To see the other types of publications on this topic, follow the link: Retrovirinae.
Dissertations / Theses on the topic 'Retrovirinae'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Retrovirinae.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Lüftenegger, Daniel. "Einfluss posttranslationaler Modifikationen auf die Funktion des Prototyp Foamy Virus Hüllproteins." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1207905094649-72075.
Full textAbstract:
Die Familie der Retrovirinae wird in zwei Unterfamilien untergliedert, die Orthoretrovirinae und die Spumaretrovirinae. Foamyviren stellen aufgrund einiger besonderer Eigenschaften die einzigen Vertreter dieser Unterfamilie, die sie als Bindeglied zwischen den Retroviren und den Hepadnaviren erscheinen lassen. So erfolgt beispielsweise die reverse Transkription des viralen Genoms nicht erst nach Eintritt in die Zielzelle, sondern, anders als bei Orthoretroviren, bereits in der Produzentenzelle noch während oder kurz nach der Morphogenese. Diese Eigenschaft teilen Foamyviren mit den Hepadnaviren ebenso wie die obligate Koexpression der Kapsidproteine mit den viralen Hüllproteinen für die Freisetzung von Viruspartikeln. Im Gegensatz zu Orthoretroviren sind Foamyviren folglich nicht in der Lage virusähnliche Partikel (VLP) zu sekretieren und die spezifische Funktion des PFV Env Proteins kann nicht durch heterologe Hüllproteine übernommen werden. Die Synthese des PFV Env Vorläuferproteins erfolgt am rER, wobei es eine Typ III Membrantopologie erhält, mit sowohl dem N- als auch dem C-Terminus im Zytoplasma. Während des Transports des Proteins zum Ort der Partikelknospung, wird es posttranslational im Golgi-Apparat, oder dem trans-Golgi Netzwerk, durch Furin oder eine Furin-ähnliche Protease in drei partikelassoziierte Untereinheiten prozessiert. Eine Partikelassoziation retroviraler Signalpeptide ist bislang nur für Foamyviren nachgewiesen worden, genauso wie eine essentielle Rolle dieses Proteins bei der Interaktion zwischen dem
2
Lüftenegger, Daniel. "Einfluss posttranslationaler Modifikationen auf die Funktion des Prototyp Foamy Virus Hüllproteins." Doctoral thesis, Technische Universität Dresden, 2007. https://tud.qucosa.de/id/qucosa%3A23754.
Full textAbstract:
Die Familie der Retrovirinae wird in zwei Unterfamilien untergliedert, die Orthoretrovirinae und die Spumaretrovirinae. Foamyviren stellen aufgrund einiger besonderer Eigenschaften die einzigen Vertreter dieser Unterfamilie, die sie als Bindeglied zwischen den Retroviren und den Hepadnaviren erscheinen lassen. So erfolgt beispielsweise die reverse Transkription des viralen Genoms nicht erst nach Eintritt in die Zielzelle, sondern, anders als bei Orthoretroviren, bereits in der Produzentenzelle noch während oder kurz nach der Morphogenese. Diese Eigenschaft teilen Foamyviren mit den Hepadnaviren ebenso wie die obligate Koexpression der Kapsidproteine mit den viralen Hüllproteinen für die Freisetzung von Viruspartikeln. Im Gegensatz zu Orthoretroviren sind Foamyviren folglich nicht in der Lage virusähnliche Partikel (VLP) zu sekretieren und die spezifische Funktion des PFV Env Proteins kann nicht durch heterologe Hüllproteine übernommen werden. Die Synthese des PFV Env Vorläuferproteins erfolgt am rER, wobei es eine Typ III Membrantopologie erhält, mit sowohl dem N- als auch dem C-Terminus im Zytoplasma. Während des Transports des Proteins zum Ort der Partikelknospung, wird es posttranslational im Golgi-Apparat, oder dem trans-Golgi Netzwerk, durch Furin oder eine Furin-ähnliche Protease in drei partikelassoziierte Untereinheiten prozessiert. Eine Partikelassoziation retroviraler Signalpeptide ist bislang nur für Foamyviren nachgewiesen worden, genauso wie eine essentielle Rolle dieses Proteins bei der Interaktion zwischen dem
3
Sowinski, Stefanie. "Transmission and immune surveillance of human T cell-tropic retroviridae." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501764.
Full text
4
Dirks, Clarissa A. "The role of cellular factors in retrovirus replication /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/5072.
Full text
5
Sayah, David. "Retrovirus restriction in primates and the discovery of TRIMCyp /." Saarbrücken : VDM Verlag Dr. Müller, 2008. http://d-nb.info/989322068/04.
Full text
6
Bolinger, Cheryl Giles. "Study of translation control by a RNA helicase A-responsive post-transcriptional control element in Retroviridae." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1226513076.
Full text
7
Olival, Guilherme Sciascia do. "Caracterização clínica e imagiológica de pacientes com esclerose múltipla e associação com retrovírus endógeno da família W." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/99/99131/tde-22012019-140839/.
Full textAbstract:
Introdução: A esclerose múltipla (EM) é uma doença inflamatória autoimune desmielinizante. Diversos estudos evidenciaram a forte associação entre a EM e a expressão do retrovírus endógeno da família W (HERV-W) e do Epstein Barr Vírus (EBV), sem definir seu real papel no desenvolvimento da doença. Objetivo: Investigar a presença de anticorpos anti EBV e a expressão de HERV-W em pacientes com EM e avaliar a correlação entre a atividade clínica e imagiológica da EM com a avaliação quantitativa do HERV-W e EBV. Métodos: Realizamos avaliações clínicas e de ressonância magnética (RM) por 36 meses de 36 pacientes com EM e a comparamos com a análise quantitativa longitudinal do PCR em tempo real do RNA do HERV-W em PBMC e uma análise transversal por ELISA do anti VCA IgG e IgM de EBV. Foram utilizados dois grupos controles sendo o primeiro com 30 indíviduos saudáveis e o segundo com 26 pacientes com outras doenças neurológicas (ODN) para comparação com os títulos de HERV-W e anti- EBV. Resultados: A dosagem do IgG EBV foi estatisticamente maior no grupo EM quando comparado ao grupo controle saudável (p = 0,024) e a expressão de HERV-W foi estatisticamente maior tanto no grupo EM (p = 0,001) como no grupo ODN (p = 0,022) quando comparados com os controles saudáveis nos grupos de pacientes. Nenhuma sorologia IgM do EBV foi positiva. A avaliação longitudinal da expressão relativa do HERV-W não apresentou correlação com nenhum dos parâmetros clínicos ou imagiológicos de avaliação da EM sendo eles: tipo de EM; medicamento em uso; EDSS; taxa anualizada de surtos; novas lesões em T2/FLAIR pela RM; lesões captando gadolíneo pela RM. Conclusão: Existe uma expressão relativa de HERV-W aumentada em pacientes com EM e em ODN quando comparados com controles saudáveis. Os pacientes com EM apresentam valores superiores de anticorpos IgG anti- EBV. Não encontramos nenhuma correlação na avaliação longitudinal entre a atividade clínica e imagiológica de pacientes com EM e a avaliação quantitativa do HERV-W e do anticorpo anti-EBV.Introduction: Multiple sclerosis (MS) is a demyelinating autoimmune inflammatory disease. Several studies have demonstrated the strong association between MS and the expression of endogenous retrovirus W (HERV-W) and Epstein Barr Virus (EBV), without defining its true role in the development of the disease. Objective: To investigate the presence of anti-EBV antibodies and HERV-W expression in MS patients and to evaluate the correlation between the clinical and imaging activity of MS with the quantitative evaluation of HERV-W and EBV. Method: We performed clinical and magnetic resonance imaging (MRI) evaluations for 36 months of 36 MS patients and compared it with the longitudinal quantitative real-time PCR analysis of HERV-W RNA in PBMC and a cross-sectional analysis by anti-VCA IgG and EBV IgM ELISA. Two control groups were used, the first with 30 healthy subjects and the second with 26 patients with other neurological diseases (OND) for comparison with HERV-W and anti-EBV titers. Results: IgG EBV was statistically higher in the MS group when compared to the healthy control group (p = 0.024). HERV-W expression was statistically higher in the MS group (p = 0.001) and the OND group (p = 0.022) when compared to healthy controls. No IgM EBV serology was positive. The longitudinal evaluation of the relative expression of HERV-W did not present any correlation with the clinical or MRI of the MS group following parameters: type of MS; medication in use; EDSS; annualized rate of relapses; new MRI T2/FLAIR lesions; MRI gadolinium enhancing lesions. Conclusion: There is a relative increased HERV-W expression in patients with MS and in OND when compared with healthy controls. Patients with MS have higher values of anti-EBV IgG antibodies. We found no correlation in the longitudinal evaluation between the clinical and imaging.
8
Romano, Camila Malta. "Caracterização e dinâmica evolutiva de retrovírus endógenos da família K (ERV-K) em genomas de primatas." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-29012010-105745/.
Full textAbstract:
Retrovírus endógenos (ERVs) são vírus que infectaram células germinativas e proliferaram no genoma do hospedeiro. A família K está integrada apenas no genoma de primatas do Velho Mundo. Os ERVs promovem alterações estruturais nos genomas hospedeiros, sendo fundamentais para a sua evolução. Esse trabalho teve como objetivo realizar uma investigação da distribuição e dinâmica evolutiva de ERV-K nos diferentes hospedeiros. Foram identificados 58 ERV-K em humanos, 38 em chimpanzés, 35 em orangotangos e 19 em macaco rhesus. Análises filogenéticas evidenciaram dois grupos principais, Grupo O/N, que compreende os provirus mais antigos e os mais recentes, e Grupo I, com provirus com tempo de integração intermediário. A dinâmica de espalhamento de ERV-K diferiu entre os hospedeiros. A fixação e eliminação dos ERV-K é resultado de fatores demográficos e populacionais, como gargalos de garrafa e expansões sofridas ao longo da evolução. Análises de quais provírus são ativos em pacientes com HIV e com cancer demonstrou que distintos ERVs são transativados, sugerindo alguma consequencia biológica para o hospedeiro. Além disso, a atividade dos ERVs não depende exclusivamente do tempo de integração, mas sim da integridade de regiões específicas contidas na LTR.Endogenous retroviruses (ERVs) are remains of ancient viral infection in the germ line cells and subsequent vertical transmission. The K family are integrated only in humans and the Old World monkeys. ERVs play a fundamental role on genome evolution and foster variability. The aim of this work was to investigate their distribution and evolutionary dynamics in primate hosts. We found 55 ERV-K genomes in the human genome, 38 in chimpanzee, 35 in orangutan and 19 in Rhesus monkey. Two main groups were recovered by phylogenetic inference, Group O/N, comprising the newest and the oldest proviruses and, Group I, enclosing those with intermediate integration time. Although the primary integration took place in the ancestral lineage of all primates investigated, their evolutionary dynamic was different among them. I propose that ERV-K dynamics depends on the host demography experienced throughout their evolution. This work also investigated the putative source of proviral transcripts detected in HIV carries and cancer patients. The differential expression found under these conditions suggested a biological role of the ERV-K overexpression. Finally, the results showed that the ERV-K overexpression depends on the integrity of specific promoters in their LTR.
