNA sequencing. The study found considerable variability in CCR5 expression with South African individuals expressing relatively high CD4+CCR5+ T-cell percentages. Ethnicity was established as a significant variable affecting CCR5 expression with Black African individuals displaying higher (p <0.05) CD4+CCR5+ T-cell percentages and densities than Caucasians. Genotypic data revealed 70 single nucleotide polymorphisms (SNPs), four insertions and the ∆32 deletion. Results showed that Black African individuals have greater genetic diversity with 39 mutations exclusive to this group. The ∆32 mutation was not detected in the Black African group but was identified in the Caucasian group at a frequency of 18.6 %. Twelve novel mutations were identified in this study with two in the open reading frame (ORF). It is evident from the data that the variability in CCR5 phenotypic expression is difficult to correlate with specific mutations in the gene. This thesis provides information on CCR5 distribution and diversity in the South African population which will be of value to patients, clinicians and health policy officials.Dissertation (MSc)--University of Pretoria, 2011.
Immunology
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Derossi, Daniela Rudgeri. "Análise do polimorfismo CCR5-delta32 e da expressão proteica de CCL5 em amostras de pacientes com carcinoma mamário." Universidade Estadual de Londrina. Centro de Ciências da Saúde. Programa de Pós-Graduação em Ciências da Saúde, 2017. http://www.bibliotecadigital.uel.br/document/?code=vtls000217404.
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Diversas moléculas, dentre as quais se destacam as quimiocinas e seus receptores, vêm sendo estudadas para uma melhor compreensão da patogênese do câncer de mama. Evidências indicam que estas participam no desenvolvimento dos órgãos, na angiogênese, na mobilidade de células tronco, na recirculação dos leucócitos, na regulação e no desenvolvimento imunológico e hematopoiético, e mais recentemente, na disseminação de células tumorais no processo metastático, inclusive no câncer de mama. Relatos atuais levantam a possibilidade de que a análise do eixo quimiocina CCL5 e receptor CCR5 possua um valor prognóstico relevante nesta neoplasia. Neste trabalho, foi avaliado um polimorfismo genético (rs333/delta32) no gene CCR5 em um estudo de associação do tipo caso-controle, bem como em relação a parâmetros prognósticos da doença. Foi ainda avaliada a expressão proteica de CCL5, tanto em sobrenadante tecidual quanto em cortes de tecidos tumoral e normal da mama, sendo as mesmas também correlacionadas aos parâmetros prognósticos das pacientes. Foram utilizadas 167 amostras de sangue periférico de pacientes portadoras de carcinoma de mama e 179 amostras de mulheres livres de carcinoma de mama, para extração de DNA, no estudo de assocciação de caso-controle. Para o método de enzimaimunoensaio foram utilizadas 49 amostras de sobrenadante de tecidos tumorais e normais a fresco.Para o estudo imunohistoquímico foram utilizados 24 blocos de parafina provenientes de cirúrgicas realizadas nas pacientes com carcinoma de mama. A análise da variante genética de CCR5 foi realizada pela reação em cadeia da polimerase (PCR) com primers específicos. A análise da expressão proteica foi realizada pelas técnicas de enzima-imuno-ensaio (ELISA) (a partir dos sobrenadantes de tecidos normais e tumorais) e imunohistoquímica (a partir de cortes de tecidos normais e tumorais embebidos em parafina). As análises estatísticas foram realizadas pelos testes de MannWhitney e Correlação Tau_b de Kendall. Não foi observada associação significativa entre a variante de CCR5 e a suscetibilidade ao câncer de mama (CCR5-delta32: OR=1.35; CI95%=0.63-2.91). As análises em relação aos parâmetros prognósticos indicaram uma correlação significativa entre CCR5-delta32 e acometimento de linfonodos e/ou metástase à distância (p= 0.02). Com relação à expressão proteica de CCL5 por imunohistoquímica, foi observada predominância de marcação citoplasmática. Não foram observadas associações significativas em relação aos parâmetros prognósticos e nem em relação aos genótipos de CCR5-delta32. Com relação a expressão de CCL5 por ELISA, foi observada uma concentração maior da proteína no sobrenadante de tecido tumoral quando comparada àquele do tecido normal adjacente (p<0.0001). Adicionalmente, quando esta expressão foi comparada em diferentes estadiamentos tumorais, foi observada uma diferença significativa entre os estadiamentos I e III (p<0.02). Ainda, quando a expressão de CCL5 foi averiguada em relação aos parâmetros prognósticos, foi observada uma maior concentração da proteína em relação ao comprometimento linfonodal (p=0.03). De um modo geral, os resultados do presente estudo indicam que o eixo CCL5/CCR5 pode ter importantes implicações prognósticas no contexto da carcinogênese mamária.Several molecules, such as chemokines and their receptors, have been studied for a better understanding of breast cancer (BC) pathogenesis. Evidences indicate that they participate in organ development, angiogenesis, stem cell mobility, leukocyte recirculation, immunological and hematopoietic regulation and development and more recently, in the spread of tumor cells in metastatic process, including in BC. Current reports raise the possibility that analysis of CCL5 chemokine and CCR5 receptor had a relevant prognostic value in this neoplasia. In the present study, a genetic polymorphism (rs333/delta32) in CCR5 gene was evaluated in a case-control study, as well as in relation to disease prognostic parameters. It was also evaluated CCL5 protein expression, both in tissue supernatant and in tumor and normal breast tissue sections, being also correlated with prognostic parameters. The peripheral blood samples (167) and tissue samples (49) were obtained from breast cancer (BC) patients, who had undergone surgery, and peripheral blood samples from 179 women free of disease, were taken as controls. Analysis of CCR5 genetic variant was performed through polymerase chain reaction (PCR) using specific primers. Protein expression analysis was performed using enzime linked immuno sorbent assay (ELISA)(from tumor and normal supernatants) and by immunohistochemistry (from normal and tumor sections embedded in paraffin). Statistical analyzes were performed using MannWhitney and Kendall's Tau_b Correlation tests. No significant association was found between CCR5 variant and BC susceptibility (CCR5-delta32: OR=1.35; CI95%=0.63-2.91). Analyzes regarding prognostic parameters indicated a significant correlation between CCR5-delta32 and lymph node involvement and/or distant metastasis (p= 0.02). Regarding CCL5 staining by immunohistochemistry, the predominance of cytoplasmic labeling was observed. No significant associations were observed in relation to prognostic parameters or in relation to CCR5 genotypes. Regarding CCL5 expression by ELISA, a higher protein concentration was observed in the tumor supernatant compared to adjacent normal supernatant (p <0.0001). In addition, when this expression was compared in different tumor stages, a significant difference was observed between stages I and III (p <0.02). Moreover, when CCL5 expression was investigated in relation to prognostic parameters, a higher protein concentration was observed in relation to lymph node involvement (p= 0.03). In general, results of the present study indicate that CCL5/CCR5 axis may have important prognostic implications in the context of mammary carcinogenesis.
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SANTOS, Erinaldo Ubirajara Damasceno dos. "Estudo de associação de polimorfismos nos genes CCR2 e CCR5 com o desenvolvimento de lesões cervicais induzidas pelo HPV." Universidade Federal Rural de Pernambuco, 2016. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4811.
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Cervical cancer (CC) affects about half a million women each year worldwide. The main etiological agent that can lead to the development of the CC is the human papillomavirus (HPV). However, not all women infected with HPV will have a progression to cancer, since the neoplastic development involves immune, genetic and environmental factors. Chemokine receptors play an important role in immune response, and progression of cervical intraepithelial neoplasia (CIN) for CC. Genetic variations related to the genes of these receptors may lead to the formation of cervical neoplasia. This study aimed to associate polymorphisms in genes of CCR2-64I chemokine receptor (rs1799864) and CCR5-Δ32 (rs333) with susceptibility to the development of cervical lesions (CIN or CC) in women from the State of Pernambuco, Brazil. The study population consisted of 139 women with cervical lesions (patients) and 151 healthy women (controls). The CCR2-64I and CCR5-Δ32 polymorphisms were analyzed by the technique of PCR-RFLP. The HPV detection was performed using the standard PCR technique. A protective effect for individuals carriers of a mutant genotypes (GA or AA) for individuals with cervical injury to the polymorphism in CCR2-64I gene (OR = 0.37, p = 0.0008). The same was observed for the A allele (OR = 0.39, P = 0.0002). In contrast, no association to the polymorphism in the CCR5-Δ32 gene was observed (p> 0.05). The prevalence of HPV types showed that 38.8% of patients were infected with HPV16; 22.3% HPV 18; HPV31 2.9%; 3.6% HPV 33; and 14.4% for other types of HPV. For multiple infection 18% of patients were co-infected with types 16 and 18. When we analyzed the association of HPV type with CCR2-64I polymorphism in the gene between individuals of the group of patients there is an effect protector of infection for HPV 16 (OR = 0.35, p = 0.0184). Moreover, when patients were stratified according to the severity of cervical lesions, 28.78% (40/139) had CIN I (low grade lesion), 62.58% (87/139) had CIN II or III (high-grade lesions) and 8.63% (12/139) had CC. In summary, our study showed CCR2-64I polymorphism protective effect of both susceptibility to infection with HPV 16 and for the development of cervical lesions (CIN and CC).
O câncer cervical (CC) afeta cerca de meio milhão de mulheres a cada ano em todo o mundo. O principal agente etiológico que pode levar ao desenvolvimento do CC é a infecção por Papillomavírus humano (HPV). Porém, nem todas as mulheres infectadas pelo HPV terão uma progressão para o câncer, visto que, o desenvolvimento neoplásico envolve fatores imunológicos, genéticos e ambientais. Os receptores de quimiocinas desempenham um importante papel na resposta imunológica e progressão de neoplasia intraepitelial cervical (NIC) para o CC. Variações genéticas relacionados com os genes destes receptores podem levar a formação de neoplasia cervical. O presente estudo teve como objetivo associar polimorfismos nos genes receptores das quimiocinas CCR2-64I (rs1799864) and CCR5-Δ32 (rs333) com a susceptibilidade para o desenvolvimento de lesão cervical (NIC ou CC) em mulheres residentes no Estado Pernambuco-Brasil. A população de estudo consistiu de 139 mulheres com lesões cervicais (pacientes) e 151 mulheres saudáveis (controles). Os polimorfismos CCR2-64I e CCR5-Δ32 foram analisados pela técnica da PCR-RFLP. A detecção do HPV foi realizada através da técnica de PCR convencional. Um efeito protetor foi observado para indivíduos carreadores de um dos genótipos mutantes (GA ou AA) em relação aos indivíduos com lesão cervical para o polimorfismo no gene CCR2-64I (OR = 0,37, p= 0,0008). O mesmo foi observado para o alelo A (OR = 0,39, P = 0,0002). Contrariamente, nenhuma associação para o polimorfismo no gene CCR5-Δ32 foi observada (p> 0,05). A prevalência dos tipos de HPV mostrou que 38,8% dos pacientes estavam infectados pelo HPV16; 22,3% HPV 18; 2,9% HPV31; 3,6% HPV 33; e 14,4% por outros tipos de HPV. Em relação a infecção múltipla, 18% dos pacientes foram co-infectados pelos tipos 16 e 18. Quando analisada a associação do tipo de HPV com o polimorfismo no gene CCR2-64I, entre os indivíduos do grupo de pacientes, observou-se um efeito protetor da infecção para o HPV 16 (OR = 0,35, p = 0,0184). Além disso, quando os pacientes foram estratificados de acordo com a gravidade das lesões cervicais, 28,78% (40/139) apresentaram NIC I (lesão de baixo grau), 62,58% (87/139) tinham NIC II ou III (lesão de alto grau) e 8,63% (12/139) tiveram CC. Em resumo, nosso estudo mostrou um efeito protetor do polimorfismo CCR2-64I tanto para susceptibilidade para a infecção pelo HPV 16 como para o desenvolvimento de lesões cervicais (CIN e CC).
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Opalek, Judy Marcus. "I. Differential gene expression in human peripheral blood monocytes and alveolar macrophages II. Macrophage colony-stimulating factor is important in the development of pulmonary fibrosis." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1075754091.
