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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Differential roles of epigenetic changes and Foxp3 expression in regulatory T cell-specific transcriptional regulation / 制御性T細胞特異的遺伝子発現調節におけるエピゲノムと転写因子FOXP3の異なる役割

Morikawa, Hiromasa 25 November 2013 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第17951号 / 医博第3835号 / 新制||医||1000(附属図書館) / 30781 / 京都大学大学院医学研究科医学専攻 / (主査)教授 河本 宏, 教授 生田 宏一, 教授 斎藤 通紀 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
62

STAT PROTEIN REGULATION OF FOXP3 EXPRESSION AND INFLAMMATORY CYTOKINE PRODUCTION IN T HELPER CELL SUBSETS

O'Malley, John Thomas 19 March 2009 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The differentiation of naïve CD4+ T cells into subsets of T helper cells (Th) is an essential process that impacts host defense and the pathogenesis of immunemediated diseases. Signal transducers and activators of transcription (STAT) proteins, activated downstream of instructive cytokines, dictate and perpetuate the lineage decision of Th cells through both positive and negative effects. This is accomplished by regulating transcription factors, surface receptors and promoting epigenetic changes in gene expression through chromatin remodeling. Transforming growth factor-β1 (TGF-β1) can induce Foxp3 in developing Th cells and these Foxp3-expressing adaptive T regulatory cells (aTregs) are able to suppress inflammation in vitro and in vivo. To define the mechanism by which STAT proteins regulate Th cell pro- and anti-inflammatory phenotypes, we examined T cells deficient in Stat3, Stat4, and Stat6 as well as T cells expressing two STAT4 isoforms after being cultured in the presence or absence of TGF-β1 and cytokines known to be instructive in Th cell development. The negative effects of STAT proteins are demonstrated by our results indicating STAT3, STAT4 and STAT6 proteins activated downstream of the instructive cytokines IL- 6, IL-12 and IL-4, respectively, negatively regulate the development of TGF-β induced Foxp3 and aTreg development. STAT3, STAT4, and STAT6 utilize a vi Mark H. Kaplan, Ph.D., Chair common mechanism to inhibit aTreg generation by inhibiting STAT5, a positive regulator of Foxp3 expression, from binding to the Foxp3 gene. STAT proteins positively effecting inflammatory immunity are demonstrated by our analysis of STAT4 isoforms and their ability to regulate the production of proinflammatory cytokines downstream of IL-12. STAT4β, a STAT4 splice isoform that lacks a Cterminal domain, and STAT4α, a full-length isoform are both capable of mediating inflammatory cell development. However, STAT4β promotes greater inflammation in vivo than STAT4α independent of its ability to repress Foxp3. Instead, the inflammation correlates with STAT4 isoform-dependent expression of inflammatory cytokines. Thus, cytokine-stimulated STAT proteins orchestrate T helper cell pro- and anti-inflammatory cell phenotypes.
63

FOXP3 is a novel X-linked breast cancer suppressor gene

Zuo, Tao 15 November 2006 (has links)
No description available.
64

Increased expression of programmed cell death ligand 1 and galectin 9 in transplant recipients who achieved tolerance after immunosuppression withdrawal / 免疫抑制剤中止後免疫寛容を達成した肝移植後レシピエントにおけるprogrammed cell death ligand 1とgalectin 9の高発現

NGUYEN, HAI NAM 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第23762号 / 医博第4808号 / 新制||医||1056(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 生田 宏一, 教授 川口 義弥, 教授 上野 英樹 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
65

Análise da expressão da proteína NY-ESO-1 no melanoma cutâneo / NY-ESO-1 protein analysis in cutaneous melanoma

Giavina-Bianchi, Mara Huffenbaecher 01 April 2016 (has links)
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
66

TRPM4, a non selective cation-permeable channel regulates Foxp3+ regulatory T cells suppressive function and survival trough modulating calcium influx / TRPM4, le canal cationique non-selective régule la fonction suppressive et la survie des lymphocytes T régulateurs Foxp3+ en régulant l'influx calcique