9
Murray, Shannon. "Foamy virus-host interactions /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/4987.
Full text
10
Caleiro, Giovana Santos. "Investigação da presença do retrovírus da Reticuloendoteliose aviária (REV) e do anticorpo IgG do vírus Oeste do Nilo (WNV) em aves." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/99/99131/tde-04092018-090320/.
Full textAbstract:
As aves podem carregar um grande número de patógenos. As aves migratórias, por viajarem longas distâncias, são as principais responsáveis pela disseminação de agentes infecciosos. Entre os agentes, destacam-se os vírus, como por exemplo o retrovírus da Reticuloendoteliose aviária (REV), amplamente distribuído; e o vírus da febre do Oeste do Nilo (WNV), uma virose reemergente, com caráter zoonótico. Os principais sintomas da Reticuloendoteliose aviária incluem anemia, doença de Runting e síndrome não neoplásica aguda. Já o agente etiológico da Febre do Nilo Ocidental, é o Flavivirus West Nile (WNV).. As aves são seus hospedeiros definitivos e os humanos são hospedeiros acidentais, podendo manifestar quadro febril, e em menor porcentagem, meningite e encefalite. Mosquitos dos gêneros Culex e Aedes spp são os principais transmissores do vírus. Ao contrário do REV que não dispõe de evidências de sua circulação no Brasil, há evidências do WNV em aves e equinos e mais recentemente, em humanos. O objetivo desse trabalho foi investigar a presença do REV e do WNV em aves silvestres e de cativeiro da cidade de São Paulo e do Norte do estado do Pará. Sangue, soro e swab de cloaca foram coletados, totalizando mais de 1000 amostras. Através de técnicas moleculares foi possível detectar a presença do REV em 74 amostras (16%), todas do estado do Pará. O sequenciamento parcial dessas amostras e sua filogenia sugeriu que a migração de aves EUA-Brasil possa ter sido a rota utilizada. Através de ELISA anti-IgG de WNV, 4 amostras de São Paulo foram positivas. Apresentamos a primeira evidência do REV no país e sugerimos a presença do WNV no estado de São Paulo.Birds can carry a large number of pathogens. The migratory birds are most responsible for the spread of infectious agents due to long distance travels. Among these pathogens, the most notable are viruses, such as the avian Reticuloendotheliosis retrovirus (REV), widely distributed; and the West Nile virus (WNV), a reemerging zoonotic disease. The main symptoms of avian reticuloendotheliosis include anemia, Runting\'s disease and acute nonneoplastic syndrome. The etiological agent of West Nile fever is Flavivirus West Nile (WNV). Birds are their definitive hosts and humans are accidental hosts, which generaly present febrile symptoms, but at less proportion,, meningitis and encephalitis. Mosquitoes of the genus Culex and Aedes spp are the main vectors of the virus. Differently from the REV that has no evidence of its circulation in Brazil, there is evidence of WNV in birds and horses and more recently in humans. The objective of this work was to investigate the presence of REV and WNV in wild birds and captive birds from the city of São Paulo and Northern from Pará State. Blood, serum and cloacal swab were collected, resulting in more than 1000 samples. Through molecular techniques it was possible to detect the presence of REV in 74 samples (16%), all from the State of Pará. The partial sequencing of these samples and their phylogeny suggested that the migration of US-Brazil may have been the route for the virus entry. Through anti-WNV IgG ELISA, 4 samples from São Paulo were positive. We present the first evidence of REV in the country and suggest the presence of WNV in the state of São Paulo.
11
Nali, Luiz Henrique da Silva. "Perfil da expressão dos retrovírus endógenos humanos da família W em pacientes com esclerose múltipla." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/99/99131/tde-26042018-115451/.
Full textAbstract:
Introdução: A Esclerose Múltipla (EM) é uma doença autoimune desmielinizante que afeta drasticamente a capacidade motora, cognitiva, e sensitiva dos pacientes. Acreditase que o Retrovírus Endógeno Humano da família W (HERV-W) possa ter um papel na patogênese da doença. Assim, o objetivo deste trabalho foi analisar o transcriptoma desses indivíduos, e analisar os loci do HERV-W diferencialmente ativos. Materiais e Métodos: PBMC e soro de pacientes com EM em surto (GS), em condições avançadas (GA) e indivíduos saudáveis (GC) foram coletadas. Amplicons de envelope de HERV-W foram sequenciados em Ion Torrent e o RNAm foi sequenciado na plataforma Illumina HiSeq2500. Além da análise do HERV-W, análises de interação gênica foram feitas e citocinas inflamatórias e quimiocinas foram testadas. Resultados: Foram analisados 23 indivíduos com EM (16 GS e 7 GA) e 36 do GC. Os pacientes com EM apresentam 3x mais expressão de HERV-W do que os indivíduos controle. O sequenciamento de amplicon revelou que os grupos com EM apresentavam mais loci ativos do que o GC. Apesar limitações decorrentes de variações entre corridas, o transcriptoma demonstrou que o HERV-K11 era diferencialmente expresso no GS, e no GA, 19 HERVs estavam diferencialmente expressos. Loci novos e já descritos como ativos em outros estudos foram encontrados no presente trabalho. O perfil de interação gênica do GS demonstrou um caráter inflamatório, confirmados pela dosagem de citocinas, onde IL-6, IL-1?, TNF-?, IFN-? estavam elevadas nos indivíduos do GS. Já os indivíduos do GA apresentavam um perfil não inflamatório com vias de reparo neuronal inativadas. Conclusões: Os pacientes com EM apresentam maior nível de expressão e maior diversidade de expressão de HERV-W do que o GC. Apesar os perfis semelhantes de expressão, há loci diferencialmente expressos dependente do grupo estudado. Os pacientes com EM apresentam perfis distintos de expressão gênica onde os indivíduos GS apresentam um perfil inflamatório e no GA, um perfil neurodegenerativo.Introduction: Multiple Sclerosis (MS) is an autoimmune disease which drastically affects motor, cognitive and sensitive capability of the patients. It seems that Human Endogenous Retrovirus W family (HERV-W) may play a role in MS pathogenesis. Therefore, the aim of this study was to analyze the transcriptome of these individuals and to analyze the HERV-W loci differentially expressed. Materials and Methods: PBMC and serum samples were collected from MS patients in relapsing conditions (GS), MS patients in advanced conditions (GA) and healthy individuals (GC). HERV-W Env amplicon was sequenced in Ion Torrent and mRNA was sequenced in illumina HISeq2500 platform. Besides HERV-W analysis, genic pathways analysis was performed and inflammatory cytokines and chemokines were tested. Results: A total of 23 MS patients (16 from GS and 7 from GA) and 36 from GC were enrolled in the study. MS patients presented 3-fold higher expression than healthy individuals. Amplicon sequencing revealed that MS groups presented more active loci than GC. Despite the limitations due to variations between sequencing runs, the transcriptome revealed that HERV-K11 was differentially expressed in GS, and 19 HERVs were differentially expressed in GA. New HERV-W loci and other loci that were reported as active loci previously are described here. The genic pathway analysis revealed that individuals from GS presented an inflammatory profile, also confirmed by cytokines dosage, where IL-6, IL-1?, TNF-?, IFN-? were significantly higher in GS. In the other hand, individuals from GA presented a non inflammatory profile with neuronal repair pathways inactivated Conclusions: MS patients present higher level and diversity of HERV-W expression than GC. Regardless the similar profile of HERV-W expression in MS groups, there are differentially expressed HERV-W loci depending of each MS group. MS patients present distinct genic expression profile, where GS presented an inflammatory pathway with vascular permeability, whereas GA presented a neurodegenerative profile
12
Boomer, Sarah M. "The evolution of host range and receptor determinants for subgroup B feline leukemia viruses /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/11513.
Full text
13
Sullivan, Timothy A. "Studies of entry, reverse transcription, and regulation of splicing in retroviruses." View the abstract Download the full-text PDF version, 2008. http://etd.utmem.edu/ABSTRACTS/2008-054-Sullivan-index.htm.
Full textAbstract:
Thesis (M.S.)--University of Tennessee Health Science Center, 2008.Title from title page screen (viewed on February 24, 2009). Research advisor: Lorraine M. Albritton Ph.D. Document formatted into pages (vii, 81p. : ill.). Vita. Abstract. Includes bibliographical references (p. 65-74).
14
Santos, Paulo Cesar Costa dos. "Banco de dados inteligente e ferramentas associadas de sequências, mutações e resistências ao antiretrovirais do vírus HIV." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-03032011-091820/.
Full textAbstract:
Os bancos de dados atualizados constituídos a partir de informações dos prontuários de pacientes HIV+ são importantes fontes para a realização de pesquisas clínicas e epidemiológicas de forma rápida e eficiente. A elevada variabilidade do HIV-1, resultado, entre outros fatores, da ausência de mecanismos eficientes de reparo durante os estágios da replicação viral, contribui para a emergência de cepas resistentes aos antiretrovirais. O objetivo deste trabalho é desenvolver e implementar um banco dados inteligente utilizando a Rede Neural Artificial Paraconsistente (RNAP), assentada na Lógica Paraconsistente Anotada, para auxiliar o mapeamento de informações contidas nos diversos formulários a fim de apoiar o mapeamento das informações provenientes dos diferentes registros médicos produzidos. O banco de dados será usado principalmente para apoiar o processo de decisão sobre a prescrição da terapia antiretroviral. Os resultados obtidos durante a pesquisa mostram que a técnica pode se tornar uma ferramenta promissora.Updated databases made from information collected from HIV+ patients are important references to quickly and efficiently design clinical and epidemiologic studies. The high levels of variability of the HIV-1 virus, among other factors, the result of the absence of repair mechanisms during replication, strongly contribute to the establishment of resistance to antiretroviral therapy. The main objective of this study is the design and implementation of an inteligent database using the concept of Paraconsistent Artificial Neural Network (PANN) based on the Paraconsistent Annotated Logic, in order to support the mapping of the information coming from the different medical records produced. The database will be used primarily to support the decision process on the antiretroviral therapy prescription. Results obtained during the research show that the technique may become a promising tool.
