La polyarthrite rhumatoïde (PR) est une maladie inflammatoire chronique d’étiologie inconnue. Les mécanismes physiopathologiques de cette maladie mettent en jeu un réseau cellulaire et cytokinique dont l’étude permet de définir des cibles thérapeutiques potentielles. L’IL-33 est une cytokine impliquée dans plusieurs maladies inflammatoires mais son rôle dans l’inflammation chronique comme la PR reste peu étudié. L’objectif de ce travail a été d’étudier le rôle de l’IL-33 et son mode d’action dans deux modèles expérimentaux d’inflammation chronique, l’arthrite au collagène (AEC) et le psoriasis induit par l’imiquimod (IMQ) chez la souris. Nous avons montré pour la première fois que l’administration d’IL-33 recombinante pendant les phases précoce et tardive de l’AEC, permet d’inhiber presque totalement les signes cliniques de la maladie. Cet effet protecteur passe par le déclenchement d’une réponse immunitaire de type 2 y compris l'expansion des ILC2, des éosinophiles et des cellules Th2. En outre, nous avons démontré que l’administration d’IL-33 dans notre modèle induit l’expansion de lymphocytes T régulateurs ST2L+ et une activité suppressive accrue. Dans un second temps, nous avons démontré que malgré l’expression de l’IL-33 dans les articulations ou la peau de souris développant une AEC ou un psoriasis induit par imiquimod, l’IL-33 endogène n’est pas nécessaire pour le développement de ces deux pathologies. En outre, l’absence de cette cytokine ne modifie pas la réponse des lymphocytes T ni dans l’AEC et ni dans le psoriasis. L'ensemble de ces résultats suggère que cette cytokine n’est pas cruciale pour le développement de l'inflammation chronique, et que la mise au point de traitement ciblant l’axe IL-33 / ST2 doit être envisagée avec précautions. / Rheumatoid arthritis (RA) is a chronic inflammatory disease that is associated with severalmediators. The physiopathological mechanisms of this disease involve cellular and cytokinenetworks whose study helps to define potential therapeutic targets. IL-33 is a cytokine involved inmany inflammatory diseases although its role in chronic inflammation such as RA remainsunclear. The aim of this work is to study the role of IL-33 and its mode of action in twoexperimental models of chronic inflammation, collagen induced arthritis (CIA) and imiquimod(IMQ) induced psoriasis. First, we showed for that the administration of recombinant IL-33 duringthe early and late phases of CIA inhibits the clinical signs of the disease in mice C57BL/6. Thisprotective effect is associated with the response type 2 including expansion of ILC2, eosinophilsand Th2 cells. Furthermore, we demonstrated that access of IL-33 in our model induced TregST2L and promotes the acquisition of regulatory phenotypes of Tregs. These Tregs achieve animportant suppressive activity leading inhibition of CIA. Secondly, despite the expression of IL-33 in the joint and skin of mice with CIA and IMQ induced psoriasis, endogenous IL-33 is notnecessary for the development of these two chronic inflammation models. In addition, the absenceof this cytokine does not alter the T cell response in the CIA or psoriasis. [...]

