Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-01-05T12:06:12Z No. of bitstreams: 1 TeseLCS.pdf: 1420745 bytes, checksum: 4dd4fbff68d9aa7235de8b5f959ba86d (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-16T12:39:26Z (GMT) No. of bitstreams: 1 TeseLCS.pdf: 1420745 bytes, checksum: 4dd4fbff68d9aa7235de8b5f959ba86d (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-16T12:39:35Z (GMT) No. of bitstreams: 1 TeseLCS.pdf: 1420745 bytes, checksum: 4dd4fbff68d9aa7235de8b5f959ba86d (MD5) / Made available in DSpace on 2017-01-16T12:39:43Z (GMT). No. of bitstreams: 1 TeseLCS.pdf: 1420745 bytes, checksum: 4dd4fbff68d9aa7235de8b5f959ba86d (MD5) Previous issue date: 2016-07-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Viral hepatitis is a major public health problem worldwide and in Brazil. They are notifiable diseases and according to estimates, billions of people have had contact with the hepatitis and millions are chronic carriers. Infection with hepatitis C virus (VHC) is a major problem worldwide public health due to the high rate of progression to chronicity, the evolutionary potential for cirrhosis and hepatocellular carcinoma, major complications leading to death. In general it can be said that in the last decade there have been major advances in the diagnosis of hepatitis C. In this period there was progressive improvement in sensitivity and specificity of the tests used to detect antibodies against the VHC virus. However, it is necessary that more accurate tests are developed. Thus, considering that the concern for the detection of hepatitis C increases every day, especially in blood banks; the diagnostic methods of this infection are of great clinical relevance and may be used as markers chronicity and indicative of therapeutic efficacy. Therefore, this work proposed to evaluate the connection and recognition of anti-VHC antibody positive and positive genotyped samples in patients with hepatitis C through the standardization of procedures and solutions used in qualitative ELISA. There was the process of awareness of microplates with recombinant chimeric protein, made the analysis of sensitivity, specificity, reproducibility and validity of the method. We obtained from ELISA assays with standardized recombinant proteins a protocol able to have a good performance of the main components of the reaction, and antigens conjugated with good resolution. This study presented ELISA results valid 95.69%, 100% reproducibility, 94.5% sensitivity and specificity 99.3%, higher than the ELISA performed with multiepitopo protein MEHCV who presented with sensitivity (92.86%) and specificity (82.89%). The standard ELISA can be used as a qualitative serological technique aimed at detection of anti-VHC antibodies, as demonstrated with great reactivity in patients infected with VHC. / As hepatites virais são um grave problema de saúde pública no mundo e no Brasil. São doenças de notificação compulsória e segundo estimativas, bilhões de pessoas já tiveram contato com vírus das hepatites e milhões são portadores crônicos. A infecção pelo vírus da hepatite C (HCV) constitui um grave problema de saúde pública mundial devido à elevada taxa de progressão para cronicidade, ao potencial evolutivo para cirrose e carcinoma hepatocelular, principais complicações conducentes à morte. Em geral, pode-se dizer que na última década houve grandes avanços no diagnóstico da hepatite C. Nesse período houve progressiva melhora na sensibilidade e especificidade dos testes utilizados para detecção de anticorpos contra o vírus HCV. Contudo, é necessário que sejam desenvolvidos testes de maior acurácia. Assim, considerando que a preocupação com a detecção da hepatite C aumenta a cada dia, principalmente em bancos de sangue; os métodos diagnósticos desta infecção são de grande relevância clínica e podem ser utilizados como marcadores de cronicidade e indicativos da eficácia terapêutica. Portanto, esse trabalho propôs avaliar a ligação e reconhecimento dos anticorpos anti-HCV de amostras positivas e positivas genotipadas de pacientes portadores de Hepatite C, através da padronização dos procedimentos e soluções utilizadas no ELISA qualitativo. Realizou-se o processo de sensibilização das microplacas com proteína recombinante quimérica, fez-se a análise da sensibilidade, especificidade, reprodutibilidade e validade do método. Obtivemos a partir dos ensaios de padronização do ELISA com proteínas recombinantes um protocolo capaz de ter um bom rendimento dos principais componentes da reação, antígenos e conjugado, com boa resolução. O presente estudo apresentou-se resultados do ELISA com validade 95,69% , reprodutibilidade 100%, sensibilidade 94,5% e especificidade 99,3%, superior ao ELISA realizado com a proteína multiepitopo MEHCV que apresentaram com sensibilidade (92,86%) e especificidade (82,89%). O ELISA padronizado pode ser utilizado como uma técnica sorológica qualitativa, visando a detecção de anticorpos anti-HCV, pois mostrou-se com ótima reatividade nos soros pacientes infectados com HCV.

