Individuals under 20 years old have the highest risk of developing type 1 diabetes because their beta cells are destroyed at a faster rate than any other age group. Previous studies have looked at delaying and slowing down the rate of beta cell destruction through the use of anti-CD3 antibody treatments. Specifically, Teplizumab and Otelixizumab drug therapies have been used to treat individuals within 12 weeks of diagnosis. Previous studies done with Teplizumab and Otelixizumab have focused on individuals between 12 and 40 years old; however, there is little research done the effects of these treatments on individuals under 12 years old. Since type 1 diabetes is primarily diagnosed in children the purpose of this proposal is to further the knowledge of the preservation of beta cells in children with the use of Teplizumab and Otelixizumab drugs over 2 years. This study will also focus on the delay of onset type 1 diabetes with the use of Teplizumab in high-risk individuals under 20 years of age. The high-risk individuals will be determined by using genetic screening on individuals with an affected immediate family member. Individuals will also be tested to see if they carry insulin autoantibodies (IAA), protein tyrosine phosphate-related IA-2 molecule (IA-2A), islet cell antibodies (ICA), and glutamic acid decarboxylase (GADA). Individuals that test positive for carrying the DR3/DR4 alleles in the genetic screening and that have two or more autoantibodies present in their immune systems will be selected to participate. The purpose of this proposal is to further understand the impact of anti-CD3 antibody treatment on young individuals diagnosed with type 1 diabetes and to further understand if treatment in young individuals with anti-CD3 antibodies can delay or prevent the onset of type 1 diabetes.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 4 uppsatser.

Trotz zahlreicher Fortschritte im Verständnis der Funktionsweise des kostimulatorischen Rezeptors CD28 in Mensch, Maus, Ratte und Makake ist nach wie vor wenig hierüber in Bezug auf das Tiermodell Schwein bekannt. Die vorliegende Arbeit untersucht die Funktion und Expression von CD28 in Schweine-T-Zellen sowie die Regulierbarkeit der T-Zellaktivierung durch anti-pCD28 mAb. Die Ergebnisse zeigen, dass hierbei vor allem CD4+ und CD8+ T-Zellen differenziert betrachtet werden müssen. Grundsätzlich unterscheiden sich die beiden T-Zellpopulationen in der CD28 mRNA Expression, im Expressionsverhältnis zwischen CD28 mRNA und Protein, sowie im proliferativen Ansprechen auf anti-pCD28mAb. So reagierten CD4+ im Vergleich zu CD8+ T-Zellen auf die kostimulatorische Inkubation mit anti-pCD28 mAb des Klons 3D11 sensibler. In direkt stimulatorischen Ansätzen zeigte sich, dass CD4+ und CD8+ T-Zellen durch unterschiedliche anti-pCD28 mAb differentiell angesprochen werden können. Eine superagonistische Funktion konnte für CD4+ T-Zell aktivierende anti-pCD28 mAb in den bisherigen Versuchen noch nicht beobachtet werden. Letzteres ist hierbei vor allem für den Transfer von vielversprechenden Therapiestrategien vom Kleintier- zum Großtiermodell auf dem Weg zur Entwicklung neuer Therapieoptionen für Autoimmunerkrankungen, Erkrankungen mit starker proinflammatorischer Aktivität und dem Myokardinfarkt von Bedeutung. / Even though tremendous progress has been made in clarifying the function of the costimulatory receptor CD28 in human, mouse, rat, and macaques, concerning pigs, an important large animal model, only little is still known about CD28 expression and function. Therefore, our work aimed at investigating the function and expression of CD28 in porcine T cells as well as the applicability of anti-pCD28 mAb as a tool to regulate T cell activation, specifically. Our results indicate that the two major T cell groups, CD4+ and CD8+, have to be considered separately. These cell populations differ in their level of pCD28 mRNA expression, their ratio of CD28 mRNA and protein expression as well as their proliferative responsiveness towards anti-pCD28 mAb. In costimulatory assays, CD4+ compared to CD8+ T cells showed higher sensitivity toward low concentrations of the anti-pCD28 mAb 3D11. Additionally, in direct stimulatory assays, CD4+ and CD8+ T cells can be specifically targeted by different anti-pCD28 mAb. With these assays, a superagonistic anti-pCD28 mAb could not been detected so far. With anti-pCD28 superagonist, promising therapeutic strategies developed in rodents could be tested in pigs as a large animal model, representing the next step on the way towards new therapeutic options for autoim-mune diseases, diseases with strong proinflammatory activity and myocardial infarction.

