Um die anderen Arten von Veröffentlichungen zu diesem Thema anzuzeigen, folgen Sie diesem Link: Les Virus.
Dissertationen zum Thema „Les Virus“
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit Top-50 Dissertationen für die Forschung zum Thema "Les Virus" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Sehen Sie die Dissertationen für verschiedene Spezialgebieten durch und erstellen Sie Ihre Bibliographie auf korrekte Weise.
1
Kamitani, Mari. „Analysis on virus-virus and virus-host interactions in Brassicaceae in natural environments“. 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225436.
Der volle Inhalt der Quelle
2
Gubser, Caroline. „Camelpox virus : the closest known virus to variola virus, the cause of smallpox“. Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393229.
Der volle Inhalt der Quelle
3
Nettleton, Peter Francis. „Studies on the relationship between bovine virus diarrhoea virus and border disease virus“. Thesis, University of Edinburgh, 1985. http://hdl.handle.net/1842/30569.
Der volle Inhalt der Quelle
4
Bentley, Emma. „The study of highly pathogenic emerging zoonotic virus envelope proteins through pseudotyped virus generation“. Thesis, University of Westminster, 2017. https://westminsterresearch.westminster.ac.uk/item/q4yzx/the-study-of-highly-pathogenic-emerging-zoonotic-virus-envelope-proteins-through-pseudotyped-virus-generation.
Der volle Inhalt der QuelleAnnotation:
Emerging zoonotic viruses pose an increasing threat, causing outbreaks with high rates of morbidity and mortality and frequently significant economic implications. Often, there is a lack or shortfall of effective prophylaxis and diagnostic capabilities. Research towards their development, together with improved surveillance activities are high priority activities to prepare and respond to outbreak threats. Yet handling these viruses commonly requires high containment levels. This can be circumvented by the use of replication defective pseudotyped viruses (PVs), incorporating the viral envelope protein of interest which constitutes the primary surface antigen. This permits the serological detection of neutralising antibodies without the need to handle live virus, as well as other viral entry studies. Hence, PVs are increasingly proving to be a valuable tool for emerging virus research. The aim of this study was to exploit novelties in the unique flexibility of the PV platform to allow the serological assessment of emerging viruses and evaluate technical aspects towards standardisation. Current prophylaxis provides robust protection against rabies virus, yet only confers limited protection against other lyssavirus species, which have a near 100% fatality rate. It is thought protection is afforded against isolates of phylogroup I rabies virus, yet there is limited biological data for the Arctic-like rabies virus (AL RABV) lineage which is endemic across the Middle East and Asia. Although other lyssaviruses pseudotype efficiently, titres of AL RABV PV were low. Within this study, high titre PV was produced by constructing chimeric envelope proteins, splicing the AL RABV ecto-transmembrane domain with the cytoplasmic domain of vesicular stomatitis virus. Comparisons showed this did not alter the serological profile of the AL RABV and they were effectively neutralised by vaccines and antivirals. It could therefore be concluded that they do not pose a significant public health risk. However it is recognised broadly neutralising prophylaxis needs to be developed to protect against more divergent lyssaviruses. In a further study, again utilising the flexibility to manipulate the envelope protein, PV was produced switching the five known antigenic sites of the envelope protein between a phylogroup I (rabies virus) and III (West Caucasian bat virus) isolate. Screening polyclonal sera via a neutralisation assay, the immunologically dominant sites for phylogroup I and III were identified as III and I respectively. This can act to inform future development of more broadly neutralising vaccines. The 2013-16 outbreak of Ebola virus focused global efforts towards the urgent need for effective vaccines and antivirals. To permit low containment level serology studies to assist their development, a panel of filovirus PVs were rapidly produced. Work was carried out to optimise their method of production; determining lentiviral core PV produced by transfecting HEK 293T/17 cells was most efficient. Efforts to repeat the use of chimeric envelope proteins to increase titre proved unsuccessful. The evaluation of target cell lines permissive to infection and appropriate for neutralisation assays identified that the CHO-K1 cell line produced the clearest data. The PV neutralisation assay was subsequently applied to a range of projects to assess candidate prophylaxis and demonstrated the value of the platform to respond to emerging virus outbreaks. Given the increasing prominence in the use of PV, work was undertaken to expand their utility and methods for standardisation. An assessment of new reporter genes found a red fluorescent protein, with a nuclear localisation signal, improved the clarity of data collection and output in additional spectrum to the current repertoire. To be able to correlate the disparate readout units of fluorescent and luminescent reporters, recorded as infectious units (IFU) and relative light units (RLU) respectively, a new construct was produced to integrate and equally express two reporters from cells transduced with PV. It was determined that approximately 1260 RLU equates to 1 IFU, although future work to determine how this fluctuates between cell lines is required. Finally, alternative methods to quantify PV were evaluated, measuring the number of particles, genome copies and reverse transcriptase (RT) activity, in addition to the currently used biological titre. It was found that measures of genome copies and RT activity, in combination with biological titre provides information on the quality of PV preparations and could be used to standardise assay input.
5
Aravapalli, Sridhar. „Dengue virus and West Nile virus protease inhibitors“. Diss., Wichita State University, 2013. http://hdl.handle.net/10057/6719.
Der volle Inhalt der QuelleAnnotation:
Dengue virus and West Nile virus are important mosquito-borne pathogens of Flaviviridae family affecting millions of people worldwide and causing a severe global healthcare threat. However, currently there are no approved effective antiviral drugs or vaccines available for the treatment of virus infection. This thesis describes the design, synthesis and discovery of two novel classes of reversible competitive inhibitors of Dengue Virus and West Nile Virus NS2B/NS3 protease. Structure-activity relationship studies have led to the identification of a low micromolar hit, which will be used in a hit-to-lead campaign to generate lead compounds that display superior ADMET and PK characteristics.Thesis (Ph.D.)--Wichita State University, Fairmount College of Liberal Arts and Sciences, Dept. of Chemistry
6
Koelzer, Anja Kathrin. „TT Virus“. Diss., lmu, 2002. http://nbn-resolving.de/urn:nbn:de:bvb:19-7124.
Der volle Inhalt der Quelle
7
Holt, Jim. „Zika Virus“. Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etsu-works/6468.
Der volle Inhalt der Quelle
8
Chan, Kenneth See Kit. „Nef from pathogenic simian immunodeficiency virus attenuates vaccinia virus /“. For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
Der volle Inhalt der Quelle
9
Schupp, Dorothee Carolin. „Elucidating virus uptake and fusion by single virus tracing“. Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-148690.
Der volle Inhalt der Quelle
10
McHugh, Paul H. „Studies on the antigenicity of bovine virus diarrhoea virus“. Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317512.
Der volle Inhalt der Quelle
11
Ward, Rebecca. „Bluetongue virus non-structural protein 1 : virus-host interactions“. Thesis, London School of Hygiene and Tropical Medicine (University of London), 2006. http://researchonline.lshtm.ac.uk/4646527/.
Der volle Inhalt der QuelleAnnotation:
Bluetongue virus (BTY) is an orbivirus of the Reoviridae family that infects sheep and other ruminants. BTY has three non-structural proteins, NS I, NS2 and NS3/3A. NS I forms tubular structures and its function is currently unknown. To investigate the role of NS I in BTY infection, the interactions of NS I with mammalian and insect cellular proteins, and BTY viral proteins, were examined. BTY NS I was identi tied as interacting with aldolase A, NUBP 1, Pyruvate kinase M2, cathespin B, SUM 0-1 and peptide TY7 using the yeast two-hybrid system, ELISA and immunofluorescence analysis. TY7 and NS I caused extensive cell death within 24h of co-expression; this cell death was not apoptosis and reduced BTY yield by 37%. The interaction of NS I with SUMO-I and its importance in BTY infection was confinned using siRNA to knockdown SUMO-I during BTY-IO infection. Knockdown of SUMO-I elicited a dramatic reduction in virus yield by 73%. NS I interactions with proteins of the insect vector Culicoides were also examined. A putative interaction between NS 1 and the ubiquitin activating enzyme El (UBA EI) ofCulicoides was identified during screening of a phage library, this has not been confirmed by other means. NS 1 interactions with other BTY proteins were analysed using immunoprecipitation and a strong interaction between NS 1 and YP7 was identified; this was confim1ed using the yeast two-hybrid system and immunoflourescence. Two main roles have been hypothesised for NS I from this data; firstly it is likely that NS I interaction with SUMO-I and UBA E I allows the targeting of specific proteins for sumoylation and ubiquitination allowing NS 1 to modify the host response to BTY infection. Secondly it is possible that NS I serves as an anchor for YP7 and virus cores allowing the build up of cores at the cytoskeleton in close proximity to YP2 for subsequent assembly and release. RNAi against NS J eliminated tubule formation but did not affect virus yield or YP7 and SUMO-J distribution and expression. It is therefore likely that the function of NS I does not rely on tubule fom1ation and that tubules are a form of storage for the active monomer of NSI.