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Thesis (Ph. D.)--Ohio State University, 20043.Title from first page of PDF file. Document formatted into pages; contains xiv, 115 p.; also includes graphics. Includes abstract and vita. Advisor: Clay B. Marsh, Dept.of Pathology. Includes bibliographical references (p. 102-115).
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Castanheira, Fernanda Vargas e. Silva. "Papel protetor do receptor quimiotático CCR5 durante a sepse experimental." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/17/17133/tde-10012017-100344/.
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A sepse é uma resposta inflamatória sistêmica resultante da inabilidade do sistema imune em controlar uma infecção, onde a taxa de sobrevida está associada ao recrutamento de neutrófilos para o local da infecção. Tem sido demonstrado que a expressão de receptores quimiotáticos pode ser alterada durante a sepse. Neutrófilos de animais naives respondem às quimiocinas CXC, mas são irresponsivos às quimiocinas CC. Entretanto, dados do nosso laboratório mostram que a expressão de CXCR2 é reduzida na sepse, prejudicando a migração de neutrófilos para o foco da infecção. Além disso, ocorre o aparecimento do receptor CCR2 nos neutrófilos, levando à infiltração dessas células no pulmão e outros órgãos. Nesse contexto, o nosso objetivo foi investigar a possível expressão do receptor CCR5 em neutrófilos e seu papel na evolução da sepse. Demostramos que animais sham-operados expressam baixos níveis de CCR5 e altos níveis de CXCR2. Entretanto, sob a condição de sepse experimental induzida por ligação e perfuração do ceco (CLP), neutrófilos circulantes e que migraram para a cavidade peritoneal expressam altos níveis de CCR5 em paralelo com a internalização de CXCR2. Além disso, animais deficientes para CCR5 (CCR5-/-), submetidos à CLP, apresentam diminuição na taxa de sobrevida, redução na migração de neutrófilos para o foco da infecção, aumento da disseminação bacteriana, aumento no infiltrado de neutrófilos no pulmão e aumento nos níveis de marcadores de lesão do coração e rim, quando comparados com animais selvagens (WT). Adicionalmente, a incubação de neutrófilos isolados da medula óssea com LPS aumentou a expressão de CCR5 e os tornou responsivos à MIP-1? (ligante de CCR5), induzindo quimiotaxia. Também demonstramos que o receptor CCR5 possui importante papel durante a adesão de neutrófilos ao endotélio vascular para posterior migração. Em conjunto, esses resultados indicam que durante a CLP, o aumento da expressão de CCR5 em neutrófilos tem um papel protetor, visto que animais CCR5-/- sépticos apresentam reduzida migração de neutrófilos para o foco infeccioso, inflamação sistêmica acentuada e baixa taxa de sobrevivência.Sepsis is a systemic inflammatory response resulted from the inability of the innate immune system to control infections, being the survival rate associated to the recruitment of neutrophils to the infection site. It has been demonstrated that chemokine receptors expression profile can be altered under sepsis conditions. Neutrophils from naïve mice respond to CXC chemokines, but are usually unresponsive to CC chemokines. However, data from our laboratory show that CXCR2 expression is down regulated, impairing the neutrophil migration to infection focus. In addition, CCR2 appears on the surface of neutrophils, mediating the accumulation of these cells in the lung and other organs. In this context, we aimed to investigate the possible expression of CCR5 receptor on neutrophils and its role on sepsis evolution. We showed that neutrophils from sham mice express high levels of CXCR2 and low levels of CCR5. However, during experimental sepsis, induced by cecal ligation and puncture (CLP), in parallel with CXCR2 internalization, neutrophils from the circulation or from the peritoneal cavity express higher levels of CCR5. Interestingly, deficient mice for the CCR5 receptor (CCR5-/-), undergone to CLP show decreased survival rate, reduction in the neutrophil migration to the site of infection, increase in the numbers of bacteria, increase in the neutrophil infiltration in lung and heart and increase in the levels of markers of injuries in heart and kidney, when compared to wild type mice (WT).In addition, the incubation of bone marrow derivedneutrophils with LPS enhances the expression of CCR5 and renders them responsive to CCL4 (a ligant of CCR5)-induced chemotaxis. Moreover, we demonstrated that CCR5 receptor has an important role during neutrophil adhesion to the vascular endothelium before transmigration. Together, these results indicate that during CLP-induced sepsis, the increase of the expression of CCR5 on neutrophils plays a host protective role, since CCR5-/- mice under sepsis present reduced neutrophil migration to infection focus, high systemic inflammation and low survival rate.
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Costa, Giselle Calasans de Souza. "Investigação de mutações nos genes da CCR5 e langerina e suas associações com a infecção pelo HIV-1." reponame:Repositório Institucional da FIOCRUZ, 2012. https://www.arca.fiocruz.br/handle/icict/4243.
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Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil
O HIV-1 é o agente etiológico da AIDS. Sabe-se que fatores virais e do hospedeiro podem influenciar na susceptibilidade à infecção pelo vírus e na progressão para a AIDS. Em relação aos fatores intrínsecos ao hospedeiro, tem sido demonstrado que algumas alterações na CCR5 podem afetar sua ligação com a gp120 do HIV-1, influenciando na infecção pelo vírus. Além disso, a proteína Langerina, encontrada na superfície das Células de Langerhans (LCs), apresenta um papel importante em relação à infecção pelo HIV-1, por ter a capacidade de se ligar à gp120 viral através de seu Domínio de Reconhecimento de Carboidrato (CRD). Esta interação permite que as LCs internalizem o vírus em Grânulos de Birbeck, os quais degradam a partícula viral, inibindo a apresentação do HIV-1 para os linfócitos T. Desta forma, diferenças na função da langerina, devido a mutações no promotor do gene Langerina e na região codificante do CRD, por exemplo, podem influenciar a susceptibilidade à infecção pelo HIV-1. Sendo assim, o objetivo principal deste trabalho foi verificar a existência de mutações nas regiões do gene CCR5 que codificam para os domínios N e Cterminal da proteína, no promotor do gene da Langerina e na região codificante do CRD, bem como verificar a existência de possíveis associações entre as mutações encontradas e a infecção pelo HIV-1. Para tal, através de sequenciamento, foi analisado um total de 128 amostras de DNA de indivíduos infectados pelo HIV-1 de Feira de Santana, Bahia e 197 amostras de DNA de indivíduos não-infectados de Salvador, Bahia. Os possíveis sítios de ligação para fatores de transcrição da região promotora do gene da Langerina foram analisados pela ferramenta MatInspector implementada no software Genomatix. Análises físico-químicas, de domínios protéicos potenciais, de predição da estrutura proteica secundária e de modelagem tridimensional proteica foram também realizadas, utilizando diferentes ferramentas de bioinformática. Os estudos na região N-terminal da CCR5 revelaram a existência de uma mutação de sentido trocado no aminoácido 55 (p.L55Q) apenas em indivíduos não-infectados, com uma frequência do alelo mutante de 1,8%. Análises físico-químicas demonstraram que esta mutação aumentou a flexibilidade e a acessibilidade da CCR5 e a modelagem protéica demonstrou que a mutação levou a um pequeno desvio para a direita, bem como alterou levemente a carga eletrostática dessa região da proteína. Foi observada diferença estatisticamente significante entre as frequências alélicas (p=0,039) e genotípicas (p=0,038) da mutação p.L55Q quando os indivíduos infectados e não-infectados foram comparados. Os estudos na região C-terminal da CCR5 demonstraram a existência de três mutações silenciosas em indivíduos infectados pelo HIV- 1: c.3,765C>T, c.3,777A>T e c.3,831A>G. Em relação à análise da região promotora do gene da Langerina, foram observadas três mutações (-577T>C, -517T>C e -160T>C) que, segundo o MatInspector, criaram novos sítios de ligação para fatores de transcrição, tais como: NFAT5, HOXB9.01 e STAT6.01. Entretanto, comparando as frequências alélicas e genotípicas dessas mutações entre os indivíduos infectados e não-infectados, não foi observada diferença estatisticamente significante. Já as análises realizadas na região gênica que codifica o CRD da Langerina demonstraram a existência de três mutações: p.K313I (c.937T>A), c.941C>T (g.4728C>T) e c.983C>T (g.4770C>T) As análises físico-químicas revelaram que a mutação p.K313I aumentou a hidrofobicidade e as hélices transmembranares e diminuiu a hidrofilicidade, a acessibilidade e a antigenicidade da proteína. Entretanto, a presença do alelo mutante não alterou a predição da estrutura secundária da Langerina e não foi observada diferença estatisticamente significante nas frequências alélicas e genotípicas quando os dois grupos estudados foram comparados. Estes resultados sugerem que a mutação p.L55Q, encontrada no domínio N-terminal da CCR5, pode afetar a entrada do HIV-1 na célula. Foi possível, também, observar que as mutações encontradas no gene da Langerina não apresentam associação com a infecção pelo HIV-1. No entanto, é importante que novos estudos sejam realizados com o intuito de compreender melhor o verdadeiro papel da mutação p.L55Q na infecção pelo HIV-1, assim como, novas análises voltadas para a busca de variações no gene da Langerina também devam ser conduzidas, uma vez que este é o primeiro estudo que investiga mutações na Langerina em indivíduos infectados pelo HIV-1.
HIV-1 is the etiologic agent of AIDS. It has been demonstrated that the mechanisms underlying HIV-1 infection and pathogenesis require a combination of viral and host factors. Concerned to the host intrinsic factors, some mutations at CCR5 human gene can affect the interaction between CCR5 protein and HIV-1 gp120, influencing the virus infection. Besides, the Langerin protein, located exclusively on Langerhans cells surface, has an important role in HIV-1 infection due to its ability of binding to gp120 through its Carbohydrate Recognition Domain (CRD). This interaction ables HIV-1 internalization into Birbeck granules, which degrade the virus and prevent LC infection and viral dissemination. So, differences in Langerin function due to mutations at promoter and CRD encoding regions of the human Langerin gene, for example, might influence the susceptibility to HIV-1 infection. Thus, the main purpose of this study is to investigate the existence of mutations at the regions of CCR5 gene that encodes the N- and C-terminal protein domains and at promoter and CRD encoding regions of the human Langerin gene, and finally to stablish possible associations among the observed mutations and HIV-1 infection. Using DNA sequencing, it was studied a total of 128 DNA samples of HIV-1 infected individuals from Feira de Santana, Bahia and 197 DNA samples of HIV-1 non-infected individuals from Salvador, Bahia. The transcription factors binding sites were analyzed using the MatInspector tool implemented in the Genomatix software. Physico-chemical, potential protein domain, prediction of protein secondary structure and protein modeling analyses were also performed, using Bioinformatic tools. The studies into the N-terminal protein domain revealed a new missense mutation at aminoacid 55 (p.L55Q), only in HIV-1 non-infected individuals, with allelic frequency of 1.8%. Physico-chemical analysis revealed that this mutation magnified the flexibility and accessibility profiles and the modeling of CCR5 structures showed that this mutation resulted in a small deviation to the right, as well as, a hydrophobic to hydrophilic property alteration. When HIV-1 infected and non-infected groups were compared, the allelic and genotypic frequencies of the p.L55Q mutation were statistically significant (p=0.039 and 0.038, respectively). Three novel silent mutations were found at encoding region of C-terminal protein domain in the HIV-1 infected individuals: c.3,765C>T, c.3,777A>T and c.3,831A>G. Concerned to the analyses at promoter Langerin region, the studies revealed three mutations: -577T>C, -517T>C and -160T>C. The search for possible transcription factors binding sites using MatInspector demonstrated that these promoter mutations created new binding sites to some transcription factors, such as NFAT5, HOXB9.01 and STAT6.01. However, when HIV- 1 infected and non-infected groups were compared, the allelic and genotypic frequencies of the analyzed promoter sites were not statistically significant. It was observed three mutations at Langerin gene region that encodes to the protein CRD: p.K313I (c.937T>A), c.941C>T (g.4728C>T) and c.983C>T (g.4770C>T). The physico-chemical analysis revealed that the p.K313I polymorphism magnified the hydropathy and transmembrane profiles and reduced the hydrophilicity, accessibility and anitigenicity profiles. However, this mutation did not modify the protein secondary structure prediction and when HIV-1 infected and non-infected individuals were compared, it was not observed a statistically significant difference in the allelic and genotypic frequencies from the p.K313I polymorphism. These results suggest that the p.L55Q mutation can affect HIV-1 infection through CCR5 entry. It was also observed that the mutations detected at the promoter and CRD encoding regions of the human Langerin gene are not associated with HIV-1 infection susceptibility. However, it is important to accomplish future studies in order to better understand the role of the p.L55Q mutation at HIV-1 infection, as well as, conduct new search for variations at Langerin gene that could influence HIV-1 infection, since this is the first study that analyzes mutations at promoter and encoding regions of Langerin gene in a HIV-1 infected population.
