Les anticorps monoclonaux (AcM) ont été utilisés pour traiter des cancers dès le début des années 1980, en particulier lors du travail pionnier de l’équipe de Ronald Levy dans le traitement des lymphomes. Ces traitements ont pendant longtemps été considérés comme une sérothérapie passive à effet immédiat et à court terme. Cependant, au cours de ces dernières années, le concept d’un effet « vaccinal » des anticorps à usage thérapeutique en oncologie a peu à peu vu le jour du fait de réponses cliniques à long terme observées chez certains patients et de différentes études précliniques. En 2010, notre équipe a démontré que des souris immunocompétentes injectées avec les cellules tumorales EL4-huCD20 et traitées avec un AcM anti-huCD20 générait une réponse immunitaire anti-tumorale à long-terme par le biais de mécanismes dépendants de la région constante de l’anticorps et de lymphocytes T CD4+. Mon travail de thèse a donc porté sur l’analyse des mécanismes cellulaires et moléculaires par lesquels le traitement par un AcM anti-CD20 génère une immunité cellulaire adaptative anti-tumorale. J’ai ainsi pu montrer que le traitement des souris avec l’AcM anti-CD20 conduit à une expansion de lymphocytes Th1 producteurs d’IFN-γ, à l’apparition de lymphocytes T CD4+ effecteurs mémoires spécifiques des cellules tumorales CD20+, et au blocage de l’expansion de lymphocytes Tregs induite par les cellules tumorales. Le rôle central dans la protection anti-tumorale et la genèse d’une réponse adaptative anti-tumorale joué par l’axe IL-12/IFN-γ et leurs principales sources cellulaires, cellules dendritiques (DCs) et cellules NK, a été démontré par des expériences de neutralisation de ces cytokines, qui provoque une importante diminution du nombre de Th1 spléniques, de déplétion des cellules NK, ainsi que par des analyses phénotypiques qui ont permis d’identifier des DCs activées par le traitement - comme le montre l’expression accrue des molécules de classe II du CMH et de co-stimulation CD80 et CD86 - comme une importante source cellulaire de l’IL-12. Enfin, nous avons pu montrer qu’un variant de l’IL-2, liant préférentiellement le récepteur de l’IL-2By et faiblement le récepteur de l’IL-2aBy exprimé majoritairement par les Tregs, permettait l’obtention d’une protection anti-tumorale accrue d’animaux porteurs de tumeurs et traités par l’AcM anti-CD20. En conclusion, nous avons démontré qu’un contexte immunitaire pro-tumoral façonné par la présence d’une tumeur en développement peut être inversé par le traitement par un anticorps anti-tumoral, aboutissant à un contexte anti-tumoral. Qu’une telle réponse immunitaire adaptative cellulaire puisse être observée chez des patients atteints de lymphomes, traités par un anticorps anti-CD20, reste encore à être déterminé. / Monoclonal antibodies have been used to treat cancers since the early 1980s, in particular with the pioneer work of Ronald Levy for the treatment of lymphomas. Those treatments have been considered for a long time as a passive serotherapy with immediate and short term actions. Yet, recently, the idea of a vaccine effect of therapeutic antibodies in oncology have appeared, after preclinical studies and clinic observations suggesting a long term immune response in patients. In 2010, our team demonstrated that immunocompetent mice injected with EL4-huCD20 tumor cells and treated with anti-huCD20 monoclonal antibody generated a long term anti-tumor immune response linked with mechanisms dependent on constant part of antibodies and CD4+ T cells. My PhD work was based on the analysis of cellular and molecular mechanisms by which the treatment by an anti-CD20 mAb generates a cellar adaptive anti-tumor immunity. I could show that the treatment of mice with anti-CD20 antibody lead to the expansion of Th1 lymphocytes IFN-γ producers, to the apparition of effector memory CD4+ T cells specific for CD20 antigen, and to the blockade of the expansion of Treg cells induced by tumor cells. The key role of an adaptive anti-tumor immune response played by IL-12/IFN- γ and their main cellular sources, dendritic cells and NK cells, in the anti-tumor protection and genesis, has been demonstrated by experiments of cytokine neutralization, provoking an important decrease of splenic Th1 number, by NK depletion and by phenotypic analysis that allowed the identification of DCs activated by the treatment – as it is shown by the increased expression of MHC-II and CD80 and CD86 costimulation molecules, - as an important cellular source of IL-12. Finally, we could show that a variant of IL-2, binding preferentially IL-2By with a lower affinity for the IL-2aBy receptor mainly expressed by Tregs, could induce an increased anti-tumor protection of tumor-bearing animals treated with anti-CD20 mAb. In conclusion, we have demonstrated that a pro-tumor immune contexture affected by a growing tumor can be modified by an anti-tumor antibody leading to an anti-tumor contexture. That such cellular adaptive immune response could be observed in lymphoma patients treated with anti-CD20 still need to be determined.