12
Bajric, Amina. „Validering av Varicella Zoster virus och Herpes Simplex virus“. Thesis, Malmö universitet, Fakulteten för hälsa och samhälle (HS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-24474.
Der volle Inhalt der QuelleAnnotation:
Syftet med denna valideringsstudie är att värdera lämpligheten att överföra den manuella analysen av aktuell infektion av Varicella Zoster Virus (aVZV IgM) och Herpes Simplex Virus (aHSV IgM) med SIEMENS Enzygnost® till en av de automatiserade analysinstrumenten EUROIMMUN Analyzer I (ELISA) eller DiaSorin LIAISON® XL. Arbetet utfördes på Klinisk Mikrobiologi i Lund. Konsekutiva serumprover för VZV IgM (n=108) och för HSV IgM (n=116) från det vardagliga flödet analyserades, tillsammans med 10 PCR- eller serokonversion-konfirmerade positiva serumprover av primär infektion VZV och HSV samt 10 positiva för reaktiverad infektion av VZV och HSV. Utöver det användes 10 serumprover konfirmerade positiva för Cytomegalovirus (CMV) respektive 10 för Epstein-Barr Virus (EBV) för att testa korsreaktionen metoderna emellan. Resultatet från VZV-valideringen i Analyzer I samt LIAISON® XL gav en överensstämmelse på 93% respektive 94% av de konsekutiva proverna, 71% respektive 86% av de primärinfekterade proverna och 75% respektive 58% av de reaktiverade proverna, samt en korsreaktivitet (positiva och gränsvärden) på totalt 33% respektive 20% av proverna. Resultatet från HSV-valideringen i Analyzer I samt LIAISON® XL gav en överensstämmelse på 84% respektive 87% av de konsekutiva proverna, 82% respektive 18% av de primärinfekterade proverna och 40% respektive 10% av de reaktiverade proverna, samt en korsreaktivitet (positiva och gränsvärden) på totalt 67% respektive 47% av proverna. Enligt rekommendation efter utförandet av denna studie så bör analysen av HSV IgM uteslutas från båda automatiserade metoder medan VZV IgM bör kontrolleras något ytterligare i Analyzer I, med förhoppning om att denna metod kan vara känsligare.The approach of this validation study is to evaluate the adequacy for transferring the manual analysis method of ongoing infection of Varicella Zoster Virus (aVZV IgM) and Herpes Simplex Virus (aHSV IgM) with SIEMENS Enzygnost® to one of the automated instruments EUROIMMUN Analyzer I (ELISA) or DiaSorin LIAISON® XL. The study was carried out at Clinical Microbiology in Lund. Consecutive serum samples for VZV IgM (n=108) and HSV IgM (n=116) from the daily local flow of tests were analyzed, along with 10 positive for primary infection of VZV and HSV, confirmed by PCR or seroconversion, and 10 with reactivated infection of VZV and HSV. Beyond those, 10 serum samples confirmed positive for Cytomegalovirus (CMV) respectively 10 for Epstein-Barr Virus (EBV) to test the cross-reaction between the three methods. The results from the validation of VZV in Analyzer I and LIAISON® XL gave an agreement of 93% and 94% respectively in the consecutive tests, 71% and 86% respectively in the primary infected tests and 75% and 58% respectively in the reactivated tests, and also a cross-reactivity (both positive and in between-values) at a total of 33% respectively 20% of the tests. The results from the validation of HSV in Analyzer I and LIAISON® XL gave an agreement of 84% and 87% respectively in the consecutive tests, 82% and 18% respectively in the primary infected tests and 40% and 10% respectively in the reactivated tests, and also a cross-reactivity (both positive and in between-values) at a total of 67% respectively 47% of the tests. According recommendations after the performance of this study, the analysis of HSV IgM should be excluded from both of the automated methods while VZV IgM should be controlled further in Analyzer I, with hopes that this new method could be more sensitive.
13
Danet, Nicolas. „Molecular characterisation of the recombinant Vesicular Stomatitis Virus- ZEBOV-GP virus, prototype vaccine against Ebola virus“. Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1009/document.
Der volle Inhalt der QuelleAnnotation:
Ebolavirus (EBOV) est un filovirus responsable de fièvres hémorragiques virales sévères chez l’humain, qui peuvent être létales dans 90% des cas. L’actuelle épidémie en République Démocratique du Congo et l’ampleur démesurée de l'épidémie de 2014-2016 en Afrique de l’Ouest, qui a causé la mort de plus de 11 000 personnes, ont poussé les agences sanitaires internationales à tester plusieurs approches thérapeutiques afin d’essayer d’endiguer rapidement la propagation virale et de limiter la mortalité liée au virus lors de futures épidémies. Parmi toutes les stratégies testées, le virus recombinant réplicatif rVSV-ZEBOV qui exprime la glycoprotéine de surface d’EBOV, semble offrir la meilleur protection, aussi bien en modèle animaliers que sur le terrain. Avant d’être testé chez l’humain, de nombreuses études ont permis de mettre en évidence l’efficacité et l’innocuité de ce vaccin prototype. Pourtant et malgré le fait que de nombreuses études ont démontré l’importance et le rôle de la glycoprotéine GP dans l’efficacité des vaccins contre ce virus, aucune étude n’a encore été réalisé sur la nature des glycoprotéines virales synthétisées par le gène GP d’EBOV inséré dans le génome du virus VSV. Ainsi, les caractérisations moléculaires des protéines virales produites lors de l’infection par le virus rVSV-GP décrites dans ces travaux de thèse offrent de nouvelles perspectives pour comprendre le succès de ce vaccin mais aussi l’origine virales dans les effets secondaires sévères observés lors de la vaccination, et pourront aider à développer un vaccin plus sûr, qui n’est actuellement pas utilisable chez les personnes immunodépriméesThe filovirus Ebolavirus (EBOV) is the causative agent of severe viral hemorrhagic fevers in humans that can be lethal in 90% of cases. The current outbreak in the Democratic Republic of Congo and the extraordinary scale of the 2014-2016 outbreak in West Africa, that caused the death of more than 11 000 disease victims, lead the international public health agencies to test several therapeutic approach to limit viral spreading and mortality. Amongst those, the recombinant replication-competent rVSV-ZEBOV virus, that expressed EBOV GP glycoprotein, appears to offer the best protection in animal models and outbreak settings. While its effectiveness and safety have been widely investigated before human trials and despite numerous studies that showed the importance the nature of the glycoproteins which are produced during the infection from the EBOV GP gene that has been inserted in VSV genome are unknown. In this respect, the molecular characterisations of the viral glycoproteins synthesised during rVSV-GP presented in this thesis, offer new insights with which to understand the success of the rVSV-GP vaccine but also the potential viral origins of the severe adverse side effects observed during vaccination and could help in developing a safer vaccine, which currently cannot be used in an immunocompromised population
14
HUGUENOT, CLAIRE. „Etude immunochimique de deux virus de plantes : le tomato spotted wilt virus et le peanut clump virus“. Université Louis Pasteur (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR13198.