T cells are an essential part of the immune system. They determine the specificity of the immune response to foreign substances and, thus, help to protect the body from infections and cancer. Recently, T cells have gained much attention as promising tools in adoptive T cell transfer for cancer treatment. However, it is crucial not only for medical purposes but also for research to obtain T cells in large quantities, of high purity and functionality. To fulfill these criteria, efficient and robust isolation methods are needed. We used three different isolation methods to separate CD3-specific T cells from leukocyte concentrates (buffy coats) and Ficoll purified PBMCs. To catch the target cells, the Traceless Affinity Cell Selection (TACS®) method, based on immune affinity chromatography, uses CD-specific low affinity Fab-fragments; while the classical Magnetic Activated Cell Sorting (MACS®) method relies on magnetic beads coated with specific high affinity monoclonal antibodies. The REAlease® system also works with magnetic beads but, in contrast to MACS®, low-affinity antibody fragments are used. The target cells separated by TACS® and REAlease® are “label-free”, while cells isolated by MACS® still carry the cell specific label. The time required to isolate T cells from buffy coat by TACS® and MACS® amounted to 90 min and 50 min, respectively, while it took 150 min to isolate T cells from PBMCs by TACS® and 110 min by REAlease®. All methods used are well suited to obtain T cells in large quantities of high viability (>92%) and purity (>98%). Only the median CD4:CD8 ratio of approximately 6.8 after REAlease® separation differed greatly from the physiological conditions. MACS® separation was found to induce proliferation and cytokine secretion. However, independent of the isolation methods used, stimulation of T cells by anti CD3/CD28 resulted in similar rates of proliferation and cytokine production, verifying the functional activity of the isolated cells.

Etiological agents causing autoimmune diseases largely remain unknown. However, several lines of evidence suggest that environmental factors such as heavy metals (arsenic, lead and mercury) play a crucial role in the development of autoimmune disorders. In our model of mercury-induced autoimmunity, administration of subtoxic doses of HgCl2 to genetically susceptible strains of mice result in an autoimmune disease characterized by the production of highly specific anti-nucleolar autoantibodies, hypergammaglobulinemia and nephritis. However, mice can be tolerized to the disease by a single low dose administration of HgCl2 (tolerogenic dose). Previous studies from our lab had demonstrated that CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) control the induction and maintenance of tolerance to mercury. We investigated the therapeutic role of Tregs in our model by utilizing agents that are known to stimulate in vivo expansion of Tregs. We studied two such agents, CD3-specific non-Fc receptor-binding [(Fab’)2 fragment] monoclonal antibody (Anti-CD3) and immune complexes containing recombinant IL-2 and anti-IL-2 monoclonal antibody (IC). In our model, treatment of mice with Anti-CD3 had no effect on Treg population. Administration of Anti-CD3 with the tolerogenic dose prevented induction of tolerance and failed to improve the maintenance period of tolerance. Anti-CD3 in presence of mercury activated the immune-system causing splenomegaly and expansion of B cell population. Overall, in contrast to its protective role in other experimental autoimmune disease models, Anti-CD3 exacerbated mercury-induced autoimmune syndrome. Treatment of mice with IC resulted in selective expansion of Tregs with a modest decrease in IgE levels and autoantibody production. Administration of IC with the tolerogenic dose led to a reduction in autoantibody response, thus IC was able to extend the maintenance period of tolerance to mercury. Lymphocyte Activation Gene-3 (LAG-3) is an inhibitory molecule that maintains lymphocyte homeostatic balance by controlling effector T cell expansion and contributing to the suppressive functions of Tregs. Thus, with the goal to understand the impact of homeostatic balance on Hg-induced autoimmunity, we investigated the role of LAG-3 in our model. Administration of an anti-LAG-3 monoclonal antibody broke tolerance to Hg resulting in autoantibody production and an increase in levels of serum IgE. Additionally, LAG-3-deficient B6.SJL mice exhibited an increased susceptibility to mercury-induced autoimmunity whereas, wild type controls suffered only from a mild disease. Moreover, adoptive transfer of wild-type CD4+ T cells protected LAG-3-deficient mice from mercury-induced autoimmunity. Therefore, we conclude that LAG-3 exerts an important regulatory effect on autoimmunity elicited by a common environmental pollutant. / Microbiology and Immunology