15
He, Jin. "Lentiviral vectors mechanisms of transgene silencing and functional characterization of novel genes /." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0006628.
Full textAbstract:
Thesis (Ph.D.)--University of Florida, 2004.Typescript. Title from title page of source document. Document formatted into pages; contains 143 pages. Includes Vita. Includes bibliographical references.
16
Boulton, Victoria J. "An investigation into the effect of myristoylation on the interactions between HIV-1 NEF and cellular proteins." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244253.
Full text
17
OhAinle, Molly. "Adaptive evolution and loss of function of a primate intrinsic immunity gene /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/4986.
Full text
18
Barros, Luciana Rodrigues Carvalho. "Células epiteliais do timo são possível reservatório viral e transmitem o HTLV-1 para linfócitos T CD4." reponame:Repositório Institucional da FIOCRUZ, 2014. https://www.arca.fiocruz.br/handle/icict/13016.
Full textAbstract:
Made available in DSpace on 2016-03-04T13:59:26Z (GMT). No. of bitstreams: 2
luciana_barros_ioc_dout_2014.pdf: 3326577 bytes, checksum: 370ee3d6142f8100a7adc37a80899e9a (MD5)
license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)
Previous issue date: 2016-01-13Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil
O timo é um órgão linfoide primário, sítio do desenvolvimento de células T, provendo fatores críticos e coordenados que induzem e suportam o comprometimento de linhagem, diferenciação e sobrevivência dessas células. A presença das células não-linfóides, principalmente as células epiteliais do timo (TEC) no parênquima tímico promove a migração e diferenciação coordenada dos linfócitos T. Os linfócitos T são o principal alvo do Virus linfotrópico T humano (HTLV-1), agente etiológico da leucemia/linfoma associado ao HTLV-1 (ATL) e de doença que compromete o sistema nervoso/muscular (HAM/TSP). É desconhecida a causa que leva a uma ou outra doença. A resposta imune antiviral mediada por células T é ineficiente nessas patologias. Mesmo que o vírus tenha tropismo pelos linfócitos T, ele é capaz de infectar outros tipos celulares por contato direto entre células ou por partículas virais livres. Linfócitos ativados recirculam pelos órgãos linfoides, incluindo o timo, onde as células epiteliais tímicas (TEC) interagem intimamente com as células recirculantes, promovendo uma possível via de transmição do HTLV-1. No nosso trabalho, observamos que as TECs possuem os receptores para a entrada do vírus (GLUT-1 e Neuropilina-1). Experimentos in vitro mostraram que as TECs podem ser infectadas pelo HTLV-1 por linhagens de linfócitos derivados de pacientes portadores de ATL e de HAM/TSP Essas infecções ocorreram tanto por contato direto entre as células, quanto por sobrenadante contendo partículas virais livres derivadas do sobrenadante dos linfócitos. O vírus pode ser observado após 24 horas e 10 dias de cultivo, quando a maioria das células estava infectada. Através de microscopia eletrônica de transmissão, foram observadas partículas virais brotando de estruturas semelhantes a corpos multivesculares nas TECs. A expressão gênica de citocinas e quimiocinas foram encontradas aumentadas nas TECs logo após contato com o sobrenadante contendo HTLV-1 derivado dos linfócitos. Somado a isso, a expressão gênica de inteferon tipo 1 e genes induzidos por interferon estavam diminuídos. A resposta migratória de linfócitos T CD4+ induzida por TEC HTLV-1+ estava aumentada em relação as TEC não-infectadas. As TEC infectadas são capazes de transmitir a infecção para linfócitos T por contato, alterando a expressão de receptores de quimiocinas e de adesão nos linfócitos T CD4+. Juntos, esses resultados sugerem que as TEC HTLV-1+ infectadas por linfócitos infectados ou por vírus livres, transmitem a infecção para outras TECs e para linfócitos T CD4+, disseminando a infecção
The thymus is a primary lymphoid organ, site of developing T cells, providing a coordinated set of critical factors to induce and support lineage commitment, di fferentiation and survival of these cells. The presence of non - lymphoid cells through the thymic parenchyma serves to provide coordinated migration and differentiation of T lymphocytes. T lymphocytes are the main target of Human T Lymphotropic Virus type 1 (HTLV - 1). This virus is the etiologic agent of HTLV - 1 associated lymphoma and leukemia (ATL) or a disease of muscular/nervous systems (HAM/TSP), but it is unknown what triggers to one or other disease. T - cell mediated immune response against viral protein s is not effective in both diseases. Although the virus has T lymphocyte tropism, it can infect other cells by cell contact and cell - free virus. Activated T lymphocytes circulates around lymphoid organs, including the thymus, where the thymic epithelial ce lls (TEC) strongly interact with recirculating cells, so infected lymphocytes could transmit the virus to TEC. Interestingly, in our work we observed that TEC expresses molecules related to the HTLV - 1 transmission (GLUT - 1, Neuropilin 1). In vitro experimen ts showed that TEC could be infected by cell lineages derived from ATL and HAM/TSP patients. These infections happened from cell contact and by cell - free virus derived from cell supernatants. The virus can be seen after 24h and after 10 days, when most cel ls in the culture were infected. By transmission electron microscopy, virus particles were observed budding from multivesicular bodies like structures in TEC. Cytokines and chemokines were incr eased at mRNA level soon after contact with HTLV - 1 containing supernatant derived from lymphocytes. In addition, type 1 interferon and interferon stimulated genes were decreased in HTLV - 1 infected TEC. Migration response from T CD4 + lymphocytes driven by H TLV - 1 + TEC were increased in relation to non - infected TEC. HTLV - 1 + TEC could transmit the infection to T CD4 + lymphocytes by cell contact, altering some chemokines and adhesion receptors in T CD4 + cells. Altogether, these results suggest that after TEC inf ection by HTLV - 1 via infected lymphocytes and cell - free virus, it is able to contaminate another TEC and transmit the virus to non - infected T lymphocytes, disseminating the infection.
19
Fratini, Paula. "Expressão do vetor retroviral pCLPG medido em receptores de transplante de medula óssea." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-13082009-103143/.
Full textAbstract:
O vetor retroviral é uma ferramenta de transferência gênica largamente utilizada em ensaios de laboratório e em protocolos clínicos. Nosso laboratório desenvolveu um novo vetor, chamado pCLPG, com expressão viral sob comando de p53, um supressor de tumor e um ativador indutível de transcrição, com alvo de estabelecer um vetor com alta expressão. O sistema pCLPG demonstrou um nível de expressão superior ao vetor não modificado em ensaios em cultura de células. Neste projeto, nosso objetivo foi caracterizar a expressão do vetor pCLPG in vivo, utilizando um modelo animal de transdução de células da medula óssea (CMO) do camundongo C57BL/6 seguido por transplante em animais recipientes previamente irradiados para abolir o sistema hematopoiético. Visando observar a expressão sustentada do transgene in vivo, padronizamos o transplante de CMO seriado, transdução do vetor retroviral, realizamos análise do gene repórter eGFP por citometria de fluxo e análise por real time PCR, além da observação de outros tecidos como baço, timo, sangue periférico. Realizamos também analises hematológicas nos animais transplantados para observação de possíveis efeitos adversos relacioanados com a presença do retrovírus. Com estes ensaios não foi observado uma diferença significante entre o desempenho do vetor parental pCLeGFP e o pCLPGeGFP. Tanto o número de células eGFP positivas quanto a expressão do gene repórter diminuíram ao longo do processo de transplante seriado. Expressão foi observada em 3-4%, 2-3% ou 2-3% das celulas recuperadas da medula ossea dos recipientes primários, secundários ou terciários de CMO transduzida com o vetor pCLeGFP, mas não no sangue periférico, timo ou baço. Semelhantemente, células eGFP-positivas (6-7%, 4-4,5% ou 3-3,5%) foram observadas após transplante seriado somente na medula óssea de animais recipientes de CMO transduzida com o vetor pCLPGeGFP. Entretanto, sangue periférico foi recuperado dos recipientes e tratado com 5-asacitidina, proporcionando a indução de expressão de eGFP a partir de ambos os vetores em aproximadamente 4% das células, implicando que o silenciamento viral poderia estar relacionado com processos de metilação. Este estudo demonstrou que as modificações no promotor do vetor pCLPG não foram suficientes para evitar silenciamento de expressão viral no modelo utilizado.The retroviral vector is a widely used gene transfer tool in both laboratory assays and clinical trials. Our laboratory developed a new vector, called pCLPG, with viral expression under the command of p53, a tumor suppressor and inducible activator of transcription, with the aim of establishing a vector with high level expression. The level of expression offered by the pCLPG system was superior to the non-modified vector in cell culture assays. In this project, our objective was to characterize the expression of the pCLPG vector in vivo utilizing an animal model where bone marrow cells (BMC) from C57BL/6 mice are transduced and then transplanted in recipient animals that have been previously irradiated in order to abolish the hematopoietic system. With the aim of observing sustained transgene expression in vivo, we standardized serial BMC transplantation, transduction with retroviral vectors and analyzed the eGFP reporter gene by flow cytometry and real time PCR, and also studied other tissues, such as spleen, thymus and peripheral blood. We also performed hematologic analyses in the transplanted animals in to observe possible adverse events related to the presence of the retrovirus.These assays did not reveal a significant difference between the performances of the parental pCLeGFP vector and pCLPGeGFP. Both the number of eGFP-positive cells and the intensity of reporter gene expression diminished during the serial transplant process. Expression was observed in 3-4%, 2-3% or 2-3% of cells recovered from bone marrow of the primary, secondary or terciary recipients of BMC transduced with the pCLeGFP vector, but not in peripheral blood, thymus or spleen. Similarly, eGFP-positive cells (6-7%, 4-4.5% or 3-3.5%) were observed after serial transplantation only in the bone marrow of animals that received BMC transduced with the pCLPGeGFP vector. However, peripheral blood was recovered from recipients and treated with 5-azacytidine, inducing the expression of eGFP from both vectors in approximately 4% of these cells, implying that viral silencing may have been related with methylation. This study demonstrated that the modifications in the promoter of the pCLPG vector were not sufficient to avoid silencing of viral expression in this model.