Les anticorps monoclonaux (AcM) ont été utilisés pour traiter des cancers dès le début des années 1980, en particulier lors du travail pionnier de l’équipe de Ronald Levy dans le traitement des lymphomes. Ces traitements ont pendant longtemps été considérés comme une sérothérapie passive à effet immédiat et à court terme. Cependant, au cours de ces dernières années, le concept d’un effet « vaccinal » des anticorps à usage thérapeutique en oncologie a peu à peu vu le jour du fait de réponses cliniques à long terme observées chez certains patients et de différentes études précliniques. En 2010, notre équipe a démontré que des souris immunocompétentes injectées avec les cellules tumorales EL4-huCD20 et traitées avec un AcM anti-huCD20 générait une réponse immunitaire anti-tumorale à long-terme par le biais de mécanismes dépendants de la région constante de l’anticorps et de lymphocytes T CD4+. Mon travail de thèse a donc porté sur l’analyse des mécanismes cellulaires et moléculaires par lesquels le traitement par un AcM anti-CD20 génère une immunité cellulaire adaptative anti-tumorale. J’ai ainsi pu montrer que le traitement des souris avec l’AcM anti-CD20 conduit à une expansion de lymphocytes Th1 producteurs d’IFN-γ, à l’apparition de lymphocytes T CD4+ effecteurs mémoires spécifiques des cellules tumorales CD20+, et au blocage de l’expansion de lymphocytes Tregs induite par les cellules tumorales. Le rôle central dans la protection anti-tumorale et la genèse d’une réponse adaptative anti-tumorale joué par l’axe IL-12/IFN-γ et leurs principales sources cellulaires, cellules dendritiques (DCs) et cellules NK, a été démontré par des expériences de neutralisation de ces cytokines, qui provoque une importante diminution du nombre de Th1 spléniques, de déplétion des cellules NK, ainsi que par des analyses phénotypiques qui ont permis d’identifier des DCs activées par le traitement - comme le montre l’expression accrue des molécules de classe II du CMH et de co-stimulation CD80 et CD86 - comme une importante source cellulaire de l’IL-12. Enfin, nous avons pu montrer qu’un variant de l’IL-2, liant préférentiellement le récepteur de l’IL-2By et faiblement le récepteur de l’IL-2aBy exprimé majoritairement par les Tregs, permettait l’obtention d’une protection anti-tumorale accrue d’animaux porteurs de tumeurs et traités par l’AcM anti-CD20. En conclusion, nous avons démontré qu’un contexte immunitaire pro-tumoral façonné par la présence d’une tumeur en développement peut être inversé par le traitement par un anticorps anti-tumoral, aboutissant à un contexte anti-tumoral. Qu’une telle réponse immunitaire adaptative cellulaire puisse être observée chez des patients atteints de lymphomes, traités par un anticorps anti-CD20, reste encore à être déterminé. / Monoclonal antibodies have been used to treat cancers since the early 1980s, in particular with the pioneer work of Ronald Levy for the treatment of lymphomas. Those treatments have been considered for a long time as a passive serotherapy with immediate and short term actions. Yet, recently, the idea of a vaccine effect of therapeutic antibodies in oncology have appeared, after preclinical studies and clinic observations suggesting a long term immune response in patients. In 2010, our team demonstrated that immunocompetent mice injected with EL4-huCD20 tumor cells and treated with anti-huCD20 monoclonal antibody generated a long term anti-tumor immune response linked with mechanisms dependent on constant part of antibodies and CD4+ T cells. My PhD work was based on the analysis of cellular and molecular mechanisms by which the treatment by an anti-CD20 mAb generates a cellar adaptive anti-tumor immunity. I could show that the treatment of mice with anti-CD20 antibody lead to the expansion of Th1 lymphocytes IFN-γ producers, to the apparition of effector memory CD4+ T cells specific for CD20 antigen, and to the blockade of the expansion of Treg cells induced by tumor cells. The key role of an adaptive anti-tumor immune response played by IL-12/IFN- γ and their main cellular sources, dendritic cells and NK cells, in the anti-tumor protection and genesis, has been demonstrated by experiments of cytokine neutralization, provoking an important decrease of splenic Th1 number, by NK depletion and by phenotypic analysis that allowed the identification of DCs activated by the treatment – as it is shown by the increased expression of MHC-II and CD80 and CD86 costimulation molecules, - as an important cellular source of IL-12. Finally, we could show that a variant of IL-2, binding preferentially IL-2By with a lower affinity for the IL-2aBy receptor mainly expressed by Tregs, could induce an increased anti-tumor protection of tumor-bearing animals treated with anti-CD20 mAb. In conclusion, we have demonstrated that a pro-tumor immune contexture affected by a growing tumor can be modified by an anti-tumor antibody leading to an anti-tumor contexture. That such cellular adaptive immune response could be observed in lymphoma patients treated with anti-CD20 still need to be determined.