L’hépatite autoimmune (HAI) est une maladie grave affectant le foie et présentant un haut taux de mortalité lorsque non traitée. Les traitements disponibles sont efficaces, mais de graves effets secondaires leur sont associés. Ces effets secondaires sont généralement le résultat d'une forte immunosuppression et d’autres sont spécifiques à chaque médicament. Aucune immunothérapie spécifique n’est présentement disponible pour le traitement de l’HAI. Récemment, un modèle murin d’HAI a été développé dans notre laboratoire par xénoimmunisation des souris C57BL/6 avec les antigènes humains de l'HAI de type 2. Ce modèle présente la plupart des caractéristiques biochimiques et cliniques retrouvées chez les patients atteints d'HAI de type 2. Dans cette étude, nous avons évaluée l’efficacité de deux types de traitement pour l’HAI de type 2 à l’aide de notre modèle murin. Dans un premier temps, l’anticorps anti-CD3ε a été étudié en prophylaxie et en traitement. Nous avons montré qu’une posologie de 5µg d’anti-CD3 i.v. par jour pendant 5 jours consécutifs induit une rémission chez les souris avec HAI de type 2 établie (traitement). Cette rémission est caractérisée par une normalisation des niveaux d’alanine aminotransférase et une diminution significative de l’inflammation hépatique. Cette rémission semble être associée à une déplétion partielle et transitoire des lymphocytes T CD3+ dans la périphérie et une augmentation des lymphocytes T régulateurs CD4+, CD25+ et Foxp3+ dans le foie. La même posologie lorsqu’elle est appliquée en prophylaxie n’a pas réussi à prévenir l’apparition de l’HAI de type 2. La deuxième voie de traitement consiste en l’administration par voie intranasale d’un forte dose de formiminotransférase cyclodésaminase murin (mFTCD), un autoantigène reconnu dans l’HAI de type 2. Une administration en prophylaxie par voie intranasale de 100µg de mFTCD par jour durant 3 jours consécutifs arrive à prévenir l’HAI de type 2 en diminuant l’inflammation hépatique au bout de deux semaines post-traitement. / Autoimmune hepatitis (AIH) is a severe liver disease with high mortality rates if left untreated. Current treatments, while effective, are associated with deleterious side-effects. These side effects are specific to each drug and the result of broad immunosuppression. Recently, a murine model of type 2 AIH has been created in our laboratory in wild-type naïve mice. In this model, DNA immunization with type 2 AIH human autoantigens breaks immune tolerance and induces an autoimmune response against the liver. Lately, new therapeutic strategies based on depletion of specific immune cell populations have been proposed for the treatment of several diseases, including autoimmune diseases. Currently, no immunotherapies using biological agents are available for the treatment of autoimmune liver diseases. Therefore, the goal of this project is to study the efficacy of new immunotherapeutic agents for the treatment of type 2 AIH in an experimental model. We evaluated the effectiveness of two approaches for treating type 2 AIH. First, we tested the anti-CD3ε antibody in prophylaxis and in treatment of type 2 AIH. We showed that a dosage of 5µg i.v. of anti-CD3ε antibody per day for 5 consecutive days induced remission in mice with established type 2 AIH. This remission was defined as a normalization of serum alanine aminostransferase levels and a significant decrease of liver inflammation in treated mice. This remission seems to be associated with a transitory depletion of CD3+ T lymphocytes in peripheral blood mononuclear cells and increased CD4+CD25+Foxp3+ regulatory T lymphocytes in the liver. But when this dosage was applied in prophylaxis, it could not prevent the induction of type 2 AIH. The second approach was to induce tolerance by nasal administration of murin formiminotransferase cyclodeaminase (mFTCD), an autoantigen of type 2 AIH. We showed that nasal administration of 100µg of mFTCD for 3 consecutive days prevented development of type 2 AIH in prophylaxis by reducing liver inflammation.