20
Leanna, Candice A. "Loss of IkB[alpha]-mediated regulation correlates with increased oncogenicity of mutant c-Rel proteins." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9901255.
Full text
21
Bagalb, Hussein Saeed. "Cellular and molecular biological studies of a retroviral induced lymphoma transmitted via breast milk in a mouse model." Connect to full text in OhioLINK ETD Center, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=mco1225294363.
Full textAbstract:
Thesis (M.S.)--University of Toledo, 2008."In partial fulfillment of the requirements for the degree of Master of Science in Biomedical Sciences." Title from title page of PDF document. Bibliography: pages 82-88, 111-116.
22
Van, Hoeven Neal Scott. "The role of cellular factors in modulation of entry by ovine betaretroviruses and murine gammaretroviruses /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/5102.
Full text
23
Meiering, Christopher David. "The complexity of persistent foamy virus infection /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/11527.
Full text
24
Kabdulov, Timur O. "Mechanisms of retroviral replication." Morgantown, W. Va. : [West Virginia University Libraries], 2001. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=2256.
Full text
25
Barros, Renata Simões. "Ocorrência de anticorpos anti-Toxoplasma gondii associada a fatores de risco em gatos com esporotricose oriundos da região metropolitana do Rio de Janeiro." reponame:Repositório Institucional da FIOCRUZ, 2013. https://www.arca.fiocruz.br/handle/icict/11966.
Full textAbstract:
Made available in DSpace on 2015-10-16T12:52:52Z (GMT). No. of bitstreams: 2
renata_barros_ini_mest_2013.pdf: 649069 bytes, checksum: ccf984958e0979b9f8cb5d6df59ab3fd (MD5)
license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)
Previous issue date: 2015-06-10Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil
A toxoplasmose é uma zoonose causada pelo protozoário Toxoplasma gondii que acomete várias espécies de vertebrados, inclusive o ser humano. Os gatos, assim como os outros felinos, têm papel de suma importância na epidemiologia da infecção, pois são os hospedeiros definitivos do T. gondii. Esse trabalho teve como objetivo determinar a frequência de anticorpos anti-T.gondii associados a fatores de risco e co-infecções em 213 gatos com esporotricose oriundos da região metropolitana do Rio de Janeiro e assistidos no LAPCLIN-DERMZOO, no período de novembro de 2007 a fevereiro de 2011. Esses animais foram acompanhados mensalmente devido ao tratamento para esporotricose, até os seus desfechos clínicos. Foram realizadas sorologias seriadas para toxoplasmose por meio da hemaglutinação indireta (HAI) e pela reação da imunofluorescência indireta (RIFI) e diagnóstico para o feline imunnodeficiency virus (FIV) e o feline leukemia vírus (FeLV) através de um imunoensaio rápido. Dos 213 gatos, 14 (6,6%) apresentaram anticorpos anti-T. gondii na RIFI (IgG) e na HAI. Houve um caso único de soroconversão, no quarto acompanhamento Houve variação de pelo menos dois títulos na IgG-RIFI nos acompanhamentos de dois animais. Apenas um animal (7,1%) apresentou co-infecção de toxoplasmose com o FIV e três animais (21,4%) com o FeLV. Não foi detectada associação entre as variáveis e co-infecções estudadas e a presença de anticorpos anti-T. gondii, porém 78,6% dos gatos com infecção toxoplásmica apresentaram falência terapêutica no tratamento para esporotricose, sendo quatro deles (27,3%) FIV ou FeLV positivos. A frequência da infecção toxoplásmica nos gatos estudados foi baixa, houve uma maior frequência de animais soropositivos para T. gondii entre aqueles que tinham livre acesso a rua, conviviam com outros gatos e possuíam mais de três anos de idade e foi observada 100% de concordância no teste diagnóstico para T. gondii entre a RIFI e a HAI
Toxoplasmosis is a zoonotic disease caused by the Toxoplasma gondii protozoan that affects several species of vertebrates, incl uding human s . Cats, as well as other felines, a re important in the epidemiology of the infection because they are the definite hosts of T . gondii . This study aim ed to determine the frequency of anti - T . gondii antibodies associated with risk factors and coinfections in 213 cats infected with sporotrichosis in the metropolitan Rio de Janeiro and assisted in the LAPCLIN - DERMZOO , in the period of november 2007 to february 2011. These animals were monthly evaluate d due to sporotrichosis treatment until their sporotrichosis treatment outcomes. Serologic series for toxoplasmosis were performed through indirect he magglutination assay (IHA) and indirect fluorescence antibody test (I F A T) , and feline immunodeficiency vi rus (FIV) and feline leukemi a vi rus ( FeLV) diagnose s were made by fast immunoassay. Am ong the 213 studied cats, 14 (6. 6%) showed anti - T. gondii antibodies in the I F A T and in the IHA. There was only one occurrence of seroconversion in the fourth clinical evaluation . There was a variation of at least two titles in the I F A T - IgG in the clinical follow up of two animals. Just one animal (7. 1%) showed coinfection of toxoplasmosis with FIV a nd three animals (21. 4%) with FeLV. The association between variables a nd studied coinfections with the presence of T. gondii antibodies has not been detected, nonetheless 78.6% of the infected cats showed therapeutical failure in the sporotrichosis treatment , and four of them (27. 3%) were FIV or FeLV positive. The frequency of toxoplasmosis infection in the cats was low ; cats that had free access to the street , coexisted with other cats and were older than three years showed a higher rate of T. gondii positivity and a 100% concordance in the diagnostic test for T. gondii between IFAT and IHA was also observed.
26
Michel, Marlène. "Etude des paramètres cellulaires et viraux associés à l'expression rétrovirale (multiple sclerosis associated retrovirus) dans les cultures cellulaires de patients atteints de sclérose en plaques." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10259.
Full textAbstract:
La sclerose en plaques (sep) est une maladie inflammatoire chronique du systeme nerveux central (snc). L'origine de la sep serait multifactorielle : predisposition genetique, auto-immunite et facteurs environnementaux, essentiellement d'origine virale. C'est a cette troisieme composante que nous nous sommes interesses et, plus particulierement a l'hypothese retrovirale. En effet dans notre laboratoire, un retrovirus a ete isole a partir de cellules leptomeningees du liquide cephalo-rachidien d'une patiente atteinte de sep. Or, depuis la mise en evidence de ce retrovirus, les lignees cellulaires productrices (lignees de cellules leptomeningees et de plexus chroroides, lignees b lymphoblastoides immortalisees par le virus d'epstein-barr (ebv)) n'ont pas permis d'obtenir une expression retrovirale continue et suffisante. L'objectif de ce travail est donc d'etudier les parametres cellulaires et viraux associes a l'expression du retrovirus msrv (multiple sclerosis associated retro virus) dans les cultures cellulaires afin d'obtenir une culture productrice et stable. Dans un premier temps, nous avons envisage de limiter la perte des cellules produisant msrv en transfectant avec des genes anti-apoptotiques. Les resultats ont montre que les plasmides n'etaient pas adaptes a nos cellules et que celles-ci ne devaient pas, par ailleurs, avoir subi de nombreux repiquages. Puis, nous nous sommes interesses aux lignees b lymphoblastoides qui presentaient plusieurs avantages : obtention aisee des cellules, nombreux repiquages possibles, co-expression ebv/particules de type retroviral dans des lignees b de patients sep, ebv cofacteur possible de l'expression retrovirale, detection de sequences arn msrv dans le surnageant de culture de patients sep. Nous avons defini des parametres de culture caracteristiques de l'expression retrovirale dans les lignees b de patients sep, visualise l'evolution de chaque parametre et correle les parametres entre eux. Les resultats ont indique que les lignees b lymphoblastoides de patients sep pourraient eventuellement etre utilisees pour une production retrovirale msrv en selectionnant une sous-population cellulaire productrice.
27
Rhodes, Terence D. "High frequencies of HIV-1 recombination and the evolutionary potential of a hybrid retrovirus." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4563.
Full textAbstract:
Thesis (Ph. D.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains vi, 143 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
28
Loiler, Scott A. "In Vitro and in vivo Studies of Murine Polytropic Retrovirus Infections: a Dissertation." eScholarship@UMMS, 2000. https://escholarship.umassmed.edu/gsbs_diss/119.
Full textAbstract:
Murine leukemia viruses (MuLV) are retroviruses that play important roles in the study of oncogenes, integration, transcriptional regulation and gene therapy. Mink cell focus-inducing (MCF) viruses are polytropic MuLVs that by definition infect cells from a wide variety of species. Their ability to infect human cells and their utility as gene therapy vectors were not well characterized. To address this issue, primary and immortalized human cells were tested for their ability to be infected by MCF packaged defective vectors as well as replication competent MCF virus. A new packaging cell line, called MPAC, was created to package defective retroviral vectors in virus particles with envelope proteins derived from a Moloney mink cell focus-inducing (Mo-MCF) virus. The cellular tropism of MPAC-packaged retroviral vectors was the same as replication competent MCF viruses. Testing various established cell lines showed some human cell lines could be infected with MPAC-packaged vectors while others cannot. In addition, I show that some human cells fully support MCF virus replication while others either partially or fully restrict MCF virus replication. This indicates that some human cells express a protein on their surface that acts as a receptor for MCF viruses and allows MCF viral entry. In addition, the human cells that express a receptor for MCF viral entry did not show any further block to viral replication.
An important determinant in the pathogenic phenotype of MCF 247 has been mapped to the enhancer region of the retroviral long terminal repeat (LTR). Recombination of endogenous genetic elements with the 3' portion of envoccurs and incorporates unique LTR sequences. Most strongly pathogenic MCF viruses have a duplication of the enhancer element found in the LTR.