Les pDC représentent la première ligne de défense de l’organisme contre les pathogènes et établissent le lien essentiel entre l’immunité innée et adaptative. Les pDC endocytent et détruisent les particules virales et ainsi détectent leur matériel génétique grâce à des senseurs antiviraux de la famille des Toll-Like Receptors (TLR). L’activation des TLR7/9 induit la production massive d’interféron de type I (IFN-I), un antiviral puissant indispensable au contrôle de la propagation virale lors des phases aigues de l’infection. Cependant, l’IFN-I peut s’avérer avoir des effets délétères dans un grand nombre d’infections chroniques et de maladies auto-immunes. Ainsi, il semble indispensable de découvrir les mécanismes régulateurs des pDC ainsi que des modulateurs de l’activation des pDC. Nous avons ainsi montré que les monoamines (histamine, dopamine, sérotonine) et les polyamines (spermine et spermidine) inhibent l’activation complète des pDC stimulées par divers virus. Par la suite, nous avons identifié CXCR4 comme étant le récepteur des amines sur les pDC. Ainsi nous avons pu montrer que les amines pouvaient réguler les pDC en passant par CXCR4 et que ce récepteur était un interrupteur d’activation potentiel des pDC lors des infections virales. Afin de comprendre le mécanisme des amines, nous avons développé une nouvelle technologie : la transfection de siRNA dans les pDC primaires humaines. D’autre part, nous avons détecté des cellules géantes multinucléées en forme de roue de bicyclette lorsque les pDC sont cultivées in vitro avec de grandes quantités de virus VIH. Ainsi, comme les monocytes et les macrophages, les pDC peuvent former in vitro des cellules géantes multinucléées exprimant de hauts niveaux de protéines virales p24 de VIH-1. Cependant, les pDC ne sont que très peu infectées (moins de 5%). Nous nous sommes alors demandé si le corécepteur CXCR4 du virus VIH était aussi important que le récepteur CD4 pour la reconnaissance de ce dernier lors de l’activation des pDC. / PDC are the first line of defense of our organism against pathogens and establish the essential link between the innate and adaptive immunity. pDC endocyte and destroy the viral particles and thus, detect the genetic material with their antiviral sensors from the Toll-Like Family (TLR). The activation of TLR7/9 induces massive production of type I interferon (IFN-I), a powerful antiviral molecule, essential to control viral propagation during the acute phases of the infection. However, type I IFN can have deleterious effects in a large number of chronic infections and autoimmune diseases. Thus, it seems essential to discover the regulatory mechanism of pDC as well as pDC activation modulators. We showed that monoamines (histamine, dopamine and serotonin) and polyamines (spermine and spermidine) inhibit completely the activation of virus-stimulated pDC. Thus, we showed that amines regulated pDC activation through CXCR4 engagement and that this receptor was a potential switch "on-off" for pDC during viral infections. To better understand the mechanism of action by which amines inhibit pDC activation, we developed a new technology: siRNA transfection in human primary pDC. Furthermore, we detected multinuclear giant cells bearing the shape of a bicycle wheel when pDC are cultured in vitro with high quantities of HIV virus. Thus, on top of monocytes and macrophages, pDC can form in vitro multinuclear giant cells with high levels of p24 viral protein of HIV-1. However, pDC barely get infected (less than 5%). We then wondered if the receptors and co-receptors of the virus were important for the viral recognition during HIV-activation of pDC.

Mutações no gene CD40LG estão associadas à Síndrome de Hiper-IgM, relacionada ao cromossomo X, que é uma Imunodeficiência Primária. A ausência da interação CD40L/CD40 (linfócitos-DCs) acarreta um aumento da suscetibilidade às infecções fúngicas. Os efeitos do tratamento in vitro com interferon-gama em células dendríticas de pacientes com mutações no CD40L demonstraram potencial sobre a imunologia das DCs e nos remete a fundamentar possíveis ensaios clínicos futuros, que tenham por tema a prevenção e o tratamento de infecções oportunistas. / Mutations in the CD40LG gene are associated with the X-linked Hyper-IgM Syndrome, which is a Primary Immunodeficiency. The absence of the CD40L / CD40 interaction (lymphocytes-DCs) leads to increased susceptibility to fungal infections. The effects of in vitro gamma-interferon treatment on dendritic cells from patients with CD40L mutations have demonstrated potential for DC immunology and suggest that future clinical trials should address the prevention and treatment of opportunistic infections.

INTRODUÇÃO: A tuberculose é um problema grave de saúde pública, acometendo indivíduos em todas as faixas etárias e em todos os estratos socioeconômicos. Apesar de estarem sob grande risco de adoecimento, as crianças carecem de meios diagnósticos sensíveis e específicos. Neste estudo avaliou-se em crianças a acurácia de um teste baseado na dosagem de interferon-gama liberado por linfócitos após estímulo com antígenos específicos do Mycobacterium tuberculosis (QuantiFERON-TB Gold In Tube® [Cellestis, Carnegie, Austrália] ).MÉTODO: Foram incluídas no estudo 184 crianças não infectadas e 11 crianças com infecção pelo Mycobacterium tuberculosis. Todas as crianças receberam previamente o BCG. Foram excluídas crianças com comprometimento do sistema imunológico. Obteve-se amostra de sangue de cada criança, e o material foi processado conforme as instruções do laboratório fabricante. O desempenho do teste foi avaliado pela construção de uma curva de características operacionais (ROC). RESULTADOS: Do total de 184 crianças sem infecção pela micobatéria, 74 (40,2%) eram do sexo feminino, e 130 (70,6%) tinham menos de quatro anos de idade. A idade média neste grupo foi de 35 meses. Seis (3,2%) crianças apresentaram resultado indeterminado do teste, uma criança (0,5%) apresentou um resultado positivo e 177 (96,2%) apresentaram resultado negativo. No grupo de 11 crianças infectadas, sete (63,0%) eram meninas, e a idade média era de 58,5 meses. Duas (18,0%) crianças neste grupo apresentaram resultado negativo do teste. A curva ROC obtida evidenciou uma área sob a curva de 0,876 (I. C 95% - 0,82 a 0,92; p<0,001), refletindo o desempenho preditivo elevado do teste. A sensibilidade do teste foi de 81,8% (IC 95% - 48,2% a 97,2%) e a especificidade de 98,8% (IC 95% - 96,0 a 99,8%), o valor preditivo positivo foi de 81,8% (IC 95%: 46,3% a 97,4%) e o valor preditivo negativo foi de 98,9% (IC 95%: 96,0% a 99,8%). CONCLUSÕES: Neste estudo o teste mostrou ter uma boa acurácia no diagnóstico da infecção pelo Mycobaterium tuberculosis em crianças previamente vacinadas com o BCG, e sua utilização rotineira pode contribuir para a melhor avaliação de crianças expostas a um doente bacilífero e na tomada de decisões sobre a introdução de quimioprofilaxia ou tratamento. / BACKGROUND: Tuberculosis is a major public health problem, affecting people from all ages and diverse socioeconomic incomes. Despite the high risk that children have to develop the disease, accurate methods for diagnosis are not yet available. In this study the accuracy of an interferon-gamma release assay (QuantiFERON-TB Gold In Tube® [Cellestis, Carnegie, Australia]) was evaluated for the diagnosis of Mycobacterium tuberculosis infection in children. METHODS: 195 children were evaluated, 184 children without mycobacterial infection, and 11 children infected by the Mycobacterium tuberculosis. All the children had been previously vaccinated with BCG. Immunocompromised children were excluded from the study. A blood sample was obtained from each child, and it was processed according the manufacturer´s instructions. The performance of the assay was evaluated by a receiver operating characteristic (ROC) curve. RESULTS: In the group of 184 noninfected children, 74 (40.2%) were female and 130 (70.6%) were younger than four years old. The mean age in this group was 35 months. Six children (3.2%) had indeterminate test result, one child (0.5%) had a positive test result, and 177 (96.2%) children had negative test results. In the group of 11 infected children, seven (63.0%) were female, and the mean age in this group was 58.5 months. Two children (18.0%) in this group had a negative test result. The ROC curve determined an area under the curve of 0.876 (95% CI 0.82 to 0.92; p< 0.001), disclosing a high positive predictive value for the test. The assay sensibility was 81.8% (95% CI, 48.2% to 97.2%) and the assay specificity was 98.8% (95% CI, 96.0% to 99.8%), the positive predictive value was 81.8% (95% CI: 46.3% to 97.4%) and the negative predictive value was 98.9% (95% CI: 96.0% to 99.8%). CONCLUSIONS: In this study, the accuracy of the assay was high for the diagnosis of Mycobacterium tuberculosis infection in children previously vaccinated with BCG. The use of this assay for the routine evaluation of children exposed to the disease may help physicians to decide on whether to start chemoprophylaxis or tuberculosis treatment.

A hepatite C é uma doença que leva à inflamação do fígado, sendo causada pelo vírus da hepatite C (VHC). Estima-se que existam 130 a 170 milhões de casos de infecção crônica pelo VHC por todo o mundo. Apesar do VHC ser principalmente hepatotrópico, foi evidenciada a detecção de RNA viral em células mononucleares do sangue periférico (PBMC). Evidências clínicas e experimentais têm demonstrado um importante tropismo do VHC por células do sistema imune, em especial por PBMCs. Apesar deste interessante achado, a importância da infecção do sistema imune na história natural da doença não é totalmente conhecida. É possível observar em alguns estudos que, em pacientes que desenvolvem infecção aguda, observa-se uma vigorosa resposta mediada por células T, específica ao VHC, mediada, por células T CD4+ e T CD8. Esta resposta é detectada na fase inicial da doença, e prolonga-se durante vários anos após a resolução do vírus. Pelo contrário, os pacientes que desenvolvem infecção crônica, apresentam, normalmente, respostas T fracas e / ou de curta duração, bem como defeitos nas funções efetoras de células T específicas. As respostas mediadas por células T com este perfil resultam, normalmente, em um baixo controlo da viremia e na sua persistência. Outra importante questão que permanece incerta até o presente momento é como a infecção das células imunes pelo VHC altera a sua função, principalmente no que concerne às PBMCs. Informações referentes às PBMCs e o VHC são pouco estudadas e referidas na literatura internacional, embora sejam de fundamental importância para a compreensão do seu peso na história natural da infecção. OBJETIVO: Baseado nessas incertezas o presente estudo tentará contribuir para a elucidação da influência do parasitismo por VHC na função de células TCD4+ e TCD8+ em pacientes naïve com indicação de tratamento com IFNpeg+RBV e comparar os dados obtidos antes, durante e pós-tratamento com os valores encontrados dos controles negativos, avaliando a influência do tratamento sobre a função dessas células. Verificar a presença do RNA-VHC nas PBMCs por RT-PCR em Tempo Real. Verificar a influência de fatores do vírus e do hospedeiro, tais como genótipo, carga viral, idade, gênero, raça, polimorfismo IL28B e biópsia hepática sobre as células parasitadas pelo VHC e sua produção de citocinas; Determinar a contagem e a função de linfócitos T CD4+ e CD8+ no sangue periférico desses pacientes; Determinar a influência do parasitismo de linfócitos pelo VHC sobre a função dos linfócitos TCD4+ e TCD8+. METODOLOGIA: Foram estudados 52 pacientes com hepatite C crônica; destes, 17 pacientes foram tratados com IFNalfa+RBV; 10 controles sadios, atendidos no Ambulatório de Hepatites da Divisão de Clínica de Doenças Infecciosas e Parasitárias do HC FMUSP. A contagem de células da subpopulação de linfócitos T CD4+ e CD8+ periféricas foram realizadas por citometria de fluxo FACSCanto II (BD) por meio do