Objectifs : Les objectifs principaux de cette thèse sont les suivants : 1) analyse de l’évolution du profil épidémiologique des patients coinfectés VIH-VHC initiant le traitement de l’hépatite C; 2) l’évaluation de l’impact des comportements de santé et des styles de vie sur l’évolution clinique de la maladie Résultats : J’ai pu mettre en évidence que le profil des patients coinfectés VIH-VHC initiant un traitement de l’hépatite C a changé en France avec l’évolution des traitements.Mes travaux ont permis de montrer que, chez les patients coinfectés VIH-VHC, une consommation élevée de café (3 tasses par jour et plus) diminue le risque de fibrose hépatique avancée. Cet effet bénéfique du café est également observé chez les patients coinfectés VIH-VHC avec une consommation élevée d’alcool. De plus, mes travaux ont mis en évidence une relation dose-dépendante entre la fréquence de consommation de cacao et la réduction du risque de fibrose hépatique avancée chez les patients coinfectés VIH-VHC. Par ailleurs, mes analyses n’ont pas mis en évidence un effet significatif de la consommation de café sur le risque de fibrose hépatique avancée chez les femmes coinfectées VIH-VHC. Enfin l’un des résultats marquant de la relation entre VHC et risque d’obésité qui est connue est que la guérison augmente davantage ce risque sur le long terme. Conclusion : Des interventions pour modifier certains styles de vie et comportements ont le potentiel de diminuer le risque de survenue ou d’aggravation de comorbidités, en particulier après la guérison VHC, un événement désormais atteignable pour tous les patients coinfectés. / Objectives: The main objectives of this thesis are: 1) analysis of the evolution of the epidemiological profile of co-infected HIV-HCV patients initiating the treatment of hepatitis C; 2) assessment of the impact of health behaviors and lifestyles on the clinical course of the diseaseResults: I was able to highlight that the profile of co-infected HIV-HCV patients initiating treatment for hepatitis C has changed in France with the evolution of treatments.My work has shown that, in HIV-HCV coinfected patients, high coffee consumption (3 cups per day or more) decreases the risk of advanced liver fibrosis. This beneficial effect of coffee is also observed in co-infected HIV-HCV patients with high alcohol consumption. In addition, my work has shown a dose-dependent relationship between the frequency of cocoa consumption and the reduced risk of advanced liver fibrosis in coinfected HIV-HCV patients. Furthermore, my analyzes did not reveal a significant effect of coffee consumption on the risk of advanced liver fibrosis in coinfected HIV-HCV women. Finally, one of the striking results of the relationship between HCV and known risk of obesity is that healing increases this risk in the long term.Conclusion: Interventions to modify certain lifestyles and behaviors have the potential to reduce the risk of developing or worsening comorbidities, particularly after HCV healing, an event now achievable for all co-infected patients.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Comme pour la plupart des virus à ARN+, le VHC induit des remaniements membranaires appelés membranous web. Les protéines non structurales virales formant le complexe de réplication du virus sont associées à ces membranes néosynthétisées. La compréhension de la mise en place de ces membranes cellulaire est encore actuellement mal connue. Afin d’étudier ce phénomène, nous avons dans un premier temps sélectionné des clones cellulaires Huh7.5 hébergeants un réplicon sous-génomiquedu virus. Nous avons ainsi pu mettre en évidence la présence d’un réseau multivésiculaire semblant provenir de l’induction de mécanismes d’autophagie. Plus récemment l’utilisation du modèle de propagation du virus complet nous a permis de mieux caractériser ce réseau multivésiculaire en déterminant trois sous réseaux vésiculaires structuralement différents. L’analyse de cette étude est effectuée principalement par microscopie électronique avec des techniques innovantes tels que la reconstruction tridimensionnelle et des immunogolds. / As other RNA viruses, HCV induces membrane alterations termed membranous web and its nonstructural proteins forming the viral replication complex are associated to these neo-synthesized membranes. The mechanism underlying these host cell membranes alterations is still currently unknown. To investigate this mechanism, we initially selected Huh7.5 cells clones harbouring a HCV subgenomic replicon. We were able to demonstrate the presence of a multivesicular network apparently linked to the autophagy induction mechanisms. More recently, using the cell culture-adapted HCVsystem, we better characterized this network by determining three multivesiculars vesicles structurally different subnets. This study was carried out mainly by performing electron microscopy observations,with using innovative techniques such as three-dimensional reconstruction and immunogold.

