Natural killer (NK) cells belong to the family of innate immune cells with the capacity to recognize and kill tumor cells. Different phenotypes and functional properties of NK cells have been described in tumor patients, which could be shaped by the tumor microenvironment. The discovery of HLA class I-specific inhibitory receptors controlling NK cell activity paved the way to the fundamental concept of modulating immune responses that are regulated by an array of inhibitory receptors, and emphasized the importance to explore the potential of NK cells in cancer therapy. Although a whole range of NK cell-based approaches are currently being developed, there are still major challenges that need to be overcome for improved efficacy of these therapies. These include escape of tumor cells from NK cell recognition due to their expression of inhibitory molecules, immune suppressive signals of NK cells, reduced NK cell infiltration of tumors, an immune suppressive micromilieu and limited in vivo persistence of NK cells. Therefore, this review provides an overview about the NK cell biology, alterations of NK cell activities, changes in tumor cells and the tumor microenvironment contributing to immune escape or immune surveillance by NK cells and their underlyingmolecular mechanisms as well as the current status and novel aspects of NK cell-based therapeutic strategies including their genetic engineering and their combination with conventional treatment options to overcome tumor-mediated evasion strategies and improve therapy efficacy.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23773号 / 医博第4819号 / 新制||医||1057(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 金子 新, 教授 杉田 昌彦, 教授 松田 秀一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Graft-versus-host disease (GvHD) is a major complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and is highly influenced by the degree of HLA matching between recipient and donor. The HLA-class Ib molecule HLA-G has been shown to promote tolerogenicity through its interaction with inhibitory receptors found on several immunocompetent cells. We hypothesized that in an allo-HSCT setting, HLA-G mismatches may negatively impact the HLA-G-mediated tolerogenicity either due to inefficient interaction with the inhibitory receptors of the transplanted immune cells or due to direct allorecognition of mismatched HLA-G on host cells by the immune cells of the donor.

La greffe rénale est le meilleur traitement de l’insuffisance rénale terminale. Par contre, la perte prématurée du greffon est un problème majeur chez les greffés qui est due majoritairement au rejet. La classification de Banff reconnait 2 catégories de rejets : une réaction médiée par les anticorps (ABMR) et/ou une réaction cellulaire (TCMR). L’ABMR est caractérisé par le développement de novo d’anticorps contre le donneur (DSA) en circulation et des dommages histologiques, comme la glomérulopathie du transplant. De novo, les DSA anti-HLA-II sont plus fréquemment associés à la glomérulopathie du transplant que les anti-HLA-I et sont associés à un moins bon pronostic clinique. Toutefois, le mécanisme par lequel les anti-HLA-II sont plus dommageables demeure mal connu. Mon hypothèse est que les anticorps anti-HLA sont suffisants pour perturber l’hémostase de l’endothélium glomérulaire. Plus particulièrement, nous croyons que les anticorps anti-HLA-II, diminuent l’expression de la thrombomoduline (TBM), ce qui pourrait mener aux lésions endothéliales glomérulaires associées à la glomérulopathie du transplant. Pour évaluer cette hypothèse, j’ai utilisé un modèle in vitro d’endothélium glomérulaire humain et du sérum de patients transplantés rénaux. Nous avons observé que l’expression membranaire de la TBM augmentait de manière dosedépendante en présence d‘anti-HLA-I, mais pas anti-HLA-II. Toutefois, lors de la mesure intracellulaire nous avons observé une accumulation cytosolique en réponse à une stimulation par les anti-HLA-II. De plus, nous avons observé une association significative entre la présence de DSA circulants anti-HLA-II dans les patients transplantés rénaux et un faible taux de TBM sérique. Ces résultats indiquent que la liaison des anticorps anti-HLA-I et II produit des effets différents sur l’expression endothéliale de la TBM. Les anticorps anti-HLA-II pourraient être associés à un état prothrombotique qui pourrait expliquer l’occurrence plus élevée de lésions microangiopathiques dans l’allogreffe et la moins bonne condition observée chez les patients ayant ces anticorps. / Kidney transplant