software MultiSet(BD). Foi analisada a presença/ausência do RNA-VHC em PBMC por PCR em tempo real no sistema TaqMan, no termociclador Applied Biosystems StepOne(TM). A função dos linfócitos TCD4+ e TCD8+ foram avaliadas através da técnica ELISPOT utilizanso o Kit Human IFN-gamma/IL-4 Dual-Color FluoroSpot. A contagem dos spots foi realizada em um leitor automatizado CTL-ImmunoSpot® S6 FluoroSpot Line. As PBMCs foram fracionadas e depletadas, utilizando-se o Kit Dynabeads FlowComp Human CD4 (Invitrogen Life Technologies) segundo as instruções do fabricante. RESULTADOS: Foram estudados 52 pacientes com hepatite C crônica; destes, 17 pacientes foram tratados com IFNalfa+RBV; 10 controles sadios. O genótipo 1 foi o mais prevalente 61,5%. O RNA do VHC foi detectado nas PBMCS em 88,4% dos pacientes. XVII Nossos resultados mostraram um aumento de células CD4 e CD8 parasitadas pelo VHC antes do tratamento, com valores estatisticamente significantes quando comparadas aos controles normais apenas no caso das CD4. Ocorreu, porém, um nítido prejuízo na produção de interleucinas por estas células parasitadas, particularmente a produção de IFN- y, com valores altamente significantes (0,009). Na semana 12, podemos ver o aumento de células CD4 no pré-tratamento, porém com diminuição na semana 12 e no follow up; entretanto a produção de IL-4 pelas células CD4 aumenta na semana 12 e cai novamente no seguimento; com as células CD8 ocorre leve queda na semana 12 porém uma tentativa de recuperação no follow up; sua produção de IFN-y cai na semana 12 e no follow up para números estatisticamente significantes. É a chamada \"exaustão\" de função destas células já descrita in vitro por alguns autores. Estes dados poderão ser muito úteis nas futuras observações desses pacientes que serão tratados com esquemas de DAAs sem interferon alfa. CONCLUSÃO: Em conclusão, os resultados desta pesquisa confirmam a importante influência do parasitismo das células CD4 e CD8 em suas funções / Hepatitis C is a disease that causes inflammation of the liver, caused by hepatitis C virus (HCV). It is estimated that there are 130 million to 170 million cases of chronic HCV infection worldwide. Although HCV is primarily hepatotropic was evidenced by detection of viral RNA in peripheral blood mononuclear cells (PBMC). Clinical and experimental evidence have demonstrated an important tropism of HCV by immune system cells, in particular by PBMC. Despite this interesting finding, the importance of infection of the immune system in the natural history of the disease is not fully known. It can be observed in some studies in patients who develop acute infection a vigorous response is observed mediated by T cells specific to HCV mediated by CD4 + and CD8. This response is detected at the initial stage of the disease, and extends for years after the resolution of the virus. Conversely, patients who develop chronic infection, are typically in the low T responses and / or short-term as well as defects in the effector functions of specific T cells. The responses mediated by T cells with the profile usually result in a low control of viremia and its persistence. Another important issue that remains unclear to date is how the infection of immune cells by HCV alters its function, especially with regard to the PBMCs. Information relating to the PBMCs and HCV are little studied and reported in the international literature, although they are of fundamental importance for the understanding of its weight in the natural history of infection. OBJECTIVE: Based on these uncertainties the present study attempts to contribute to the elucidation of the influence of parasitism by HCV on CD4 T cell function + and CD8 + in naïve patients with treatment indication with IFNpeg + RBV and compare the data obtained before, during and after treatment with the values found negative controls, assessing the influence of treatment on the function of these cells. Verify the presence of HCV-RNA in PBMC by RT-PCR in real time. Check the influence of virus and host factors such as genotype, viral load, age, gender, race, IL28B polymorphism and liver biopsy on the parasitized cells with HCV and their cytokine production; Determine count and function of lymphocytes T CD4 + and CD8 + peripheral blood of patients; To determine the influence of parasitism lymphocytes HCV on the function of CD4 + and CD8 + T lymphocytes. METHODS: We studied 52 patients with chronic hepatitis C; of these, 17 patients were treated with IFNalpha + RBV; 10 healthy controls, treated at the Hepatitis Clinic of the Division of Clinical Infectious and Parasitic Diseases of the FMUSP. The lymphocyte subpopulation of T-cell count CD4 + and CD8 + peripheral been made by FACSCanto II flow cytometer (BD) through the multiset software (BD). the presence / absence of HCV-RNA in PBMC by real-time PCR was analyzed in the TaqMan system, Applied Biosystems thermal cycler StepOne (TM). The role of CD4 + T lymphocytes and CD8 + were assessed by ELISPOT technique utilizanso the Human Kit IFN-gamma / IL-4 Dual-Color FluoroSpot. The counting of the spots was carried out in an automated reader CTL-ImmunoSpot® S6 FluoroSpot Line. And fractionated PBMCs were depleted using Dynabeads kit is the Human CD4 FlowComp (Invitrogen Life Technologies) according to manufacturer\'s instructions. RESULTS: We studied 52 patients with chronic hepatitis C; of these, 17 patients were treated with IFNalpha + RBV; 10 healthy controls. Genotype 1 was the most prevalent 61.5%. The HCV RNA was detected in PBMC in 88.4% of patients. Our results showed an increase of CD4 and CD8 cells parasitized with HCV prior to treatment, with statistically significant amounts compared to controls only if CD4. There was however, a marked impairment in production of interleukins for these parasitized cells, particularly the production of IFN- y, with highly significant values (0.009). At week 12, we can see the increase in CD4 cells before treatment, but with decreased at week 12 and at follow up; However IL-4 production by CD4 cells increased at week 12 and again falls in the following; with the CD8 cells is slightly lower at week 12 but a recovery attempt at follow up; their IFN-y production drops at week 12 and follow up to statistically significant numbers. It is called \"exhaust\" function of these cells in vitro been described by some authors. This data is very useful in future observations of these patients are treated with AADs regimens without interferon alfa. CONCLUSION: In conclusion, the results confirm the important influence of the parasitism of CD4 and CD8 cells in their functions