Le carcinome hépatocellulaire (HCC) est une tumeur de mauvais pronostic caractérisée, comme la plupart de cancers, par l'association paradoxale de télomères courts et d'une importante activité télomérase. Cette attrition télomérique joue un rôle central dans l'instabilité chromosomique à l'origine de la promotion et de l'évolution tumorale. Les premières causes d'HCC correspondent aux infections chroniques par les virus hépatotropes : virus de l'hépatite B (VHB) et virus de l'hépatite C (VHC). Dans une première étape nous avons disséqué les dérégulations télomériques dans les HCC et les cirrhoses liées au VHB, VHC ou encore à l'alcool. Nous avons observé que ces dérégulations sont acquises tôt, au stade prétumoral, et persistent au stade tumoral. Ces dérégulations sont spécifiques d'un carcinogène donné. Aux stades tardifs et tumoraux de l'infection par le VHB, les cellules hépatiques expriment fréquemment une protéine tronquée en partie C-terminale d'HBx ainsi que des formes réarrangées du gène PreS/S telle que PreS2. Dans une seconde étape nous avons trouvé qu'à l'opposé de la forme sauvage, HBx tronquée réprime hTERT, diminue l'activité télomérase, raccourcit les télomères, augmente la proportion de ponts anaphasiques et déclenche la sénescence de cellules primaires. Sachant qu'au stade tumoral les cellules transformées ré-expriment hTERT nous avons testé l'effet d'une coexpression de PreS2 et d'HBx tronquée et avons pu montrer que PreS2 contrecarrait l'effet répresseur d'HBx sur hTERT. Néanmoins de façon étonnante, PreS2 ne parvenait pas à rallonger les télomères en présence d'HBx tronquée. Les facteurs protégeant les télomères coopèrent avec la télomérase pour l'élongation et plusieurs de ces protéines sont par ailleurs impliquées dans la réparation des dommages à l'ADN. Nous avons trouvé qu'HBx tronquée modifiait spécifiquement l'expression de la plupart des protéines du télosome selon un patron connu pour inhiber l'effet de la télomérase. Nous avons montré que des dommages à l'ADN télomérique liés à l'incubation de cellules primaires avec la néocarcinostatine inhibaient l'élongation des télomères par hTERT. Ayant trouvé que PreS2 et HBx tronquée induisaient des dommages à l'ADN, nous proposons que cet effet explique l'impossibilité pour PreS2 d'allonger les télomères de cellules exprimant HBx tronquée / Among the numerous genetic defects that underly with hepatocarcinogenesis, telomere abnormalities seem to play a role both in tumor promotion and maintenance. Telomeres, the chromosome extremities, are protected by specific proteins, the Shelterin complex and by additional factors. Besides telomerase dysregulation, changes in the expression of these telomere factors have been observed in cancers. Herewe first tested the hypothesis that such dysregulations might occur in HCC with patterns depending onthe cause of HCC. For HBV-, HCV- and alcool-dependant HCC we found that telomeric dysregulations appear to be carcinogen-specific and occur early during the course of the disease and are persistent in the tumor. At the late stage of HBV-dependent disease and corresponding tumors, hepatocytes produce 3’ deleted mutants of HBx (3’DM HBx) but also a rearranged form of the PreS/S gene: PreS2. We then found that, unlike WT HBx, 3’ DM HBx repress hTERT transcription, decrease telomerase activity, shorten telomere length, increase anaphase bridges and trigger senescence in transfected primary cells. It’s well known that hTERT it re-expressed in tumors, so we tested PreS2 and 3’DM HBx transfection. We show that PreS2 counteracts 3’DM HBx effect on hTERT transcription and telomerase activity. However surprisingly PreS2 wasn’t able to elongate telomeres in 3’DM HBx expressing cells. Telomeric factors interact with telomerase allowing telomere elongation. Moreover many of these factors are implicated in DNA damage repair systems. We found that all Shelterin’s and some other telomeric factors’s expression in dyregulated in 3’DM HBx expressing cells. Moreover we show that neocarcinostatin dependent DNA damage in MRC5 primary cell prevent hTERT-based telomere elongation. Also finding that PreS2 and 3’DM induce DNA damage, we suggest that 3’DM HBx prevents PreS2 and hTERT- based telomere elongation