Der volle Inhalt der QuelleAnnotation:
L'etude immunochimique du tomato spotted wilt virus (tswv) a ete abordee selon deux approches: la production d'anticorps monoclonaux, et la production d'anticorps diriges contre des peptides synthetiques. La premiere a permis la mise au point, en elisa, d'un test de diagnostic. La seconde a prouve la localisation sur le segment moyen de l'arn genomique, des genes des deux glycoproteines d'enveloppe du tswv, ceci etant un element de similitude supplementaire pour l'integration du tswv a la famille des virus animaux des bunyaviridae. Des anticorps monoclonaux diriges contre un isolat africain de peanut clump virus (pcv) ont permis la definition de cinq serotypes parmi les isolats d'origines geographiques diverses. L'un des anticorps monoclonaux produits reconnait egalement l'indian peanut clump virus (ipcv), permettant pour la premiere fois, de relier serologiquement ces deux virus
15
Rollison, Dana Elise Maher. „The association between the polyomaviruses JC virus, BK virus, and simian virus 40, and human brain tumors“. Available to US Hopkins community, 2002. http://wwwlib.umi.com/dissertations/dlnow/3080754.
Der volle Inhalt der Quelle
16
Dhillon, Simrat. „Investigating virus entry using cell-culture adapted hepatitis C virus“. Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3616/.
Der volle Inhalt der QuelleAnnotation:
Hepatitis C virus (HCV) is a major cause of chronic hepatitis worldwide. Present estimates predict that between 120-130 million people worldwide are infected with HCV with the majority of all infections progressing to chronicity, ultimately leading to fibrosis, cirrhosis and hepatocellular carcinoma. The virus, which belongs to the family Flaviviridae, has a single-stranded RNA genome of positive polarity that codes for a unique polyprotein of approximately 3000 amino acids. The structural proteins E1 and E2 constitute the viral envelope glycoproteins. These glycoproteins have multiple functions in the viral life cycle such as promoting viral entry and fusion, assembly of infectious virions and aid in viral persistence through immune escape. Numerous cell culture-adaptive mutations have been reported within the HCV glycoproteins. The value of such mutations in understanding the virus interaction(s) with cellular receptors and neutralizing antibodies was first recognised from studies characterizing the E2 cell culture adaptive mutation G451R. This single mutation altered the affinity of HCV to the cell surface receptors CD81 and SRB1 as well as increasing its sensitivity to neutralizing antibodies targeting the viral glycoproteins. A striking observation from previously reported E2 cell culture adaptive mutations is their frequent occurrence within a highly conserved region of E2, spanning residues 412-423. Indeed, the long-term passaging of JFH1 infected cells here in this study also created an adapted virus with a substitution at residue 415. The aim of this study was to determine the phenotypic changes to viral entry caused by mutations in this region. To do this, four JFH1 viruses containing the mutations N415D, T416A, N417S and I422L were constructed and characterized. These mutant viruses were found to have very similar phenotypes to the G451R virus, suggesting all E2 adaptive mutations are selected to alter a specific function in viral entry. Residues 412-423 of HCV E2 also constitute the epitope of the in-house generated broadly neutralizing antibody AP33. ELISA binding and virus infection inhibition assays using AP33 with the E2 mutant viruses provided important information regarding the E2 contact residues of this antibody. In a separate study, intergenotypic chimeric JFH1 viruses were generated and characterised. Viable intra- and intergenotypic JFH1 chimeric viruses have previously been generated by different research groups by replacing the core to NS2 genes of JFH1 with those from different genotypes. Many of these chimeric viruses required numerous cell culture adaptive mutations to permit efficient infectious virus production. In the present study, 5 intergenotypic viruses were constructed by replacing the JFH1 envelope genes with those from other HCV genotypes. Despite these chimeric genomes replicating efficiently, none were capable of producing infectious virus. These viral genomes also failed to acquire infectivity during pro-longed cell passaging, suggesting that replacing the JFH1 envelope glycoproteins with those from other genotypes may confer total incompatibility for virus assembly. In addition to this work, the infectivity of a previously generated genotype 4a/JFH1 chimera was improved by repeatedly passaging the virus infected cells. The chimeric virus contained the core to NS2 genes of a genotype 4a strain in place of the those from the original JFH1 sequence. A total of six-adaptive mutations were identified throughout the adapted genome that enhanced infectivity by more than 100-fold. Achieving higher titers with this chimera permitted studies on its viral entry properties as well as its sensitivity to neutralizing antibodies. The ability of the adapted virus 4a/JFH1 virus to spread during multiple rounds of infection was greatly reduced compared to WT/JFH1 due to its inefficient cell-to-cell spread. The 4a/JFH1 virions were also highly sensitive to neutralizing antibodies targeting both linear and conformational E2 epitopes, suggesting that the glycoproteins are more exposed on the surface of this virus. In its totality, this study has provided key insights into the viral entry and antibodymediated neutralization properties of cell-culture adapted and intergenotypic chimeric forms of the JFH1 virus.
17
Kallies, René [Verfasser]. „Ljungan virus – prevalence in rodents and virus pathogenesis / René Kallies“. Berlin : Freie Universität Berlin, 2012. http://d-nb.info/1030291136/34.
Der volle Inhalt der Quelle
18
Thuenemann, Eva. „Virus-like particle production using cowpea mosaic virus-based vectors“. Thesis, University of East Anglia, 2010. https://ueaeprints.uea.ac.uk/20539/.
Der volle Inhalt der Quelle
19
Bouraï, Mehdi. „Caractérisation d'un interactome virus-hôte : l'exemple du virus du Chikungunya“. Paris 7, 2011. http://www.theses.fr/2011PA077183.
Der volle Inhalt der QuelleAnnotation:
Récemment, la levée de nombreux verrous technologiques a permis le développement de la « génomique fonctionnelle », désignant l'approche systémique appliquée à la biologie moléculaire et cellulaire. Les virus, parasites intracellulaires obligatoires, interagissent avec de nombreux composants de la cellule afin de se répliquer. Mieux définir les interactions entre les protéines virales et cellulaires permet de mieux comprendre le cycle de réplication et la pathogenèse virale, et ouvre la voie à de nouvelles approches thérapeutiques innovantes. Au cours de mon travail de thèse, j'ai cherché à définir la carte d'interaction, ou interactome, du virus du chikungunya (CHIKV), virus dont les interactions avec la cellule à l'échelle moléculaire restent encore mal connues. J'ai pour cela utilisé des approches par double-hybride à haut débit en levure (HT-Y2H) et de validations en cellules de mammifère (notamment la technique de protein complémentation assay ou PCA). Nous avons criblé toutes les protéines matures du CHIKV contre 3 banques différentes d'ADNc humains, et une banque normalisée de 12. 000 ORFs (open reading frame) humaines entières. Nous avons ainsi mis en évidence 22 interactions dont la plupart impliquent la protéine non structurale 2 (nsP2) du CHIKV. Parmi les interacteurs cellulaires mis en évidence, nous avons pu montrer le rôle important joué par hnRNP-K (heterogeneous nuclear ribonucleoprotein K) et l'ubiquiline 4 dans la réplication du virus in vitro. Par ailleurs, nous avons démontré l'implication de la protéine TTC7B (tétratricopeptide 7B) dans l'activité d'inhibition transcriptionnelle induite par la protéine nsP2 du CHIKV. Les techniques utilisées au laboratoire m'ont également permis de participer à la caractérisation de trois interactions virus-hôte identifiées par un autre étudiant en thèse du laboratoire et jouant un rôle dans la réplication du virus de la rougeole (VR) et du virus parainfluenza humain (hPIV3). J'ai notamment pu cartographier avec précision des domaines peptidiques impliqués dans ces interactions, grâce à une technique adaptée du Y2H. Ce travail m'a donc permis d'appréhender les techniques actuelles permettant de définir les interactomes virus-hôte, et de proposer ainsi une carte d'interactions virus-hôte pour le CHIKV, mais aussi d'apporter des éléments de réponses quant aux mécanismes viraux impliquées dans le cycle réplicatif et la pathogenèse de ce virusThe lifting of many technological barriers in recent years has allowed the development of « functional genomics », an innovative systemic approach to molecular and cell biology. Viruses, being intracellular parasites, interact with several components of the cell to replicate. Thus, defining and improving our knowledge of the interactions between viral and cellular proteins ensures a better understanding of the viral replication cycle and pathogenesis and opens the pathway to new therapeutic approaches. In my thesis, I defined the interaction map, or interactome, of the chikungunya virus (CHIKV), a virus whose interactions with the cell at the molecular level have been poorly understood. For this, I performed high throughput two-hybrid approaches in yeast (HT-Y2H) and validations in mammalian cells (including protein complementation assay technique or PCA). We screened all the CHIKV mature proteins across three different human cDNA libraries and a normalized 12,000 human full-length open reading frames (ORF) library. We identified 22 interactions, the majority of which involve non-structural protein 2 (nsP2) of CHIKV. Among the identified cellular interactors, we showed the important role of hnRNP-K (heterogeneous nuclear ribonucleoprotein K) and ubiquilin 4 in virus replication in vitro. Furthermore, we demonstrated the involvement of the TTC7B protein (tétratricopeptide 7B) in the transcriptional inhibition activity induced by the nsP2 protein of CHIKV. Such techniques conducted in the laboratory also allowed me to participate in thé charaterization of three virus-host interactions identified by a fellow PhD student and contribute to researching the replication of measles virus (MV) and type 3 human parainfluenza virus (hPIV3). In particular, I was able to accurately map the peptide domains involved in these interactions, using a technique adapted from Y2H. This work has allowed me to not only understand the current techniques for defining virus-host interactomes and consequently produce a map of virus-host interactions for CHIKV, but also to shed some light on the viral mechanisms involved in the replication cycle and the pathogenesis of this virus
20
Upadhyay, Mohita. „Dinucleotide frequencies in DNA virus genomes: implications on virus evolution“. Thesis, IIT Delhi, 2016. http://localhost:8080/xmlui/handle/12345678/6989.