O melanoma maligno é uma forma de câncer com alto índice de morte devido, em parte, à falta de tratamentos eficazes e à sua tendência de formar metástases. Nosso grupo tem desenvolvido vetores virais para a transferência gênica de fatores anti-tumorais e, inicialmente, foi construído um vetor adenoviral, AdPG, no qual a expressão do transgene é controlada por p53, um supressor de tumor e fator de transcrição. Sendo que aproximadamente 90% dos casos de melanoma retêm p53 selvagem, foi proposto que isto pudesse ser utilizado como uma ferramenta para dirigir a expressão do transgene codificado pelo vetor AdPG, um mecanismo apoiado por resultados anteriores de nosso grupo. Por exemplo, a transdução de células B16 (melanoma de camundongo, p53-selvagem, deleção de p19Arf) com vetores AdPG portadores de p19Arf ou interferon-<font face=\"Symbol\">b (IFN<font face=\"Symbol\">b) resultou em morte celular maciça enquanto a transferência de apenas um destes fatores isolados não causou o mesmo efeito. O trabalho descrito aqui inclui dois avanços tecnológicos críticos em comparação com trabalhos anteriores do grupo. Primeiramente, os transgenes de interesse (eGFP, p19Arf e IFN<font face=\"Symbol\">b) foram inseridos num vetor adenoviral que apresenta o tripetídeo RGD na sua proteína fibra. Essa modificação no vetor permite a eficiente transdução de um amplo espectro de células alvos sem a dependência do receptor viral do adenovírus selvagem, CAR. Além disso, foi construído um vetor bicistrônico, que contém a combinação de ambos os genes terapêuticos, como forma de garantir a transferência dos dois fatores ao mesmo tempo para as células-alvo. A inclusão de p19Arf, um supressor de tumor e inibidor de MDM2, como um gene terapêutico deve complementar as atividades do p53 celular endógeno e, como consequência, atuar na promoção da expressão a partir do vetor e também na inibição da proliferação das células tumorais. Porém, a transferência de p19Arf sozinho acarretaria efeito somente nas células que foram transduzidas e, então, seu efeito seria limitado. Por este motivo, descreve-se, além do p19Arf, a utilização de IFN<font face=\"Symbol\">b, uma proteína secretada com funções anti-tumorais, incluindo inibição de angiogênese, indução de apoptose e ativação da resposta imunológica. A estratégia do projeto contemplou vários níveis relacionados ao mecanismo do processo de transferência, incluindo a eficiência da transdução, o mecanismo de controle da expressão dos transgenes e as atividades dos transgenes. Assim, foi proposto que a combinação de p19Arf e IFN<font face=\"Symbol\">b pudesse ser uma estratégia interessante para induzir morte no tumor primário e uma resposta imunológica contra as células metastáticas. Com este projeto, foi iniciada a construção destes novos vetores aprimorados para transferência gênica nas células de melanoma. / Malignant melanoma is a type of cancer with high death rates, in part, because of a lack of efficient treatments and its tendency to generate metastases. Our group has developed viral vectors for the gene transfer of anticancer factors and, initially, we constructed an adenoviral vector, AdPG, in which transgene expression is controlled by p53, a tumor suppressor and transcription factor. As 90% of melanoma cases maintain wild-type p53, it was proposed that this could be used as a tool to drive transgene expression encoded by the AdPG vector, as evidenced by previous studies from our group. For example, transduction of B16 cells (mouse melanoma, wild-type p53, p19Arf-null) with vectors encoding p19Arf or interferon-<font face=\"Symbol\">b (IFN<font face=\"Symbol\">b) resulted in massive death cell, while transfer of just one of these factors alone did not cause the same effect. The work described here includes two critical technologic advances in comparison with our previous work. First, transgenes of interest (eGFP, p19Arf and IFN<font face=\"Symbol\">b) were inserted into an adenoviral vector which presents the RGD tripeptide in its fiber. This vector modification allows efficient transduction in a wide range of target cells without dependence on the wild type adenovirus receptor, CAR. In addition, a bicistronic vector was constructed which contains the combination of both therapeutic genes, ensuring the transfer of both factors to the target cells at the same time. Use of p19Arf, a tumor suppressor and MDM2 inhibitor, as a therapeutic gene should complement endogenous p53 activities and, as a consequence, promote expression from the AdPG vector and inhibit tumor cell proliferation. However, p19Arf gene transfer alone should have an effect only in transduced cells and, therefore, its effect would be limited. For this reason, we describe, in addition to p19Arf, the application IFN<font face=\"Symbol\">b, a secreted protein with antitumor functions, including inhibition of angiogenesis, induction of apoptosis and activation of immunologic response. This strategy involves several mechanistic levels related with the gene transfer process, including transduction efficiency, control over transgene expression and transgene activity. Therefore, it was proposed that the combination of p19Arf and IFN<font face=\"Symbol\">b could be an interesting strategy to induce primary tumor death and an immunologic response against metastatic cells. In this project, the construction of new vectors optimized for gene transfer in melanoma cells was initiated.

