O carcinoma espinocelular (CEC) é a segunda forma de neoplasia cutânea mais prevalente. Os mecanismos exatos envolvidos na progressão desse tipo de tumor ainda não estão elucidados. Estudos recentes têm mostrado que a citocina IL33 é uma citocina reguladora da resposta imune adaptativa, principalmente como potente indutor do perfil Th2. Juntamente com seu receptor ST2, apresenta-se com os níveis elevados em alguns tipos de câncer, corroborando para a evidência de que essa citocina contribui para a carcinogênese. Baseado nessas informações, testamos a hipótese de que a presença de IL33 em carcinoma espinocelular, poderia estar relacionada a um melhor prognóstico. Neste estudo foram utilizadas amostras de carcinoma espinocelular, em diferentes gradações de malignidade tumoral (Grau I, Grau II e Grau III). Os resultados mostraram um infiltrado inflamatório mais intenso em tumores com Grau I e II. Imunorreatividade para IL33 foi observada em tumores de Grau I e II tanto por células epiteliais como por células do infiltrado inflamatório. A análise por microscopia confocal evidenciou que um grande número de células TCD4+ e TCD8+ que expressavam IL33 foi observado em tumores de Grau II. Esses resultados indicam a presença de um intenso infiltrado inflamatório e expressão de IL33 em amostras de carcinoma espinocelular com níveis menores de malignidade tumoral. / Squamous cell carcinoma (SCC) is the second most common form of cutaneous neoplasm. The exact mechanisms involved in the progression of this type of tumor have not yet been elucidated. Recent studies have shown that the cytokine IL33 is a cytokine regulating the adaptive immune response, mainly as a potent inducer of Th2 profile. Together with its ST2 receptor, its presents with elevated levels in some types of cancer, corroborating to evidence that this cytokine contributes to carcinogenesis. Based on this information, we tested the hypothesis that the presence of IL33 in squamous cell carcinoma could be related to a better prognosis. In this study, squamous cell carcinoma samples were used in three different gradations of tumor malignancy (Grade I, Grade II and Grade III). The results showed that a more intense inflammatory infiltrate in Grade I and II tumors. Immunoreactivity for IL33 was observed in Grade I and Grade II tumor, by epithelial cells and by inflammatory infiltrate cells. The analysis by confocal microscopy evidenced that a great number of TCD8+ and TCD4+ cells expressing IL33 was observed in grade II tumors. These results indicate the presence of an intense inflammatory infiltrate and expression of IL33 in samples of squamous cell carcinoma with lower levels of tumor malignancy.

O carcinoma espinocelular (CEC) é a segunda forma de neoplasia cutânea mais prevalente. Os mecanismos exatos envolvidos na progressão desse tipo de tumor ainda não estão elucidados. Estudos recentes têm mostrado que a citocina IL33 é uma citocina reguladora da resposta imune adaptativa, principalmente como potente indutor do perfil Th2. Juntamente com seu receptor ST2, apresenta-se com os níveis elevados em alguns tipos de câncer, corroborando para a evidência de que essa citocina contribui para a carcinogênese. Baseado nessas informações, testamos a hipótese de que a presença de IL33 em carcinoma espinocelular, poderia estar relacionada a um melhor prognóstico. Neste estudo foram utilizadas amostras de carcinoma espinocelular, em diferentes gradações de malignidade tumoral (Grau I, Grau II e Grau III). Os resultados mostraram um infiltrado inflamatório mais intenso em tumores com Grau I e II. Imunorreatividade para IL33 foi observada em tumores de Grau I e II tanto por células epiteliais como por células do infiltrado inflamatório. A análise por microscopia confocal evidenciou que um grande número de células TCD4+ e TCD8+ que expressavam IL33 foi observado em tumores de Grau II. Esses resultados indicam a presença de um intenso infiltrado inflamatório e expressão de IL33 em amostras de carcinoma espinocelular com níveis menores de malignidade tumoral. / Squamous cell carcinoma (SCC) is the second most common form of cutaneous neoplasm. The exact mechanisms involved in the progression of this type of tumor have not yet been elucidated. Recent studies have shown that the cytokine IL33 is a cytokine regulating the adaptive immune response, mainly as a potent inducer of Th2 profile. Together with its ST2 receptor, its presents with elevated levels in some types of cancer, corroborating to evidence that this cytokine contributes to carcinogenesis. Based on this information, we tested the hypothesis that the presence of IL33 in squamous cell carcinoma could be related to a better prognosis. In this study, squamous cell carcinoma samples were used in three different gradations of tumor malignancy (Grade I, Grade II and Grade III). The results showed that a more intense inflammatory infiltrate in Grade I and II tumors. Immunoreactivity for IL33 was observed in Grade I and Grade II tumor, by epithelial cells and by inflammatory infiltrate cells. The analysis by confocal microscopy evidenced that a great number of TCD8+ and TCD4+ cells expressing IL33 was observed in grade II tumors. These results indicate the presence of an intense inflammatory infiltrate and expression of IL33 in samples of squamous cell carcinoma with lower levels of tumor malignancy.