AKR mice are an inbred strain of mice that develop spontaneous T-cell lymphomas between 6 and 12 months of age. 12-25 % of MCF induced early lymphomas of AKR mice show MCF viral integration's near c-myc in an opposite transcriptional orientation. A replication competent MCF virus containing a bacterial amber suppressor tRNA gene (supF) was used to investigate the changes in the enhancer region following injection of MCF containing one enhancer in the LTR. Newborn AKR mice were injected with the supF tagged replication competent virus and observed for signs of leukemia development (ruffled fur, lethargy, and tumor development). When these signs were detected, the animals were sacrificed and DNA was prepared from the isolated tumors. Thirty-one tumors DNA were analyzed for the presence of supF tagged virus and rearrangement of the c-myc locus. Nine supF tagged proviral LTRs integrated near c-myc from four animals were PCR amplified, sequenced, and/or cloned. All of the enhancer elements analyzed were derived from proviruses that integrated in a reverse orientation with respect to c-myc locus. Two of the isolated enhancer elements contained only a few base changes whereas the majority contained duplications of different sizes that encompassed different transcription factor binding sites. The duplicated enhancer regions contained duplications from 82-134 bp in length. One tumor contained a proviral enhancer with only 5 bp changes relative to the injected virus. This suggests that the enhancers need only a few specific base changes relative to the injected virus to accelerate leukemogenesis. The other three tumors contained proviral enhancers with various size duplications and additional transcription factor binding sites. These data suggest that the injected virus is not pathogenic unless the enhancer region is altered. One proviral integration site encompassing a duplicated enhancer region and 139 bp of the c-myc gene locus was PCR amplified, cloned and sequenced. A search of the current transcription factor database (Transfac 3.3) showed no known transcription factor binding site sequences were created at the junction of the enhancer duplications. The common motif of LVb, core NF-1, and GRE transcription factor binding sites, described by Golemis at al (57), was conserved throughout the isolated enhancers. Most of the enhancer elements contained additional NF-кB and/or GRE sites in close proximity to the conserved LVb-core region. These results support the hypothesis that additional NF-кB and/or GRE binding sites cooperatively interact with the conserved GRE-NF-1-LVb-core motif in c-myc induced leukemogenesis. In addition, two unique families of enhancer duplications were identified. The two families contained enhancers isolated from different tumors that displayed sequence homology and transcription factor binding site organization unique to each group.
29
Coronel, Agnès. "Etude de la persistance virale chez les Spumarétrovirus : analyse moléculaire d'une lignée chroniquement infectée et mise en évidence de délétions spécifiques dans les LTRs." Paris 5, 1997. http://www.theses.fr/1997PA05CD03.
Full textAbstract:
Les spumarétrovirus (ou virus foamy) constituent la troisième sous-famille des rétrovirus complexes, à côté des oncovirus et des lentivirus. L'isolat humain HFV (Human Foamy Virus) fut le premier rétrovirus mis en évidence chez l'homme. Les spumarétrovirus sont caractérisés par un fort effet cytopathogène en culture mais semblent non pathogènes chez leurs hôtes naturels, chez lesquels ils induisent des infections à long terme. Afin de mieux cerner les mécanismes de la persistance virale, nous avons analysé l'ADN proviral et l'expression de HFV dans un modèle d'infection persistante que nous avons établi dans la lignée cellulaire Dami d'origine mégacaryocytaire. Nous avons montré que ces lignées chroniques qui ne produisent pas de virus et ne sont pas lysées , ont majoritairement intégré le génome viral dans celui de la cellule hôte. Cette situation contraste avec l'infection aigue͏̈ par HFV, où l' ADN proviral est presque totalement sous forme libre. Nous avons également mis en évidence dans ces lignées la présence de la délétion spécifique dans le transactivateur Bel1, conduisant à l'absence du transactivateur viral indispensable à la réplication du virus. Nous avons montré que la différence majeure entre l'infection lytique et l'infection persistante est l'absence de synthèse des protéines virales structurales. En effet, seule la protéine Bet est exprimée dans les clones Dami chroniques et nos expériences suggèrent qu'elle pourrait être impliquée dans l'établissement et/ou le maintien de la persistance virale. Au cours d'études sur la variabilité des LTRs des spumarétrovirus, nous avons mis en évidence une nouvelle délétion dans la LTR de HFV (nommée " S "), à côté des deux autres formes de LTR déjà décrites (nommées " L " et " M "). Nous avons alors recherché ces différentes formes dans les systèmes en infections virales aigue͏̈s et chroniques, in vivo et in vitro. Nos études ont montré la coexistence au cours d'infections virales aigue͏̈s des trois formes de LTRs alors que les formes délétées sont majoritairement ou exclusivement présentes dans des cas d'infections chroniques aussi bien in vivo que in vitro. Les fonctions promotrices des LTRs ne sont pas altérées par ces délétions, néanmoins, des nuances dans les taux d'activation et les activités basales apparaissent. Nous avons également montré que ces LTRs différaient les unes des autres par des délétions spécifiques bordées par des répétions directes de quelques paires de bases. En nous basant sur des modèles établis antérieurement, nous avons émis l'hypothèse que ces LTRs délétées soient générées à partir de la forme entière par un mécanisme non aléatoire impliquant un saut de la transcriptase inverse facilité par ces séquences répétées. Le rôle de ces délétions et leur possible implication dans l'établissement de la chronicité sont discutés.
30
Alici, Evren. "Therapeutic potential of natural killer cells in multiple myeloma /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-998-X/.
Full text
31
Bru, Thierry. "Les rétrovirus recombinants : un outil pour l'étude de la transcription inverse et de la mobilisation d'ARNs hétérologues." Tours, 2004. http://www.theses.fr/2004TOUR3301.
Full textAbstract:
Les rétrovirus ont été les premiers virus utilisés comme vecteurs en thérapie génique. La conservation de séquences d'origine virale dans les vecteurs est à l'origine de recombinaisons pouvant conduire à l'obtention de virus partiellement réplicatifs. D'autres évènements de recombinaison ont également été mis en évidence lors de la transcription inverse des ARN viraux. Nombre d'études ont montré que la transcriptase inverse pouvait réaliser des sauts intra- ou inter-moléculaires entre 2 ARNs génomiques. Le premier objectif de notre étude a été d'analyser et de quantifier les évènements de sauts inter-moléculaires réalisés par la transcriptase inverse lors de la synthèse de l'ADN proviral. Pour cela, nous avons construit une série de vecteurs rétroviraux défectifs pour leur réplication, ne pouvant réaliser une réaction complète de transcription inverse. Différentes séquences identiques ont été clonées dans les vecteurs complémentaires afin de comparer les fréquences de recombinaison induites par chacune d'entre elles. Nous nous sommes également intéressés au signal d'encapsidation des vecteurs rétroviraux. Nous avons remplacé, au sein d'un provirus recombinant, le par une banque de séquences aléatoires. Ces vecteurs ont été sélectionnés par une technique dérivée du SELEX. Le crible devait sélectionner, par infection, les séquences capables de se substituer efficacement au sauvage. Enfin, certaines études ont montré que l'expression isolée du gène gag dans un vecteur dérivé du Semliki Forest Virus (SFV) permettait d'obtenir de particules ayant recrutées les ARN hétérologues du vecteur SFV. Nous avons tiré profit de cette observation pour promouvoir le recrutement rétroviral d'un vecteur SFV défectif. Nous avons également montré que les réplicons ARN de SFV pouvaient être mobilisés dans des pseudoparticules formées par la seule expression de l'enveloppe du VSVRetroviral vectors have been the first used in clinical gene therapy. The presence of viral sequences in these vectors can promote homologous recombination leading to the formation of fully or partially replicative competent retrovirus. Other recombination events have been identified during the reverse transcription of the viral RNA. Many studies have shown that the reverse transcriptase can realise intra-molecular switches within the RNA template and inter-molecular switches between identical sequences present in copackaged viral RNA. The first aim of our study was to analyse and quantify the events of inter-molecular switches during the proviral DNA synthesis. For that, we designed different couple of retroviral vectors defective for the completion of reverse transcription. Different homologous sequences were cloned in complementary vectors to compare the frequencies of recombination initiated by each sequence. We have realised a second study concerning the MoMLV packaging signal in retroviral vectors. We have replaced, in a recombinant provirus, the by a bank of random sequences. These vectors have been selected by a technique derivated from the SELEX. This approach should have allowed us to select, by infection, all the sequences able to efficiently replaced the wild type. Others studies have shown that the expression of the gag gene in an SFV (Semliki Forest Virus ) vector promoted to the formation of particles mobilising heterologous SFV RNA. We have first tested the mobilisation of SFV RNA within retroviral particles. We have also shown that SFV RNA could be efficiently mobilised in virus-like particles obtained by the expression of VSV glycoprotein alone. Preliminary studies were realised to understand this mechanism of SFV RNA mobilisation
32
Petit, Vincent. "De l'editing par les désaminases APOBEC et ADAR, de puissants mutateurs des acides nucleiques viraux et cellulaires." Paris 7, 2008. http://www.theses.fr/2008PA077214.
Full textAbstract:
Les protéines APOBEC comprennent une grande famille de cytidines désaminases éditant spécifiquement TARN ou l'ADN simple brin. APOBEC-1 agit de manière extrêmement spécifique en éditant un unique résidu dans un ARN messager cellulaire particulier, tandis que les cibles cellulaires des APOBEC-3 n'ont pour l'heure pas été identifiées, bien qu'elles pourraient participer au contrôle des rétrotransposons. Deux des sept membres du groupe APOBEC-3 restreignent l'infection par le VIH-1 in vitro et in vivo. Nous montrons par nos résultats que l'hyperediting des transcrits inverses d'un gammarétrovirus exogène par APOBEC-1 et APOBEC-3 est possible in vitro. APOBEC-1 murine est également capable d'hyperéditer les cytidines dans l'ARN génomique de MLV. Des séquences virales hyperéditées ont été retrouvées in vivo, et l'analyse fine des sites édités suggère que l'editing in vivo est vraisemblablement le fait d'APOBEC-1 plus que d'APOBEC-3 chez la souris. Bien plus, APOBEC-1 murine est capable d'hyperéditer son substrat physiologique, l'ARN messager de l'apolipoprotéine B, et divers ARN hétérologues. Aussi APOBEC-1 murine est-elle un mutateur puissant des ARN et de l'ADN simple brin in vivo, et pourrait occasionner des effets néfastes pour la cellule en cas d'expression au mauvais endroit et/ou au mauvais moment. Nous montrons également que le segment ARN de l'hémagglutinine du virus influenza H1N1 fait l'obje d'hypermutations de type A vers G dues à la protéine ADAR in vivo chez le poulet, et retrouvons de séquences éditées dans les suspensions vaccinales destinées à la vaccination humaine. Il s'agit de I; première description d'un editing du virus influenza par une désaminaseMammalian APOBEC molecules comprise a large family of cytidine deaminases with specificity for RNA and single-stranded DNA. APOBEC-1 s are invariably highly specific and edit a single residue in a cellular mRNA, while the cellular targets for APOBEC-3s are not clearly established, although they may curtail the transposition of some retrotransposons. Two of the seven member human APOBEC-3 enzymes strongly restrict human immunodeficiency virus type 1 in vitro and in vivo. We show here that single-stranded DNA hyperediting of an infectious exogenous gammaretrovirus, the murine leukemia virus (MLV), by murine APOBEC-1 and -3 deaminases occurs -in vitro. Murine APOBEC-1 was able to hyperdeaminate cytidine residues in MLV genomic RNA as well. Analysis of the edited sites shows that the deamination in vivo was due to mouse APOBEC-1 rather than APOBEC-3. Furthermore, murine APOBEC-1 is able fo hyperedit its primary substrate in vivo, the apolipoprotein B mRNA, and a variety of heterologous RNAs. In short, murine APOBEC-1 is a hypermutator of both RNA and single-stranded DNA in vivo, which could exert occasional side-effects upon over-expression. We show that the RNA encoding HA gene of influenza virus can be hyperedited by ADAR in vivo, and we found edited sequences harboring A to G mutations in vaccine preparation for human vaccination purpose as well. This is the first description influenza virus can be targeted by a deaminase
33
Dzik, Carlos. "Resposta imune contra HERV-K em pacientes com câncer de próstata localizado e metastático." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/5/5146/tde-14122017-105022/.