Analisamos a expressão de IL-10, IFN-<font face=\"symbol\">g e, seus receptores pelas células trofoblásticas de camundongos, citocinas anti e pró-inflamatórias. Cones ectoplacentários aos 7,5 dias de gestação foram cultivados por 48 h e em seguida tratados com 100 U/mL IFN-<font face=\"symbol\">g ou 10 <font face=\"symbol\">hg/mL IL-10. Após 6 h e 14 h, as amostras foram processadas para análise da expressão gênica por RT-PCR e protéica por imunohistoquímica, respectivamente. Grupos controle não receberam tratamento. IFN-<font face=\"symbol\">g aumentou a expressão de IL-10R1 mas não a de IL-10 nas células trofoblásticas. IL-10, ao contrário, aumentou a expressão de IFN-<font face=\"symbol\">g, mas diminuiu IFN-<font face=\"symbol\">gR<font face=\"symbol\">a e não alterou IFN-<font face=\"symbol\">gR<font face=\"symbol\">b. Reações imunohistoquímicas confirmaram os resultados de expressão gênica. Isto sugere que o trofoblasto pode participar da imunidade da interface materno-placentária aumentando a expressão de IFN-<font face=\"symbol\">g em situações em que no meio há aumento de citocinas anti-inflamatórias, o que deve ser o reflexo da necessidade e importância desta citocina para o sucesso da gestação. / Key cytokines such as IL-10 and IFN-<font face=\"symbol\">g, essential for immune response regulation, have also been found locally at maternal-placental interface during mouse pregnancy. Particularly, levels of IL-10 characterize an anti-inflammatory environment associated to the inhibition of T helper-1 lymphocytes (Th1) development and the proliferative stimulation of the B lymphocytes (humoral response). On the other hand, increases in IFN-<font face=\"symbol\">g profile prevent T helper-2 lymphocytes (Th2) activation leading to an inflammatory response that favors a Th1 response. The local production of these cytokines by NK uterine cells and T gd lymphocytes are relevant, but not exclusive. Thus, this study analyzed the potential contribution of the trophoblast in the maintenance of Th1/Th2 balance in the maternal-placental interface, represented, respectively by the expression of IL-10 and IFN-<font face=\"symbol\">g cytokines. The expression of the anti-inflammatory cytokine IL-10 and its receptor was evaluated in the presence of an inflammatory environment mimetized by IFN-<font face=\"symbol\">g addition to the culture medium. On contrary, the expression of the IFN-<font face=\"symbol\">g (and its receptor) was evaluated in the presence of IL-10 characterizing an anti-inflammatory condition. Mouse trophoblast cells were isolated from implantation sites at gestational day 7.5 and cultured in standard conditions. Gene and protein expression were determined by immunohistochemistry and RT-PCR. IL-10 and IFN-<font face=\"symbol\">g and their receptors were expressed in cultured trophoblast cells in the absence or presence of IFN-<font face=\"symbol\">g and IL-10, respectively. IFN-<font face=\"symbol\">g treatment increased IL-10R1 expression but do not alter IL-10 expression. On contrary, in the presence of IL-10 the IFN-<font face=\"symbol\">g expression increased significantly while the expression of its receptor decreased. These results suggest that a proinflammatory environment increases trophoblast responsiveness to IL-10 whereas an anti-inflammatory condition seems to reinforce the importance of IFN-<font face=\"symbol\">g expression at the maternal-placental interface, on the initial periods of gestation.

O melanoma representa menos de 5% de todos os cânceres de pele, porém, quando em estádio metastático possui prognóstico ruim. Entretanto, o genótipo dos melanomas pode prover uma oportunidade para intervenção terapêutica pelo fato de 90% dos casos de melanoma possuem p53 selvagem e grande parte destes possuem deleção na região cromossômica codificadora de interferon beta. Em prévios estudos, desenvolvemos o vetor adenoviral AdRGD-PG que fornece expressão do transgene em resposta à p53 através do promotor PG e ainda o tripeptídeo RGD, que possibilita que o adenovírus transduza uma maior gama de células pela alteração de seu mecanismo de entrada. Temos utilizado este vetor para entrega da versão murina de interferon beta em modelos de terapia gênica e imunoterapia de melanoma murino, revelando uma significativa habilidade do interferon beta em inibir a proliferação celular in vitro e in vivo e promover resposta imune antitumoral. No presente trabalho, os esforços se aplicam em adaptar essa estratégia em modelo de melanoma humano para observar se a mesma interação é encontrada. O vetor AdRGD-PGhIbeta, portador do cDNA de interferon beta humano (hIbeta) foi construído e expressão do transgene observada após transdução das linhagens estabelecidas de melanoma humano SK-MEL-05 e SK-MEL-147 (ambas p53 selvagem). Foi observado um robusto efeito antitumoral in vitro onde transferência de hIbeta promoveu acumulo de células hipodiploides (mais que 80% da população celular 96 horas após transdução) e evidências de morte por apoptose (exposição de fosfatidilserina e atividade de caspases 3/7) em ambas as linhagens. Nas duas linhagens, o efeito bystander foi demonstrado quando a presença de poucas células transduzidas (ex., 10%) foi suficiente para promover o acumulo significativo de células hipodiploides (mais que 40% neste exemplo). Em modelo de terapia gênica in situ utilizando células SK-MEL-147, também foi observado forte efeito antitumoral da hIbeta com total remissão do tumor de todos os animais tratados sem recidiva durante noventa dias. A presença de hIbeta na circulação dos animais foi confirmada 48h após o tratamento com AdRGD-PG hbeta mas presente em somente dois de sete animais 90 dias após o tratamento, sugerindo que o tratamento inicial e não um efeito off target foi responsável pela resposta. Com a finalidade de investigar efeitos colaterais do sequestro do vetor adenoviral pelo fígado, observamos a concentração circulante das enzimas aminotransferase de aspartate e aminotransferase de alanine (AST e ALT, respectivamente), que se mostrou não alterada quando comparadas entre animais que receberam injeção do vetor tratamento, vetor controle e solução salina. Com nossos