Yang, Heng 05 October 2012 (has links)
TRPM4, un canal cationique non-sélective activé par le Ca2+ intracellulaire, est un acteur moléculaire important impliqué de la régulation du signal calcique et l’activation des lymphocytes T conventionnels mais son rôle dans la fonction des lymphocytes T régulateurs (Tregs Foxp3+) reste inconnu. Dans un modèle de souris transgéniques dans lequel le gène Trpm4 a été sélectivement invalidé dans la population des Tregs Foxp3+ (souris Foxp3(YFP)Cre+Trpm4flox/flox), nous avons démontré dans différents modèles in vivo d’inflammation aiguë et chronique que TRPM4 contrôle la fonction suppressive et la mort de ces cellules. Dans le modèle de fibrosarcome induit par le méthylcholanthrène (3-MCA) ou implanté (modèle MCA205), dans lequel le rôle des Tregs est documenté, l’absence de fonction de TRPM4 induit une diminution significative de l’incidence et de la croissance tumorale. Dans l’environnent inflammatoire chronique et hypoxique de ces tumeurs, l’expression de TRPM4 protège les Tregs infiltrant la tumeur de la mort cellulaire induit par l’ATP extracellulaire et stimule ainsi le développent et la progression tumorale. L’absence d’expression de TRPM4 dans les Tregs stimule la réponse anti-tumorale médiée par l’IFNg et induit la régression des tumeurs. En conclusion, en inhibant l’entrée de Ca2+ extracellulaire, TRPM4 régule négativement les fonctions suppressives des Tregs et protège ces cellules de la mort cellulaire induite par l’activation. / TRPM4, a Ca2+-activated non-selective cation ion channel is an important regulator of Ca2+ signaling and cell activation in conventional T cells, but its role in Foxp3+ Tregs function remains unknown. Using a model in which Trpm4 gene was selectively invalidated in Foxp3+ Tregs population (Foxp3(YFP)Cre+Trpm4flox/flox mice) we have shown in different in vivo models of acute and chronic inflammation that TRPM4 is an important regulator of Tregs functions and survival. In a model of primary carcinogenesis induced by methylcholantrene (3-MCA) or implanted fibrosarcoma (MCA205 model), in which Tregs role has been documented, lack of TRPM4 expression and function induced significantly decreased incidence and tumor growth. We found that within chronic inflammatory and hypoxic tumor microenvironment, TRPM4 protected Tregs from ATP-induced cell death and therefore promoted tumor initiation and progression. In contrast, TRPM4 deficiency in Tregs favored IFN-g-mediated spontaneous anti-tumor immune response. Thus, through inhibiting Ca2+ influx, TRPM4 acts as a negative modulator of Tregs suppressive functions and protects Tregs from activation-induced cell death.
67

Análise da expressão da proteína NY-ESO-1 no melanoma cutâneo / NY-ESO-1 protein analysis in cutaneous melanoma

Mara Huffenbaecher Giavina-Bianchi 01 April 2016 (has links)
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
68

Regulation und funktionelle Rolle des murinen Transkriptionsfaktors Foxp3 in T-Zellen