Introdução: A infecção pelo VHC é uma epidemia de proporções globais, que se torna crônica em cerca de 85% dos indivíduos. Sobrecarga de ferro secundária a mutações HFE vem sendo proposta como fator agravante na evolução da hepatite crônica C. Objetivos: Avaliar se sobrecarga de ferro, mutações no gene HFE estão associadas a progressão da fibrose hepática e a carcinoma hepatocelular (CHC) em portadores crônicos VHC. Casuística e Métodos: De um banco de 2300 pacientes matriculados nos Ambulatórios de Hepatologia e de Transplante Hepático do HCFMUSP, selecionaram-se 320 portadores de hepatite crônica C. Os homens (55,6%) apresentaram 50,8 anos de idade em média e as mulheres 54,3. Obtiveram-se dados clínicos e laboratoriais da época da biópsia hepática, admissionais ou com pelo menos um ano de wash-out do tratamento antiviral. Considerou-se sobrecarga bioquímica níveis de ferro, saturação da transferrina e ferritina acima dos valores de referência. Sobrecarga de ferro tecidual foi identificada pela coloração de Perls graus 3-4. As mutações HFE C282Y e H63D foram pesquisadas pela técnica de PCR em tempo real, em DNA extraído de sangue total, após assinatura de TCLE aprovado pelo comitê de ética local. A fibrose hepática foi considerada avançada para graus 3-4 da classificação SBH/SBP e Metavir (n=167, 52,2%). CHC foi definido por biópsia ou por imagem típica por 2 métodos e AFP 400 mg/dL (n=45, 14,1%). Investigaram-se antecedentes de etilismo, diabetes mellitus, IMC e esteatose em biópsia hepática. A partir dos resultados de genotipagem HFE, constituiu-se um subgrupo caso-controle (n=182) com os portadores de mutações e pares de idade, sexo, etnia e IMC similares. Procederam-se análises de correlação bivariada e multivariada (IC=95%) nos grupos geral e caso-controle. Resultados: Quando se compararam casos com fibrose leve vs avançada, observaram-se níveis elevados de ferro em 17,7% vs 25,2% (p=0,019); saturação da transferrina em 24,3% vs 36,7% (p=0,001); ferritina em 25,8% vs 32,4% (p=0,040) e sobrecarga de ferro tecidual em 3,6% vs 1,4% (p=0,126). Quanto à mutação C282Y, observaram-se frequências alélicas de 0,9% vs 2,0% (p=0,110) e à H63D 5,0% vs 8,0% (p=0,033). No subgrupo casocontrole, as associações de C282Y e H63D com fibrose avançada ocorreram com significâncias de p=0,072 e 0,008, respectivamente. A análise multivariada, tendo fibrose como variável dependente nesse mesmo subgrupo, confirmou as associações com C282Y (OR=31,45; p=0,006) e H63D (OR=33,70; p=0,001). Neste mesmo subgrupo, a presença de pelo menos um alelo mutante esteve associada à ocorrência de CHC (p=0,015). Não se identificaram outros parâmetros associados a transformação carcinomatosa. Na análise multivariada, foram variáveis associadas a evolução da fibrose idade avançada (OR=2,36; p=0,000), etilismo (OR=2,18; p=0,007), saturação da transferrina (OR=2,11; p=0,010) e mutação H63D (OR=1,97; p=0,03). Discussão e Conclusões: Houve correlação de graus mais avançados de fibrose com níveis elevados de ferro, saturação da transferrina e ferritina; contudo, esses marcadores também podem estar igualmente elevados nos indivíduos com pouca fibrose. Ao contrário, em muitos casos, a sobrecarga bioquímica de ferro pode ser conseqüência da progressão da doença hepática, e não sua causa. As mutações H63D e C282Y ocorreram em associação com maiores graus de alteração arquitetural; mas, como não houve associação