Der volle Inhalt der Quelle
21
Cullen, Ben Sandford 1964-1995. „The cultural virus“. Phd thesis, School of Archaeology, Classics and Ancient History, 1993. http://hdl.handle.net/2123/9055.
Der volle Inhalt der Quelle
22
Nelson, M. R., A. Nadeem, W. Ahmed und T. V. Orum. „Cotton Virus Diseases“. College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210398.
Der volle Inhalt der QuelleAnnotation:
Virus diseases of cotton have historically been of only sporadic importance to global cotton production. Recent devastating epidemics in Pakistan and other areas have brought new awareness to the potential for disaster of a pathogen once considered to be of a minor importance. Under changing conditions this pathogen (cotton leaf curl virus) has emerged as a serious problem in Pakistan and India. Cotton leaf curl virus does not occur in the United States or the rest of the western hemisphere but recent experience worldwide is a reminder that pathogens, such as this geminivirus, can be moved easily from one part of the world to another and therefor we need to be aware of the potential impact of such pathogens on local crops.
23
Höfer, Chris Tina. „Influenza virus assembly“. Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17251.
Der volle Inhalt der QuelleAnnotation:
Influenza A Viren besitzen ein segmentiertes, einzelsträngiges RNA-Genom, welches in Form viraler Ribonukleoprotein (vRNP)-Komplexe verpackt ist. Während das virale Genom im Zellkern repliziert wird, finden Assemblierung und Knospung reifer Viruspartikel an der apikalen Plasmamembran statt. Für die Virusbildung müssen die einzelnen viralen Komponenten hierher gebracht werden. Während intrinsische apikale Signale der viralen Transmembranproteine bekannt sind, sind der zielgerichtete Transport und der Einbau des viralen Genoms in neuentstehende Virionen noch wenig verstanden. In dieser Arbeit wurden potentielle Mechanismen des vRNP-Transportes untersucht, wie die Fähigkeit der vRNPs mit Lipidmembranen zu assoziieren und die intrinsische subzellulären Lokalisation des viralen Nukleoproteins (NP), eines Hauptbestandteils der vRNPs. Es konnte gezeigt werden, dass vRNPs nicht mit Lipidmembranen assoziieren, was mittels Flotation aufgereinigter vRNPs mit Liposomen unterschiedlicher Zusammensetzung untersucht wurde. Die Ergebnisse deuten jedoch darauf hin, dass das virale M1 in der Lage ist, Bindung von vRNPs an negativ-geladene Lipidmembranen zu vermitteln. Subzelluläre Lokalisation von NP wurde des Weiteren durch Expression fluoreszierender NP-Fusionsproteine und Fluoreszenzphotoaktivierung untersucht. Es konnte gezeigt werden, dass NP allein nicht mit zytoplasmatischen Strukturen assoziiert, stattdessen aber umfangreiche Interaktionen im Zellkern eingeht und mit hoher Affinität mit bestimmten Kerndomänen assoziiert, und zwar den Nukleoli sowie kleinen Kerndomänen, welche häufig in der Nähe von Cajal-Körperchen und PML-Körperchen zu finden waren. Schließlich wurde ein experimenteller Ansatz etabliert, welcher erlaubt, den Transport vRNP-ähnlicher Komplexe mittels Fluoreszenzdetektion aufzuzeichnen und Einzelpartikelverfolgungsanalysen durchzuführen. Unterschiedliche Phasen des vRNP-Transportes konnten beobachtet werden und ein 3-Phasen-Transportmodell wird skizziert.Influenza A viruses have a segmented single-stranded RNA genome, which is packed in form of viral ribonucleoprotein (vRNP) complexes. While the viral genome is replicated and transcribed in the host cell nucleus, assembly and budding of mature virus particles take place at the apical plasma membrane. Efficient virus formation requires delivery of all viral components to this site. While intrinsic apical targeting signals of the viral transmembrane proteins have been identified, it still remains poorly understood how the viral genome is transported and targeted into progeny virus particles. In this study, potential targeting mechanisms were investigated like the ability of vRNPs to associate with lipid membranes and the intrinsic ability of the viral nucleoprotein (NP) – which is the major protein component of vRNPs – for subcellular targeting. It could be shown that vRNPs are not able to associate with model membranes in vitro, which was demonstrated by flotation of purified vRNPs with liposomes of different lipid compositions. Results indicated, however, that the matrix protein M1 can mediate binding of vRNPs to negatively charged lipid bilayers. Intrinsic subcellular targeting of NP was further investigated by expression of fluorescent NP fusion protein and fluorescence photoactivation, revealing that NP by itself does not target cytoplasmic structures. It was found to interact extensively with the nuclear compartment instead and to target specific nuclear domains with high affinity, in particular nucleoli and small interchromatin domains that frequently localized in close proximity to Cajal bodies and PML bodies. An experimental approach was finally established that allowed monitoring the transport of vRNP-like complexes in living infected cells by fluorescence detection. It was possible to perform single particle tracking and to describe different stages of vRNP transport between the nucleus and the plasma membrane. A model of three-stage transport is suggested.
24
Smith, H. G. „Comparative epidemiology and host : Virus interactions of beet yellow virus and beet mild yellowing virus in sugar beet“. Thesis, University of East Anglia, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374298.
Der volle Inhalt der Quelle
25
Costa, Ana Catarina de Almeida. „Serological surveillance of West Nile virus and molecular diagnostic of West Nile virus, Usutu virus, avian influenza and Newcastle disease virus in wild birds of Portugal“. Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2021. http://hdl.handle.net/10400.5/21604.