Full textAbstract:
Objetivo: Retrovirus Endógeno Humano (HERV) compreende ao redor de 8% do genoma humano. Apesar do fato de que em sua maioria são genes não-funcionais devido a processos de mutação ou perda de material genético no processo de retrotransposição, existem evidências do aumento da expressão de HERVs em tecido de câncer de próstata. Nós estudamos e comparamos a imunogenicidade de peptídeos da família HERV em 2 coortes de pacientes com câncer de próstata. Posteriormente examinamos o estado de ativação e senescência linfocitária nestas coortes. Desenho Experimental: Células Mononucleares de Sangue Periférico (CMSP) de 65 pacientes com câncer localizado da próstata em situação de hormônio-sensibilidade e de 24 pacientes com câncer de próstata metastático e em situação de resistência à castração, comparados a um grupo controle de 12 indivíduos normais foram avaliados em relação ao seu estado de resposta imune pela técnica de ELISPOT contra um conjunto de peptídeos derivados dos exons gag e env do gene da família HERV-K HML-2. Como parte de nosso estudo, foi realizado de forma preliminar uma análise genômica in silico de 500 pacientes com câncer de próstata sequenciados e disponíveis para análise pública do banco de dados TCGA, com o objetivo de reforçar o racional de nossa interrogação científica. Além disso , como estudo de correlação, fizemos uma análise por citometria de fluxo da ativação celular de linfócitos T de nossas coortes para determinarmos a imunofenotipagem e ontogenia linfocitária em nossos indivíduos investigados, no momento de nossa pesquisa de sua resposta imune. Resultados: Nossa análise da resposta imune contra peptídeos de HERV-K HML-2 por ELISPOT-Interferon Gama não mostrou nenhum resultado significativo. Nenhum paciente apresentou dados significativos de resposta de acordo com nossos critérios, apesar de nossos dados preliminares de expressão gênica terem mostrado expressão gênica em torno de 17% em pacientes com doença localizada. Nossos dados de ativação linfocitária mostraram maior ativação e senescência nos pacientes com doença disseminada e resistente à castração. Conclusões: Este parece ser o primeiro estudo a interrogar a presença de resposta celular imune contra peptídeos de HERV-K em pacientes com câncer de próstata. Nosso achados não mostraram resposta imune relevante em doença localizada ou disseminada e em diferentes estados de ativação linfocitária ou status de integridade hormonal. Apesar destes resultados, pesquisa posterior poderia utilizar diferente metodologia, como por exemplo a utilização de citometria de fluxo bem como a busca de diferentes citoquinas envolvidas, tais como as relacionadas a resposta Th2, ao invés de Th1Purpose: Human Endogenous Retrovirus (HERV) comprises 8% of human genome. Despite the fact that most of it is non-functional due to mutations or loss of genetic material in the process of retrotransposition, there are some evidence of increased expression of HERV in prostate cancer tissue. We studied the cellular immunogenicity of peptides from HERV-K family in 2 cohorts of prostate cancer patients. Experimental Design: PBMCs from 65 patients with hormone-intact localized prostate cancer and 24 patients with castrate-metastatic disease, matched with 12 normal controls were evaluated for cellular immune response by ELLISPOT against a pool of gag and env peptides from HERV-K family of HML-2 type. As an independent supportive study we did in silico genomic analysis of 500 prostate cancer patients from TCGA database to give another evidence of the prevalence of HERV-K gene expression in prostate cancer genome, reinforcing the rational of our questions. Results: Our analysis of cellular immune response against HERV-K HML-2 peptides by Interferon-gama ELISPOT did not show any meaningful results. No patient showed any minimal criteria of response, despite the fact that in our preliminary genomic analysis we obtained HERV expression in about 17% of a cohort of 500 patients with localized prostate cancer. In regards to the flow cytometry data of the lymphocytes we showed stronger activation and senescence status in the cohort of patients with castration sensitive and resistant disseminated disease, compared to the localized disease cohort. Conclusions: To the authors\'s knowledge this is the first study to look for cellular immune response against peptides derived from coding HERV-K transcripts in prostate cancer patients. Our findings did not show relevant immune response in neither localized nor metastatic castrate prostate cancer patients. Despite those results, further research could continue using different methodology, like flow cytometry as well as looking for different cytokines involved, such as those related to a Th2 response, instead of Th1
34
Freimanis, Graham L. "The detection and role of human endogenous retrovirus K (HML-2) in rheumatoid arthritis." Thesis, University of Wolverhampton, 2008. http://hdl.handle.net/2436/41777.
Full textAbstract:
Human endogenous retroviruses are the remnants of ancient retroviral infections present within our genome. These molecular fossils show similarities with present day exogenous retroviruses but act as typical Mendelian elements that are passed vertically between generations. Despite being repeatedly linked to a number of autoimmune diseases and disorders, no conclusive proof has been identified. Rheumatoid arthritis (RA) is one such disease which has been associated with an increase in HERV expression, compared to controls. In order to elucidate a clear role for HERVs in RA pathogenesis, autoantigens implicated in disease pathogenesis were scanned for sequence homology to retroviral genes. Such epitopes would induce antibodies cross reactive with host proteins, resulting in disease. Short peptides mimicking these regions were synthesised and the prevalence of anti-HERV antibodies was determined in RA patients and disease controls. Additionally, a novel real-time Polymerase Chain Reaction (PCR) assay was developed to accurately quantify levels of HERV-K (HML-2) gag expression, relative to normalised levels of housekeeping gene expression. Both serological and molecular assays showed significant increases in HERV-K (HML-2) activity in RA patients compared to disease controls with CD4+ lymphocytes harbouring the highest activity. The real-time assay was also used to determine whether factors within the synovium could modulate HERVs, resulting in their upregulation. Exogenous viral protein expression and pro-inflammatory cytokines were shown to exert a significant modulatory effect over HERV-K (HML-2) transcription. From this data, it is clear that RA patients have increased levels of HERV-K (HML-2) gag activity compared to controls. Despite this it is likely that factors within the synovium such as exogenous viral expression and pro-inflammatory cytokines also influence HERV-K (HML-2) transcription possibly contributing to a role of bystander activation, i.e. being influenced by external factors, rather than actively contributing to disease processes. The exact role of HERVs in RA pathology remains elusive; however this research proposes several mechanisms by which HERV-K (HML-2) may contribute to disease.
35
Cheynier, Rémi. "Electrotransfection de cellules eucaryotes : expression du retrovirus hiv par des cellules lymphoides humaines apres electrotransfection." Paris 6, 1987. http://www.theses.fr/1987PA066046.
Full text
36
Sachdev, Shrikesh. "Autoregulatory feedback control of c-Rel by IkB[alpha] : loss of IkB[alpha]-mediated control over nuclear import and DNA-binding enables oncogenic activation of c-Rel /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9901276.
Full text
37
Bruland, Torunn. "Studies of early retrovirus-host interactions. Viral determinants for pathogenesis and the influence of sex on the susceptibility to Friend murine leukaemia virus infection." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Medicine, 2003. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-534.
Full textAbstract:
The studies in the present thesis sought to define virus and host factors that can influence on the susceptibility to murine retrovirus infection. In addition, we wanted to study possible correlations between events of early infection and subsequent disease progression. For an extensive discussion of the major findings, the reader is referred to papers I-IV. The following section will give a general discussion concerning 1) some methodological aspects; 2) the course of FIS-2 infection; 3) determinants responsible for erythroleukaemia; 4) determinants responsible for immunosuppression; and, 5) does sex matter?
38
Voronin, Yegor A. "Investigation of initiation of reverse transcription in retroviruses using vectors with two primer-binding sites." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=3136.
Full text
39
Law, Wendy. "Characterization of FH3-derived and MC29-derived Gag-Myc fusion proteins : correlation of transcriptional repression and protein stability with cellular transformation /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/5069.
Full text
40
Svarovskaia, Evguenia S. "Structural determinants of murine leukemia virus reverse transcriptase that are important for template switching, fidelity, and drug-resistance." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1538.
Full textAbstract:
Thesis (Ph. D.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains xi, 185 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
41
Lereboulet, Sylvie Canton Philippe. "Le complexe démentiel du sida à l'ère des traitements antirétroviraux hautement actifs." [S.l] : [s.n], 2004. http://www.scd.uhp-nancy.fr/docnum/SCDMED_T_2004_LEREBOULET_SYLVIE.pdf.
Full text
42
Prats, Anne-Catherine. "Etude de l'expression genetique et de la constitution des particules virales infectieuses chez le retrovirus murin mulv." Toulouse 3, 1988. http://www.theses.fr/1988TOU30172.
Full text
43
Gaudray, Gilles. "Implication de l'hétérodimérisation de CREB-2 dans la régulation de la transcription du génome du virus de la leucémie T humaine de type-I, HTLV-I." Montpellier 1, 2003. http://www.theses.fr/2003MON1T010.