is the best treatment for end-stage renal disease. However, premature graft loss is an important problem in kidney allograft, mostly caused by rejection. Banff classification recognizes two allograft rejection categories: antibody-mediated rejection (ABMR) and/or cellular rejection (TCMR). ABMR is characterized by: development of circulating de novo antibodies against the donor (DSA) and histological damages like transplant glomerulopathy. De novo, anti-HLA-II antibodies are more frequently associated with transplant glomerulopathy than anti-HLA-I antibodies. However, the mechanistic of how anti-HLA-II antibodies are more damaging is still not fully understood. My hypothesis is that anti-HLA antibodies are sufficient to disrupt surface hemostasis (process which causes bleeding to stop) of glomerular endothelium. More importantly, we think that anti-HLA-II antibodies could decrease expression of thrombomodulin (TBM), which could lead to glomerular endothelial lesions associated with transplant glomerulopathy. To evaluate this hypothesis, I used an in vitro model of human glomerular microvascular endothelium and sera from transplant recipients. We observed that membrane TBM expression is up-regulated in a dose-dependent manner with anti- HLA-I, but not anti-HLA-II. However, when we measured intracellular TBM, we observed a cytosolic accumulation in response to anti-HLA-II stimulation. Furthermore, we observed a significant association between anti-HLA-II DSA in renal transplant recipients and low serum levels of TBM. These results show that anti-HLA I or II antibodies binding produce differential effects on TBM endothelial expression and on TBM serum levels in transplant recipients. Anti-HLA-II antibodies could be associated with prothrombotic state, which could explain the higher occurrence of microangiopathic lesions in the allograft and the poor outcomes observed in patients with these antibodies.

Le virus de l’immunodéficience humaine de type 1 (VIH-1) infecte et se réplique dans les cellules du système immunitaire. À sa sortie de la cellule, le virus s’enveloppe d’une partie de la membrane cellulaire et acquiert alors certaines des protéines membranaires de la cellule hôte. C’est le cas de la protéine HLA-DR du complexe majeur d’histocompatibilité de classe II (CMH-II) nécessaire à la présentation antigénique. Son incorporation par le virus augmente le potentiel infectieux et contribue à la persistance du virus. Vpu est une protéine du VIH-1 qui contribue au bourgeonnement viral. Une étude récente a montré que Vpu pourrait diminuer l’expression de HLA-DR mature à la surface des cellules infectées. Toutefois, il est aussi reconnu que Vpu module l’acquisition de HLA-DR mature par le VIH-1. Ces résultats pouvaient être expliqués par un contrôle de la localisation intracellulaire de HLA-DR et/ou des protéines structurales du VIH-1 par Vpu. En somme, Vpu pourrait favoriser les interactions spécifiques entre HLA-DR mature et le VIH-1 tout en diminuant l’expression générale de HLA-DR mature à la surface de la cellule. Nous avons souhaité confirmer ce double rôle de Vpu qui est important dans la pathogénèse du virus puisqu’il bénéficie ainsi des avantages de l’incorporation du HLA-DR mature tout en court-circuitant son rôle dans la réponse antigénique normale. Il est également admis que le virus bourgeonne à partir des microdomaines (radeaux lipidiques) de la cellule hôte. Ces régions de la membrane sont riches en cholestérol et constituent le lieu d’expression préférentiel des molécules de HLA-DR mature. Lors d’un traitement avec de la Simvastatin™, les radeaux lipidiques sont affectés car cette drogue inhibe la synthèse du cholestérol et de surcroit, diminue l’expression de HLA-DR mature à la surface cellulaire. L’usage de la Simvastatin™ nous a renseigné sur l’endroit où le virion pouvait interagir et éventuellement incorporer la molécule de l’hôte HLA-DR dans son enveloppe. Ce projet de recherche à permis de caractériser les interactions entre Vpu et HLA-DR et ainsi de mieux comprendre les mécanismes par lesquels Vpu module à la fois l’expression de HLA-DR à la surface des cellules infectées ainsi que son incorporation sur les virions. Les études conduites en microscopie confocale par co-marquage fluorescent de Vpu et HLA-DR ont conduit à la mise en évidence de l’existence d’une interaction entre Vpu et HLA-DR au sein de la cellule infectée. Les mesures de l’expression de HLA-DR à la surface de cellules infectées et de son incorporation à la surface des virions à l’aide des techniques de