Der volle Inhalt der QuelleAnnotation:
Dissertação de Mestrado Integrado em Medicina VeterináriaABSTRACT - The worldwide changes in the environment and climate of natural ecosystems detected in the last few decades have been responsible for the emergence of new infectious diseases in both animals and humans. This work focused on surveillance of four zoonotic pathogens, namely West Nile virus (WNV), Usutu virus (USUV), avian orthoavulavirus-1 (AOaV-1), also known as Newcastle disease virus (NDV), and influenza A virus (IAV) in wild birds of continental Portugal. Blood and tissues samples from both live and dead birds (were collected in three wildlife rehabilitation centres of Portugal between 2018 and 2019: Wildlife Rehabilitation and Research Centre of Ria Formosa, Wildlife Rehabilitation Centre of Lisbon and University of Trás-os-Montes and Alto Douro Veterinary Teaching Hospital – Wildlife Rehabilitation Centre. Samples from a total of 192 animal were collected (82 in vivo and 110 post-mortem). A total of one hundred and eighty-two samples were tested for WNV, USUV, IAV and for AOaV-1 by real time RT-PCR (RT-qPCR) or RT-PCR. AOaV-1 positive samples from two Eurasian collared doves (Streptopelia decaocto) (1.10% sample positivity) collected in the south of Portugal were sequenced, and their phylogenetic relationships analysed. Phylogenetic analysis confirmed that these sequences clustered with other AOaV-1 sequences from genotype XXI, subgenotype XXI.2. Tissue samples were all negative for WNV, USUV and IAV. Plasma samples were also tested for WNV antibodies by seroneutralization test. WNV neutralizing antibodies were detected in ten (13.70%) out of 73 samples namely: four Buteo buteo, two Hieraaetus pennatus, an Accipiter nisus, a Aegypius monachus, a Circaetus gallicus, and a Ciconia ciconia. This study has established a baseline for future epidemiological studies of WNV and AOaV-1 in wild birds of continental Portugal. Further monitoring and epidemiological studies of both diseases in Portugal is advised, considering the threat that both diseases can pose to humans, animals and to the ecosystems themselves.
RESUMO - MONITORIZAÇÃO SEROLÓGICA DO VÍRUS DO NILO OCIDENTAL E DIAGNÓSTICO MOLECULAR DO VÍRUS DO NILO OCIDENTAL, VÍRUS USUTU, INFLUENZA AVIÁRIA E VÍRUS DA DOENÇA DE NEWCASTLE EM AVES SELVAGENS DE PORTUGAL - As profundas alterações ambientais e climáticas dos ecossistemas naturais que o mundo tem sofrido nas últimas décadas têm sido responsáveis pelo aparecimento de novas doenças infeciosas em animais e humanos. Este trabalho focou-se na monitorização de quatro agentes zoonóticos em aves selvagens de Portugal continental, nomeadamente vírus do Nilo Ocidental (WNV), vírus Usutu (USUV), orthoavulavirus-1 aviário, também conhecido como vírus da doença de Newcastle (NDV) e vírus influenza A (IAV). Amostras de sangue e tecidos de animais vivos e mortos foram recolhidas entre 2018 e 2019 em três centros de recuperação de fauna selvagem em Portugal: Centro de Recuperação e Investigação de Animais Selvagens da Ria Formosa, Centro de Recuperação de Animais Silvestres de Lisboa e Centro de Recuperação de Animais Selvagens do Hospital Veterinário da UTAD. Foram recolhidas amostras de um total de 192 animais (82 in vivo e 110 post-mortem). Um total de cento e oitenta e duas amostras foram testadas para a presença de WNV, USUV, IAV e AOaV-1 por RT-PCR em tempo real (RT-qPCR) e RT-PCR convencional. Duas amostras positivas de duas rolas turcas (Streptopelia decaocto) (1.10% positividade) recolhidas no sul de Portugal foram sequenciadas e as suas relações filogenéticas foram analisadas. A análise filogenética confirmou que estas sequências agrupam com estirpes de AOaV-1 do genótipo XXI, subgenótipo XXI.2. Amostras de tecidos foram todas negativas para a presença de WNV, USUV e IAV. Amostras de plasma foram testadas para a presença de anticorpos neutralizantes de WNV pelo teste da seroneutralização. Das 73 amostras, dez (13.70%) apresentavam anticorpos neutralizantes para WNV: quatro Buteo buteo, duas Hieraaetus pennatus, um Accipiter nisus, um Aegypius monachus, uma Circaetus gallicus e uma Ciconia ciconia. Este estudo estabeleceu uma base para futuros estudos epidemiológicos sobre WNV e AOaV-1 em aves selvagens em Portugal continental. Aconselha-se a realização futura de outros estudos epidemiológicos e monitorizações, considerando a ameaça que ambas as doenças apresentam para humanos, animais e para os próprios ecossistemas.
N/A
26
Gao, Zhanhai School of Mathematics UNSW. „Modelling Human Immunodeficiency Virus and Hepatitis C Virus Epidemics in Australia“. Awarded by:University of New South Wales. School of Mathematics, 2001. http://handle.unsw.edu.au/1959.4/18187.
Der volle Inhalt der QuelleAnnotation:
This thesis is concerned with the mathematical modelling for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) epidemics in Australia. There are two parts to this thesis. Part I is aimed at modelling the transmission of HIV and HCV via needle sharing among injecting drug users (IDUs). The dynamical model of an epidemic through needle sharing among IDUs is derived. This model reveals the correlation between needle sharing and the epidemic prevalence among IDUs. The simulations of HIV and HCV prevalence and incidence among IDUs in Australia are made with this model. The comparison of simulated results with literature estimates shows that the modelled results are consistent with the literature estimates. The effects of needle sharing and cleaning on HIV and HCV prevalence and incidence among IDUs in Australia are evaluated. Part II is devoted to modelling the spread of HIV in the general community in Australia. A mathematical model is formulated to assess the epidemiological consequences of injecting drug use and sexual transmission in Australia. The effects of highly active antiretroviral therapies (HAART) on the HIV epidemic are included. The modelled results are in broad agreement with the literature estimates and observed data. The long-term effects of HAART are also discussed.
27
Halasz, Robert. „Epidemiology and clinical importance of GB virus C/hepatitis G virus /“. Stockholm, 2000. http://diss.kib.ki.se/2000/91-628-3997-7/.
Der volle Inhalt der Quelle
28
Law, Mansun. „Vaccinia virus spread : the roles of virus proteins, antibody and complement“. Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365358.
Der volle Inhalt der Quelle
29
Spagnuolo-Weaver, Martha. „Studies on the pathogenesis of bovine virus diarrhoea virus in calves“. Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388078.
Der volle Inhalt der Quelle
30
Sorensen, George Edwin Peter. „Host-virus interactions in porcine reproductive and respiratory syndrome virus infection“. Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/10040.
Der volle Inhalt der QuelleAnnotation:
Porcine reproductive and respiratory syndrome virus (PRRSV) is a rapidly evolving virus that has significant economic and welfare implications for the pig industry. Vaccination strategies have proved largely ineffective in controlling PRRSV, in some cases even reverting to virulence. An increasing body of evidence suggests a host genetic basis for PRRSV resistance so there is a need to examine the role of host genetics in a biologically relevant in vitro cell culture system. However, PRRSV research is inhibited by the current scarcity of suitable in vitro culture systems. With the aim of developing a convenient in vitro model, porcine bone marrow-derived macrophages (BMDM) were evaluated as a PRRSV cell culture system. BMDM were found to be highly permissive to Type I PRRSV and amenable to genetic manipulation. BMDM proved to be excellent cells for virus production, producing significantly higher titres of PRRSV than commonly used alternative cell types. Surprisingly, PRRSV entry into BMDM was found to be independent of both the prototypic PRRSV receptors, CD163 and CD169, providing further evidence for the existence of alternate PRRSV entry mechanisms in primary cell types. To explore the genetics of pig susceptibility to PRRSV, network-based analysis of host transcriptional datasets, following PRRSV challenge, revealed important differences in co-regulated gene pathways between samples from pigs with different PRRSV-permissiveness. These pathways included genes with important, recently characterised, anti-pathogen activities. The incorporation of network-based transcriptional analysis and published genetic variation data led to the identification of a member of the guanlyate binding protein family, GBP-1, as a candidate host gene involved in controlling PRRSV replication. Overexpression of GBP-1 in BMDM revealed a significant anti-PRRSV function for this protein. Further investigation of published genetic variation in GBP-1 suggested a potential role of this gene in PRRSV tolerance. The results presented in this thesis provide evidence for an alternate PRRSV entry pathway in a biologically relevant cell type. The discovery of a highly PRRSV-infectable cell type with potential for genetic manipulation adds a useful new tool to the area of PRRSV research. The identification of GBP-1 as a novel anti-viral protein with a significant inhibitory effect on PRRSV infection, together with genetic variation in this gene, prompts further research into the genetic basis for PRRSV resistance.