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Bonfá, Giuliano. "Papel de CCR5 na infecção oral por Toxoplasma gondii." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/17/17147/tde-08072010-152818/.
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Toxoplasma gondii é um protozoário intracelular obrigatório que causa a toxoplasmose. Em modelo experimental, camundongos C57BL/6 infectados por via oral com 100 cistos de T. gondii, cepa ME-49, desenvolvem sérias lesões intestinais similares as observadas em doenças inflamatórias intestinais. Ao invadir as células epiteliais intestinais, o parasito induz uma resposta inflamatória de padrão T helper (Th) 1 elevada, ativada pela produção de quimiocinas e citocinas envolvidas na migração e ativação celular. Para que ocorra essa migração celular para o sítio de infecção é necessário a presença de receptores de quimiocinas. O receptor de quimiocinas CCR5 é muito importante para o recrutamento celular em algumas infecções e está envolvido com a migração de vários subtipos celulares como células dendríticas, células T e, em particular, células T reguladoras. CCR5 pode estar relacionado também a mecanismos independentes da migração celular, no qual a sinalização intracelular e ativação de NF-B podem levar a intensificação da resposta imunológica. Ainda não está claro o papel do receptor CCR5 no modelo de infecção oral por T. gondii. Dessa forma, animais C57BL/6 e deficientes em CCR5 foram infectados por via oral com 5 cistos de T. gondii, cepa ME-49, e alguns parâmetros imunológicos e bioquímicos foram avaliados no 8º dia de infecção. Os resultados mostraram que animais CCR5-/- apresentaram alta suscetibilidade à infecção oral por T. gondii, exibindo um intenso infiltrado inflamatório no íleo e regiões de ulceração epitelial, quando comparados com animais C57BL/6. Independentemente de serem deficientes ou não de CCR5, os camundongos apresentaram focos inflamatórios dispersos pelo parênquima do fígado, entretanto camundongos CCR5-/- apresentaram uma extensiva vacuolização dos hepatócitos, com excessivo acúmulo de lipídeos no órgão e elevada concentração sérica de triglicérides e de transaminases. A carga parasitária foi significativamente mais elevada no intestino delgado e no fígado dos animais CCR5-/- em comparação com animais C57BL/6. Foi observada também uma menor migração de células NK no intestino delgado, bem como um aumento na frequência de células T CD4+ neste órgão e uma menor concentração de IFN- e IL-12p40 no macerado do fígado dos animais CCR5-/- em comparação com C57BL/6. Análise de expressão gênica no fígado revelou redução na formação de transcritos para PPAR nos animais deficientes em CCR5, e quando os camundongos foram tratados com Gemfibrozil, um agonista de PPAR, houve reversão na vacuolização hepática e na concentração de triglicérides no soro dos animais CCR5-/-. Estes dados sugerem que a migração celular dependente de CCR5 é essencial para a modulação da resposta inflamatória induzida por T. gondii no intestino delgado. Além do mais, a ausência de CCR5 compromete a integridade hepática durante a infecção oral por T. gondii e os mecanismos moleculares envolvidos podem estar relacionados à expressão de PPAR.T. gondii is an obligate intracellular protozoan parasite which is the causative agent of toxoplasmosis. In experimental model, C57BL/6 mice orally infected with a high parasitic load develop serious intestinal lesions, whose injuries are similar to those observed in Inflammatory Bowel Disease. This inflammation is caused due to parasite invasion of intestinal epithelial cells that elicit a robust Th1 type immune response. Moreover, chemokines produced by intestinal epithelial cells are involved in the migration and activation of inflammatory cells. In particular, the chemokine receptor CCR5 is important for cell recruitment in some infections and is involved with the migration of various cells subsets such as dendritic cells, T cells and, in particular regulatory T cells. CCR5 may also be related to mechanisms independent of cell migration, in which the intracellular signaling and activation of NF-B may lead to intensification of the immune response. The role of CCR5 has not been clear in the experimental oral T. gondii infection. Thus, wild type C57BL/6 mice and CCR5-/- littermates were infected with T. gondii by gavage and immune and biochemical parameters, were analyzed at day 8 after infection. The CCR5-/- mice showed to be highly susceptible to the parasite, with intense inflammatory infiltration in the ilea and regions of epithelial ulcerations in comparison with WT mice. Both strain of mice presented inflammatory foci scattered by parenchyma of the liver, however the CCR5-/- mice presented an extensive hepatocyte vacuolization with an excessive accumulation of lipids in the organ and elevated serum triglycerides and transaminases concentration. The parasite load was significantly higher on small intestine and liver samples of CCR5-/- in comparison with WT mice. There was also a minor migration of NK cells in the small intestine, as well as greater frequency of CD4+ T cells in this organ and a lower IFN- and IL-12p40 levels in liver homogenate samples in the CCR5-/- mice compared with WT mice. Gene expression analysis revealed a reduction in the formation of transcripts for PPAR in mice deficient in CCR5, and when the animals were treated with Gemfibrozil, a PPAR agonist, there was an improvement in the level of vacuolization and reduced triglycerides. These data suggest that a CCR5-dependent cell migration is essential for the modulation of T. gondii-induced inflammatory response in the small intestine. In addition, hepatic integrity during T. gondii oral infection is compromised in the absence of CCR5, and the molecular mechanisms involved can be related to PPAR expression.
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Desmetz, Caroline. "Rôle de la densité membranaire en CCR5 dans la migration des lymphocytes T vers CCL5 : application à la polyarthrite rhumatoïde." Montpellier 1, 2006. http://www.theses.fr/2006MON1T004.
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Le système des chimiokines et de leurs récepteurs permet aux leucocytes de migrer à l'endroit approprié afin de mettre en oeuvre une réponse immunitaire efficace. Notre hypothèse de travail est que le nombre moyen de récepteurs en surface d'une cellule, ou densité membranaire, détermine l'efficacité de sa fonction de migration. Nous nous intéressons plus particulièrement au récepteur CCR5, également corécepteur du virus de l'immunodéficience humaine (VIH). Nous avons montré que la densité membranaire en CCR5 conditionne l'intensité de migration de lymphocytes primaires vers CCL5 (RANTES), son principal ligand. Nous avons également vérifié notre hypothèse en conditions physiopathologiques au cours d'une maladie auto-immune, la polyarthrite rhumatoïde, et montré que la densité membranaire conditionne l'intensité de migration de lymphocytes T vers du surnageant de synoviocytes activés de patients. Ce phénomène a une implication physiopathologique importante puisque la densité membranaire en CCR5 varie de manière significative entre les individus. Nos résultats impliquent qu'il pourrait y avoir un polymorphisme dans la capacité individuelle de réponse aux CC chimiokines, et par conséquent, dans la survenue et/ou le déroulement des pathologies où ces chimiokines sont impliquées. Ces travaux suggèrent en outre que des molécules antagonistes de CCR5 pourraient avoir un effet bénéfique dans la PR et de manière plus générale, au cours des situations inflammatoires dans lesquelles CCR5 joue un rôle.
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Hirata, Bruna Karina Banin. "Estudo de associação dos polimorfismos genéticos CCR2-V64I e CCR5-Delta32 com suscetibilidade e parâmetros clinicopatológicos do câncer de mama." Universidade Estadual de Londrina. Programa de Pós- Graduação em Patologia Experimental, 2014. http://www.bibliotecadigital.uel.br/document/?code=vtls000190140.
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Entre os diversos tipos de cânceres, o de mama representa um grave problema de saúde pública correspondendo ao segundo tipo mais freqüente no mundo e o primeiro na população feminina. As células tumorais podem expressar receptores de quimiocinas, tais como o CCR2 e o CCR5, que estão implicados na progressão tumoral, podendo modular não apenas o recrutamento leucocitário, mas também a angiogênese, invasão e proliferação de células tumorais. Polimorfismos em muitos destes receptores são considerados fatores de risco para o desenvolvimento de diferentes tipos de câncer. A proposta deste estudo foi investigar o impacto dos polimorfismos CCR2-V64I (rs1799864) e CCR5-Delta32 (rs333) sobre a suscetibilidade e características clinicopatológicas do câncer de mama. A genotipagem foi realizada por PCR convencional e por PCR-RFLP em 118 pacientes com diagnóstico confirmado histologicamente e 180 controles livres de neoplasia de mama. O estudo de associação caso-controle foi analisado pelo cálculo da Odds Ratio (OR) com intervalo de confiança a 95% (IC=95%). E as análises de correlação entre os dados de genotipagem e os parâmetros histopatológicos (tamanho tumoral, comprometimento de linfonodos, estadiamento e grau nuclear) e subtipos tumorais do câncer de mama (triplo negativo, HER2+ e receptor hormonal positivo) foram realizadas pelo teste de Spearman rho. Nenhuma associação positiva ou negativa entre as variantes polimórficas de CCR2-V64I e CCR5-Delta32 e a suscetibilidade ao câncer de mama foi encontrada (CCR2-V64I: OR=1.32; IC95%=0.57-3.06; CCR5-Delta32: OR=1.04; IC95%=0.60-1.81). Entretanto, a análise de correlação mostrou significância entre o polimorfismo CCR2-V64I e os tumores que apresentavam a superexpressão do oncogene HER2 (p=0.026). Este estudo mostrou que os polimorfismos CCR2-V64I e CCR5-Delta32 não conferem suscetibilidade e também não estão correlacionados a um pior prognóstico no câncer de mama, em uma amostra da população brasileira da região sul. Contudo, uma vez que a freqüência dos alelos Delta32 (do gene CCR5) e A (do gene CCR2) foram baixas na população estudada (4% e 5% para o alelo Delta32 em controles e pacientes com câncer de mama, respectivamente e 12% para o alelo A em controles e pacientes), pode ser necessária a inclusão de um número maior de indivíduos com o intuito de confirmar a ausência de associação entre estes polimorfismos e a suscetibilidade ao câncer de mama. Adicionalmente, a correlação observada entre a variante alélica do gene CCR2 com o subtipo molecular HER2+ ressalta a importância de se estudar marcadores moleculares especificamente dentro dos subgrupos do câncer de mama, dadas a heterogeneidade e variabilidade de resposta desta doença.Among the various types of cancer, breast cancer presents as a serious public health problem, being the second most common type in the world and first in the female population. The tumor cells can express chemokine receptors, such as CCR2 and CCR5, wich are implicated in tumor progression, can modulate not only leucocyte recruitment, but also the angiogenesis, invasion and proliferation of tumor cells. Polymorphisms of several receptors were found to be risk factors for development of different types of cancer. The purpose of this study was to investigate the impact of CCR2-V64I (rs1799864) and CCR5-Delta32 (rs333) polymorphisms on the susceptibility and clinicopathological characteristics of breast cancer. The genotyping was done by conventional PCR and PCR-RFLP methods in 118 histologically confirmed patients and 180 controls. The case-control association study was analyzed by Odds Ratio (OR) with a 95% confidence interval (IC=95%). The correlation analysis between the genotyping data and the histopathological parameters (tumor size, lymph nodes commitment, staging and nuclear grade) and breast cancer subtypes (triple negative, HER2+ and hormonal receptors positive) were realized by Spearman rho test. No association between polymorphic variants of CCR2-V64I and CCR5-Delta32 and breast cancer susceptibility was found (CCR2-V64I: OR=1.32; CI95%=0.57-3.06; CCR5-Delta32: OR=1.04; CI95%=0.60-1.81). However, the correlation analysis showed significance between the CCR2 polymorphism and tumors with overexpression of the oncogene HER2+ (p=0.026). This study shows that CCR2-V64I and CCR5-Delta32 polymorphisms does not confers susceptibility and also are not correlated with poor prognosis in breast cancer in Southern Brazilian population sample. However, since the frequency of the Delta32 (CCR5 gene) and A (CCR2 gene) allele were low in the studied population (4 and 5% of Delta32 allele in controls and breast cancer patients, respectively and 12% to A allele in both groups, there may be a need the inclusion of a greater number of individuals in order to confirm the absence of association between these polymorphisms and breast cancer susceptibility in Brazilian population. Additionally, the correlation observed between the variant allele of the CCR2 gene with the molecular subtype HER2+ highlights the importance of studying molecular markers specifically within subgroups of breast cancer, given the high heterogeneity and variability of response in this disease.