cytométrie en flux et d’immunocapture ont également permis de confirmer la modulation de l’expression de HLA-DR par Vpu. Enfin, le traitement des cellules infectées avec la Simvastatin™ nous a permis d’émettre l’hypothèse que l’acquisition de HLA-DR s’effectuait à une étape antérieure au bourgeonnement viral. Pour finir, nous avons tenté de corréler les différences observées dans la pathogénèse de certains sous-types viraux avec la variabilité de la séquence de Vpu entre ceux-ci, en lien avec une différence de localisation subcellulaire de Vpu. Les études conduites dans le cadre de mon projet de maîtrise ont contribués à une meilleure compréhension des mécanismes d’acquisition des molécules de l’hôte et de leur possible répercussion sur la pathogénèse du VIH-1 par différents sous-types viraux. Elles renseignent également de manière substantielle sur le rôle de Vpu, protéine dont le rôle est demeuré relativement méconnu dans la pathogénèse du VIH-1 ainsi que sur les mécanismes d’acquisition des molécules de l’hôte par le VIH-1. Les résultats présentés dans ce mémoire devraient susciter un regain d’intérêt pour cette protéine ainsi que pour les mécanismes d’incorporation des molécules de l’hôte par le VIH-1. / The type-1 human immunodeficiency virus (HIV-1) infects and replicates itself in the immune system cells. When it buds out, the virus covers itself with a part of the plasma membrane and then acquires some of the host membrane proteins. It is the case for the HLA-DR protein from the major histocompatibility complex class II (MHC-II) necessary for antigen presentation. Its viral incorporation increases the infectious potential and contributes to viral persistence. Vpu is an HIV-1 protein which contributes to the viral budding process. A recent study showed that Vpu could decrease the mature HLA-DR expression at the infected cell surface. Nevertheless, it is also known that Vpu modulates the mature HLA-DR acquisition by HIV-1. Those results could be explained by a control of the intracellular localization of HLA-DR and/or some HIV-1 structural protein by Vpu. In summary, Vpu could promote specific interactions between mature HLA-DR and HIV-1 while decreasing the general expression of mature HLA-DR at the cell surface. We wished to confirm the dual role of Vpu which is important in the viral pathogenesis by getting the mature HLA-DR incorporation advantages while short-circuiting its role in the normal antigen response. It is also accepted that the virus buds out from the infected cell lipid raft. These region are highly enriched with cholesterol and the preferential expression location of mature HLA-DR. With a Simvastatin™ treatment, the lipid raft are disrupt because this drug inhibit the synthesis of cholesterol, therefore down-modulating the mature HLA-DR expression at the cell surface. Using Simvastatin™ inform us on where the virus could possibly acquire the mature host molecule HLA-DR in its envelop. This research project allowed us to characterise the possible interactions between Vpu and HLA-DR that led to a better understanding of the mechanism by which Vpu modulates HLA-DR at the infected cell surface and its viral incorporation. The study conducted by confocal microscopy using multiple fluorescent tagging of Vpu and HLA-DR has led to the evidence of an interaction between Vpu and mature HLA-DR in an infected cell. The measurement of the cell surface expression of HLA-DR and its viral incorporation by flow cytometer and immunocapture techniques also allowed the confirmation of the Vpu modulation on HLA-DR expression. Finally, the Simvastatin™ treatment on infected cells allowed us to hypothesis that the mature HLA-DR acquisition was done at an earlier stage that the viral budding. To conclude, we also attempted to correlate the difference in the pathogenesis of some HIV-1 subtype with the sequence variability of Vpu between them: a link with a different subcellular localization of Vpu. The studies that have been performed in order to complete my master diploma have contributed to a better understanding of the acquisition mechanism of certain host molecules and their impact on different sub-types of HIV-1 pathogenesis. They also give substantial information on the roles of Vpu, a virus-encoded protein whose involvement in HIV-1 pathogenesis remains to be defined and on the acquisition mechanism of some host molecule by HIV-1. The results presented in this thesis will probably arouse an interest renewal for this protein and for the host molecule incorporation mechanism used by HIV-1.