INTRODUÇÃO: o câncer é a doença que mais mata pessoas com idade abaixo de 85 anos e é um problema de saúde pública. Os tumores podem expressar em determinada fase de seu desenvolvimento proteínas anômalas que podem ser alvo de métodos diagnósticos e de intervenções terapêuticas. A expressão de NY-ESO-1 é detectada em 20 a 40% dos melanomas. Há evidências que esta expressão é mais freqüente em tumores de estágios mais avançados e está associada a um pior prognóstico. OBJETIVOS: determinar a frequência de expressão da proteína NY-ESO-1 no melanoma cutâneo e tentar correlacioná-la com o índice de Breslow, aspectos histopatológicos do melanoma, incluindo o infiltrado linfocítico tumoral, e a morbi-mortalidade dos pacientes. MÉTODOS: o presente estudo é longitudinal de coorte retrospectiva e foi realizado de agosto de 2009 a outubro de 2015. Foram selecionados 89 melanomas de 87 pacientes do Ambulatório de Tumores do Departamento de Dermatologia da FMUSP, divididos em 3 grupos, sendo: grupo 1: 34 melanomas com índice de Breslow <= 1,0 mm; grupo 2: 29 melanomas com índice de Breslow entre 1,1 - 4,0 mm e grupo 3: 26 melanomas com índice de Breslow >= 4,0 mm. As lâminas dos exames anátomo-patológicos destes pacientes foram revisadas quanto ao diagnóstico de melanoma, seu índice de Breslow e a presença de infiltrado linfocítico tumoral. A seguir, realizou-se exame de imunohistoquímica para a determinação da presença do antígeno NY-ESO-1 em todos os 89 tumores coletados e em mais 20 nevos (11 displásicos e 9 intradérmicos) escolhidos ao acaso. Através da revisão dos dados do prontuário, foram obtidos os dados clínicos de: idade, sexo, raça, fototipo da pele, local de aparecimento do melanoma, status do linfonodo sentinela quando realizado, desenvolvimento de metástases e sobrevida dos pacientes. Os dados anátomo-patológicos do tumor analisados foram: tipo histológico, presença de ulceração, e tipo de infiltrado linfocítico tumoral. Nos melanomas que apresentavam infiltrado linfocítico tumoral, foram realizados testes imunohistoquímicos para pesquisa de células CD3+, CD8+, FoxP3+ e CD8+FoxP3+ (duplamente positivas). RESULTADOS: O antígeno NY-ESO-1 esteve presente em 19% dos melanomas cutâneos primários e não foi detectado em nenhum dos 20 nevos pesquisados. A expressão do antígeno NY-ESO-1 esteve estatisticamente relacionada a tumores com espessuras maiores. Apresentou também uma associação inversa com o tipo extensivo superficial em relação aos outros tipos histológicos. O infiltrado linfocítico tumoral dos melanomas NY-ESO-1 positivos continha menor número de células CD3+, que se encontravam isoladas ou arranjadas em pequenos grupos de até 5 células, o que contrastava significantemente com os tumores NY-ESO-1 negativos, com maior densidade de células CD3+, dispostas em grandes grupos, com 6 ou mais células. A expressão da proteína NY-ESO-1 não esteve associada à idade, ao sexo, ao fototipo, ao sítio primário do tumor, à presença de ulceração, ao status do linfonodo sentinela, ao desenvolvimento de metástases ou à sobrevida. CONCLUSÕES: Há expressão de NY-ESO-1 em uma porcentagem considerável dos melanomas, principalmente nos mais espessos. O menor número de células CD3+ no infiltrado linfocítico tumoral, acrescido ao fato destas células estarem isoladas ou em pequenos grupos, sugere que embora imunogênico, a expressão do antígeno NY-ESO-1 não resulta num estímulo eficaz do sistema imune no combate ao tumor. O desenvolvimento de uma vacina para estes pacientes poderá, no futuro, aumentar as possibilidades terapêuticas do melanoma / INTRODUCTION: cancer is the disease that leads to the greatest number of deaths in people over 85 years old and it has become a major public health problem. Tumors may express aberrantly proteins during certain phases of their development, which can be target for diagnostic or treatment purposes. NY-ESO-1 is detected in 20 to 40% of melanomas. There is evidence that it is more frequent in advanced stages and that is associated with a worse prognosis. OBJECTIVES: to determine the frequency of NY-ESO-1 protein expression in cutaneous melanoma and to try to correlate it to Breslow index, melanoma histopathological aspects, including the tumor infiltrating lymphocytes, and patients morbi-mortality. METHODS: the present study is longitudinal of retrospective cohort. The research was carried on from August 2009 to October 2015. Eighty nine melanomas were selected from 87 patients in Oncology Outpatient Clinic, Dermatology Division, University of