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Kono, Fumihiko. "Interferon-γ/CCR5 expression in invariant natural killer T cells and CCL5 expression in capillary veins of dermal papillae correlate with development of psoriasis vulgaris." Kyoto University, 2015. http://hdl.handle.net/2433/202644.
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Blanpain, Cédric. "Etude des relations structure fonction de CCR5 et ses ligands." Doctoral thesis, Universite Libre de Bruxelles, 2001. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211524.
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Masters, Jennefer. "Myxoma virus induced activation of CC-chemokine receptor 5, CCR5." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0019/MQ53479.pdf.
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Junior, Samuel de Barros Ferreira. "Modulação da severidade da doença periodontal experimental por células CCR5+." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/25/25142/tde-02072009-112551/.
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As doenças periodontais (DP) afetam os tecidos de suporte dos dentes e são desencadeadas por micro-organismos gram-negativos anaeróbios presentes no biofilme periodontal. A evolução da doença é influenciada pela resposta inflamatória e imunológica do hospedeiro e envolve a participação de diversos tipos celulares, que atuam no micro ambiente local modulando a resposta do hospedeiro em busca do controle da infecção. Acredita-se que citocinas inflamatórias, quimiocinas e seus receptores estão envolvidos na migração celular para os tecidos periodontais, contudo, pouco se sabe sobre os mecanismos de determinação de resistência ou susceptibilidade às DP; ou no desencadeamento do dano tecidual decorrente da resposta. Neste projeto, avaliou-se o papel das células CCR5+ na DP experimental induzida pela inoculação oral de Aggregatibacter actinomycetemcomitans em camundongos C57BL/6 wild type e camundongos CCR5-knockout. Os resultados mostram que a maioria das células CCR5+ possuem fenótipo compatível com células T do subtipo Th1, devido a co-expressão de CD3 e CXCR3; além de co-expressarem RANKL. Na ausência das células CCR5+, houve uma significativa diminuição da migração de células inflamatórias totais e RANKL+ para os tecidos periodontais, diminuição da reabsorção óssea alveolar, diminuição dos níveis de expressão de citocinas pró-inflamatórias TNFα-, IL-1β e IFN-γ, assim como diminuição na expressão de MMP-1, MMP-2 e MMP-13. Sua ausência não interferiu no controle da infecção periodontal apesar da diminuição dos níveis de iNOS. Estes resultados conduzem à conclusão de que a maioria das células CCR5+ são células T do subtipo Th1, que atuam como importantes moduladoras das citocinas TNFα-, IL-1β e IFN-γ, das metaloproteinases de matriz MMP-1, MMP-2 e MMP-13, e que também expressam e modulam a expressão de RANKL, tendo participação importante na imunopatogenese da DP experimental, sem interferir no controle da infecção periodontal. Estes fatos tornam as células CCR5+ potenciais alvos para intervenção terapêutica visando ao controle das doenças periodontais.The periodontal diseases (PD) affect the supportive tissues of the teeth and are triggered by periodontopathogens present in the dental biofilm. The clinical outcome is highly influenced by the host inflammatory and immune response with participation of many cellular types, that act in the local microenvironment modulating the host response to control the infection. Inflammatory cytokines, chemokines and its receptors are thought to be involved in the cellular migration to the periodontal tissues, but there is little knowledge about the mechanisms of determination of resistance or susceptibility to the PD and in the triggering of tissue damage by immune response components. This study evaluated the role of CCR5+ cells in the experimental PD induced by oral inoculation of Aggregatibacter actinomycetemcomitans in C57BL/6 wild type mice and CCR5-knockout mice. The phenotypic analysis of inflammatory infiltrate demonstrated that the most of CCR5+ cells coexpress CD3 and CXCR3, suggesting a phenotype compatible with Th1-type cells, and also co-express RANKL. In the absence of CCR5+ cells there was a significant overall reduction of inflammatory cells and RANKL+ cells influx to the periodontal tissues, reduction in the alveolar bone resorption, reduction in the levels of pro-inflammatory cytokines TNFα-, IL-1β and IFN-γ expression, as a reduction in the expression of MMP-1, MMP-2 and MMP-13. The absence of CCR5+ cells did not impair the control of periodontal infection, despite the reduction of iNOS levels. In conclusion, these data demonstrate that the most of CCR5+ cells are Th1 cells, which act as important modulators of TNFα-, IL-1β and IFN-γ, MMP-1, MMP- 2 and MMP-13 levels, and which also express and modulate the expression of RANKL, playing an important role in the immunopathogenesis of experimental PD, without impairing the control of periodontal infection. These facts point to CCR5+ cells as potentials targets to therapeutic interventions aimed to control periodontal diseases.
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Kroetz, Danielle N. "The Role of CCR5 in Protection Against Histoplasma capsulatum Infection." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1305030008.
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Raborg, Thomas. "Development of Bivalent Ligands Targeting the Putative CCR5-MOR Heterodimer." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3553.
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Chemokine receptor CCR5 (CCR5) is a G-protein coupled receptor (GPCR) predominantly expressed on leukocytes, or white blood cells.1–3 During inflammation, the body releases chemokines that bind to receptors such as CCR5 and attract leukocytes to the area of inflammation, leading to an immunological response.1 CCR5 is also an important receptor in the human immunodeficiency virus's (HIV-1) invasion of host cells, as CCR5 acts as a co-receptor that facilitates HIV-1 viral entry.4,5 The continued destruction of leukocytes as a result of HIV-1 viral entry produces a disease state called acquired immunodeficiency syndrome (AIDS).5 Of note, this receptor is also expressed on the glial cells of the central nervous system (CNS).6,7 The mu-opioid receptor (MOR) is also a GPCR is predominantly expressed in the central nervous system.8–10 It binds to signal molecules such as endorphins and produces analgesic effects upon activation.9 The protein binds to morphine and morphine derivatives, which are extracts from the opium poppy plant.10 Besides the analgesic effects produced from MOR activation, morphine and its derivatives are also highly addictive and can result in drug dependence.11 Like CCR5, MOR is also expressed on the glial cells of the CNS.8 The accelerated progression of AIDS-like symptoms, in particular HIV-associated neurocognitive disorders (HANDS), has been observed in opiate-addicted patients.6,7,12–14 It has been discovered that opiate-addicted patients who have AIDS are susceptible to higher levels of HIV-1 viral proliferation and a greater level of CNS host cell destruction.12–14 This is because the activation of MOR by opiates appears to increase the expression of CCR5 on glial cells and may alter CCR5's conformational state to one more susceptible to HIV-1 binding.15 Then, entry and subsequent destruction of glial cells by HIV-1 leads to the release of neurotoxic HIV-1 proteins that destroy primary neuronal cells.15 A bivalent ligand targeting the putative CCR5-MOR heterodimer was proposed to probe the interaction between the two proteins and act as a potential therapeutic ligand to combat neuroAIDS.16 A bivalent ligand attaching maraviroc, a CCR5 antagonist, with naltrexone, a non-selective opioid receptor antagonist, was synthesized and tested in vitro.16 The initial bivalent ligand was separated by a 21-atom spacer (Figure 1), the length of which was dictated by modeling studies and other bivalent ligands.17 The spacer was attached to the 6-position of 6β-naltrexamine, a modified variation of naltrexone replacing the 6 position ketone with an amino group, and the 4'-position of the maraviroc phenyl ring.16 These positions were chosen based on separate modeling studies of naltrexone and maraviroc docked in homology models of MOR and CCR5, respectively.18,19 From these studies, it appeared as if these positions were optimal given that they faced outward from their respective binding pockets and hence could tolerate spacer attachment.18,19 However, based on these modeling studies there was also room for structure optimization of the bivalent molecule.17–19 The original 21-atom spacer was subjected to numerous structural changes by our laboratory in an effort to increase CCR5 and MOR binding. The first type of structural modification included changing maraviroc's point-of-attachment to the spacer from the 4'- to the 3'-position. Based on results from calcium mobilization functional assays involving CCR5-transfected human acute lymphoblastic leukemia (MOLT-4) cells, the activity of the bivalent molecule decreased from an IC50 of 126.0 ± 28.0 to 1340.0 ± 110.0 when the point-of-attachment was changed to the 3'-position. Thus, the 4'-position was kept in future structural studies. After this, additional structural modification was pursued in the form of changing spacer length. We synthesized two additional bivalent ligands, i.e., 19-atom and 23-atom bivalents with their controls. It is important to note that each of these molecules had a separate synthetic route starting with a specified diamine spacer. For the 19-atom bivalent molecule and its controls, the starting material was 1,5-diaminopentane. For the 23-atom bivalent molecule and its controls, the starting material was a 1,9-diaminononane molecule. Once these molecules were synthesized, in vitro biological testing was conducted. The bivalent molecules and 6β-naltrexamine controls were subjected to a competitive radioligand binding assay involving hMOR membranes and then to a calcium mobilization functional assay involving hMOR-transfected chinese hamster ovarian (CHO) cells (Figure 2). The affinities from the radioligand binding assay were similar in order-of-magnitude to other modified opioid antagonists and had a fold-decrease in affinity relative to naltrexone ranging from 1.1 to 9.3. The IC50 values from the calcium mobilization assay were similar in order-of-magnitude to other modified opioid antagonists and had a fold-decrease in activity relative to naltrexone ranging from 7.6 to 32. Thus, it was concluded that spacer attachment to the 6-position of 6β-naltrexamine was tolerated in MOR-binding. The bivalent molecules and maraviroc controls were then tested in calcium mobilization assays involving CCR5-transfed MOLT-4 cells to assess CCR5 activity. Unlike in the hMOR-CHO calcium mobilization assay, the activity of the bivalent molecules for CCR5 was not similar in magnitude to the receptor's antagonist, maraviroc. The 23-atom bivalent and 19-atom bivalent had fold-decreases in activity relative to maraviroc of 1,100 and 250, respectively. Recently, the co-crystal structure of maraviroc bound to CCR5 was published in Science.20 Contrary to our previous understanding, it appeared as if modifications to the phenyl ring in maraviroc were not tolerated.20 After the biological testing, conformational analysis on the 19-, 21- and 23-atom bivalent compounds using Confort conformational modeling software was conducted. This was done to observe the possible viable conformations of each molecule. It was hypothesized that 1) the molecules could adopt viable conformations for binding to two different receptors simultaneously and that 2) the molecules could adopt similar conformations relative to each other. The first hypothesis was proposed to assess the realism of the project's design strategy whereas the second was to analyze whether significant conformational differences could account for differences in binding activity between the three molecules. Results from this experiment showed that the molecules all adopted viable conformations for binding to two receptors simultaneously and that the conformational differences between the three molecules were negligible enough to conclude that significant differences in binding were not because of conformational differences. In conclusion, our laboratory synthesized a set of bivalent compounds to probe the CCR5-MOR heterodimer and tested such compounds in vitro. While spacer modifications to the 6-position of naltrexone were tolerated in hMOR competitive radioligand binding assays and in hMOR-CHO calcium mobilization assays, spacer modifications to maraviroc's 4'-position on the phenyl ring were not tolerated very well in CCR5-MOLT-4 calcium mobilization assays. Therefore, future design strategies might focus on changing the spacer's point-of-attachment to the maraviroc molecule.
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Bennett, Laura Danielle. "Trafficking regulation of the chemokine receptor CCR2B compared to CCR5." Thesis, University of York, 2012. http://etheses.whiterose.ac.uk/3169/.