Le virus de l’immunodéficience humaine (VIH) cause quotidiennement 14 000 nouvelles infections et 8 000 décès (1). Certes, les antirétroviraux actuels aident le système immunitaire des porteurs du VIH à contenir le virus. Néanmoins, ils sont inefficaces pour guérir l’infection vu l’intégration du génome viral dans celui de la personne infectée. Ainsi, la prévention de l’infection demeure, en ce moment, la meilleure arme dont nous disposions contre ce rétrovirus. La connaissance du cycle de réplication du VIH-1 constitue la pierre angulaire de la conception de médicaments et d’outils de prévention. C’est pourquoi nous en étudions des étapes encore peu définies comme le bourgeonnement, et plus particulièrement l’incorporation de molécules d’origine cellulaire dans l’enveloppe virale. Les résultats présentés dans cette thèse montrent que des isolats cliniques du VIH-1 acquièrent les molécules HLA-DR, ICAM-1, CD40, CD86 et CD40L des cellules qu’ils infectent dans des modèles de culture de cellules reflétant au mieux la réalité du corps humain, telles des cultures ex vivo de portions d’amygdales palatines. Par le fait même, nous sommes les premiers à mentionner la présence de CD40L dans l’enveloppe du VIH-1. Également, nos résultats relatifs à l’appropriation des protéines cellulaires HLA-DR et CD40L par ce virus prouvent que celle-ci découle d’un mécanisme indépendant des glycoprotéines de l’enveloppe virale. Nos résultats démontrent aussi que les lymphocytes B d’amygdales palatines sont activés suite à la sollicitation de leur récepteur CD40 par la molécule CD40L insérée dans l’enveloppe du VIH-1. Ainsi, la translocation de NF-κB au noyau de ces cellules est induite, de même que la sécrétion d’anticorps IgG et d’IL-6 et l’adhésion cellulaire homotypique. La molécule CD40L permet au virus de mieux se lier aux lymphocytes B qui le transmettent par ailleurs aux lymphocytes T CD4+. Enfin, caractériser davantage le mécanisme d’acquisition de molécules de l’hôte par le VIH-1 et son impact sur la pathogenèse associée au virus contribuera peut-être à identifier des molécules pouvant être ciblées par une nouvelle thérapie, voire une immunisation. / Ever since mankind faced human immunodeficiency virus (HIV), advances in research have been compromised by many difficulties, some of them being related to the complexity of the virus. Because HIV causes 14 000 new infections and 8 000 deaths daily (1), we must work intensely to fight this pathogen. Although antiretroviral drugs help the immune system of HIV-infected individuals to contain the virus, these drugs are ineffective to cure the infection, considering that the viral genome is integrated within the host genome. Thus, the best way to fight HIV infection at this point is to prevent it. The design of new therapies and prevention tools rely on our knowledge of the replication cycle of HIV. Therefore, we study steps of the viral cycle that are less defined, such as budding, and particularly the incorporation of molecules of cellular origin in the viral envelope. The results we present in this thesis show that host-derived HLA-DR, ICAM-1, CD40, CD86 and CD40L molecules are acquired by clinical isolates of HIV-1 produced in the most natural culture models, such as pieces of palatine tonsils cultured ex vivo. Moreover, we are the first to report the CD40L molecule as being part of HIV-1’s envelope. Also, our results indicate that incorporation of host HLA-DR and CD40L is independent of viral envelope glycoproteins. Furthermore, our results show that B lymphocytes from tonsils are activated following the binding of their CD40 receptor by the CD40L molecule inserted in the envelope of HIV-1. The translocation of NF-κB to the nucleus of cells is then induced, as for the secretion of IgG antibodies, production of IL-6 and homotypic cell-to-cell adhesion. The CD40L protein facilitates binding of virions to B lymphocytes which transfer them to T CD4+ lymphocytes. In the future, further investigation of the mechanism of HIV-1 host molecule incorporation and its impact on HIV-1 pathogenesis may help in the identification of new molecules being able to be targeted by a new therapy or immunization.