Freyer, Jennifer Sandra Silvia 10 November 2008 (has links)
In dieser Arbeit wurde die funktionelle Rolle und Regulation des murinen Transkriptionsfaktor Foxp3 untersucht. Der erste wesentliche Teil zur Analyse der funktionellen Rolle war dabei die Erzeugung einer BAC- transgenen Maus. Hierfür wurde ein Zielgenvektor mit der kodierenden Region des eYFPs und einer dualen Selektionskassette sowie die Methode des ET- Klonierens verwendet. Leider war die homologe Rekombination des Zielgenvektors in den BAC nicht erfolgreich. Es kam zu einer ungeklärten Rekombination mit Fremd- DNS. Die Erzeugung der transgenen Maus wurde nach diesem Ergebnis eingestellt, und es wurde mit einer von unserem Kooperationspartner zur Verfügung gestellten BAC- transgenen Maus weitergearbeitet. Diese Maus, die DEREG- Maus, wurde nach dem gleichen Prinzip erstellt, wie die in dieser Arbeit gestartete transgene Maus, an Stelle des eYFPs trägt die DEREG- Maus die kodierenden Region des GFPs und des Diphtheria- Toxin- Rezeptors. Mit dieser Maus wurden erste Analysen zur Überprüfung der transgenen Maus unternommen. Es wurde die Koexpression von GFP und Foxp3, sowie die Depletion der Foxp3+ T- Zellen mittels Diphtheria- Toxin analysiert. Als nächstes wurde die funktionelle Rolle des Transkriptionsfaktors Foxp3 analysiert. Als einer der ersten Schritte wurde die Stabilität von Foxp3 in vivo überprüft und gezeigt, dass T- Zellen, die das Foxp3- Protein exprimieren, bis zu 14 Tage in vivo stabil sind. Weiterhin wurde die Stabilität der Foxp3- Expression in in vitro Kulturen nach Induktion durch TGF-beta untersucht. Die induzierten Tregs zeigten keine stabile Foxp3- Expression und auch bei der Methylierungsanalyse der TSDR zeigten diese T- Zellen nicht das für ex vivo isolierte Foxp3+ T- Zellen beschriebene Methylierungsmuster. Die Stabilität scheint mit der Demethylierung der TSDR zu korrelieren. Die induzierten Tregs zeigten neben dem nicht stabilen Foxp3- Phänotyp auch eine von der Foxp3- Expression abhängige Suppression von naiven Zellen im in vitro Proliferations- Test. Im dritten Teil der Arbeit wurde die Struktur und Regulation des Transkriptionsfaktors Foxp3 untersucht. Der Lokus wurde auf konservierte Regionen im Vergleich zu den Spezies Maus, Mensch, Ratte, Huhn, Schimpanse, Hund und Frosch untersucht. Die in Floess*, Freyer* et al. (63) gefundenen Region TSDR enthält einen hochkonservierten Bereich. Die Region wurde auf mögliche Transkriptionsfaktor- Bindungsstellen hin analysiert, und ebenfalls wurden in diesem Bereich Histon- Modifikationen für die Acetylierung der Histone H3 und H4, sowie Tri- Methylierung des Lysin4 des Histons H3 gefunden. Die TSDR wurde in Luciferase- Tests auf ihre transkriptionelle Aktivität hin getestet und zeigte einem Enhancer ähnliche unterstützende Aktivität. Die Methylierung der TSDR in den Luciferase- Tests führte zu einer Reduktion der transkriptionellen Aktivität. Deletionsmutanten der TSDR konnten den Bereich für die transkriptionelle Aktivität weiter einschränken und zeigten ein 275pb großes Fragment auf, in welchem viele interessante, mögliche Transkriptionsfaktor- Bindungsstellen und auch die größte Anzahl der differentiell methylierten CpG- Motive liegen. / The aim of the study was to analyze the function and regulation of the transcription factor Foxp3. In a first step we designed a BAC-transgenic mouse with eYFP under the control of the Foxp3 promoter. For creating these mice we use the ET- cloning method. The step of homologous recombination of the target vector into the BAC failed. Because of that, we decided to work in cooperation with the group of Tim Sparwasser from Munich and their BAC- transgenic mouse called DEREG- mouse. This mouse expresses the coding region of eGFP fused to the diphtheria- toxin- receptor under the control of the Foxp3 promoter. Therefore Foxp3+ T cells can be easily detected by eGFP expression and can even be depleted by diphtheria- toxin- application. We confirmed the co- expression of Foxp3 and eGFP and furthermore tested the functionality of the depletion- process of Foxp3+ T cells by treatment with diphtheria- toxin. In a second study, we analyzed the stability of Foxp3 expressing cells in vivo. Therefore we transferred Foxp3+ T cells in syngenic mice and analyzed these cells after 14 days for their Foxp3- expression. Furthermore, we tested the induction of Foxp3 expression through TGF-beta and the suppressive activity of these cells. We also analyzed those cells for their methylation pattern, comparing cells, which showed an induction of Foxp3- expression after one week of culture with TGF-beta to cells, which received TGF-beta for one week and were then restimulated in the absence of TGF-beta. The stability of Foxp3 expression seems to correlate with the demethylated state of the TSDR (Treg Specific Demethylated Region). To get a closer look on the region called TSDR in the murine foxp3 locus, we decided to analyze this region under different aspects. First, we checked for putative binding sites of transcription factors by database analysis of the TSDR. We also analysed histon modifications, such as acetylation of histon H3 and H4 and tri- methylation of lysine 4 at histon3, in this region. Presence of these modifications hinted an epigenetic regulation of Foxp3 involving the TSDR. In a last step, the transcriptional activity of TSDR was tested to delineate whether the TSDR serves as an alternative promoter or acts as a regulative element like an enhancer. Luciferase assays showed that TSDR is a regulative enhancer element, which loses transcriptional activity when methylated. Deletion mutants determined the most important fragment of the TSDR.
69