entre siderose tecidual e fibrose, é possível que seu papel na agressão hepática não ocorra diretamente por meio da sobrecarga de ferro. Os portadores de mutações HFE apresentam CHC com maior frequência que seus casos-controle. / Introduction: HCV infection is an epidemic of global proportions, which becomes chronic in about 85% of individuals. Iron overload due to HFE mutations has been proposed as aggravating factor in the evolution of chronic hepatitis C. Objectives: To assess whether iron overload, mutations in the HFE gene are associated with progression of liver fibrosis and hepatocellular carcinoma (HCC) in chronic HCV. Patients and Methods: From a database of 2300 patients enrolled in the outpatient clinics of Hepatology and Liver Transplantation, HCFMUSP, 320 patients with chronic hepatitis C were selected. Men (55.6%) were 50.8 years old on average and women 54.3. Admissional clinical and laboratory data at the time of liver biopsy were obtained; when patient had been previously treated with antiviral drugs, the wash-out period required was of at least one year. Biochemical iron overload was defined as iron, ferritin and transferrin saturation above the reference values. Tissue iron overload was identified by Perls staining of grades 3-4. The HFE C282Y and H63D mutations were searched by real-time PCR technique in DNA extracted from whole blood, after signing of FICT approved by the local ethics committee. The liver fibrosis was considered advanced for grades 3-4 in the classification SBH/SBP and METAVIR(n = 167, 52.2%). HCC was defined by biopsy or by typical image by 2 methods and AFP 400 mg / dL (n = 45, 14.1%). Personal history of alcoholism, diabetes mellitus, BMI and steatosis in liver biopsy were obtained. A casecontrol group was constituted based on the results of HFE genotyping (n = 182), subjects were paired by age, gender, ethnicity and BMI. Bivariate correlation and multivariate analysis (CI = 95%) groups in general and case-control were carried-out. Results: When comparing patients with mild vs advanced fibrosis, biochemical high levels of iron were detected in 17.7% vs 25.2% (p = 0.019), transferrin saturation in 24.3% vs 36.7% (p = 0.001), ferritin in 25.8% vs 32.4% (p = 0.040) and tissue iron overload in 3.6% vs 1.4% (p = 0.126). Regarding to HFE mutations, the allelic frequencies of C282Y were 0.9% vs 2.0% (p = 0.110); and of H63D, 5.0% vs 8.0% (p = 0.033). In casecontrol group, associations of C282Y and H63D with advanced fibrosis occurred with significance of p=0.072 and 0.008, respectively. Multivariate analysis with fibrosis as the dependent variable in that group, confirmed the associations with C282Y (OR = 31.45, p = 0.006) and H63D (OR = 33.70, p = 0.001). In this same subgroup, the presence of at least one mutant allele was associated with occurrence of HCC (p = 0.015). There were not any other parameters found in association with carcinomatous transformation. The multivariate analysis using fibrosis as dependent variable showed association with age (OR = 2.36, p = 0.000), alcoholism (OR = 2.18, p = 0.007), transferrin saturation (OR = 2.11, p = 0.010) and H63D mutation (OR = 1.97, p = 0.03). Discussion and Conclusions: Advanced degrees of fibrosis were correlated with high levels of iron, transferrin saturation and ferritin; however, these markers can also be elevated in individuals with slight fibrosis. In contrary, in many cases, the biochemistry of iron overload may be a consequence of progression of liver disease. C282Y and H63D mutations occurred in association with more advanced fibrosis. However, as there was not any correlation between tissue siderosis and fibrosis, it might be possible that liver injury occurs not by the iron overload pathway. Finally, carriers of HFE mutations were found with HCC more frequently than their casecontrol.