Les maladies pulmonaires, responsables de 3,1 millions de décès de part le monde représentent un problème majeur de santé publique. En particulier, la fibrose pulmonaire et la broncho-pneumopathie chronique obstructive (BPCO) conduisent à la perte de la fonction pulmonaire. Aucun traitement efficace n’a été identifié à ce jour pour lutter contre ces maladies, la seule alternative étant la transplantation. Au cours de ma thèse, j’ai exploré les mécanismes du développement de ces maladies en utilisant différents modèles chez la souris, soit par l’instillation de nanoparticules de métaux ou de bléomycine, conduisant à l’inflammation et/ou à la fibrose pulmonaire, soit par exposition à la fumée de cigarette provoquant une inflammation. Nous avons montré le rôle de la voie de signalisation IL-33/ST2 dans les réponses inflammatoires induites par les nanoparticules ou la bléomycine et identifié de nouveaux mécanismes de régulation de l’IL-33 au sein des macrophages, différents de ceux décrits pour les cellules épithéliales. Nos résultats indiquent que l’expression intracellulaire de l’IL-33 et de son récepteur ST2, joue un rôle important dans l’inflammation, ainsi que la translocation nucléaire de l’IL-33. D’autre part, mes travaux de thèse ont permis d’identifier le rôle clef du senseur intracytosolique NLRP6 dans l’inflammation provoquée par l’exposition à la fumée de cigarette. Nos résultats indiquent que NLRP6, aux fonctions pulmonaires inexplorées, contrôle l’activation des cellules épithéliales et le recrutement des neutrophiles de façon indépendante de la formation d’un inflammasome mais dépendante de la signalisation par les récepteurs des interférons de type I et III. / Pulmonary diseases are a major health problem with 3.1 million deaths in the worldwide. Among them pulmonary fibrosis and chronic obstructive pulmonary disease (COPD), which occur after repeated lung epithelium injury, are characterized by impaired lung functions. To date, no effective therapy against pulmonary fibrosis and COPD were developed, lung transplantation being the only alternative. During my thesis, I studied the mechanisms leading to disease development using different experimental models in mice in particular by metal dioxide nanoparticles or bleomycin instillation leading to inflammation and/or pulmonary fibrosis, or by cigarette smoke exposure promoting pulmonary inflammation which may lead to emphysema. We show the crucial role of IL-33/ST2 signaling pathway in response to nanoparticles or bleomycine and identify new mechanisms for IL-33 regulation in macrophages which are different from those described in epithelial cells. Our results indicate that intracellular expression of IL-33 and of its receptor ST2, together with nuclear IL-33 translocation, play an important role in inflammatory response to nanoparticles instillation. On the other hand, my thesis work allowed identifying that the cytosolic sensor NLRP6 as a key player in pulmonary inflammation developed upon mouse cigarette smoke exposure. Interestingly, our results show that the receptor NLRP6, whose pulmonary functions are still unexplored, controls epithelial cells activation leading to neutrophils recruitment in the airways, in an inflammasome-independent manner but dependently of type I and III interferon receptors signaling.

Introduction: Staphylococcus aureus skin infection is an almost ubiquitous feature of patients with atopic dermatitis (AD). TLR1, 2 and 6 are important in immune sensing of these bacteria. The aim of this study was to determine whether defects in TLR1, 2 and/or 6 expression/function may explain the propensity to infection in humans and the NC eczema mouse model. Methods: Fibroblast cell lines from severe AD, nonatopic controls, and mouse embryonic fibroblasts (MEFs) from the NC, MSM/Ms wild-type strain and a 3T3 control strain TLR1, 2 and 6 expression were measured by qPCR and FACS. IL-6, TNF-α, TSLP and IL-33 production was measured by qPCR and ELISA at baseline and after stimulation with LPS, HKSA and a live strain of Staphylococcus aureus that produced only SEB. Results: No differences were found in either TLR expression or function in human fibroblasts derived from patients and controls. The MSM/Ms MEFs expressed significantly more TLR1 and 2, as well as exhibited high inflammatory profile after stimulation comparing with 3T3 and the NC MEFs. Live Staphylococcus aureus, but not HKSA, LPS or SEB, was a potent stimulus for the Th2-inducing cytokines (TSLP and IL-33), and induce cell death. Cytokines levels were found to be similar in AD and NC MEFs when compared to healthy controls. Conclusion: Eczema in both the human and NC mouse is not associated with abnormalities in fibroblasts TLR1, 2, and 6. Live, but not killed Staphylococcus aureus or its enterotoxin, is a potent inducer of TSLP and IL-33 in both species.