Avaliação do efeito de derivados lipofílicos da genisteína na ativação de macrófagos in vitro e na modulação da resposta imune no modelo de EAE

Castro, Sandra Bertelli Ribeiro de 08 December 2011 (has links)
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No. of bitstreams: 1 sandrabertelliribeirodecastro.pdf: 21642592 bytes, checksum: ba2c7d8539f06b1e9a8e8f3ca1c34c08 (MD5) Previous issue date: 2011-12-08 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / A Esclerose Múltipla (EM) caracteriza-se por ser uma doença inflamatória crônica desmielinizante do Sistema Nervoso Central (SNC), que afeta aproximadamente um milhão de pessoas em todo o mundo. Entre os agentes terapêuticos aprovados atualmente para o tratamento da EM podemos citar o interferon beta (IFN-β) e o acetato de glatirâmer, entretanto, estes agentes não promovem a cura da doença ou a recuperação total dos pacientes que estão em fase avançada. Diversos estudos demonstram a propriedade que os hormônios sexuais, como o estradiol e progesterona possuem em diminuir a gravidade da Encefalomielite Autoimune Experimental (EAE). Estruturalmente, as isoflavonas compartilham muitas similaridades com os estrógenos endógenos. Estudos realizados com genisteína mostram os efeitos benéficos deste isoflavonóide na EAE. Entretanto, alguns fatores limitam sua aplicação clínica, como por exemplo, sua rápida excreção e declínio dos níveis séricos, sendo que estas características podem estar relacionadas à sua estrutura química. Dentro deste contexto, este trabalho teve por objetivo avaliar o efeito de sete derivados lipofílicos da genisteína na modulação da resposta in vitro de macrófagos murinos J774.A1 ativados com lipopolissacarídeo e IFN-g, e verificar a atuação de um análogo selecionado na etapa in vitro na modulação da resposta imune in vivo no modelo de EAE. Na etapa in vitro foi avaliada a citotoxicidade dos compostos, no sobrenadante da cultura foram dosados óxido nítrico, IL-12 e TNF-α. Na etapa in vivo foi investigado o uso do derivado da genisteína 3 (7-Otetradecanoil-genisteína – TDG) na evolução da EAE induzida em camundongos C57Bl/6 através da aplicação do MOG35–55. No 14° dia após a indução com o MOG, os camundongos foram tratados com TDG por sete dias. No 21° dia após a indução, as porcentagens de células mononucleares isoladas de cérebro expressando marcadores de superfície (CD4+, CD3+ e CTLA-4) e produzindo citocinas IL- 17+CD4+, IL-10+CD4+ ou fator de transcrição Foxp3+CD4+ foram determinadas por citometria de fluxo. A concentração de IL-6, IFN-γ e IL-10 em macerado de cérebro e medula foram determinadas por ELISA. As análises histológicas de cérebro e medulas foram realizadas por coloração de Hematoxilina e Eosina. Os resultados apresentados indicam que a modificação estrutural da genisteína originou derivados não citotóxicos, com elevada capacidade de inibir a concentração de IL-12. Entretanto, estes derivados da genisteína não foram capazes de inibir TNF-α. A produção de NO foi significativamente inibida pelos derivados monoésteres (2,3) e monoéter (6,7) de maneira dose-dependente. Os dados obtidos in vivo indicam que o tratamento com o TDG melhora os sinais clínicos da EAE e isto pode ser correlacionado com uma redução na porcentagem de células produzindo