Full textAbstract:
LES FACTEURS DE TRANSCRIPTION DE TYPE bZIP, QUI COMPORTENT UN DOMAINE BASIQUE EN AMONT D'UNE STRUCTURE EN LEUCINE ZIPPER, SONT DES PROTEINES LARGEMENT REPANDUES DANS LES CELLULES EUCARYOTES. CES PROTEINES SONT IMPLIQUEES DANS LE CONTROLE DE LA TRANSCRIPTION CELLULAIRE. LORS DE LEUR EVOLUTION, LES VIRUS ONT DEVELOPPE DES PROTEINES PARTICULIERES DONT LE ROLE EST DE DETOURNER CES FACTEURS bZIP DE LEUR FONCTION, AU PROFIT DU CYCLE VIRAL. PARMI CES PROTEINES VIRALES, LA PROTEINE TAX DU VIRUS DE LA LEUCEMIE T HUMAINE DE TYPE I (HTLV-I) NE SE POSITIONNE PAS DIRECTEMENT SUR L'ADN. DES ETUDES RECENTES ONT MONTRE QUE TAX RECRUTAIT EN PARTICULIER LE FACTEUR bZIP CELLULAIRE CREB-2 AU NIVEAU DU PROMOTEUR VIRAL. OR, CREB-2, DANS UNE CELLULE SAINE, EST PLUTOT CONNU POUR S'HETERODIMERISER. LORS DE NOTRE ETUDE, NOUS AVONS CARACTERISE UN NOUVEAU FACTEUR bZIP, HBZ (HTLV-I bZIP FACTOR), CODE PAR LE BRIN COMPLEMENTAIRE DU GENOME DU HTLV-I. NOUS AVONS MONTRE QUE HBZ ET LE FACTEUR bZIP CELLULAIRE CHOP DIMERISENT TOUS LES DEUX AVEC CREB-2. CETTE DIMERISATION A POUR EFFET DE REPRIMER LA TRANSCRIPTION VIRALE, EN EMPECHANT CREB-2 DE SE POSITIONNER AU NIVEAU DU LTR (LONG TERMINAL REPEAT) DU HTLV-I. NOTRE ETUDE A EGALEMENT MONTRE QUE C/EBPß REPRIME LA TRANSCRIPTION VIRALE DEPENDANTE DE TAX, EN EMPECHANT, PAR INTERACTION DIRECTE, TAX DE SE POSITIONNER AU NIVEAU DU LTR VIRAL. IL SEMBLE QUE L'HETERODIMERISATION DE CREB-2 SOIT UN MOYEN EFFICACE DE CONTROLER LA TRANSCRIPTION VIRALE. CELA POURRAIT PERMETTRE DE COMPRENDRE LA PHASE DE LATENCE DU HTLV-I.
44
HERMES, Renata Bezerra. "Investigação dos polimorfismos nos genes FAS e FASL em indivíduos infectados pelo Vírus da imunodeficiência humana-1 (HIV-1)." Universidade Federal do Pará, 2009. http://repositorio.ufpa.br/jspui/handle/2011/4859.
Full textAbstract:
Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-11T16:43:01Z
No. of bitstreams: 2
license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
Dissertacao_InvestigacaoPolimorfismosGenes.pdf: 2189382 bytes, checksum: c2c98617b43c03be9d1706ad6571449a (MD5)Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-04-03T15:40:43Z (GMT) No. of bitstreams: 2 Dissertacao_InvestigacaoPolimorfismosGenes.pdf: 2189382 bytes, checksum: c2c98617b43c03be9d1706ad6571449a (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
Made available in DSpace on 2014-04-03T15:40:43Z (GMT). No. of bitstreams: 2 Dissertacao_InvestigacaoPolimorfismosGenes.pdf: 2189382 bytes, checksum: c2c98617b43c03be9d1706ad6571449a (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2009
No presente estudo foram investigadas as freqüências dos polimorfismos nos genes FAS e FASL em um grupo de 198 indivíduos soropositivos para o HIV-1 e 191 indivíduos controles soronegativos, com o objetivo de avaliar a ocorrência de uma possível associação entre os polimorfismos nestes genes e a infecção pelo HIV-1. A identificação dos alelos A e G do polimorfismo -670 FAS foi realizada por meio da técnica de PCR, utilizando seqüências de iniciadores específicos e posterior digestão enzimática (RFLP) com a enzima MvaI. A identificação dos alelos A e G do polimorfismo -124 FASL, bem como T e delT do polimorfismo -169 FASL foi realizada através da técnica de ACRS, seguido de RFLP com as endonucleases de restrição FokI e HincII, respectivamente. As análises das freqüências alélicas e genotípicas dos polimorfismos analisados não mostraram qualquer diferença significativa entre soropositivos e soronegativos. A análise da quantificação dos linfócitos T CD4+ entre os portadores dos diferentes genótipos do polimorfismo -670 FAS revelou uma associação significativa, sugerindo que o estado de portador do alelo G, em homo ou heterozigose, nos indivíduos infectados pelo HIV-1 pode ser um fator de proteção à depleção destas células no curso da infecção pelo HIV-1. As associações entre o número de linfócitos TCD8+, a carga viral plasmática e os polimorfismos analisados não foram estatisticamente significantes. Desse modo, pode-se sugerir, que o polimorfismo -670 do gene FAS, influencie na apoptose dos linfócitos T CD4+ no curso da infecção pelo HIV-1, assim, faz-se necessário estudos adicionais visando confirmar ou não esta associação, uma vez que a identificação desse polimorfismo pode ser, no futuro, uma importante ferramenta a ser utilizada no acompanhamento da infecção.
The present study investigated the frequency of the polymorphisms in the FAS and FASL gene in a sample of 198 HIV-1 seropositives individuals and 191 healthy control individuals, in order to evaluate the occurrence of a possible association between the polymorphisms and HIV-1 infection. The A and G alleles identification of the -670 FAS polymorphism was performed through a PCR followed by restriction endonucleases analyses (RFLP), with the enzyme MvaI. The identification of A and G alleles of -124 FASL polymorphism, T and delT of the -169 FASL polymorphism was performed using ACRS assay, followed by RFLP with the restriction endonucleases FokI and HincII, respectively. The analysis of allele and genotype frequencies of polymorphisms examined did not show any differences between seropositives and seronegatives individuals. The analysis of the quantification of CD4+ T lymphocytes from individuals with different genotypes of -670 FAS polymorphism showed a significant association, suggesting that the state of carrier of the G allele in homo or heterozygosity in HIV-1 individuals infected may be a protection factor from depletion of these cells in the course of HIV-1 infection. Associations between the FAS and FASL genes polymorphisms and the number of CD8+ T-cells and plasma viral load were not statistically significant. These findings suggest that the -670 FAS gene polymorphism, influences the apoptosis of CD4+ T lymphocytes in the course of HIV-1 infection, thus it is necessary further studies to confirm or not this association since that the identification of this polymorphism may be in the future, an important tool to be used in monitoring the infection.
45
Gachon, Frédéric. "Régulation de la transcription par l'oncoprotéine Tax de HTLV-I." Montpellier 1, 2001. http://www.theses.fr/2001MON1T007.
Full textAbstract:
Les virus ont developpe au cours de leur evolution differentes strategies permettant d'utiliser les fonctions de leur cellule hote dans le but de permettre leur replication. Cependant, ce detournement des fonctions cellulaires de l'hote entraine une levee des systemes de regulation pouvant conduire a la transformation de la cellule. C'est la principale raison de l'effet oncogenique des virus. Htlv-i (human t-cell leukemia virus type i) est un bon representant de ces virus utilisant la machinerie cellulaire pour permettre sa propre replication. Cette fonction est principalement due a sa proteine transactivatrice tax. Au cours de mes recherches il a ete mis en evidence l'interaction entre tax et le facteur de transcription cellulaire creb-2. [. . . ] ce mecanisme fait intervenir d'autres facteurs cellulaires comme l'acetyltransferase cbp (creb binding protein) et pourrait egalement permettre a tax d'activer de facon anarchique l'expression de genes cellulaires regules par creb-2. Enfin, la capacite de creb-2 a former des heterodimeres avec d'autres proteines de type bzip peut reguler cette activation par tax puisqu'il semble que seul l'homodimere de creb-2 puisse activer la transcription en cooperation avec tax. Cette etude a donc permis de caracteriser les mecanismes utilises par tax pour reguler la transcription par l'intermediaire de creb-2, et ainsi de contribuer a la comprehension du mecanisme conduisant au potentiel oncogenique de htlv-i.
46
Souyri-Caporale, Michèle. "Etude du pouvoir tumorigene de l'oncogene n-ras." Paris 7, 1987. http://www.theses.fr/1987PA077083.
Full text
47
Fitzgerald, Amanda Ann. "Folding and Assembly of Multimeric Proteins: Dimeric HIV-1 Protease and a Trimeric Coiled Coil Component of a Complex Hemoglobin Scaffold: A Dissertation." eScholarship@UMMS, 2007. https://escholarship.umassmed.edu/gsbs_diss/341.
Full textAbstract:
Knowledge of how a polypeptide folds from a space-filling random coil into a biologically-functional, three-dimensional structure has been the essence of the protein folding problem. Though mechanistic details of DNA transcription and RNA translation are well understood, a specific code by which the primary structure dictates the acquisition of secondary, tertiary, and quarternary structure remains unknown. However, the demonstrated reversibility of in vitroprotein folding allows for a thermodynamic analysis of the folding reaction. By probing both the equilibrium and kinetics of protein folding, a protein folding mechanism can be postulated. Over the past 40 years, folding mechanisms have been determined for many proteins; however, a generalized folding code is far from clear. Furthermore, most protein folding studies have focused on monomeric proteins even though a majority of biological processes function via the association of multiple subunits. Consequently, a complete understanding of the acquisition of quarternary protein structure is essential for applying the basic principles of protein folding to biology.
The studies presented in this dissertation examined the folding and assembly of two very different multimeric proteins. Underlying both of these investigations is the need for a combined analysis of a repertoire of approaches to dissect the folding mechanism for multimeric proteins. Chapter II elucidates the detailed folding energy landscape of HIV-1 protease, a dimeric protein containing β-barrel subunits. The folding of this viral enzyme exhibited a sequential three-step pathway, involving the rate-limiting formation of a monomeric intermediate. The energetics determined from this analysis and their applications to HIV-1 function are discussed. In contrast, Chapter III illustrates the association of a coiled coil component of L. terrestriserythrocruorin. This extracellular hemoglobin consists of a complex scaffold of linker chains with a central ring of interdigitating coiled coils. Allostery is maintained by twelve dodecameric hemoglobin subunits that dock upon this scaffold. Modest association was observed for this coiled coil, and the implications of this fragment to linker assembly are addressed.