Apžvelgiami klinikiniai tyrimai atlikti VU Imunologijos institute Molekulinės imunologijos laboratorijoje, bendradarbiaujant su Vilniaus universitetinės Greitosios pagalbos ligoninės Bendrosios chirurgijos centro Ginekologijos skyriumi bei „Vaisingumo klinika“. Tyrimams atlikti buvo gauti du Lietuvos Bioetikos komiteto leidimai. Darbo tikslas - nustatyti gimdos gleivinės imunines ląsteles bei įvertinti jų vaidmenį reprodukcijos procese. Medžiaga ir metodai. Tyrimuose dalyvavo vaisingos moterys (kontrolinė grupė) (n=142), nevaisingos moterys (121), moterys patyrusios savaiminį persileidimą (n=35) ir endometrioze sergančios moterys (n=181). Naudoti tyrimo metodai: ląstelių morfologiniam įvertinimui - citologinis, imuninių ląstelių fenotipo nustatymui - tėkmės citometrijos, tirpių medžiagų (citokinų, HLA-G molekulių) koncentracijos nustatymui – imunofermentinis metodas. Rezultatai ir išvados. Menstruacinio ciklo metu kito endometriumo imuninių ląstelių sudėtis, limfocitų ir makrofagų aktyvacijos molekulių ekspresija: priešmenstruaciniu periodu daugėjo makrofagų (proliferacijos fazėje – 7,3±2,8%, vėlyvos sekrecijos fazėje - 13,7±3,1%) ir NK ląstelių (proliferacijos fazėje – 18,3±5,8%, vėlyvos sekrecijos fazėje – 51,1±9,8%). Didžiausias skaičius aktyvuotų makrofagų gimdos gleivinėje, ekspresuojančių CD69 ir CD54 molekules, buvo randamas proliferacijos fazėje (14,3±5,6% ir 26,2±4,8% atitinkamai). Decidualiniame audinyje nustatėme ypatingo fenotipo intensyviai CD56... [toliau žr. visą tekstą] / Clinical tests performed in the Laboratory of Molecular Immunology of the Institute of Immunology of Vilnius University in cooperation with the Gynaecological Department of the General Surgery Center of Vilnius University Emergency Aid Hospital and Fertility Clinic, Vilnius are reviewed. Two permissions have been obtained from the Lithuanian Committee of Bioethics for carrying out the tests. The aim of the study was to determine endometrial immune cells and to evaluate their role in the reproduction process. Materials and methods. The following groups of women took part in our study: fertile women (they formed control group) (n=142), infertile women (n=121), women after miscarriage (n=35) and women with endometriosis (n=181). The following laboratory methods were used: cytological (to define the morphology of cells); flow cytometry (for detection of the phenotype of immune cells) and immunoenzyme assay – to quantify the concentration of soluble substances, such as cytokines and HLA-G molecules. Results and Conclusions. Composition of the endometrial immune cells, expression of lymphocyte and macrophage activation molecules has been changing during the menstrual cycle. In the pre-menstrual period the number of macrophages and NK cells has increased: in the stage of proliferation-7.3±2.8%; in the late stage of secretion – 13.7±3.1% and in the stage of proliferation – 18.3±5.8%, in the late stage of secretion – 51.1±9.8, respectively. The highest amount of activated macrophages... [to full text]

Les maladies immunitaires chroniques incluant les maladies auto-immunes et inflammatoires touchent 20 à 25% de la population des pays occidentaux. La comparaison des taux de concordance chez les jumeaux ou l’histoire familiale de sujets atteints de la maladie cœliaque (maladie auto-immune de l’intestin) ou de l’œsophagite éosinophilique (maladie inflammatoire de l’œsophage) indiquent que des facteurs génétiques et environnementaux interviennent dans la susceptibilité à ces maladies. Cependant, ces études ne distinguent pas de manière claire la prédisposition génétique selon l’hétérogénéité clinique (enfants versus adultes) ou ethnique (stratification des populations). Méthodes. Les haplotypes HLA de prédisposition à la maladie cœliaque et les polymorphismes des gènes candidats IL-13 (R130Q), IL-5 (-746 T/G) et IL-5R (-80A/G) impliqués dans la physiopathologie de l’œsophagite éosinophilique, ont été caractérisés par la technique PCR-SSP sur l’ADN génomique. Résultats: Nos études familiales et cas-contrôles réalisées chez une population Québécoises avec un fond génétique très homogène nous a permis : i) d’éviter le problème de stratification des populations, ii) de confirmer que les gènes HLA sont également associés à la maladie cœliaque (enfants et adultes) au Québec comme dans les autres populations Caucasiennes, iii) de mettre en évidence le rôle du gène IL-13 dans la prédisposition à l’œsophagite éosinophilique (garçons et filles) et d’exclure les gènes IL-5 et IL-5R comme facteurs de susceptibilité dans notre population. Conclusion: Ce travail confirme pour la première fois l’impact des gènes HLA dans la