Orientador: Jose Andres Yunes / Tese (doutorado) - Universidade Estadual de Campinas. Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-15T09:06:10Z (GMT). No. of bitstreams: 1 Vasconcellos_JairaFerreirade_D.pdf: 12382146 bytes, checksum: 9d05fdf79968e31e12ded32312675286 (MD5) Previous issue date: 2010 / Resumo: A leucemia linfóide aguda (LLA) é a neoplasia mais freqüente na infância. As interações dos blastos da LLA com as células do estroma da medula óssea (MO) têm um impacto positivo na sobrevivência das células e resistência a quimioterapia. A LLA estimula as células do estroma da MO que reciprocamente promovem a sobrevivência da leucemia. Para identificar moléculas envolvidas na interação leucemia-microambiente foi realizada análise do perfil de expressão gênica de células mesenquimais (MSC) da MO estimuladas com células primárias da LLA. O estímulo da LLA nas MSC ativou várias quimiocinas próinflamatórias, incluindo CCL2 e IL-8. Os níveis plasmáticos de CCL2 e IL-8 em crianças com LLA ao diagnóstico foram significativamente maiores do que em controles normais. A maioria das amostras de LLA primária expressou transcritos dos receptores de CCL2 e IL-8. Ensaios funcionais in vitro demonstraram que a LLA não é afetada pela adição de CCL2, IL- 8 ou anticorpos neutralizantes. Porém ambas as quimiocinas demonstraram estimular a sobrevivência das MSC em meio sem soro e aumentar sua proliferação em meio com quantidades limitadas de soro. Para explorar o efeito da IL-8 no microambiente da MO leucêmica foi sintetizado um antagonista do receptor CXCR2 da IL-8, denominado SB225002 (N-(2-hydroxy-4-nitrophenyl)-N'-(2-bromophenyl)urea). O SB225002 demonstrou efeito deletério contra as linhagens da LLA (Nalm6, REH, Jurkat, CEM e Molt4). Mas nem todas as linhagens da LLA sensíveis ao SB225002 expressaram o receptor CXCR2, sugerindo que seu mecanismo de ação ocorreria através de receptor alternativo. Recentemente foi descrito que o SB225002 também se liga a outros receptores acoplados a proteína G, dentre eles os receptores da histamina e dos canabinóides. Ambos foram testados in vitro e o receptor CNR2 dos canabinóides demonstra desempenhar função no mecanismo de ação do SB225002. Além disso, para identificar moléculas envolvidas na resposta celular ao SB225002 foi realizada a análise do perfil de expressão gênica de células Jurkat tratadas com SB225002. Eventos celulares de resposta inicial ao SB225002 incluíram (i) ativação de phospho-p44/42 ERK e (ii) ativação de GLIPR1 que demonstrou mediar a indução de morte do SB225002. Em conclusão, este trabalho indica a importância das quimiocinas CCL2 e IL-8 no microambiente da LLA, e demonstra o potencial do SB225002 como agente antileucêmico. / Abstract: The interactions of Acute Lymphoblastic Leukemia (ALL) blasts with bone marrow (BM) stromal cells have a positive impact on leukemia cell survival and resistance to chemotherapy. ALL stimulates BM stromal cells, which reciprocally promote leukemia cell survival. To identify molecules critically involved in leukemia-microenvironment crosstalk, we performed gene expression profiling analyses of primary BM mesenchymal stem cells (BMMSC) following stimulation by primary ALL cells. Leukemia stimulation of BMMSC up regulated the expression of several inflammatory chemokines, including CCL2 and IL-8. Secretion of these molecules was confirmed by ELISA assays of in vitro co-culture experiments and in BM plasma samples from pediatric ALL patients. Most primary ALL samples were found to express mRNA for CCL2 and IL-8 receptors. In vitro functional studies revealed that primary ALL cells co-cultured with BMMSC were not affected by addition of CCL2, IL-8 or neutralizing antibodies to these chemokines. On the other hand, both chemokines were found to enhance BMMSC survival in serum-free medium and to increase their proliferation in serum-starved conditions. To further explore the effect of IL-8 in the ALL-BM microenvironment the CXCR2 -IL-8 receptor-antagonist SB225002 ( N - ( 2 - hydroxyl - 4 - nitrophenyl ) - N' - ( 2 - bromophenyl ) urea) was synthesized. SB225002 had a deleterious effect against ALL cell lines (Nalm6, REH, Jurkat, CEM, and Molt4). Suprisingly, not all the ALL cells lines that were sensitive to SB225002 expressed CXCR2 receptor. This find suggested that the SB225002's mechanism of action occurred through a different receptor. SB225002 was recently described to also bind histamine and cannabinoid receptors that were investigated in ALL and the CNR2 cannabinoid receptor demonstrated to play a role in SB225002 mechanism of action. To identify molecules involved in the cellular effects promoted by SB225002, gene expression profiling analyses was performed of Jurkat cells treated with SB225002. Early cellular effects enhanced by SB225002 included (i) activation of phospho-p44/42 ERK and (ii) up regulation of GLIPR1 that shown to mediate SB225002-induced apoptosis. In conclusion, this work support a significant role for the chemokines CCL2 and IL-8 in the ALL-BM microenvironment, and demonstrate SB225002's therapeutic potential. / Doutorado / Ciencias Biomedicas / Doutor em Ciências Médicas

A breakdown of intestinal homeostasis due to dysregulated immune responses against intestinal bacteria underlies the pathogenesis of inflammatory bowel disease (IBD) in genetically susceptible individuals. Amongst mucosal immune cells, innate lymphoid cells (ILCs) are a heterogeneous group of cells whose functions in pathogenic inflammatory processes in the intestine are beginning to emerge from experimental murine models. However, less is known about the role of ILCs in chronic intestinal inflammation in humans. In this thesis, human ILCs were examined in the context of IBD and potential mechanisms by which these cells may contribute to IBD pathogenesis were investigated. We identified phenotypically and functionally distinct ILC1, ILC2 and ILC3 populations in the human intestinal lamina propria and peripheral blood and found that ILCs enriched for expression of IL-17A and IFNγ accumulated in the inflamed intestine, potentially through increased in situ proliferation and chemokine-mediated recruitment from blood. Based on their in situ localization, we investigated potential functional interactions between ILCs and CD4+ T cells and found that a proportion of human ILCs in peripheral blood and the intestinal lamina propria expressed HLA-DR and co-stimulatory molecules. ILCs were capable of taking up and processing protein antigen at levels equivalent to B cells, but in contrast to monocytes, antigen-pulsed ILCs failed to activate antigen-specific memory CD4+ T cells in vitro. Reciprocal activation between ILCs and monocytes enhanced the antigen-presenting potential and bactericidal capacity of myeloid cells and induced upregulation of co-stimulatory ligand expression by ILCs. This innate activation loop resulted in an augmentation of CD4+ T cell activation. These findings extend our knowledge of the complex interactions between human ILCs and other key immune cell populations, and suggest mechanisms by which rare ILCs may contribute to the pathogenesis of IBD by augmenting myeloid cell and CD4+ T cell responses.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22368号 / 医博第4609号 / 新制||医||1043(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 髙折 晃史, 教授 松田 文彦, 教授 滝田 順子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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Thesis: M.S., Massachusetts Institute of Technology, Department of Nutrition and Food Science, 1980 / Bibliography: leaves 56-57. / by Julianne Elizabeth Radkowski Opperman. / M.S. / M.S. Massachusetts Institute of Technology, Department of Nutrition and Food Science

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付記する学位プログラム名: 京都大学卓越大学院プログラム「メディカルイノベーション大学院プログラム」 / 京都大学 / 新制・課程博士 / 博士(医科学) / 甲第24535号 / 医科博第149号 / 新制||医科||10(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 濵﨑 洋子, 教授 江藤 浩之, 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

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24195号 / 医博第4889号 / 新制||医||1060(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 戸井 雅和, 教授 藤田 恭之, 教授 伊藤 貴浩 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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