Dexamethasone has been shown to inhibit IgE-mediated mast cell activation, and the present research investigated its role in suppressing IL-33-mediated mast cell activation. We have found that micromolar concentrations of Dexamethasone are capable of suppressing IL-33-mediated mast cell cytokine production, on several genetic backgrounds, and in not only bone marrow derived mast cells, but also peritoneal mast cells. Intracellular staining demonstrated that Dexamethasone significantly reduces expression of the IL-33 receptor, T1/ST2, in mast cells; however, the cytokine suppression is independent of T1/ST2 downregulation. At the same time, Dexamethasone pretreatment significantly reduced ERK phosphorylation, but our data suggests that inhibition occurs even prior to ERK blockade. Finally, Dexamethasone treatment in vivo reduced IL-33-mediated cytokine production and neutrophil infiltration in the murine peritoneum. Thus, Dexamethasone, a well-established therapy for inflammatory disease, can suppress IL-33-mediated mast cell activation, and may therefore be effective for treating diseases now being attributed to IL-33 effects.

Les lymphocytes T Vgamma9Vdelta2 humains constituent la sous-population majoritaire de lymphocytes Tgammadelta dans le sang chez l'adulte sain et représentent 1% à 4% des cellules mononucléées du sang périphérique (PBMC). Ce sont des lymphocytes T non conventionnels activés par des antigènes non peptidiques, les phosphoantigènes (PAgs) sans nécessité de restriction par les molécules du CMH. Ils jouent un rôle essentiel dans l'immunité anti-infectieuse et antitumorale, notamment en sécrétant des cytokines pro-inflammatoires et des molécules lytiques au contact de leurs cellules cibles. L'efficacité des lymphocytes T Vgamma9Vdelta2 en immunothérapie anticancéreuse est aujourd'hui démontrée mais reste fortement limitée en raison de la grande toxicité de l'IL-2 requise pour leur expansion. Toutes les cytokines de la famille de l'IL-2 possèdent la même toxicité intrinsèque, en raison de la chaîne gamma commune à tous les récepteurs de cette famille. Il est donc nécessaire de trouver une molécule alternative à l'IL 2, moins toxique mais tout aussi efficace, dont la transduction du signal ne dépend pas de la chaîne gamma. L'IL-33 est une cytokine de la famille de l'IL-1 appartenant au groupe des alarmines, dont le récepteur ST2/IL-1 RAcP est gamma chain-indépendant. Elle est naturellement présente dans le microenvironnement tumoral et son récepteur ST2 est exprimé sur de nombreuses cellules de l'immunité innée et adaptative. L'IL-33 est une cytokine pluripotente, pouvant induire à la fois des réponses immunitaires de type Th2 ou Th1. Néanmoins, aucune donnée n'était disponible quant à la bioactivité de l'IL-33 sur les lymphocytes T Vgamma9Vdelta2. Mes travaux de thèse ont donc consisté à déterminer si l'IL-33 pouvait potentialiser les fonctions anticancéreuses des lymphocytes T Vgamma9Vdelta2. Au cours de cette étude, nous avons montré que l'IL-33 associée à un PAg induit la prolifération et l'amplification des lymphocytes T Vgamma9Vdelta2 au sein des PBMC. Après amplification, les lymphocytes T Vgamma9Vdelta2 induits avec de l'IL-33 sécrètent des cytokines de type Th1 INF-gamma et TNF-alpha et ont une activité cytotoxique semblable à ceux induits avec de l'IL-2. De plus, nous avons mis en évidence que la prolifération des lymphocytes T Vgamma9Vdelta2 induite par l'IL-33 est issue d'un mécanisme complexe dépendant d'une interaction avec les lymphocytes T CD4. L'ensemble de ces résultats suggère que l'IL-33 pourrait représenter une bonne alternative à l'IL-2 dans les protocoles d'immunothérapie anticancéreuse impliquant des lymphocytes T Vgamma9Vdelta2. / Human Vgamma9Vdelta2 T cells represent the most prominent subset of gammadelta T cells in the blood of healthy adults, representing 1 to 4% of peripheral blood mononuclear cells (PBMC). These cells are non-conventional lymphocytes activated by non peptidic antigens, the phosphoantigens (PAgs), without restriction by MHC molecules. They are very important actors of anti-infectious and antitumor immune responses. Indeed, their activation upon a contact with their target cells lead them to secrete pro-inflammatory cytokines and lytic granules mediating cell cytotoxicity. Their efficacy in cancer immunotherapy is now demonstrated but appears strongly limited by the toxicity of IL-2 which is essential for their expansion. All the cytokines of the IL-2 family have the same toxicity owing to the gamma chain shared by all the receptors of the family. Therefore, it appears crucial to find as effective but safer alternative to IL-2 which signaling does not depend on the gamma chain. IL-33 is a member of IL-1 family belonging to the alarmins which its receptor ST2/IL-1RAcP does not require the gamma chain. It is naturally present in the tumor microenvironment and ST2 is expressed on numerous innate and adaptive immune cells. IL 33 is a multipotent cytokine able to sustain both Th2 and Th1 immune responses. However, its bioactivity on Vgamma9Vdelta2 T cells has never been studied. The aim of my PhD thesis consisted in determining if IL-33 could promote Vgamma9Vdelta2 T cell anticancer functions. We found that IL-33 enhances the proliferation and the amplification of PAg-activated Vgamma9Vdelta2 T cells. Moreover, we found that IL-33-induced Vgamma9Vdelta2 T cells display the same anticancer functions than those induced by IL-2, through their secretion of Th1 type cytokines and to their cytotoxic activity towards cancer cells. Interestingly, we found that Vgamma9Vdelta2 T cell proliferation induced by IL-33 is due to a complex mechanism requiring interaction with CD4 T cells. Altogether, these results suggest that IL-33 represents a potential alternative to IL-2 in Vgamma9Vdelta2 T cell-based immunotherapies.