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The closely-related CC chemokine receptors 2B and 5 are seven-transmembrane domain receptors coupled to heterotrimeric G proteins. The two receptors bind inflammatory chemokines and play important complementary roles in the recruitment of specific leukocyte sub-populations to sites of infection. To enable fine-tuning of cellular responses to chemokines, CCR2B and CCR5, like other GPCRs, can be desensitised in response to agonist stimulation or cross-talk with other receptors. This involves down-modulation of cell surface active receptor through two essential transportation events, endocytosis and recycling. The CCR5 endocytic and recycling pathways are well established and several mechanisms involved have been clearly defined. Conversely, less is known about the route followed by CCR2B upon stimulation. This study investigated the regulation, trafficking and fate of CCR2B in the context of THP-1 cells endogenously expressing the receptor and HEK293 transfectants. Comparison with CCR5 highlighted marked differences in the behavious of the two receptors. However, my initial findings indicate that certain aspects of the regulation of CCR5 as well as CCR2B may be cell type-dependent. Flow cytometry, immunofluorescence and biochemical analyses showed that unlike CCR5, internalised CCR2B can be both degraded and recycled following agonist stimulation. In HEK293, CCR2B follows an EGF receptor-like pathway, transiting through early endosomes containing EEA1, transferrin and Rab4, reaching CD63 and Lamp1 positive late endosomes/lysosomes before being degraded. Importantly, I showed that CCR2B cell surface molecules are N- and O-glycosylated, and only this glycosylated form of the receptor is targeted for agonist-induced degradation. This thesis also presents findings from proteomics approaches developed in an attempt to identify interacting proteins implicated in the trafficking of each receptor. This study brings new insights to the endocytic regulation of agonist-treated CC chemokine receptors, revealing receptor- and cell type-specific behaviours, which add complexity to a relatively conserved process.
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Fredrich, Andréa Longoni. "Imunoexpressão de rankl, CCL5/RANTES e CCR5 em inflamação pulpar aguda em ratos, induzida por exposição tecidual, ácido lipoteicóico ou lipopolissacarídeo." Pontifícia Universidade Católica do Rio Grande do Sul, 2014. http://hdl.handle.net/10923/6650.
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Previous issue date: 2014Studies on dental caries demonstrate inflammation on dental pulp tissues following infection. Cytokines are able to activate those cells linked to inflammatory and immune response thus neutralizing potentially aggressive agents and allowing tissue repair. Some of those cytokines, denominated chemokines, could contribute to the establishment of an immunotherapy able to control those cytokines involved with the triggering of dental pulp inflammation. Research on chronic inflammation has provided some relevant insights. However, the role of certain chemokines on acute inflammation is yet not conclusive. This study attempts to unveil the role of the chemokines CCL5/RANTES, CCR5 and RANKL on initial and acute pulpal inflammation. Methods: 18 Wistar rats were subjected to anesthesia. Access was performed on their first lower molars until pulp exposure. They were divided into three experimental groups considering the solution administered: Saline, lipopolysaccharide (LPS) and lipoteichoic acid (LTA) (n=6 each group). Higid second lower molars were used as controls. The cavities were sealed with amalgam and euthanasia occurred after 48 h and the jaws were dissected for histologic evaluation. CCL5/RANTES is expressed in all groups, unlike CCR5, that was not expressed. RANKL appears only in inflammatory cells, including control group. Only RANKL could be expressed during initial pulpal inflammation, being able to detect inflammatory cell activity.
Estudos de cárie demonstraram aspectos inflamatórios nos tecidos pulpares decorrentes de infecção estabelecida. Citocinas seriam capazes de ativar células ligadas à resposta inflamatória e imune no sentido de neutralizar potenciais agentes invasores e permitir o reparo dos tecidos pulpares. Algumas destas, denominadas quimiocinas, poderiam contribuir no estabelecimento de uma imunoterapia capaz de bloquear aquelas citocinas responsáveis pelo processo inflamatório. Na inflamação crônica estas pesquisas já possuem resultados satisfatórios. Na inflamação aguda, os estudos ainda estão inconclusivos. Este estudo teve como objetivo testar as quimiocinas CCL5/RANTES, CCR5 e RANKL na inflamação pulpar aguda. Métodos: 18 Ratos Wistar foram anestesiados. Foram feitas cavidades até a exposição pulpar nos primeiros molares inferiores. Eles foram divididos em três grupos onde se administrou solução salina estéril, lipopolissacarídeo (LPS) e ácido lipoteicóico (LTA) (n= 6 por grupo). Os segundos molares inferiores hígidos foram utilizados como controle. As cavidades foram seladas com amálgama e a eutanásia foi realizada após 48h. As mandíbulas foram dissecadas para exame histológico e da imunoexpressão das quimiocinas em estudo. Obteve-se como resultados: CCL5/RANTES é expressa em todos os grupos, ao contrário do CCR5, que não foi expressa. RANKL aparece apenas em células inflamatórias. Somente a expressão de RANKL foi capaz de demonstrar atividade celular na inflamação pulpar inicial.
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TORRETTA, SIMONE. "Extracellular Nicotinamide phosphoribosyltransferase (eNAMPT): a cytokine with a still unknown receptor." Doctoral thesis, Università del Piemonte Orientale, 2018. http://hdl.handle.net/11579/97203.
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El-Asmar, Laila. "Etude des interactions de CCR5 avec des partenaires cytosoliques et membranaires." Doctoral thesis, Universite Libre de Bruxelles, 2004. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211160.
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CCR5 est un récepteur couplé aux protéines G répondant aux CC-chimiokines MIP-1&61537; MIP-1&61538; RANTES et MCP-1. Le récepteur structurellement le plus proche est CCR2b, qui répond à MCP-1. CCR5 est exprimé à la surface des lymphocytes T mémoire, les monocytes, macrophages et cellules dendritiques. Ce récepteur joue un rôle important dans l'établissement des réponses inflammatoires contre les agents pathogènes, mais aussi dans la pathogenèse de maladies inflammatoires chroniques. CCR5 constitue aussi avec CXCR4 un des co-récepteurs qui permettent l'entrée du virus de l'immunodéficience humaine dans ses cellules cibles. CCR5 présente donc un grand intérêt en thérapeutique, et tous les éléments susceptibles de mieux comprendre sa structure, ses mécanismes d'activation ou ses cascades de signalisation sont à même de contribuer au développement d'agents à usage thérapeutique.Deux nouveaux concepts sont apparus dans la littérature au cours des quelques années qui ont précédé le début de notre travail. D'une part, il est apparu que les récepteurs couplés aux protéines G pouvaient interagir directement avec un éventail de partenaires intracellulaires et réguler de cette façon des cascades de signalisation indépendamment des protéines G hétérotrimériques. D'autre part, un nombre croissant de récepteurs se sont révélés capables de former des homodimères et des hétérodimères. Nous avons dès lors appliqué ces deux concepts à l'étude de CCR5.
Nous avons donc recherché de nouveaux partenaires de CCR5 par deux approches complémentaires, le double hybride et le « GST-pulldown ». Dans les deux cas, nous nous sommes focalisé sur le domaine C-terminal du récepteur CCR5, d'une part parce que la majorité des interactions mises en évidence pour d'autres récepteurs concernent ce domaine, d'autre part parce que l'extrémité C-terminale de CCR5 est conservée dans l'évolution et comporte différents motifs dont la relevance fonctionnelle a été démontrée. Par ailleurs, nous avons appliqués les techniques d’immunoprécipitation et de BRET pour étudier les phénomènes d’homodimérisation de CCR5, ainsi que son hétérodimérisation avec le récepteur apparenté CCR2b. Les conséquences fonctionnelles de ces interactions ont ensuite été étudiées.
Par les techniques de double hybride et de pull-down, nous n’avons pas pu identifier de nouveaux partenaires de CCR5. Seules des interactions non-spécifiques ont pu être mises en évidence. Malgré une recherche intensive menée par d’autres groupes, un seul nouveau partenaire de CCR5 a été décrit entre-temps dans la littérature.
Lors des études d'oligomérisation de récepteurs, nous avons mis en évidence la formation d'homodimères de CCR5 et CCR2b par des expériences d’immunoprécipitations et de BRET, ainsi que d'hétérodimères CCR5-CCR2b. Les conséquences fonctionnelles de ces observations sur la liaison de chimiokines, la signalisation et l'internalisation des récepteurs ont été étudiées. Contrairement aux données de la littérature, nous n'avons pas montré de coopérativité positive entre les récepteurs co-exprimés, quant à leur capacité à induire la libération de calcium intracellulaire. Par contre, nous avons mis en évidence une coopérativité négative en termes de liaison de chimiokines. Il apparaît ainsi que chaque dimère ne peut lier qu'une seule chimiokine, et qu'en conséquence, les ligands d'un récepteur peuvent entrer en compétition avec la liaison d'un traceur sur l'autre récepteur au sein d'un hétérodimère. Ces dimères de récepteurs apparaissent cependant comme dissociables, suite à la liaison d'agonistes ou de chimiokines induisant leur internalisation, car aucun phénomène de co-internalisation ne peut être mis en évidence. Ces observations, qui sont originales dans le domaine des récepteurs couplés aux protéines G, peuvent sans doute être généralisées à l'ensemble des récepteurs de chimiokines, voire à d'autres classes de récepteurs. Elles sont importantes pour l'interprétation de la pharmacologie des récepteurs dans leur environnement naturel, et sont susceptibles de développements importants permettant de mieux comprendre la structure des dimères, la dynamique de leur association, et les mécanismes d'activation des récepteurs en général au sein de leur structure dimérique.
Doctorat en sciences, Spécialisation biologie moléculaire
info:eu-repo/semantics/nonPublished
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Sandford, Rebecca M. "The role of the CCR5 Δ32 polymorphism in abdominal aortic aneurysms." Thesis, University of Leicester, 2008. http://hdl.handle.net/2381/29904.
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C-C Chemokine receptor 5 (CCR5) is involved in the regulation of the inflammatory response. Abdominal aortic aneurysms (AAA) may arise as the result of a chronic inflammatory process which is influenced by genetic predisposition. The CCR5 gene is associated with a 32 base pair deletion (the Δ32 polymorphism). The aim of this study was to investigate the role of the CCR5 Δ32 polymorphism in the development of AAA. A case control study was conducted including 285 patients with AAA and 273 control subjects. A blood sample was taken from each individual and DNA extracted. CCR5 genotype was determined using the polymerase chain reaction (PCR). Flow cytometry was used to investigate the biological activity of the Δ32 polymorphism. There was no significant difference between the AAA and the control group in relation to the Δ32 allele frequency (AAA group10%, control group=12%, P=0.82, chi squared analysis). Genotype analysis revealed no significant difference between the groups (AAA vs controls, wild type homozygotes=82% vs 77% heterozygotes=16% vs 21%, vs Δ32 homozygotes= 2% and 2% respectively, P=33, chi squared analysis). The polymorphism was shown to be biologically active with the number of Δ32 alleles correlating with cell expression of CCR5 as detected with flow cytometry (P = < 0.05). This study demonstrates that the CCR5 Δ32 is a biologically active genetic polymorphism, however, there is no association between this polymorphism and AAA.
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Jacobs, Caron Adrienne. "The nanoscale organisation of HIV cell surface receptors CD4 and CCR5." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10056281/.
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The plasma membrane serves as the cell’s front line for interactions with, and response to, the external environment. The molecular mechanisms and regulation of cellular responses to extracellular signals are determined by the spatial organisation and dynamics of the various components comprising the plasma membrane. CD4 and CCR5 are two key cell surface molecules with important roles in immune cell function and regulation. They are also co-opted as the primary receptor and a co-receptor, respectively, by HIV. Biochemical studies have provided a detailed understanding of the molecular mechanisms of these interactions. Until recently, however, the small scale and rapid dynamics of these interactions has meant that a detailed view of the topology of the cell membrane and the organisation of receptors first encountered by the virus has been beyond the resolving power of available tools. The increasing capabilities of the emerging and rapidly developing super-resolution microscopy technologies are now optimally poised for us to address some of these questions. In this work, I have applied single molecule localization microscopy to unveil some of the nanoscale organisational properties of the cell surface receptors CD4 and CCR5. I have worked on the development of small labelling probes for CD4 and addressed some of the key aspects of sample preparation and labelling that can artificially alter the distribution of membrane associated target molecules. Here I report the first quantitative characterisation of the nanoscale organisation of CD4 and CCR5 in lymphoid cell plasma membranes, as well as how this organisation changes under different conditions, such as in response to cell signal-mimicking stimulation, or exposure to HIV envelope. This approach to characterising membrane receptor organisation can be further applied to in-depth studies of early host cell-virus interactions, as well as to other cell surface receptors and their organisation in the context of key cellular functions.