IL-17 e um aumento de células Foxp3+CD4+ no cérebro. Além disso, o tratamento com o TDG aumentou a liberação de IL-10 e a expressão de CTLA-4 além de reduzir a liberação de IFN-γ e IL-6. Desta forma, os dados sugerem um papel imunomodulatório do TDG na EAE e possivelmente na EM / Multiple Sclerosis (MS) is a severe and disabling chronic autoimmune inflammatory demyelinating disease of the central nervous system (CNS), that affect around one million people at entire world. Among the therapeutic agents currently approved for the treatment of MS can be cited the interferon beta (IFN-β) and the glatiramer acetate, however, these agents do not promote the cure or full recovery of patients in advanced stages. Several studies showed that hormones, such as estradiol and progesterone, could reduce the severity of experimental autoimmune encephalomyelitis (EAE). The isoflavones share many structural similarities with endogenous estrogens. Studies with genistein showed the beneficial effects of isoflavones in EAE. However, the chemical structure of genistein has characteristics that limit its clinical application, such as rapid excretion and decreased serum levels. This study aimed evaluate the effect of seven lipophilic derivatives of genistein in the modulation of in vitro response of murine J774A.1 macrophages activated with lipopolysaccharide and IFN-g, and verify the performance of one in vitro selected analogue on modulating in vivo the immune response in EAE. The lipophilic derivatives were evaluated in LPS+IFN-g-activated J774A.1 macrophage cultures to their effects on cytotoxicity and nitric oxide, IL-12 and TNF-α production. The effects of the selected genistein derivative 3 (7-O-genistein-tetradecanoil - TDG) on the development of EAE induced in C57BL/6 mice immunized with MOG35-55 were performed. At 14th day after induction, mice were treated with TDG for seven days. At 21st day the percentage of mononuclear cells isolated from brains expressing CD4+, CD3+, CTLA-4+ and Foxp3+ and producing IL-17+ and IL-10+ were determined by flow cytometry. The concentration of IL-6, IFN-g and IL-10 in brain and spinal cord were determined by ELISA. Histological analysis of brain and spinal cord were performed by hematoxylin and eosin staining. The results showed that the modification of genistein enables the generation of non-cytotoxic compounds with increased IL-12 inhibition, despite of failed TNF-α inhibition. The NO production was inhibited by the monoester (2,3) and monoether (6,7) compounds in a dose-dependent manner. The in vivo data indicated that treatment with TDG improved the clinical signs of EAE which can be correlated with a reduction in the percentage of cells producing IL-17 and the increment of Foxp3+CD4+ cell population at brain. Furthermore, treatment with TDG increased the release of IL-10 and expression of CTLA-4 and reduced the release of IFN-g and IL-6. Altogether, the data suggest an immunomodulatory role of the TDG in EAE and possibly MS.
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Rôles des cellules de Langerhans épidermiques dans l'induction et la rupture de la tolérance immunitaire aux allergènes cutanés / Role of epidermal Langerhans cells in the induction and breakdown of immune tolerance to skin allergens