Le traitement utilisé actuellement contre le virus de l’hépatite C présente une efficacité limitée et induit d’importants effets secondaires. La délivrance de molécules antivirales spécifiquement dans les cellules infectées devrait permettre d’améliorer leur efficacité.Ce travail présente le développement d’une nouvelle approche utilisant à son profit la machinerie de réplication virale pour délivrer une molécule antivirale aux seules cellules infectées. Cette stratégie repose sur l’utilisation d’ARN non codants réplicables (nrRNA) portant les structures reconnues par le complexe de réplication du VHC, encadrant la séquence complémentaire d’un gène antiviral. Le complexe de réplication du VHC réplique le nrRNA comme s’il s’agissait du génome viral, permettant ainsi la synthèse d’un ARN codant à partir duquel la molécule antivirale est exprimée. Les cellules non-infectées n’exprimant pas le complexe de réplication, cette machinerie spécifique peut être utilisée et détournée, de façon à cibler les cellules infectées sans impact sur les cellules saines.Nous montrons ici que cette approche s’avère efficace contre le réplicon (génotype 1b) et le virus JFH-1 (génotype 2a) : les nrRNA induisent une forte baisse de la quantité d’ARN et de complexe de réplication viral. Ces effets sont corrélés à une forte activation de la transcription de différents gènes de la réponse IFN de type I.Nous avons également vérifié l’innocuité de ce système sur les cellules non infectée en utilisant des nrRNA RicineA. La réplication et la traduction de ces nrRNA conduit à la mort cellulaire par inactivation des ribosomes. Mais la viabilité des cellules non infectées par le VHC n’est pas perturbée, signe que les nrRNA RicineA ne sont ni répliqués ni traduits en absence du complexe de réplication viral.La vectorisation des nrRNA a également été développée au moyen de particules lentivirales modifiées. Nous testons désormais la réplication et la traduction des nrRNA dans un modèle murin, en vectorisant ces ARN par injection hydrodynamique ou par l’intermédiaire des particules lentivirales. / The current treatment used against Hepatitis C Virus has a limited efficacy and is often hampered by the induction of side-effects. The specific delivery of antiviral proteins in infected cells should increase their efficiency and reduce their impact on healthy cells.Here, we describe the development of a new approach which takes advantage of the viral replication machinery to specifically target the antiviral protein expression to the infected cells. The strategy is based on the delivery of a non-coding replicative RNA (nrRNA) carrying the structures required for the binding of the viral replication complex, flanking the complementary sequence of an antiviral gene. The HCV replication complex replicates the nrRNA similarly to the viral genome to give a coding RNA from which the antiviral protein will be expressed. As non-infected cells do not express the replication complex, this specific machinery can be used to target virus-infected cells without affecting healthy cells.We show that this approach can be successfully applied in both replicon-harboring cells (genotype 1b) and JFH-1 infected cells (genotype 2a) : nrRNAs induced a strong decrease in genomic RNA and viral protein NS5A. These effects were correlated with a strong activation of several interferon stimulated genes.We also verify the harmlessness of the system in uninfected cells by transfecting a RicinA nrRNA. The replication and translation of this nrRNA lead to the cell death by ribosomes inactivation. But nothing occurs in non?infected cells, showing that nrRNA are neither replicated nor translated in absence of the HCV replication complex.The vectorisation of nrRNa was also developed by the use of modified lentivirale particles. We now test the efficient replication and translation of nRNAs in a murin model by using hydrodynamic transfection or the lentiviral delivery of nrRNAs.