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Marasca, Joao Adalberto. "Receptor de quimiocina CCR5 e a suscetibilidade ao Lúpus Eritematoso sistêmico." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2002. http://hdl.handle.net/10183/1664.
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Meyer, Laurence. "Délétion CCR5-delta 32 et progression de la maladie VIH-1." Paris 11, 1999. http://www.theses.fr/1999PA11T021.
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Les relations entre la délétion Δ32 sur le gène codant pour le récepteur CCR5 aux β chemokines et la progression de la maladie VIH ont été étudiées chez des patients infectés par le VIH-1 suivis dans plusieurs cohortes prospectives françaises ou étrangères. Environ 17% des patients à contage daté de la cohorte SEROCO étaient porteurs de la délétion sur un des deux allèles du gène ; ces patients progressaient moins vite depuis la contamination vers le SIDA et le décès que les autres patients. Cet effet a été retrouvé lors d'une collaboration avec la cohorte d'Amsterdam d'hommes homosexuels, indépendamment de 2 autres mutations ultérieurement décrites sur les gènes codant pour le corécepteur CCR2 et pour le ligand SDF-1 du corécepteur CXCR4. La charge virale précoce sérique était plus basse d'environ 0,25 log chez les hétérozygotes pour la délétion que chez les autres patients. Cette charge virale plus basse expliquait dans l'analyse multivariée une partie de l'effet protecteur conféré par la délétion. Par ailleurs, notre étude a permis de décrire le deuxième cas d'homozygote infecté par le VIH, confirmant que la protection conférée par la délétion à l'état homozygote n'est pas totale. Enfin, les liens entre la délétion Δ32 et la survenue de certaines infections opportunistes ont été étudiés en réunissant les données de 3 cohortes, SEROCO, HEMOCO et SEROGEST. La toxoplasmose survenait significativement moins souvent comme pathologie inaugurale de SIDA chez les hétérozygotes que chez les autres patients, y compris après prise en compte de l'âge, du taux de lymphocytes CD4 et de la prescription d'une prophylaxie primaire spécifique. Grâce au suivi des patients actuellement traités, ce travail va être poursuivi en étudiant la relation entre délétion Δ32 et la réponse aux traitements antirétroviraux. Par ailleurs la physiopathologie de la primo-infection VIH et ses liens avec la délétion vont être étudiés dans la cohorte PRIMO de patients récemment infectésThe role of the Δ32 deletion on the gene coding for the CCR5 receptor for beta chemokines on HIV-1 disease progression was studied in HIV-infected patients followed in several prospective multicenter cohorts. Around 17% of patients with a known date of infection from the SEROCO cohort were heterozygous for the deletion : these patients progressed less rapidly since infection to AlDS or death than the other patients. Ln a collaborative study with the Amsterdam cohort study, this protective effect was observed independently of two other mutations on genes coding for the CCR2 receptor and the SDF-1 ligand. Early serum viral load was 0. 25 log lower in Δ32 heterozygous patients than in wild-type patients; this lower viral load explained partiy. The protective effect of the deletion in the Cox multivariate analysis. This study allowed us to describe an HIV-infected subject who was homozygous for the deletion, which confirms that homozygous patients are not totally protected from HIV infection. The relationship between the Δ32 deletion and the occurrence of several opportunistic infections was studied in 1657 patients followed in the SEROCO, HEMOCO and SEROGEST cohorts. The risk of toxoplasmosis as a first AIDS-defining illness since inclusion was significantly reduced in heterozygous patients, even after adjustment for age, CD4 cell count and primary specifie prophylaxis. Since most patients who are still followed in these cohorts are now treated by highly active antiretroviral therapy, we are going to study whether the deletion affects the response treatment. The relationship between pathophysiology of primary HIV-1 infection and the Δ32 deletion will be studied in the PRIMO cohort which has recruited since 1996 recently infected patients
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Salo, Alex. "The role of the CCR5 co-receptor conformation in HIV fusion." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/3150.
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Includes bibliographical references (leaves 71-80).This thesis aimed to better define the co-receptor conformation by determining whether mutants of the CCR5 receptor stabilized in the active conformation were less able to mediate HIV fussion. Eight mutant receptors were generated by site-directed mutagenesis and screened for constitutive activity using intracellutal signaling assays.
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Issafras, Hassan. "Étude de l'oligomérisation du récepteur CCR5 par la technique de BRET." Paris 7, 2002. http://www.theses.fr/2002PA077211.
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Duquenne, Charline. "Modulation de l’activité des corécepteurs CCR5 et CXCR4 du VIH 1 comme stratégie thérapeutique : étude des deux isoformes de CXCR4 et interaction de CCR5 avec le récepteur S1P1." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20188/document.
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CCR5 et CXCR4 sont les corécepteurs d'entrée du VIH utilisés par le virus in vivo en plus du récepteur principal CD4 pour infecter les cellules. Au début et tout le long de l'infection, on retrouve chez les patients infectés par le VIH, des virions R5 utilisant le corécepteur CCR5 pour infecter les cellules. Dans les stades tardifs de l'infection et chez environ la moitié des personnes infectées par le VIH, on observe en plus de ces souches R5, l'apparition de souches X4, utilisant le corécepteur CXCR4 pour infecter les cellules. Cette apparition de souches X4 est un facteur d'aggravation de la maladie. Les causes de cette commutation de R5 vers X4 sont mal définies. Le but de mon travail de thèse a été de trouver de nouvelles stratégies thérapeutiques visant l'un ou l'autre de ces corécepteurs. La première partie de mon travail compare les deux isoformes de CXCR4 en tant que corécepteurs du VIH. Ces deux isoformes, CXCR4-A et CXCR4-B, diffèrent de 9 acides aminés en NH2 terminal suite à un épissage alternatif. Nous avons montré que l'isoforme CXCR4-B est la plus performante en tant que corécepteur du VIH mais que ces deux variants sont équivalents pour la migration vers leur ligand commun SDF-1. Ainsi, nous proposons qu'en ciblant exclusivement l'isoforme B qui est la plus favorable à l'infection, via par exemple des siRNA, il serait possible de limiter les infections par des souches X4 tout en gardant une partie des fonctions essentielles de ce récepteur dans l'organisme, assurées par l'isoforme A. Nos résultats suggèrent également que l'infection par des souches R5 augmente le ratio en ARNm CXCR4-B / CXCR4-A dans des PBMC, et que ce ratio est en partie responsable de la commutation de R5 vers X4 associée à une aggravation de la maladie. Cibler cette isoforme CXCR4-B pourrait donc se révéler bénéfique. La deuxième partie de cette thèse étudie la modulation de la fonction de corécepteur du VIH de CCR5 par S1P1, un autre membre de la famille des récepteurs couplés aux protéines G qui permet la remise en circulation des lymphocytes après leur séjour dans les organes lymphoïdes secondaires par chimiotactisme vers son ligand S1P, abondant dans le sang. Nous montrons que S1P1 interagit physiquement avec CCR5 et gêne l'entrée des virus R5 dans la cellule-hôte. A l'inverse, S1P1 active les étapes post-entrée du cycle viral, notamment l'expression génique virale. La résultante de ces effets opposés est une augmentation de la production virale par des cellules infectées in vitro. Ce projet a également montré que l'utilisation de FTY720, un antagoniste fonctionnel de S1P1, diminue l'infection de cellules dendritiques par des virus HIV-R5 in vitro, ainsi que la virémie dans un modèle de souris SCID infectées après reconstitution immunologique. La mise en évidence des interactions entre CCR5 et S1P1 ouvre donc des perspectives thérapeutiquesCCR5 and CXCR4 are the two HIV entry coreceptors used by the virus in addition to the main receptor CD4 in vivo to infect cells. R5 virions, that use CCR5 as a coreceptor to infect cells, are detected in most HIV patients. At late stages of infection and in about half of HIV infected persons, there is an emergence of X4 virions that use CXCR4 as a coreceptor, in addition to R5 virions. This emergence is associated with an increase in disease progression. The reasons for this R5 to X4 switch are poorly understood. The goal of my PhD work was to find new therapeutic strategies that target these coreceptors.The first part of this work compares the two CXCR4 isoforms as HIV coreceptors. Those two isoforms, CXCR4-A and CXCR4-B, differ by 9 amino acids at their NH2 terminal extremity as a consequence of an alternative splicing. We have shown that CXCR4-B isoform is more efficient as an HIV coreceptor but that those two variants are equivalent in terms of chemotaxis toward their common ligand SDF-1. Thus, we propose that by targeting specifically the B isoform that supports infection, via siRNA by example, it is possible to limit X4 development while keeping essential functions of this receptor. Our results also suggest that R5 infection increases CXCR4-B / CXCR4-A mRNA ratio in PBMC and that this ratio is in part responsible for R5 to X4 switch. Thus, targeting CXCR4-B isoform could be beneficial.The second part of this PhD thesis studies the effect on CCR5 coreceptor function of S1P1, another G protein-coupled receptor that enables lymphocytes egress from lymph nodes by chemotaxis toward its ligand S1P that is abundant in blood. We have shown that S1P1 physically interacts with CCR5 and blocks R5 virus entry. On the other hand, S1P1 activates post-entry steps of the viral cycle, in particular gene expression. The resulting effect is an increase in viral production by infected cells in vitro. We also showed that the use of FTY720, a S1P1 functional antagonist, decreases dendritic cell infection by R5 viruses in vitro, and in vivo infection in a SCID mouse model. The emphasis of CCR5 and S1P1 interactions opens new therapeutic strategies
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Koensgen, Florian. "Modélisation du récepteur aux chimiokines C-C de type 5 : caractérisation des états conformationnels et conception rationnelle de modulateurs de la dimérisation." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF026/document.
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De nombreuses études des RCPGs révèlent que leur activation n’implique pas que deux états conformationnels, l’un activé et l’autre inactivé, mais une diversité plus importante de ces états, impliquant également des états intermédiaires. Nous avons utilisé la simulation par dynamique moléculaire et l’analyse des interactions intramoléculaires non-covalentes pour étudier la plasticité structurale du récepteur CCR5 sous sa forme monomérique et dimérique. En couplant notre analyse avec diverses données expérimentales, nous avons pu proposer trois architectures dimériques du récepteur et associer des mouvements et des interactions clefs aux états conformationnels de CCR5 libre, lié à un agoniste, lié à un agoniste inverse et constitutivement activé ou inactivé par mutation d’acides aminés. Nous avons également développé une méthode d’identification des motifs d’interactions intramoléculaires transmembranaires, permettant de discriminer les états d’activations des RCPGsMany studies reveal that GPCR activation does not simply involve two conformational states, one activated and the other inactivated, but a variety of these states coupled to intermediate states. By using molecular dynamics simulations and analyzing non-covalent intramolecular interactions, we studied the structural plasticity of monomeric and dimeric CCR5. By coupling our analysis with various experimental data, we identified three dimeric organizations states of the receptor and associated key motions and intramolecular interactions to free CCR5, bound to an agonist, bound to an inverse agonist and constitutively activated or inactivated by mutated residues. We have also developed a method to identify intramolecular transmembrane interactions patterns, which allow the discrimination of GPCRs activation states
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Kohem, Charles Lubianca. "Estudo do polimorfismo e expressão do CCR5 em pacientes com artrite reumatóide." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2005. http://hdl.handle.net/10183/5218.
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Pakalnienė, Jolita. "Genų, koduojančių penktą chemokino ir trečią Toll-like receptorius, polimorfizmų reikšmė erkinio encefalito viruso infekcijos metu." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140930_085230-33015.