31
Colledge, W. H. „Cellular transformation by simian virus 40 and Abelson murine leukaemia virus“. Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38266.
Der volle Inhalt der Quelle
32
Bęczkowski, Paweł. „Virus evolution in the progression of natural feline immunodeficiency virus infection“. Thesis, University of Glasgow, 2013. http://theses.gla.ac.uk/4186/.
Der volle Inhalt der QuelleAnnotation:
Feline immunodeficiency virus (FIV) is an important pathogen of domestic cats which in some cases can lead to feline AIDS. It shares many similarities with its human counterpart and is studied to understand correlates of immune-protection and mechanisms of disease progression in cats, both to improve the welfare of infected cats and as an animal model for the pathogenesis of HIV infection in humans. FIV is believed to evolve during the course of infection as a result of the error prone nature of reverse transcriptase and recombination between viral variants, but relatively little is known about this process in naturally occurring infection. Ultimately, it remains unknown why some infected cats remain healthy while others progress to AIDS rapidly. The studies reported in this thesis addressed this lack of knowledge by examining sequential blood samples obtained during the course of natural FIV infection in a population of 44 privately owned domestic cats. Employing Bayesian coalescent framework, it was demonstrated that the FIV env gene is relatively stable genetically. Although not necessary a prerequisite, this is likely to explain why many naturally infected cats can remain healthy and do not progress to AIDS. By determining the cell tropism of isolated viral variants, it was shown that sick cats were more likely to harbour viruses of the “late” phenotype than healthy animals, similar to the co-receptor switch observed during the progression of HIV infection. Intra-host diversity analyses highlighted a likely role for the leader region of the env gene in viral pathogenesis. Furthermore, recombination was demonstrated to be abundant in natural infection, indicating a requirement for the current phylogenetic classification of FIV to be revised. By assessing the strength and breadth of neutralising antibodies (NAbs), it was shown that NAbs did not appear to influence the course of natural FIV infection, arguing against a role in controlling infection and disease progression. Following an examination of samples collected from a group of privately owned Australian vaccinates, it was shown that the Fel-O-Vax FIV vaccine did not induce cross-reactive neutralising antibodies. Furthermore, in the country where commercial FIV vaccine is licenced, we identified and characterised the virus strain which was likely able to establish infection in vaccinated cat and raised concerns of vaccine’s efficacy. Overall this study broadens our understanding of natural FIV infection, and highlights that much can be learned, not from the similarities but rather by studying the differences between the feline and human lentiviruses. Such comparative studies are likely to contribute to design of highly desirable, safe and fully efficacious lentiviral vaccines.
33
Badge, Joanne Louise. „The molecular characterisation of Narcissus latent virus and Maclura mosaic virus“. Thesis, University of Leicester, 1997. http://hdl.handle.net/2381/35608.
Der volle Inhalt der QuelleAnnotation:
Narcissus latent virus (NLV) and Madura mosaic virus (MacMV) are serologically related. However, they have poor serological relationships with other plant viruses with which they have shared characteristics. Coat protein size, particle shape and structure, mode of vector transmission, cytology and serology proved insufficient to classify them. Molecular techniques were employed in order to create tools for the rapid and accurate classification of plant viruses. A carlavirus-specific PCR primer test failed to amplify NLV or MacMV but confirmed that several other viruses belonged to the carlavirus genus. The nucleotide sequences of part of the nuclear inclusion body (NIb) gene, the complete coat protein gene and the 3' untranslated regions of narcissus latent virus (NLV) and Madura mosaic virus (MacMV) were determined. Deduced amino acid sequences for the Nib and coat protein genes revealed that NLV and MacMV are closely related. Comparison of the NIb sequences with other viruses showed that NLV and MacMV have closer affinities with viruses of the Potyviridae than to those of the carlavirus genus with which they were initially classified. It is proposed that NLV and MacMV may form a new genus within the Potyviridae, the Macluraviruses. The viruses associated with narcissus yellow stripe disease were re-evaluated. In order to identify further members for the new genus a second PCR primer was designed to amplify a region shared by the bymoviruses and macluraviruses. Sequence data obtained for the 3'-terminal region of rice necrosis mosaic virus (RNMV) using a fragment amplified by this primer confirmed that RNMV was a member of the bymovirus genus. MacMV and barley mild mosaic bymovirus replicase sequences were used to transform tobacco plants in an attempt to create transgenic resistance.
34
Gaston, Fabrice. „Développement d’inhibiteurs d’entrée du virus VIH [Virus de l’Immunodéficience Humaine]-1“. Aix-Marseille 1, 2008. http://theses.univ-amu.fr.lama.univ-amu.fr/2008AIX11021.pdf.
Der volle Inhalt der QuelleAnnotation:
La première étape du cycle viral du virus de l’immunodéficience humaine se déroule grâce à l’interaction entre les glycoprotéines d’enveloppe gp120/gp41 et les récepteurs CD4 et CCR5/CXCR4. Les différentes fonctions activées par cette étape, incluant l’attachement, la pénétration et la signalisation cellulaire représentent des cibles potentielles pour le développement d’antirétroviraux. Dans ce travail, nous avons développé des approches permettant d’agir sur chacune de ces étapes à l’aide de peptides synthétiques, d’anticorps anti-peptide et d’inhibiteurs des voies de signalisation. Dans la première approche, nous nous sommes intéressé au développement d’analogues peptidiques de la région HRII en évitant les limitations, incluant courte demi-vie et émergence d’isolats de résistance, rencontrées lors de l’utilisation du peptide T-20 (Fuzeon). Nous avons synthétisé un peptide de 34 acides aminés modélisant la région HRII en incluant des acides aminés non naturels de série D uniquement au niveau de certains sites sensibles à la protéolyse ou dans la totalité de la séquence. Les résultats obtenus montrent que les modifications ponctuelles permettent de : i) maintenir la structure en hélice a du peptide, ii) maintenir sa capacité à interagir avec la région HRI, iii) d’augmenter sa demie-vie et iv) de conserver son activité antivirale. Dans la deuxième approche, nous avons testé la capacité des peptides analogues de la région HRII de VIH-1 et de la boucle V3 de SIV à induire la production d’anticorps neutralisants. Cette étude nous a permis d’aboutir à deux conclusions principales : i) les anticorps anti-HRII peuvent interférer avec l’activité antivirale du peptide administré lors du traitement antiviral, ii) contrairement aux anticorps anti-V3 du VIH-1, les anticorps anti-V3 de SIV sont incapables de neutraliser le virus SIV suggérant des fonctions différentes pour cette région chez HIV-1 et SIV. Dans la troisième partie, nous avons montré que l’attachement du virus VIH sur son récepteur s’accompagne de l’activation de la voie PKC dont l’isoforme PKC-d. L’inhibition de cet isoforme bloque totalement la réplication virale. Ce blocage semble s’opérer en interférant avec les étapes post-entrée du virus en inhibant la formation des pseudopodes et des filaments d’actine, structure nécessaire pour l’étape de la transcription inverse.
35
Pore, Adam. „Studies on Host-Virus interaction for Viral Hemorrhagic Septicemia Virus (VHSv)“. University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1336766667.
Der volle Inhalt der Quelle
36
Chewachong, Godwill Mih. „Engineering Plant Virus " Vaccines" Using Pepino mosaic virus as a Model“. The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1384203201.
Der volle Inhalt der Quelle
37
Cuceanu, Narcisa Manuela. „Structural and genetic analysis of hepatitis G virus/GB virus-C“. Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/22126.