São Paulo and divided in 3 groups, such as: group 1: 34 melanomas with Breslow index <= 1,0 mm; group 2: 29 melanomas with Breslow index between 1,1 - 4,0 mm e group 3: 26 melanomas with Breslow index >= 4,0 mm. All specimens were reviewed for diagnostic, Breslow index and tumor infiltrating lymphocytes. After that, immunohistoquimical test for the presence of NY-ESO-1 antigen was performed in all 89 melanomas collected and in 20 nevi (11 dysplastic nevi and 9 dermal nevi) that were randomly chosen. By reviewing clinical charts, the following data was obtained: age, sex, skin phototype, site of the tumor, lymph node sentinel status, development of metastases and survival of the patients. The histological data analyzed was: histological melanoma type, presence of ulceration, grade of tumor infiltrating lymphocytes. In those melanomas that had tumor infiltrating lymphocytes, we performed immunohistoquimical tests for the presence of CD3+, CD8+, FoxP3+ and CD8+FoxP3+ (double positive) cells. RESULTS: antigen NY-ESO-1 was present in 19% of primary cutaneous melanomas and none of the 20 nevi. The expression of antigen NY-ESO-1 was statistically related to thicker melanomas. It presented also an inverse association with superficial spreading melanoma type compared to other subtypes. Tumor infiltrating lymphocytes of NY-ESO-1 positive melanomas had fewer CD3+ cells, that were isolated or arranged in small groups up to 5 cells, which was significantly different from tumors NY-ESO-1 negatives, with higher density of CD3+ cells, displayed in large groups of 6 or more cells. The expression of NY-ESO-1 protein was not associated to age, sex, phototype, site, ulceration, lymph node sentinel status, development of metastases and survival. CONCLUSIONS: A considerable amount of melanomas express NY-ESO-1, mainly thicker tumors. The fewer number of CD3+ cells in the tumor infiltrating lymphocytes, added to the fact of those cells being isolated or in small groups suggest that, although immunogenic, the expression of NY-ESO-1 antigen does not result in a efficient stimulus of the immune system to fight the tumor. The development of a vaccine to those patients may, in the future, enhance the roll of therapeutic possibilities for melanoma

INTRODUÇÃO: o câncer é a doença que mais mata pessoas com idade abaixo de 85 anos e é um problema de saúde pública. Os tumores podem expressar em determinada fase de seu desenvolvimento proteínas anômalas que podem ser alvo de métodos diagnósticos e de intervenções terapêuticas. A expressão de NY-ESO-1 é detectada em 20 a 40% dos melanomas. Há evidências que esta expressão é mais freqüente em tumores de estágios mais avançados e está associada a um pior prognóstico. OBJETIVOS: determinar a frequência de expressão da proteína NY-ESO-1 no melanoma cutâneo e tentar correlacioná-la com o índice de Breslow, aspectos histopatológicos do melanoma, incluindo o infiltrado linfocítico tumoral, e a morbi-mortalidade dos pacientes. MÉTODOS: o presente estudo é longitudinal de coorte retrospectiva e foi realizado de agosto de 2009 a outubro de 2015. Foram selecionados 89 melanomas de 87 pacientes do Ambulatório de Tumores do Departamento de Dermatologia da FMUSP, divididos em 3 grupos, sendo: grupo 1: 34 melanomas com índice de Breslow <= 1,0 mm; grupo 2: 29 melanomas com índice de Breslow entre 1,1 - 4,0 mm e grupo 3: 26 melanomas com índice de Breslow >= 4,0 mm. As lâminas dos exames anátomo-patológicos destes pacientes foram revisadas quanto ao diagnóstico de melanoma, seu índice de Breslow e a presença de infiltrado linfocítico tumoral. A seguir, realizou-se exame de imunohistoquímica para a determinação da presença do antígeno NY-ESO-1 em todos os 89 tumores coletados e em mais 20 nevos (11 displásicos e 9 intradérmicos) escolhidos ao acaso. Através da revisão dos dados do prontuário, foram obtidos os dados clínicos de: idade, sexo, raça, fototipo da pele, local de aparecimento do melanoma, status do linfonodo sentinela quando realizado, desenvolvimento de metástases e sobrevida dos pacientes. Os dados anátomo-patológicos do tumor analisados foram: tipo histológico, presença de ulceração, e tipo de infiltrado linfocítico tumoral. Nos melanomas que apresentavam infiltrado linfocítico tumoral, foram realizados testes imunohistoquímicos para pesquisa de células CD3+, CD8+, FoxP3+ e CD8+FoxP3+ (duplamente positivas). RESULTADOS: O antígeno NY-ESO-1 esteve presente em 19% dos melanomas cutâneos primários e não foi detectado em nenhum dos 20 nevos pesquisados. A