These studies depict the complexity of multimeric folding reactions. Chapter II demonstrates that a detailed energy landscape of a dimeric protein can be determined by combining traditional equilibrium and kinetic approaches with information from a global analysis of kinetics and a monomer construct. Chapter III indicates that fragmentation of large complexes can show the contributions of separate domains to hierarchical organization. As a whole, this dissertation highlights the importance of pursuing mulitmeric protein folding studies and the implications of these folding mechanisms to biological function.
48
Godoy, José Luiz de. "Régénération hépatique et transfert de gènes." Paris 5, 1999. http://www.theses.fr/1999PA05CD04.
Full textAbstract:
Le transfert de gène dans le foie pourrait représenter une alternative à la transplantation hépatique pour traiter certaines maladies métaboliques. Plusieurs vecteurs ont été décrits pour réaliser un transfert de gène, notamment des vecteurs rétroviraux dont l'intégration à l'ADN chromosomique permettrait une expression stable à long terme du transgène. L'intégration du vecteur rétroviral dans le génome des cellules n'est possible qu'au cours de la mitose. Par conséquent, ces vecteurs doivent être administrés au cours de la régénération hépatique induite, par exemple, par une hépatectomie partielle. Un autre obstacle qui doit être surmonté correspond au risque de dissémination extra-hépatique de ces vecteurs en particulier au niveau de cellules germinales, ce qui risquerait de modifier le patrimoine génétique constitutionnel de la descendance. Nous avons développé dans ce travail 3 axes de recherche concernant la régénération hépatique et le transfert de gène par vecteurs rétroviraux. Dans le premier, nous avons montré que la régénération hépatique ex vivo dans le système de foie isolé-perfusé en normothermie se développe de façon similaire à la régénération in vivo chez le rat, et que les foies perfusés ex vivo peuvent être transplantés avec succès. Dans le deuxième, nous avons montré que la perfusion de vecteurs rétroviraux par le tractus biliaire d'un foie de rat en régénération permettait une transduction très efficace des hépatocytes jusqu'à 59 ± 24%. Dans le troisième travail, nous avons cherché à éviter l'étape de perfusion ex vivo et à éviter le risque de dissémination systémique des vecteurs rétroviraux ; nous avons donc développé un système de perfusion in vivo-in situ du foie du rat en régénération, le foie étant exclu temporairement de la circulation splanchnique pendant la perfusion des vecteurs. Le taux moyen de transduction des hépatocytes était de 34 ± 19%. Ce modèle pourrait être compatible en terme d'efficacité et de sécurité avec la perspective d'une application clinique du transfert de gène.
49
Gollan, Timothy J. "Altering the Tropism of Retroviral Vectors For In Vivo Gene Therapy: Pseudotyped Virus Targeting by Ligand-Receptor Interactions: A Dissertation." eScholarship@UMMS, 2002. http://escholarship.umassmed.edu/gsbs_diss/226.
Full textAbstract:
A potential approach to in vivo gene therapy is to target retrovirus to specific receptors through a ligand-receptor interaction. Previous studies have placed a ligand at or close to the N-terminus of the ecotropic Moloney murine leukemia virus envelope and require co-expression of a wild type envelope on the pseudotyped virus for successful transduction of human cells. In this study, over forty chimeric envelopes were generated, which have single or multiple insertions of a 13 or 21 amino acid RGD containing sequence, flanked by cysteine residues, that target the cellular integrin receptors (Chapter III). Virus displaying only the chimeric envelopes was generated from packaging cell lines that express the gag and pol genes. Many of the mutant envelopes demonstrated the formation of syncytia when they were transfected into the XC indicator cell line, which is frequently used to determine envelope binding and fusion capabilities. Pseudotyped virus for several of the chimeric envelopes, transduced both NIH 3T3 mouse fibroblasts and human A375 melanoma cells. Ligands placed in the N-terminal region, within the VRA variable domain, and close to the N-terminus of the proline-rich region (PRR), demonstrated transduction into human melanoma cells. Ligands placed within the PRR and the C-terminus of the envelope did not demonstrate transduction into melanoma cells, although host cell transduction was demonstrated. Pseudotyped virus expressing an RGE containing target sequence, replacing the RGD sequence, had significantly lower transduction efficiency of melanoma cells. These data indicate that the MLV envelope tropism can be altered by insertion of short ligands at various locations throughout the envelope.
These initial results were promising and helped to define regions within the envelope that could accommodate the insertion of small targeting ligands, that could redirect the tropism of pseudo typed virus to human cells. In the second part of this study, the focus shifted to targeting receptors that were expressed on specific cells, such as carcinoma cells. We inserted short ligands, flanked with cysteines, into the envelope to generate numerous targeting constructs that bind to receptors over-expressed on a variety of carcinoma cells. These pseudotyped retroviral vectors were generated by packaging cell lines that express only the viral Gag and Pol genes, with no wild-type envelope present. Select chimeric envelopes that express the 21 amino acid bombesin (BN)/gastrin releasing protein (GRP) binding sequence successfully transduced human melanoma cells, breast cancer cells, and cells that express the cloned GRP receptor gene. Nine additional chimeric envelopes were generated, that express a modified 56 amino acid heregulin sequence (HRG), that targets c-rbB-3 (Her-3) and c-erbB-4 (Her-4) receptors on breast carcinoma cells. Pseudotyped virus expressing only the BN/GRP mutant envelopes, transduced NIH 3T3 host cells, and two human carcinoma cell lines; A375 melanoma and MDA-MB-231 breast cells. The HRG chimeric envelopes demonstrated transduction of NIH 3T3 cells and human MDA-MB-453 breast carcinoma cells. Finally, a pseudotyped virus that expressed the chimeric BN/GRP envelopes and packaged the thymidine kinase gene, transduced melenoma and breast carcinoma cells and demonstrated ganciclovir cytotoxicity. Collectively, these data indicate that ligands of various sizes can be used to target pseudotyped virus to a variety of human cancer cells and transfer genes of interest. These findings may expand the feasibility and potential scope of gene therapy.
50
SOUZA, Ranilda Gama de. "Perfil nutricional de portadores do HIV e ou AIDS e sua correlação com a TARV, na cidade de Belém, Pará, Brasil." Universidade Federal do Pará, 2009. http://repositorio.ufpa.br/jspui/handle/2011/4850.
Full textAbstract:
Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-12T13:44:18Z
No. of bitstreams: 2
license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
Dissertacao_PerfilNutricionalPortadoresHiv.pdf: 656593 bytes, checksum: c3122ef5d4a4f56f507c6403371aa19a (MD5)Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-04-01T13:58:30Z (GMT) No. of bitstreams: 2 Dissertacao_PerfilNutricionalPortadoresHiv.pdf: 656593 bytes, checksum: c3122ef5d4a4f56f507c6403371aa19a (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5)
Made available in DSpace on 2014-04-01T13:58:30Z (GMT). No. of bitstreams: 2 Dissertacao_PerfilNutricionalPortadoresHiv.pdf: 656593 bytes, checksum: c3122ef5d4a4f56f507c6403371aa19a (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2009
A estimativa de pessoas vivendo com HIV-1 no Brasil, até junho de 2008, é de 432.890 casos, sendo que 3% destes residem na região Norte. O presente trabalho teve como objetivo descrever o perfil nutricional de portadores do HIV-1 no Estado do Pará e sua correlação com fatores da dieta usual, aspectos demográficos, sociais e laboratoriais que possam estar influenciando a sua qualidade de vida. O grupo populacional constou de 58 indivíduos, atendidos na Unidade de Referência Especializada em Doenças Infecciosas e Parasitárias Especiais (URE-DIPE) e avaliados longitudinalmente (19 meses). Houve predominância do sexo masculino, na faixa etária entre 20 e 50 anos e com escolaridade menor que 8 anos. O perfil antropométrico da maioria, com relação ao peso corporal (% peso atual, % peso usual e IMC) mostrou eutrofia, porém quando avaliadas as reservas de gordura (prega cutânea triciptal, PCT) e proteínas (circunferência braquial, CB e circunferência muscular braquial, CMB), a maioria mostrou desnutrição. A contagem de linfócitos T CD4+ foi maior do que 350 células/mm³ e a carga viral, menor do que 10.000 cópias/mL. Níveis de colesterol total, LDL-colesterol, triglicerídeos, glicemia, ferro sérico e hemograma encontravam-se dentro dos padrões de referência, mas não o de HDL-colesterol. A correlaçãodos resultados laboratoriais com o estado nutricional mostrou significância estatística em pelo menos uma variável antropométrica (CMB), a exceção da contagem de linfócitos T CD4+ e triglicerídeos. O uso da TARV foi observado em 83% do grupo, no entanto, não houve correlação com o perfil nutricional. A dieta usual mostrou equilíbrio qualitativo (normoproteica, normoglicídica e normolipídica), porém insuficiente quantitativamente (hipocalórica). A correlação entre a alimentação utilizada e o perfil nutricional mostrou diferença estatística apenas quando associada ao consumo de proteínas e carboidratos.
There are approximately 432,890 persons in Brazil (reported until June 2008) infectedwith HIV-1 and 3% of them are located in the North region of the country. The present work intended to describe the nutritional profile of HIV-1 infected persons in the State of Para and its correlation with dietary habits, demographic, social and laboratory variables influencing their life quality. The group included 58 individuals, attending the State Reference Unit for Infectious Diseases (URE-DIPE), and was followed for 19 months. There was a predominance of males, aged 20 to 50 years old, with less than 8 school years. The anthropometrical profile of the majority in relation to body weight (% of the current weight, % of usual weight and body mass index) showed a majority of eutrophic individuals, but lipid reserves (triceps skinfold thickness, TST) and protein reserves (arm circumference, AC, and arm muscle circumference, AMC) showed undernourishment. Counts of T CD4+ lymphocytes were greater than 350 cells/mL and plasma viral loads were lower than 10,000 copies/mL. Blood measurements of lipids (cholesterol, LDL, HDL and triglycerides), glucose, iron, red blood cell counts, white bood cell counts, hemoglobin and hematocrit were within reference values, except for HDL-cholesterol. Nutritional status correlated most of the time, with laboratory results when considering arm muscle circumference (AMC), except for T CD4+ lymphocyte counts and triglycerides. Most of the persons (83%) were currently undergoing ARVT, but no statistical correlation was associated to their nutritional profile. The nutritional assessment indicated that the group was placed as normal in relation to protein, carbohydrate and lipid intake, but quantitatively insufficient (hypocaloric). The correlation between food intake and nutritional profile did not show statistical significance, except when associated to the consumption of proteins and carbohydrates.