prédisposition à la maladie cœliaque et le rôle du facteur génétique dans l’œsophagite éosinophilique chez une population Canadienne Française avec un fond génétique ayant un fort effet fondateur. / Chronic immune diseases including autoimmune and inflammatory diseases affect 20 to 25% of Western country population. The higher concordance of disease in twins or in first-degree relative of patients with celiac disease (bowel autoimmune disease) or eosinophilic esophagitis (inflammatory disease of the esophagus) indicate that genetic and environmental factors are involved in susceptibility to these diseases. However, these studies do not distinguish clearly genetic predisposition according to clinical heterogeneity (children versus adults) or ethnicity (population stratification). Methods: HLA haplotypes predisposing to celiac disease and polymorphisms of candidate genes IL-13 (R130Q), IL-5 (-746 T / G) and IL-5R (-80A / G) involved in physiopathology of eosinophilic esophagitis, have been evaluated by PCR-SSP on genomic DNA. Results: Our familial and case-control studies performed in populations having a very similar genetic background with a strong founder effect, allowed us: i) to avoid the problem of population stratification, ii) to confirm that HLA genes are also associated with celiac disease in Quebec (children and adults) as in other Caucasian populations, iii) to identify the role of IL-13 gene in susceptibility to eosinophilic esophagitis (boys and girls) and to exclude IL-5 and IL-5R genes as susceptibility factor in our population. Conclusion: This study confirms for the first time the impact of HLA genes in predisposition to celiac disease and the role of genetic factors in eosinophilic esophagitis in a French Canadian population with a strong founder effect.

Kidney transplantation is the most appropriate treatment for end-stage kidney failure. The risk of graft failure in retransplanted patients is generally higher than in first-transplant patients due to immunological and non-immunological reasons. An important risk factor to consider for retransplant patients is their sensitization, i.e. the presence of antibodies directed to HLA antigens of previous donor(s). For that reason, a project called Forbidden (Non-acceptable) Antigens was launched by IKEM with the aim of reducing the incidence of acute cellular and antibody-mediated rejection in retransplant patients. Work on the project was carried out between the years 2011-2013. Forbidden antigens were defined as mismatched HLA antigens of previous kidney donor(s) against which patients waiting for retransplantation produced antibodies. The aim of this diploma thesis is to evaluate whether the incidence of rejection is lower in patients with forbidden HLA antigens in comparison with a control cohort, where no forbidden antigens are defined. 234 patients (162 males and 72 females) were included in the study. Almost all tested patients were producing HLA antibodies (90.2%) and forbidden antigens were determined in 71.4% of patients. In a control group of 267 patients waiting for their first transplantation, the...

Infecção persistente por tipos oncogênicos de papilomavírus humano (HPV) é considerada como o principal fator de risco para desenvolvimento de carcinoma invasivo do colo uterino (CCU) e de lesões intraepiteliais cervicais (SIL). Fatores genéticos do hospedeiro, como o polimorfismos de genes HLA (human leukocyte antigen), também têm sido implicados na suscetibilidade a estas patologias e à infecção por (HPV), como observado em diversos estudos caso-controle. Neste estudo investigou-se em uma coorte de mulheres (Ludwig-McGill cohort) se a variabilidade dos genes HLA-DRB1 e -DQB1 influenciam na história natural das infecções por HPV e no risco de SIL. A tipificação de DRB1 e DQB1 foi realizada em 620 amostras provenientes de um estudo epidemiológico prospectivo. A positividade para HPV foi testada em amostras da mesma paciente coletadas a cada 4 meses, obtidos durante o primeiro ano de seguimento, enquanto os resultados de citologia perfazem os 2 primeiros anos de seguimento. Infecções persistentes de curta ou longa duração foram definidas como 2 e 3 resultados consecutivos positivos para o mesmo tipo de HPV, respectivamente. As associações foram estimadas através de razões de chance e intervalos de confiança de 95%, ajustadas para potenciais fatores de confusão. Os resultados obtidos indicam que a prevalência da infecção por HPV e o risco de persistência variam dependendo do haplótipo HLA. O haplótipo DRB1*0301-DQB1*0201 mostrou-se protetor contra a infecção por HPV, e DRB1*1102-DQB1 *0301 contra infecções persistentes. Já