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Erkinis encefalitas (EE) – pati dažniausia ir sunkiausia virusinė nervų sistemos infekcija Lietuvoje, kuria per metus vidutiniškai suserga 400 žmonių. Užsikrėtus EE virusu (EEV), galima besimptomė arba klinikinius požymius sukelianti ligos eiga, turinti platų požymių spektrą – nuo lengvos, meningitinės ligos formos iki sunkaus encefalito. Nors mirštamumas nuo EE yra nedidelis, svarbiausia problema – ilgai trunkantis sveikimo laikotarpis ir ilgalaikiai liekamieji reiškiniai, kurie būdingi 26–46 proc. persirgusiųjų. Neaišku, kodėl užsikrėtę identiško virulentiškumo virusu, vieni žmonės perserga besimptome arba lengva EE forma, o kitiems atsiranda sunkus nervų sistemos pažeidimas. Manoma, kad didelę reikšmę turi žmogaus genetiniai veiksniai. Nesant specifinio priešvirusinio EE gydymo, šios sunkios centrinės nervų sistemos infekcijos patogenezės ir genetinių rizikos veiksnių tyrimai yra ypač svarbūs, siekiant nustatyti galimas veiksmingo gydymo paieškos kryptis ateityje. Šio darbo tikslas – nustatyti CCR5 ir TLR3 genų polimorfizmų paplitimą tarp EE sirgusių asmenų ir šių genų polimorfizmų reikšmę polinkiui sirgti EE bei skirtingoms EE klinikinėms formoms išsivystyti. Šis darbas yra didžiausias iki šiol atliktas genetinių veiksnių reikšmės EEV infekcijos metu tyrimas ir pirmasis tokio pobūdžio vaikų tyrimas. Tyrimo rezultatai patvirtino hipotezę, kad nefunkcionuojantis CCR5 ir funkcionuojantis TLR3 yra reikšmingi simptominės EE formos išsivystymo veiksniai, užsikrėtus EEV.Tick-borne encephalitis (TBE) is the most common and severe viral infection of the central nervous system in Lithuania, with the average number of 400 cases per year. The clinical spectrum of TBE virus infection varies considerably from asymptomatic to mild meningitis or severe encephalitis. Although the mortality of TBE is relatively low, as many as 26–46% of the patients experience long-lasting sequelae. No specific treatment for TBE exists. A most intriguing question is why certain individuals respond with seve¬re clinical symptoms after infection with TBEV while the majority either remains asymptomatic or develops only mild disease. Studies of host genetic susceptibility to infectious diseases aim to in¬crea¬se our understanding of why some individuals are more susceptable than others. Knowledge of genetic susceptibility may be used in develope¬ment of new therapeutic means and also to recognize individuals who are at increased risk of severe symptoms if infected with a pathogen. The aim of this study – to establish the prevalence of the polymorphisms in CCR5 and TLR3 genes in TBE patients and their role in susceptibility to clinical TBE and disease severity. This study is the largest study on the host genetic risk factors predis¬posing to TBEV infection, and the first study of such kind performed in the pediatric population. The results of this study confirmed that a non¬func¬tional CCR5 protein and a functional TLR3 receptor are associated with the clinical expression... [to full text]
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CAMPELO, JUNIOR Evônio de Barros. "Coinfecção GBV-C e HIV em pacientes acompanhados no serviço de doenças infecciosas e parasitárias do HC-UFPE." Universidade Federal de Pernambuco, 2012. https://repositorio.ufpe.br/handle/123456789/18505.
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Desde 1967, momento do seu surgimento no mundo científico, o GB vírus C (GBV-C) permanece conhecido como vírus indolente, todavia não obstante,pesquisas têm reveladoadespeito da ausência de vinculação do GBV-C com alguma doença, que a associação entre o GBV-C e HIV promove uma progressão mais lenta na doença pelo HIV em indivíduos coinfectados. Essa interaçãoteriacomo mecanismo a competição com o vírus da imunodeficiência humana (HIV) na ligação aos correceptores CCR5 e CXCR4 edessa formatem sidoobjeto de análise com intuito de promover a compreensão da dinâmica imunológica do HIV. Portanto, admitindoaimportância do GBV-C na pandemia de HIV/aids, esse trabalho determinou a prevalência da infecção pelo GBV-Cem pessoas vivendo com HIV/aids acompanhadas noServiço de Doenças Infecciosas e Parasitárias do HC-UFPE, verificou o perfil sócio-demográficoda população, identificou fatores de riscoe fez a associação entre a contagem de linfócitos TCD4 e a infecção peloGBV-C.Representou um estudode corte transversal, analisado como caso-controle, no qual a presença do GBV-C RNA foi investigada em249 pessoas vivendo com HIV/aids, de acordo com a demanda espontânea do ambulatório de Doenças Infecciosas e Parasitárias HC-UFPE,no período de junho adezembro de 2011 e que preenchiam os critérios de inclusão. Foram coletadas amostras de sangue de cada participante, os quais também assinaram um termo de consentimento livre e esclarecido e responderam questionário elaborado especificamente para a pesquisa. Adetecção do RNA do GBV-C foi realizado por PCR (Reação em CadeiadaPolimerase).O resultado da pesquisa indicou uma prevalência de 24,3%, compatível com outros estudos nacionais e internacionais,indicou o perfil sócio-demográfico, apontoua via parenteral como a mais prevalente na infecção pelo GBV-Ceassociou a contagem de linfócitos T CD4 e a infecção peloGBV-C,em pessoas vivendo com HIV/aids na fase inicial da infecção. Também a discussão apontou a necessidade de realização de trabalhos de coorte para melhor compreensão de fatores implicados na transmissão do GBV-C.
Since 1967, the time of its emergence in the scientific world, the GB virus C (GBV-C) virus remains known as indolent, but nevertheless, research has revealed despite the absence of binding of GBV-C with some disease, the association between GBV-C and HIV promotes a slower progression in HIV disease in coinfected individuals. This interaction mechanism would compete with the human immunodeficiency virus (HIV) in binding to CCR5 and CXCR4coreceptorsand thus has been the subject of analysis in order to promote understanding of the dynamics of HIV immune.Therefore, admitting the importance of GBV-C in the HIV/AIDS pandemic, this study estimated the prevalence of GBV-C infection in people living with HIV/AIDS followed in the Service of Infectious and Parasitic HC-UFPE, there the socio-demographic profile of the population, identified risk factors and made the association between CD4 count and GBV-C infection.Represented a cross-sectional study, analyzed as case-control study in which the presence of GBV-C RNA was investigated in 249 people living with HIV/AIDSat the outpatient of Infectious and Parasitic Diseases HC-UFPE, between June and December 2011 and who met the inclusion criteria. Blood samples were collected from each participant, who also signed a consent form and a questionnaire developed specifically for research. Detection of GBV-C RNA was performed by PCR (Polymerase Chain Reaction).The result of the survey indicated a prevalence of 24.3%, consistent with other national and international studies, said the socio-demographic profile, pointed the parenteral route as the most prevalent in the GBV-C infection and associated with CD4 count and GBV-C infection in people living with HIV/AIDS in the early phase of infection. Also the discussion pointed to the need to perform cohort studiesto better understand the factorsinvolvedinthe transmission of GBV-C.
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Becker, Marie-Christine. "Generierung und Charakterisierung von Makrophagen-Zelllinien aus CCR5-/-/p53-/- und p53-/- Mäusen." Diss., lmu, 2008. http://nbn-resolving.de/urn:nbn:de:bvb:19-80603.
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Buhler, Marc McWilliams. "Genetics of the immune cell receptors TCRB and CCR5 in human disease." University of Sydney, 2003. http://hdl.handle.net/2123/601.
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Abstract Early in the evolution of the vertebrates it is thought that two genomic duplications occurred, providing a basis for the evolution in body plan and neural crest of very early vertebrates and substantive material for further evolution of various gene families such as those making up a number of components of the adaptive vertebrate immune system. While the bony fish possibly had another, genome duplications are not generally a feature of vertebrate evolution and indeed the appearance of an antigen-adaptive immune recognition system may have served to limit the size that various vertebrate genomes, including that of the human, can in fact achieve. This initial step in vertebrate immune evolution, the establishment of recognition of non-self against the unique set of 'self' epitopes for an individual, provided an immensely powerful weapon in immune function with the ability to tailor a defense against as-yet-unseen dangers at any time albeit with the pitfall of autoimmune disease. As the recognition sites of the antigen receptor molecules such as TcR are produced by clonal modification of the segments provided in the germline and are thus not in the genome itself, pathogens have not been able to hijack this one component of the immune system in the way so many other components have been put to use throughout evolution, nor do these components necessarily reveal themselves as associated with disease through genome screens. Importantly, overall immune function is determined not just by the potential repertoire of recognition receptors but also by the ability of immunocompetent cells to migrate in a tissue specific fashion through the use of various chemokines and their receptors. Typical of the hijacking of an immune system component by a pathogen is the use of a chemokine ligand gene in the viral ancestor to SIV and HIV, allowing for virus binding to immunocompetent cells as is seen in the use of the CCR5 chemokine receptor by macrophage-tropic HIV strains. This thesis describes the allele and genotype frequencies for several TcR beta-chain variable segment polymorphisms in a population of MS patients compared with controls before and after stratification for HLA-DR15, polymorphism in the Apo-1 / Fas promoter, the DRB1 Val86/Val86 genotype, CCR5-delta32 and the HLA-DRA promoter. The thesis continues with CCR5-delta32 genotyping in IDDM, MS and SLE cohorts and then examines the question of the population of origin of the delta-32 allele of the CCR5 receptor for chemokine. Here, a case / control comparison of 122 RR-MS patients with 96 normal individuals was made for allele and genotype frequencies and for haplotypes formed by pairs of TCRB markers. Further analysis was made after HLA-DR15 stratification. Linkage disequilibrium was found between pairs of alleles of bv8s1, bv10s1, bv15s1 and bv3s1 loci in both patients and controls. In the RR-MS cohort, an increase in the allele frequency of bv8s1*2 was seen (p = 0.03) and the haplotype bv8s1*2 / bv3s1*1 was increased (p = 0.006), and both were found to be statistically significant. In the DR15-positive group, association between MS and TCRB was seen with the bv8s1*2 allele (p = 0.05) and the bv8s1*2 / bv10s1 haplotypes (p = 0.048), while the haplotype associations seen among the DR15-negative patients included the bv3s1*1 allele (bv10s1*1 / bv3s1*1, p = 0.022; bv8s1*2 / bv3s1*1, p = 0.048). While no associations were found after stratification for SDF1-3'A, Apo-1 / Fas or DRB1 there were modest interactions between bv3s1, bv10s1 and bv15s1 and the HLA-DRA promoter. These results support the involvement of the TCRB region in MS susceptibility. The further study of autoimmune disease here includes genotype analysis of CCR5-delta32 in type 1 diabetes (IDDM) and SLE. CCR5 is the major co-receptor for viral entry used by macrophage-tropic HIV strains and protection from infection is seen in homozygotes for CCR5-delta32. In diabetes, infiltration of pancreatic tissue by autoreactive T-cells involves secretion of multiple cytokines and chemokine receptor expression. Variation in the chemokine receptor CCR5 may result in differences in inflammatory cell migration in response to relevant chemokines. Adolescents with type 1 diabetes were genotyped for CCR5-delta32 (n = 626). The allele frequency was compared with that of 253 non-diabetic adolescents and with that of 92 adults with SLE. A reduced allele frequency was seen in type 1 diabetes compared with controls (0.092 vs 0.123, p = 0.05). This difference was not seen for the cohort of patients with SLE (freq = 0.114). A reduction in the number of CCR5-delta32/delta32 homozygotes, who lack CCR5, in the type 1 diabetes cohort was also seen and while not statistically significant (2 observed compared to 5.25 expected; p = 0.12) is interesting. These results suggest a partial protection from type 1 diabetes for CCR5-delta32 homozygous individuals is possible and that CCR5 has a potential role in the pathogenesis of type 1 diabetes. Global surveys of the CCR5-delta32 allele have confirmed a single mutation event in a Northeastern European population as the source of this allele. Here, Australian Ashkenazi Jews (n = 807) were found to have a CCR5-delta32 allele frequency of 14.6% while Australian Sephardic Jews (n = 35) had a frequency of 5.7% and non-Jewish Australian controls (n = 311) had an allele frequency of 11.25%. Data on birthplace of grandparents showed a gradient with highest CCR5-delta32 frequencies from Eastern European Ashkenazim (~19.5% for those whose four grandparents come only from Russia, Poland, Hungary, Austria and Czechoslovakia; n = 197) which differs significantly from the frequency seen in Ashkenazi Jews from Western Europe (n = 101, p = 0.001). Homozygotes for CCR5-delta32 were genotyped with 3p21 region microsatellites. This has defined an ancestral haplotype on which the mutation first occurred and helped to date this event to between 40 and 50 generations ago or just over a thousand years ago. The population gradient, combined with the dating of the mutation by microsatellite allele frequencies, suggests an origin for the CCR5-delta32 allele in a population ancestral to the Ashkenazim. The distribution in non-Jewish populations in northern Europe has led others to postulate spread of the mutation by Vikings. It is hypothesised here that the link between the two populations could be the kingdom of Khazaria with subsequent admixture into both Swedish Vikings and Ashkenazi Jews. The basic driving force of evolution is through selection and the immune system has a role which, through the survival pressure exerted by viruses and other pathogens, has the potential to exert a great deal of selective force on the various components of this system. The effects of this pronounced selection on an immune system component can be seen for example in the increase of the CCR5-delta32 allele over the last thousand years to the current frequency. As mentioned, some immune system components are not affected by such straightforward selection. In the case of the TCRBV segments, effects on the immune repertoire can occur through MHC interaction at the point of thymic entry and in the effects of various superantigens, but the actual binding pockets that recognise antigen are themselves unable to be selected for (or against). The findings presented in this thesis provide support for the association of TCRBV gene segments with multiple sclerosis and also provide support for the further study of the role of the CCR5-delta32 allele in type 1 diabetes. Furthermore, data presented here suggests that the CCR5-delta32 allele had an origin in the Khazar Kingdom just over a thousand years ago, accounting for the allele frequencies in both the Ashkenazi Jews and in lands frequented by the Vikings. The definition of an extended ancestral haplotype for the CCR5-delta32 allele shows how the effect of selection of an allele of one gene can carry with it specific alleles of a large number of other genes as well.