Der volle Inhalt der QuelleAnnotation:
This thesis describes the genetic analysis of the heterogeneity of HGV/GBV-C and the characterization of the terminal regions of the viral genome. The sequence diversity across the HGV/GBV-C genome was significantly lower than that observed with HCV isolates. Comparative analysis of twenty-seven complete genome HGV/GBV-C sequences indicated the presence of four phylogenetic groups and this study demonstrated that these groupings could be reproduced by analysis of the 5'-untranslated region (5'-UTR) and of various sub-fragments. At the same time, the analysis of the 5'-UTR variability indicated the existence of group-specific polymorphisms, many of which are covariant and consistent with the proposed secondary structure of this region. An important difference between the polyproteins of HGV/GBV-C and HCV is the absence of a putative HGV/GBC-C core protein which is usually encoded at the 5'-end of the genome of flaviviruses. The buoyant density of HGV/GBV-C particles in human plasma was estimated to be between 1.07-1.12 g/ml, much lower than that of the other members of Flaviviridae family, except HCV. No HGV/GBV-C RNA was detected in fractions with densities higher than 1.17 g/ml which is expected for virus particles in immune complexes or in fractions with densities higher than 1.21 g/ml, the density range of HCV nucleocapsids. These biophysical properties correlate with the absence of a core-like protein in the genome of HGV/GBV-C isolates from different phylogenetic groups. The absence of the HGV/GBV-C nucleocapsid was also revealed by the sequence analysis data since no conserved open reading frame capable of encoding a core-like protein was identified. Generally, the untranslated regions at the 5' and 3' termini of a RNA virus genome contain regulatory elements important for viral RNA replication, transcription, translation and viral packaging. A comprehensive comparison and analysis of the primary sequence and secondary structure of the 3'-UTR of different HGV/GBV-C isolates allowed the construction of a common secondary structure model for this region and the identification of structural elements that may be involved in viral replication.
38
Magoffin, Danielle E. „Molecular analysis of J-virus and Beilong virus using reverse genetics“. Thesis, Curtin University, 2006. http://hdl.handle.net/20.500.11937/560.
Der volle Inhalt der QuelleAnnotation:
The emergence of viruses in the family Paramyxoviridae, especially those such as Hendra virus and Nipah virus (NiV) that are zoonotic, highlighted the severity of disease that could be caused by infection with viruses belonging to this family. In addition to causing disease outbreaks, several newly discovered paramyxoviruses were found to have unique genetic features, which provoked renewed interest in the study of previously unclassified or uncharacterised viruses in this family. J-virus (JPV) was isolated from wild mice, in Queensland, Australia, in 1972, and has been suggested to be a natural respiratory pathogen of mice. Beilong virus (BeiPV), another paramyxovirus, was first isolated from human mesangial cells in Beijing, China, in 2003, and was subsequently detected in rat mesangial cells. Following initial characterisation, the genomes of JPV and BeiPV were found to contain two genes, SH and TM, not common to other paramyxoviruses, as well as an extended attachment protein gene. BeiPV has the largest genome in the family Paramyxoviridae, which is, in fact, larger than that of any other virus within the order Mononegavirales. The genetic material of paramyxoviruses is not amenable to manipulation via classical genetics; a reverse genetics approach was therefore employed to study the evolution and classification of JPV and BeiPV. Minireplicon systems utilising green fluorescent protein as a reporter were established for JPV, BeiPV and NiV, and were used to better assess the taxonomic status of JPV and BeiPV, and to determine the relationship between these viruses and henipaviruses, which also have exceptionally large genomes. These studies indicate that JPV and BeiPV are closely related and should be classified in the same genus and their replication and transcription machinery is different from that of the henipaviruses.To gain an understanding of the biology of JPV and BeiPV, viral surface proteins from JPV were expressed and evaluated. Chimeric JPV virions containing recombinant surface proteins were generated and electron microscopy was used to determine the localisation of the proteins encoded by those JPV genes which are uncommon in other paramyxoviruses. Analysis of the attachment protein gene of JPV indicated that the virus was able to assemble an exceptionally large protein (156 kDa) into the virion structure, providing evidence in support of the hypothesis that JPV and BeiPV may represent an ancient lineage of viruses within the family Paramyxoviridae. In order to determine tissue tropism of JPV during experimental infection and to aid future work with a full-length JPV infectious clone, a real-time PCR assay for JPV was developed and assessed on tissues collected from mice infected with JPV. A multiplex microsphere assay for JPV and BeiPV was developed and used to analyse the seroprevalence of these viruses in Australian and Malaysian rodents. Although there is currently no evidence for disease caused by JPV or BeiPV, this does not preclude the emergence of a zoonotic rodent paramyxovirus related to these viruses. If this were to occur, the tools for virus detection and serological monitoring are now established.
39
Magoffin, Danielle E. „Molecular analysis of J-virus and Beilong virus using reverse genetics“. Curtin University of Technology. Division of Health Sciences, 2006. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17641.
Der volle Inhalt der QuelleAnnotation:
The emergence of viruses in the family Paramyxoviridae, especially those such as Hendra virus and Nipah virus (NiV) that are zoonotic, highlighted the severity of disease that could be caused by infection with viruses belonging to this family. In addition to causing disease outbreaks, several newly discovered paramyxoviruses were found to have unique genetic features, which provoked renewed interest in the study of previously unclassified or uncharacterised viruses in this family. J-virus (JPV) was isolated from wild mice, in Queensland, Australia, in 1972, and has been suggested to be a natural respiratory pathogen of mice. Beilong virus (BeiPV), another paramyxovirus, was first isolated from human mesangial cells in Beijing, China, in 2003, and was subsequently detected in rat mesangial cells. Following initial characterisation, the genomes of JPV and BeiPV were found to contain two genes, SH and TM, not common to other paramyxoviruses, as well as an extended attachment protein gene. BeiPV has the largest genome in the family Paramyxoviridae, which is, in fact, larger than that of any other virus within the order Mononegavirales. The genetic material of paramyxoviruses is not amenable to manipulation via classical genetics; a reverse genetics approach was therefore employed to study the evolution and classification of JPV and BeiPV. Minireplicon systems utilising green fluorescent protein as a reporter were established for JPV, BeiPV and NiV, and were used to better assess the taxonomic status of JPV and BeiPV, and to determine the relationship between these viruses and henipaviruses, which also have exceptionally large genomes. These studies indicate that JPV and BeiPV are closely related and should be classified in the same genus and their replication and transcription machinery is different from that of the henipaviruses.To gain an understanding of the biology of JPV and BeiPV, viral surface proteins from JPV were expressed and evaluated. Chimeric JPV virions containing recombinant surface proteins were generated and electron microscopy was used to determine the localisation of the proteins encoded by those JPV genes which are uncommon in other paramyxoviruses. Analysis of the attachment protein gene of JPV indicated that the virus was able to assemble an exceptionally large protein (156 kDa) into the virion structure, providing evidence in support of the hypothesis that JPV and BeiPV may represent an ancient lineage of viruses within the family Paramyxoviridae. In order to determine tissue tropism of JPV during experimental infection and to aid future work with a full-length JPV infectious clone, a real-time PCR assay for JPV was developed and assessed on tissues collected from mice infected with JPV. A multiplex microsphere assay for JPV and BeiPV was developed and used to analyse the seroprevalence of these viruses in Australian and Malaysian rodents. Although there is currently no evidence for disease caused by JPV or BeiPV, this does not preclude the emergence of a zoonotic rodent paramyxovirus related to these viruses. If this were to occur, the tools for virus detection and serological monitoring are now established.
40
Jalouli, Jamshid. „Human Papilloma Virus, Epstein-Barr Virus, and Herpes Simplex Virus Type-1 in Oral Squamous Cell Carcinomas from Three Populations“. Doctoral thesis, Uppsala universitet, Käkkirurgi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-128912.