os haplótipos DRB1*1601-DQB1*0502 e DRB1 *0807-DQB1*0402 foram fatores de risco para infecções persistentes por HPV. Não foi observada uma forte concordância entre risco de infecção por HPV e risco de SIL associados a determinado HLA, em parte porque o número de pacientes com SIL foi um fator limitante neste estudo. Um risco aumentado de SIL, independente da infecção por HPV, foi associado com DRB1*0301 e DR12. Portadoras de DR4 e DQB1*0601 tiveram uma maior probabilidade de desenvolver SIL e HSIL, respectivamente. Uma associação negativa entre o alelo DQB1*0301 e HSIL foi verificada. Análise do dimorfismo na posição 86 da cadeia β de HLA-DR mostrou que valina nesta posição tem um efeito protetor para prevalência e persistência de infecção por HPV, e maior risco de SIL no grupo com infecções transitórias por HPV. Em outra análise, investigamos a distribuição de grupos alélicos de DRB1 em uma série independente de amostras provenientes de pacientes com CCU. Observamos um risco diminuído de desenvolvimento de CCU associado a DR3. Por outro lado, DR4 e DR8/12 mostraram-se fatores de risco para o CCU nesta população. Estes resultados sugerem que o polimorfismo de HLA desempenha um papel na história natural das infecções por HPV, SIL e CCU. Também analisamos respostas linfoproliferativas em pacientes com CCU, contra peptídeos derivados de E6 e E7 de HPV16. As respostas positivas foram mais freqüentes contra peptídeos de E6 do que E7. Não observamos resposta contra um peptídeo ou região em particular. Parte desta diversidade nas respostas linfoproliferativas pode ser relacionada com o polimorfismo de genes HLA e seu papel na seleção de epítopos. / Persistent infection with oncogenic human papillomavirus (HPV) is the major risk factor for the development of malignant lesions in the uterine cervix. Host factors have also been implicated in the pathogenesis of these diseases. Associations between human leukocyte antigen (HLA) polymorphisms and cervical cancer, precursor lesions or HPV infections have been reported by case-control studies in several populations. This study investigated through cohort analysis if human leukocyte antigen (HLA)-DRB1 and DQB1 variability is related to human papillomavirus (HPV) infection and squamous intraepithelial lesions (SIL) prevalence and persistence. HLA-DRB1 and DQB1 genes were typed in 620 samples from the Ludwig-McGill cohort. HPV positivity was tested in specimens collected every 4 months during the first year of follow-up. Persistent and long-term infections were defined as at least 2 or 3 consecutive positive results for the same HPV type, respectively. Analysis of SIL included data obtained during the two first years of follow-up. The magnitudes of associations were estimated by unconditional logistic regression analysis adjusted for potential confounders. Certain HLA alleles and haplotypes were associated with HPV either HPV prevalence or persistence. The DRB1*0301-DQB1*0201 haplotype was associated with a lower risk for HPV infection and DRB1*1102-DQB1*0301 for HPV persistence. DRB1*1601-DQB1*0502 and DRB1*0807-DQB1*0402 were associated with a increased risk for persistent HPV infection. It was not observed a strong concordance between the associations verified for HPV prevalence/persistence and SIL, possibly due to the limited number of SIL specimens. A higher risk for SIL, independent of HPV infection, was observed for DRB1*0301 and DR12. DR4 and DQB1*0601 carriers showed a higher frequency of SIL and HSIL, respectively. A negative association between DQB1*0301 and HSIL was verified. Valine at position 86 of the DRβ chain was associated with reduced risks of HPV positivity and persistence, as compared to glycine carriers. However, valine carriers had a higher risk of SIL if transiently infected by HPV. We also analyzed an independent sample of patients with invasive cervical, and a protective effect was observed for DR3. On the other hand, DR4 and DR8/12 were associated with a higher risk for cervical cancer in this population. Our results suggest that HLA class II polymorphisms and pocket 1 profile are involved in clearance and maintenance of HPV infection and the risk of SIL and CCU, consistent with the hypothesis that genetic background is important in the natural history of HPV infections and associated lesions. We also analyzed lymphoproliferative responses against HPV16 E6 and E7 peptides, in patients with invasive cervical cancer. Lymphoproliferative responses were more frequent for E6 peptides than for E7 peptides. The responses were not restricted to a particular peptide, which is expected based on HLA variability observed among patients.