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Buhler, Marc McWilliam. "Genetics of the immune cell receptors TCRB and CCR5 in human disease /." Connect to full text, 2003. http://setis.library.usyd.edu.au/adt/public_html/adt-NU/public/adt-NU20040405.141449/index.html.
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Qureishi, Amer Naveed. "Ribozymes against the chemokine receptors CCR5 and CXCR4 for inhibiting HIV-1." Thesis, King's College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408060.
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Jin, Jun. "Study of the multiple conformations of the HIV-1 co-receptor CCR5." Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC053.
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Les récepteurs couples aux protéines G représentent la majorité des récepteurs cibles en thérapie. Différentes conformations de ces récepteurs semblent coexister à la surface cellulaire. Toutefois, leur caractérisation moléculaire et l'impact de ses conformations sur la fonction des récepteurs restent peu connus. Nous nous sommes intéressés à cette question, en prenant comme modèle le récepteur de chimiokines CCR5. En plus de son rôle physiologique, CCR5 est utilisé par la majorité des souches VIH -1 primaires dites « R5 ». Elles sont responsables in vivo de la transmission et du maintien de l'infection. Des individus qui n'expriment pas CCR5, à cause d'un polymorphisme naturel, sont protégés contre l'infection et ne souffrent pas du manque de CCR5. Ce récepteur représente donc une cible de choix pour une stratégie antivirale. Nous avons d'abord montre dans un article publié en 2014 (Jin, JBC 2014) l'existence de conformations particulières de CCR5 à la surface cellulaire, nommées « spare receptors» pour « récepteurs de réserves ». Nous avons exploite les caractéristiques de l'analogue de chimiokine psc-rantes, qui présente une puissante activité antivirale et induit une séquestration intracellulaire des récepteurs à long terme. Nous relevons l'existence d'une population de récepteurs « de réserves » (non reconnues par les chimiokines natives) dans des expériences de compétition de liaison, d'internalisation et de désensibilisation. Nous montrons en particulier que les chimiokines natives sont incapables d'inhiber la liaison de psc-rantes, l'internalisation induite par psc-rantes ou l'induction d'une réponse calcique médiée par psc-rantes. La capacité de cet analogue à cibler une large quantité de récepteurs explique le recrutement massif de B-arrestine2 observe a la membrane plasmique et l'internalisation importante du récepteur, a l'origine de son fort pouvoir antiviral. Ces récepteurs de réserves pourraient être ceux cibles par les VIH pour échapper à la barrière des chimiokines. Ils représentent des lors une cible prioritaire pour inhiber l'infection. Nous nous sommes ensuite intéressés à l'organisation moléculaire de ses conformations. Différents travaux indiquent d'une part que les récepteurs de chimiokines s'organiseraient sous forme d'oligomères constitutifs et, d'autre part, que cette organisation serait nécessaire au transport des récepteurs vers la surface cellulaire, à la liaison des ligands, à la signalisation et au trafic intracellulaire après stimulation. Cette propriété structurale des récepteurs, sujette à controverse pour les GPCR de classe A, pourrait aussi influencer l'entrée des VIH -1 dans certaines conditions, mais cet effet reste mal connu. Par homologie avec les structures cristallographiques récemment décrites de cxcr4 et du récepteur mu opioïde, nous avons proposé en collaboration avec Esther Kellenberger (Strasbourg) un nouveau modèle de dimérisation de ccr5. A partir de ce modèle, nous avons identifié les résidus impliques dans plusieurs interfaces de dimérisation par des approches biochimique et biophysique. En ciblant ces interfaces par mutagénèse dirigée et en utilisant un test original de suivi de l'export des protéines, nous montrons l'importance de la dimérisation de ce récepteur pour son transport a la surface cellulaire. Ce travail nous a également permis de révéler de nouvelles caractéristiques du compose maraviroc, unique antiviral ciblant CCR5 actuellement sur le marché. Celui-ci par interaction avec CCR5 au niveau du reticulum endoplasmique induit une nouvelle conformation de CCR5 qui favorise son export. Ces résultats bientôt soumis pour publication, révèlent plusieurs conformations de CCR5 et montrent leur rôle fonctionnel. A travers cette thèse, nous abordons l'enjeu d'avoir aujourd'hui une vision des conformations des GPCRS, et discutons l'impact qu'elles pourraient avoir sur la fonction de ces récepteurs et leur ciblage thérapeutiqueCCR5 (c-c chemokine receptor type 5), a seven-transmembrane receptor, exhibits multiple conformations at the cell surface based on interactions with ligands, heterotrimeric G proteins, B-arrestins, neighboring gpcrs and membrane lipids, and also based on the location and trafficking of the receptor. These conformations play an important role in receptor functions including ligand binding, cell signaling and trafficking. CCR5 also serves as a co-receptor for r5-tropic human immunodeficiency virus, type 1 (HIV-1) entry. The native chemokines ccl3, ccl4, and ccl5 can compete with HIV-1 gp120 for binding CCR5, and are supposed to form a natural barrier against HIV-1. However, their antiviral activity is limited by a pool of CCR5 adopting conformations that have low-chemokine affinity at the cell surface. We demonetrated that this pool of CCR5 that is not stabilized by chemokines could represent a target for inhibiting HIV-1 infection. We exploited the characteristics of the chemokine analog psc-rantes, which displays potent anti-HIV-1 activity. We show that native chemokines fail to prevent high-affinity binding of psc-rantes, analog-mediated calcium release (in desensitization assays), and analog-mediated CCR5 internalization. These results indicate that this pool of spare CCR5 may bind psc-rantes but not native chemokines. Improved recognition of CCR5 by psc-rantes may explain why the analog promotes higher amounts of b-arrestin2/ccr5 complexes, thereby increasing CCR5 down-regulation and HIV- 1 inhibition. Together, these results highlight that spare CCR5, which might permit HIV-1 to escape from chemokines, should be targeted for efficient viral blockade. Numerous studies also showed that gpcr form dimers or larger oligomers, a process that is involved in gpcr conformational changes. The molecular and functional relevance as well as the interaction interfaces of this organization are still poorly understood. To this aim, by using the HIV-1 coreceptor CCR5, we defined by chemical cross-link and molecular modeling two non-exclusive dimer interfaces, and a third one stabilized by the inverse agonist maraviroc, which indicates that CCR5 could also exhibit multiple conformations through homo-dimerization. We then showed, by site directed mutagenesis combined with saturation time-resolved fluorescence resonance energy transfer and a novel export assay, the essential role of dimerization in receptor transport to the cell surface. These results produce a consensual picture of the interfaces between protomers of class a dimers and reveal the impact of dimerization during biogenesis. They also provide new features of the marketed drug maraviroc highlighting both pharmacological chaperone and allosteric inhibitor activities. Overall, distinguishing multiple CCR5 conformations and their corresponding receptor functions has implications for understanding the selective use of CCR5 by HIV-1 and the development of improved strategies to block CCR5 use by HIV-1
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Achour, Lamia. "Contrôle de l'expression à la surface cellulaire du récepteur de chimiokine CCR5." Paris 5, 2009. http://www.theses.fr/2009PA05T011.
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CCR5 est un récepteur de chimiokine appartenant à la famille des récepteurs couplés aux protéines G (RCPG), jouant un rôle important dans l'entrée du VIH, en association avec la glycoprotéine CD4. Nous avons pu démontrer que la grande majorité de CCR5 (90%) était maintenue à l'état fonctionnel dans les compartiments intracellulaires des cellules immunitaires humaines et des fibroblastes transfectés. CCR5 est particulièrement localisé dans le réticulum endoplasmique (RE) et le Golgi. Les mécanismes moléculaires qui régulent l'export de CCR5 en provenance des compartiments intracellulaires s'avèrent différents dans le RE et le Golgi. La progression de CCR5 hors du RE est lente, et favorisée par son association avec CD4, qui fonctionne comme une protéine d'escorte et régule l'adressage de CCR5 vers la membrane plasmique. D'un point de vue mécanistique, CD4 induirait un changement conformationnel de CCR5, permettant de lever sa rétention dans le RE par PRAF2, une protéine résidente de ce compartiment. Dans le Golgi, la libération de CCR5 est beaucoup plus rapide (5-10min) et contrôlée par des signaux extracellulaires initiés par l'adhésion cellulaire. La rétention dans les compartiments intracellulaires de CCR5 et, plus généralement, des RCPG, pourrait constituer un système d'adaptation permettant de maintenir une réponse physiologique prolongée, dans des contextes cellulaires qui requièrent une réactivité de réponse soutenue, comme au cours du chimiotactisme des leucocytes, via le remplacement progressif des récepteurs de surface désensibilisés et internalisésCCR5 a chemokine receptor belonging to the G protein-coupled receptor (GPCR) family, plays a major role in HIV entry, by forming the viral receptor in association with the glycoprotein CD4. We report that the vast majority of fully functional CCR5 (=90%) is maintained within the intracellular compartments of human immune cells and of transfected fibroblasts. Intracellular CCR5 is mostly localized in the endoplasmic reticulum (ER) and the Golgi apparatus. The molecular mechanisms which control the export of CCR5 from the intracellular compartments are different in the ER and the Golgi. In the ER, the progression of CCR5 is slow and depends on its association with CD4 which functions as an escort protein and controls the CCR5 exit. Association with CD4 would induce a conformational change of CCR5, which would release the receptor from its retention in the ER by a resident protein, PRAF2. In the Golgi, the release of CCR5 is faster (5-10min) and is controlled by extracellular signals promoted by cell adhesion. The intracellular retention of CCR5 and, more generally, of GPCRs could represent an adaptive mechanism to maintain a prolonged physiological response. In particular contexts, which require sustained receptor response such as leukocyte chemotaxis, intracellular receptors would allow the permanent replacement of cell surface desensitized and internalized receptors