resultados concluímos que vetores adenovirais carreando interferon-beta humano são capazes de transduzir a linhagem de melanoma SK-MEL-147 in vitro e in vivo, promovendo efeito bystander e remissão tumoral sem indução de efeitos adversos / Melanoma represents less than 5% of all cases of skin cancer, although, when metastatic, prognosis is dire. However, the genotype of melanomas might provide an opportunity for therapeutic intervention since 90% of melanoma cases possess wild-type p53 and a great portion of these possess deletion of the chromosomal region encoding interferon beta. In previous studies, we developed the adenoviral vector AdRGD-PG that supplies expression of the transgene in response to p53 through the PG promoter and that utilizes the RGD tripeptide, allowing the adenovirus to transduce a wider range of cells due to the alterated mechanism of entrance. We have used this vector to deliver the murine version of interferon beta in murine models of melanoma gene therapy and immunotherapy, revealing a significant ability of interferon beta to inhibit cellular proliferation in vitro and in vivo and promote an anti-tumor immune response. In the present project, we aimed to adapt this strategy for a human melanoma model in order to reveal if the same impact will be observed. The AdRGD-PGhIbeta vector encoding the human interferon beta (hIbeta) cDNA was constructed and expression of the transgene confirmed after transduction of the established human melanoma cell lines SK-MEL-05 and SK-MEL-147 (both wild-type p53). A striking anti-tumor effect was observed in vitro where the transfer of hIbeta promoted an accumulation of hypodiploid cells (over 80% of the cellular population 96 hours after transduction) and evidence of death by apoptosis (exposure of phosphatidylserine and activity of caspases 3/7) in both cell lines. In these cell lines, a bystander effect was demonstrated when the presence of few transduced cells (ex., 10%) was enough to promote significant accumulation of hypodiploid cells (over 40% in this example). In a model of in situ gene therapy using SK-MEL-147 cells, hIbeta induced a strong anti-tumor effect including total tumor remission in all treated animals without relapse during ninety days. The presence of hIbeta in the circulation of the animals was confirmed 48h after treatment with AdRGD-PGhIbeta, but was present in only two of the seven animals 90 days post-treatment, suggesting that the initial treatment, not off target effects, was responsible for the response. With the goal of investigating collateral effects of adenoviral sequestration by the liver, we assayed the circulating concentration of aspartate aminotransferase and alanine aminotransferase (AST and ALT, respectively), which showed no alteration when compared with animals that received the treatment with a control vector or saline solution. We conclude that our adenoviral vector carrying human interferon-beta is capable of transducing the human melanoma cell line SK-MEL-147 in vitro and in vivo, promoting a bystander effect and tumor remission without inducing adverse effects

L’immunité innée représente la première ligne de défense d’un organisme face à une infection virale, en engendrant une réponse rapide capable de restreindre la menace microbienne. Dans la cellule, les récepteurs Toll-likes (TLRs) et les hélicases cytosoliques RIG-I like (RLRs) représentent les deux systèmes majeurs de reconnaissance des virus. Les acides nucléiques viraux sont notamment reconnus les hélicases cytosoliques RIG-I et MDA5. Ces deux protéines possèdent deux domaines CARD impliqués dans le recrutement de la protéine adaptatrice MAVS, capable d’induire l’activation des promoteurs interférons (IFNs) de type I et de NF-B pour la mise en place d’une réponse antivirale. De façon surprenante, MAVS est localisée au niveau de la mitochondrie et a besoin de cette association au compartiment mitochondrial pour exercer sa fonction. Bien que de nombreuses études aient montré le rôle crucial de la protéine mitochondriale MAVS dans la signalisation antivirale des RLRs, sa régulation est encore mal connue à ce jour. Ce travail de doctorat a permis de mettre en évidence que la dégradation de MAVS suite à une infection virale est nécessaire à la transduction du signal antiviral. Nous avons ainsi déterminé que l’E3 ubiquitine ligase TRIM25 induit l’ubiquitination puis la dégradation de MAVS quelques heures après une infection virale. De plus, nous avons montré que l’activation du signalosome aboutissant à la production des IFNs de type I et dépendant de MAVS n’a lieu que suite à sa translocation de la mitochondrie vers le cytosol permise par la dégradation de MAVS. Enfin, nous avons mis en évidence le rôle essentiel de l’élongation du réseau mitochondrial suite à une infection virale pour la transduction du signal dépendant de MAVS. / Innate Immunity acts as the first line of the host defense against viral infection, providing a rapid response to restrict the microbial threats. Toll-like receptors (TLRs) and cytosolic RIG-I-like helicases (RLRs) are the two major receptor systems for detecting virus. Viral nucleic acids are recognised by the helicases RIG-I and MDA5. These receptors contain two CARD domains involve in the recruitment of the mitochondrial antiviral signaling adaptor MAVS whose activation triggers a rapid production of type 1 interferons (IFNs) and of pro-inflammatory cytokines. Interestingly, it has been reported that MAVS must be localized to mitochondria to exert its function. While MAVS is essential for this signaling, its function and regulation remain unclear. In this work, we report that RLR activation triggers MAVS ubiquitination by the E3 ubiquitin ligase TRIM25 and marks it for proteasomal degradation concomitantly with downstream signaling. MAVS appears to function as a recruitment platform to first assemble a signaling complex, then the proteasome-mediated MAVS degradation is required to unleash into the cytosol this signaling complex allowing the signalosome activation and ensuing type I IFNs production. Futhermore, we reported that mitochondrial dynamics regulate MAVS-mediated signaling after viral infection.