expressão do antígeno NY-ESO-1 esteve estatisticamente relacionada a tumores com espessuras maiores. Apresentou também uma associação inversa com o tipo extensivo superficial em relação aos outros tipos histológicos. O infiltrado linfocítico tumoral dos melanomas NY-ESO-1 positivos continha menor número de células CD3+, que se encontravam isoladas ou arranjadas em pequenos grupos de até 5 células, o que contrastava significantemente com os tumores NY-ESO-1 negativos, com maior densidade de células CD3+, dispostas em grandes grupos, com 6 ou mais células. A expressão da proteína NY-ESO-1 não esteve associada à idade, ao sexo, ao fototipo, ao sítio primário do tumor, à presença de ulceração, ao status do linfonodo sentinela, ao desenvolvimento de metástases ou à sobrevida. CONCLUSÕES: Há expressão de NY-ESO-1 em uma porcentagem considerável dos melanomas, principalmente nos mais espessos. O menor número de células CD3+ no infiltrado linfocítico tumoral, acrescido ao fato destas células estarem isoladas ou em pequenos grupos, sugere que embora imunogênico, a expressão do antígeno NY-ESO-1 não resulta num estímulo eficaz do sistema imune no combate ao tumor. O desenvolvimento de uma vacina para estes pacientes poderá, no futuro, aumentar as possibilidades terapêuticas do melanoma / INTRODUCTION: cancer is the disease that leads to the greatest number of deaths in people over 85 years old and it has become a major public health problem. Tumors may express aberrantly proteins during certain phases of their development, which can be target for diagnostic or treatment purposes. NY-ESO-1 is detected in 20 to 40% of melanomas. There is evidence that it is more frequent in advanced stages and that is associated with a worse prognosis. OBJECTIVES: to determine the frequency of NY-ESO-1 protein expression in cutaneous melanoma and to try to correlate it to Breslow index, melanoma histopathological aspects, including the tumor infiltrating lymphocytes, and patients morbi-mortality. METHODS: the present study is longitudinal of retrospective cohort. The research was carried on from August 2009 to October 2015. Eighty nine melanomas were selected from 87 patients in Oncology Outpatient Clinic, Dermatology Division, University of São Paulo and divided in 3 groups, such as: group 1: 34 melanomas with Breslow index <= 1,0 mm; group 2: 29 melanomas with Breslow index between 1,1 - 4,0 mm e group 3: 26 melanomas with Breslow index >= 4,0 mm. All specimens were reviewed for diagnostic, Breslow index and tumor infiltrating lymphocytes. After that, immunohistoquimical test for the presence of NY-ESO-1 antigen was performed in all 89 melanomas collected and in 20 nevi (11 dysplastic nevi and 9 dermal nevi) that were randomly chosen. By reviewing clinical charts, the following data was obtained: age, sex, skin phototype, site of the tumor, lymph node sentinel status, development of metastases and survival of the patients. The histological data analyzed was: histological melanoma type, presence of ulceration, grade of tumor infiltrating lymphocytes. In those melanomas that had tumor infiltrating lymphocytes, we performed immunohistoquimical tests for the presence of CD3+, CD8+, FoxP3+ and CD8+FoxP3+ (double positive) cells. RESULTS: antigen NY-ESO-1 was present in 19% of primary cutaneous melanomas and none of the 20 nevi. The expression of antigen NY-ESO-1 was statistically related to thicker melanomas. It presented also an inverse association with superficial spreading melanoma type compared to other subtypes. Tumor infiltrating lymphocytes of NY-ESO-1 positive melanomas had fewer CD3+ cells, that were isolated or arranged in small groups up to 5 cells, which was significantly different from tumors NY-ESO-1 negatives, with higher density of CD3+ cells, displayed in large groups of 6 or more cells. The expression of NY-ESO-1 protein was not associated to age, sex, phototype, site, ulceration, lymph node sentinel status, development of metastases and survival. CONCLUSIONS: A considerable amount of melanomas express NY-ESO-1, mainly thicker tumors. The fewer number of CD3+ cells in the tumor infiltrating lymphocytes, added to the fact of those cells being isolated or in small groups suggest that, although immunogenic, the expression of NY-ESO-1 antigen does not result in a efficient stimulus of the immune system to fight the tumor. The development of a vaccine to those patients may, in the future, enhance the roll of therapeutic possibilities for melanoma

No description available.