Der volle Inhalt der QuelleAnnotation:
Most oral squamous cell carcinoma (OSCC) is believed to develop via a multistep process of cumulative gene damage in epithelial cells. Increasing incidence of OSCC and evidence that traditional risk factors may not be responsible directed us to investigate the prevalence of virus in pre- and malignant samples.The integration of the DNA from human papillomavirus (HPV), Epstein-Barr virus (EBV), and Herpes simplex (HSV) into the human genome is associated with the expression of oncogenes and the down-regulation of tumor-suppressor genes in OSCC carcinogenesis. This thesis compared samples from India and Sudan, two countries on two continents having a documented high incidence of oral cancer, with specimens from Sweden, with its known low incidence of oral cancer. Each region has, in addition to smoking, a unique non-smoked tobacco habits with documented carcinogenic effects. These countries also typify areas of low and high socioeconomic living conditions with their expected impact on disease development. The study populations were selected from tobacco users and nonusers with OSCC, oral sub-mucous fibrosis (India), oral lichen planus (Sweden), oral leukoplakia with and without dysplasia and snuff-induced lesions (Sweden and Sudan). An expedient method was developed for extracting DNA from old formalin-fixed and paraffin-embedded biopsies. The prevalence of HPV, EBV, and HSV was investigated using PCR/DNA sequencing and southern blot hybridization analysis. We found HPV and EBV to be most prevalent in samples of tissue characterized as normal, with decreasing prevalence in dysplastic and malignant lesions. This intriguing finding that prevalence decreases as neoplastic development proceeds warrants further investigation. Our data do not at first sight support the conclusion that viruses and tobacco use jointly interact with cell mechanisms in the development of oral cancer.
41
Ruiss, Romana. „Induktion Epstein-Barr Virus-spezifischer Immunantworten durch Exosomen und Virus-like Particles“. Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-119153.
Der volle Inhalt der Quelle
42
Wanas, Essam A. „Cloning and expression of the glycoproteins of pichinde virus by vaccinia virus“. Thesis, University of Ottawa (Canada), 1993. http://hdl.handle.net/10393/6489.
Der volle Inhalt der QuelleAnnotation:
Pichinde virus (Pic), like the other arenaviruses, possesses two glycoproteins, GP1 and GP2, that are derived by proteolytic cleavage from a precursor molecule, GPC. Within the arenaviruses, GP1 is the most heterogeneous protein, and GP1 of Pic differs from that of the other arenaviruses in having twice as many potential N-linked glycosylation sites, most of which appear to be utilized. In order to examine the effects of this heavy glycosylation on Pic GP1 structure and inmunogenicity, GPC of Pic was cloned and expressed in vaccinia virus. The recombinant vaccinia (vvGPC) expresses authentic Pic GPC as demonstrated by immunoprecipitation with MAb and several polyclonal anti-Pic sera. GPC expressed in vaccinia is fully glycosylated as it comigrates with Pic GPC. At the same time, sequence analysis of cDNA shows both nucleotide and amino acid changes compared to published sequences for Pic GPC, indicating that variation in the same strain of this virus occurs as virus is passaged in separate laboratories. Experiments to assess the ability of Pic GPC expressed in vaccinia to elicit anti-Pic antibody show that rabbit anti-vvGPC detects authentic Pic GPC and GP1. Site-directed mutagenesis was employed to remove a potential N-linked glycosylation site (aa 181-183) in Pic GPC. Attempts were made to produce recombinant vaccinia, vvGPC-183, harbouring the mutant Pic GPC.
43
Johal, Harpreet Biotechnology & Biomolecular Sciences Faculty of Science UNSW. „The mouse mammary tumour virus - like virus in hormonally influenced human tissues“. Awarded by:University of New South Wales. Biotechnology & Biomolecular Sciences, 2009. http://handle.unsw.edu.au/1959.4/44734.
Der volle Inhalt der QuelleAnnotation:
The identification of Mouse Mammary Tumour Virus (MMTV) as the causal factor for breast cancer in mice, initiated investigation into a viral cause for human breast cancer. MMTV-like virus has been detected in human breast cancers, lymphomas and primary biliary cirrhosis (PBC), suggesting the virus is not restricted to human breast cancers. We hypothesized that the virus is detected in human tissues influenced by steroid hormones. We detected a region of the envelope (env) gene of MMTV-like virus in 53/210 (25%) of liver disease, 4/21 (19%) of hepatocellular carcinoma (HCC), 14/89 (16%) of ovarian cancer, 53/147 (36%) of prostate cancer, 5/50 (10%) of endometrial cancer and 13/141 (9%) of skin cancer samples but not in lung cancers (0/51). Viral env DNA was also detected in 4/81 (5%) of placentae and 5/90 (6%) of breast milk cells from healthy women whilst viral env RNA was detected in 2/90 (2%) of breast milk supernatants and (0/81) placentae. Immunohistochemistry staining for the presence of estrogen receptor alpha (ER-??) and progesterone receptor (PgR) demonstrated a significant association between ER-??/PgR and MMTV-like virus in human ovarian, prostate, endometrial and skin cancers though no significant association was observed between ER-??/PgR and the virus in liver tissues. We were also unable to demonstrate a significant association between accumulation of p53 tumour suppressor protein and MMTV-like virus in liver disease and HCC. Despite the demonstration of viral env integration in genomic DNA from human placentae using Southern Blots, other regions of the virus were not detected following PCR attempts with published primer sets. This study adds to the current knowledge of distribution of MMTV-like virus in humans. The detection of the virus in hormonally influenced human tissues (positive for ER-?? or PgR) indicates an association between MMTV-like virus and steroid hormones in some human tissues. The detection of the virus in placentae and breast milk also suggests potential routes of transmission of the virus in humans. Although the exact role of the virus in these tissues is not known, the presence of the virus together with other genetic alterations and/or the influence of steroid hormones could be involved in the transformation of various human tissues (i.e.pathogenesis).
44
Schupp, Dorothee Carolin [Verfasser]. „Elucidating virus uptake and fusion by single virus tracing / Dorothee Carolin Schupp“. München : Verlag Dr. Hut, 2012. http://d-nb.info/1028783922/34.
Der volle Inhalt der Quelle
45
Samman, Ayman. „The role of virus neutralisation in immunity to feline immunodeficiency virus infection“. Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/1554/.
Der volle Inhalt der QuelleAnnotation:
Feline immunodeficiency virus (FIV) is an important veterinary pathogen with comparative significance because of its similarities to its human counterpart HIV. Since FIV is the only non-primate lentivirus which induces AIDS-like symptoms in its natural host, it serves as a valuable animal model for both prophylactic and therapeutic studies of HIV. It is accepted that the induction of neutralising antibodies (NAbs) is a key element in the control of lentiviral infection, since T-cell based vaccines alone failed to prevent infection in most experimental animal model systems. In this project a robust and reproducible in vitro neutralisation assay was developed and optimised, permitting the assessment of the NAb response in naturally infected cats and with the potential to evaluate candidate vaccines. It was demonstrated that, in general, primary FIV strains in the UK belong to subtype A, and therefore the development of a regional, subtype A-specific, FIV vaccine could be considered for use in the UK. The identification of a neutralisation resistant isolate of FIV led to the finding that a linear neutralisation determinant was located within the V5 region of Env and mutations in this region may lead to immune evasion in vivo. In addition, a second neutralisation determinant was identified in the C3/V4 region of Env. Finally, it was observed that a small proportion of naturally infected cats generated NAbs against FIV. Of these, only a very small proportion of the cats had antibodies with the potential to cross neutralise strains within the same subtype as the homologous isolate. Nonetheless, a plasma sample from a single cat was identified that neutralised all strains tested, including strains from different subtypes and geographical regions. It is likely that studies of the homologous isolate that induced the broad NAb response may be capable of inducing a similar broad response in vaccinated cats. Such a finding would have important implications for the design of potential novel lentiviral immunogens.
46
Watson, J. P. „Hepatitis C virus : studies of the molecular basis of virus/host interaction“. Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319188.
Der volle Inhalt der Quelle
47
Martin, Caroline. „Hepatitis C virus - cell interactions : comparisons of virus and host lipoprotein binding“. Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424130.
Der volle Inhalt der Quelle
48
Green, P. C. „Serological and immunocytochemical studies on influenza virus and influenza virus infected cells“. Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356114.
Der volle Inhalt der Quelle
49
Williams, Cigdem Hayat. „Mutagenesis and virus blocking studies on virus-receptor interactions of Coxsackievirus A9“. Thesis, University of Essex, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390959.
Der volle Inhalt der Quelle
50
Soards, Avril Jacqueline. „The Cucumber mosaic virus 2b protein : influences on the plant-virus interaction“. Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619971.
Der volle Inhalt der Quelle