Gomez de Agüero Tamargo, Mercedes 19 November 2011 (has links)
La tolérance périphérique vis-à-vis de molécules potentiellement allergéniques en contact avec la peau joue un rôle essentiel pour prévenir le développement de l’eczéma allergique de contact (EAC). Au cours de ma thèse, j'ai contribué à l'identification des mécanismes et des acteurs responsables de l'induction de la tolérance par voie cutanée et à préciser le rôle respectif des sous-populations de cellules dendritiques (DC) cutanées dans la rupture de la tolérance et l'induction de lymphocytes T (LT) CD8+ initiant l'EAC. A l'aide d'un modèle murin d'induction de tolérance aux haptènes, j’ai pu montrer que les cellules de Langerhans (LC) épidermiques sont les cellules clés pour induire la tolérance cutanée et empêcher le développement d'un EAC médié par les LT CD8+. En effet, suite à l’application épicutanée d’un allergène/haptène faible, le DNTB, les LC migrent de la peau aux ganglions lymphatiques pour présenter l’antigène aux LT CD8+. Des expériences de déplétion in vivo et de transfert adoptif montrent que les LC sont responsables de la suppression de l’EAC en prévenant la différentiation des LT CD8+ spécifiques de l'allergène en cellules T cytotoxiques via deux mécanismes complémentaires: i) l’anergie/délétion des LT CD8+ et ii) l'activation de LT régulateurs Foxp3+ exprimant ICOS. Après avoir identifié des conditions d'immunisation conduisant au développement d'un EAC au DNTB, j'ai montré que la rupture de tolérance à ce type d'allergène est associée à i) à des modifications phénotypiques des LC épidermiques, ii) au recrutement rapide de monocytes inflammatoires Gr1+ dans la peau et iii) à une capacité équivalente des LC et des DC dermiques Langerin- à présenter l'allergène aux LT CD8+ dans les ganglions. Dans cette situation, les LC jouent un rôle pro-inflammatoire puisque leur déplétion réduit de manière dramatique l'induction de LT CD8+ effecteurs et l'EAC. Ces résultats indiquent que les LC jouent un rôle essentiel à la fois dans la prévention et dans l’induction de l’EAC, et que leur fonction tolérogène ou stimulatrice est vraisemblablement conditionnée par le microenvironnement cutané lors de la pénétration de l’allergène / Induction of peripheral tolerance to potentially allergenic molecules in contact with the skin is essential to prevent the development of allergic contact dermatitis (ACD). During my PhD, I contributed to the identification of the mechanisms and actors responsible for the induction of skin tolerance and clarified the respective roles of dendritic cell (DC) subsets in the breakdown of skin tolerance leading to the priming of cytotoxic CD8+ T cells and developpement of ACD. Using a mouse model of cutaneous tolerance to a model weak allergen, we show that epidermal Langerhans cells (LC) are essential to induce CD8+ T cell tolerance and prevent the development of ACD. Indeed, following the epicutaneous delivery of the weak allergen/hapten DNTB, LC were found to migrate from skin to draining lymph nodes to present the allergen to CD8+ T cells. Depletion and adoptive transfer experiments revealed that LC protect from development of ACD by preventing the priming of allergenspecific cytotoxic CD8+ T cells via two complementary mechanisms: i) anergy/deletion of allergen-specific CD8+ T cells and ii) activation of highly suppressive Foxp3+ regulatory T cells expressing ICOS. We identified DNTB skin delivery conditions that allow for CD8+ T cell priming and initiation of ACD. Breakdown of tolerance to this weak allergen was associated with i) phenotypic modifications of epidermal LC, ii) recruitment of inflammatory monocytes to the skin and iii) allergen presentation to CD8+ T cells by both LC and dermal Langerin- DC. In addition, LC are involved in tolerance breakdown as their depletion prior to skin immunization abrogated induction of CD8+ effector cells and ACD. These results demonstrate that LC are essential for both the induction of skin tolerance to weak skin allergens and for the induction of ACD, and suggest that their tolerogenic versus immuno-stimulatory function is likely dictated by signals from the skin microenvironment after penetration of the allergen

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