L’hépatite autoimmune (HAI) est une maladie grave affectant le foie et présentant un haut taux de mortalité lorsque non traitée. Les traitements disponibles sont efficaces, mais de graves effets secondaires leur sont associés. Ces effets secondaires sont généralement le résultat d'une forte immunosuppression et d’autres sont spécifiques à chaque médicament. Aucune immunothérapie spécifique n’est présentement disponible pour le traitement de l’HAI. Récemment, un modèle murin d’HAI a été développé dans notre laboratoire par xénoimmunisation des souris C57BL/6 avec les antigènes humains de l'HAI de type 2. Ce modèle présente la plupart des caractéristiques biochimiques et cliniques retrouvées chez les patients atteints d'HAI de type 2. Dans cette étude, nous avons évaluée l’efficacité de deux types de traitement pour l’HAI de type 2 à l’aide de notre modèle murin. Dans un premier temps, l’anticorps anti-CD3ε a été étudié en prophylaxie et en traitement. Nous avons montré qu’une posologie de 5µg d’anti-CD3 i.v. par jour pendant 5 jours consécutifs induit une rémission chez les souris avec HAI de type 2 établie (traitement). Cette rémission est caractérisée par une normalisation des niveaux d’alanine aminotransférase et une diminution significative de l’inflammation hépatique. Cette rémission semble être associée à une déplétion partielle et transitoire des lymphocytes T CD3+ dans la périphérie et une augmentation des lymphocytes T régulateurs CD4+, CD25+ et Foxp3+ dans le foie. La même posologie lorsqu’elle est appliquée en prophylaxie n’a pas réussi à prévenir l’apparition de l’HAI de type 2. La deuxième voie de traitement consiste en l’administration par voie intranasale d’un forte dose de formiminotransférase cyclodésaminase murin (mFTCD), un autoantigène reconnu dans l’HAI de type 2. Une administration en prophylaxie par voie intranasale de 100µg de mFTCD par jour durant 3 jours consécutifs arrive à prévenir l’HAI de type 2 en diminuant l’inflammation hépatique au bout de deux semaines post-traitement. / Autoimmune hepatitis (AIH) is a severe liver disease with high mortality rates if left untreated. Current treatments, while effective, are associated with deleterious side-effects. These side effects are specific to each drug and the result of broad immunosuppression. Recently, a murine model of type 2 AIH has been created in our laboratory in wild-type naïve mice. In this model, DNA immunization with type 2 AIH human autoantigens breaks immune tolerance and induces an autoimmune response against the liver. Lately, new therapeutic strategies based on depletion of specific immune cell populations have been proposed for the treatment of several diseases, including autoimmune diseases. Currently, no immunotherapies using biological agents are available for the treatment of autoimmune liver diseases. Therefore, the goal of this project is to study the efficacy of new immunotherapeutic agents for the treatment of type 2 AIH in an experimental model. We evaluated the effectiveness of two approaches for treating type 2 AIH. First, we tested the anti-CD3ε antibody in prophylaxis and in treatment of type 2 AIH. We showed that a dosage of 5µg i.v. of anti-CD3ε antibody per day for 5 consecutive days induced remission in mice with established type 2 AIH. This remission was defined as a normalization of serum alanine aminostransferase levels and a significant decrease of liver inflammation in treated mice. This remission seems to be associated with a transitory depletion of CD3+ T lymphocytes in peripheral blood mononuclear cells and increased CD4+CD25+Foxp3+ regulatory T lymphocytes in the liver. But when this dosage was applied in prophylaxis, it could not prevent the induction of type 2 AIH. The second approach was to induce tolerance by nasal administration of murin formiminotransferase cyclodeaminase (mFTCD), an autoantigen of type 2 AIH. We showed that nasal administration of 100µg of mFTCD for 3 consecutive days prevented development of type 2 AIH in prophylaxis by reducing liver inflammation.