Interleukin-33 (IL-33) is a multifunctional cytokine that mediates local inflammation upon tissue damage. IL-33 is known to act on multiple cell types including group 2 innate lymphoid cells (ILC2s), Th2 cells, and mast cells to drive production of Th2 cytokines including IL-5 and IL-13. IL-33 signaling activity through transmembrane ST2L can be inhibited by soluble ST2 (sST2), which acts as a decoy receptor. Previous findings suggested that modulation of IL-13 levels in mice lacking decoy IL-13Rα2, or mice lacking IL-13, impacted responsiveness to IL-33. In this study, we used Il13-/- mice to investigate whether IL-13 regulates IL-33 activity by modulating the transmembrane and soluble forms of ST2. In Il13-/- mice, the effects of IL-33 administration were exacerbated relative to wild type (WT). Il13-/- mice administered IL-33 i.p. had heightened splenomegaly, more immune cells in the peritoneum including an expanded ST2L+ ILC2 population, increased eosinophilia in the spleen and peritoneum, and reduced sST2 in the circulation and peritoneum. In the spleen, lung, and liver of mice given IL-33, gene expression of both isoforms of ST2 was increased in Il13-/- mice relative to WT. Because IL-13 and IL-4 signal through a shared receptor complex IL-13Rα1/IL-4Rα, we also studied the combined deficiency of IL-4 and IL-13 using Il4rα-/- mice which are defective in both IL-4 and IL-13 signaling. Responses of Il4rα-/- mice were indistinguishable from those of Il13-/- mice in our model system of IL-33-induced inflammation, suggesting that IL-4 does not play a distinct role separate from IL-13 in regulation of IL-33 activity. Through in vitro experiments, we confirmed fibroblasts to be an IL-13-responsive cell type that can regulate IL-33 activity through production of sST2. This study elucidates the important regulatory activity that IL-13 exerts on IL-33 through induction of IL-33 decoy receptor sST2 and through modulation of ST2L+ ILC2s.

No description available.

No description available.

No / IL-33 is a member of the IL-1 family of cytokines that is constitutively expressed in healthy skin and was found to be increased in the skin of patients with atopic dermatitis (AD). Because it can be released after tissue damage or physical stress including scratching of the skin,1 it has been classified as an alarmin concerned with alerting the immune system.2 It enhances TH2 responses by inducing IL-5 and IL-13 as well as TH1 responses via upregulation of IFN-γ. Keratinocytes are known producer cells of IL-33 and also express the receptor complex consisting of ST2 and IL-1RAcP on their surface. The aim of this study was to investigate the effect of IL-33 on keratinocytes, skin biopsies, and living skin equivalents with regard to the regulation of the skin barrier molecule filaggrin (FLG).