912 resultados para IL-4


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PURPOSE. Interleukin (IL)-17, which is responsible for the initial influx of leukocytes into the target tissue, was recently described as the main cytokine involved in autoimmune diseases. Vogt-Koyanagi-Harada (VKH) syndrome is a significant cause of noninfectious blindness in the world. Herein the authors aimed at unraveling the involvement of IL-17 in VKH and in experimental autoimmune uveitis, focusing on the signaling pathways involved in IL-17 synthesis. METHODS. Mice were immunized with 161-180 peptide and pertussis toxin. Draining lymph node cells, harvested 21 days after immunization, were cultured in the presence or absence of p38 alpha mitogen-activated protein kinase (MAPK) inhibitor (SB203580) and assayed for cytokine production and quantification of CD4(+)IL-17(+) cells. Mice received intraocular injections of SB203580, and disease severity was evaluated by histologic examination of the enucleated eyes at day 21. CD4(+) lymphocytes from MSK-1/2-deficient mice, human CD4(+) cells silenced with MSK1 siRNA, or peripheral blood mononuclear cells (PBMCs) from VKH patients were cultured in the presence or absence of p38 alpha MAPK inhibitor and then assayed for IL-17, IFN-gamma, and IL-4 production. RESULTS. The inhibition of p38 alpha MAPK fully blocked the synthesis of IL-17 by PBMCs from VKH patients and lymphocytes from EAU mice. The absence of the msk1/2 gene resulted in failure to produce IL-17 by murine and human lymphocytes. Interestingly, intraocular injections of SB203580 in EAU mice did not suppress development of the disease. CONCLUSIONS. These data show that p38 alpha MAPK-MSK1/2 is involved in the control of IL-17 synthesis by CD4(+) T cells and that inhibition of p38 alpha MAPK in vitro suppresses IL-17 synthesis but that inhibition of this kinase in vivo did not protect from EAU. (Invest Ophthalmol Vis Sci. 2010;51:3567-3574) DOI: 10.1167/iovs.09-4393

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Helminths and their products have a profound immunomodulatory effect upon the inductive and effector phases of inflammatory responses, including allergy. We have demonstrated that PAS-1, a protein isolated from Ascaris strum worms, has an inhibitory effect on lung allergic inflammation due to its ability to down-regulate eosinophilic inflammation, Th2 cytokine release and IgE antibody production. Here, we investigated the role of IL-12, IFN-gamma and IL-10 in the PAS-1-induced inhibitory mechanism using a murine model of asthma. Wild type C57BL/6, IL-12(-/-), IFN-gamma(-/-) and IL-10(-/-) mice were immunized with PAS-1 and/or OVA and challenged with the same antigens intranasally. The suppressive effect of PAS-I was demonstrated on the cellular influx into airways, with reduction of eosinophil number and eosinophil peroxidase activity in OVA + PAS-1-immunized wild type mice. This effect well correlated with a significant reduction in the levels of IL-4, IL-5, IL-13 and eotaxin in BAL fluid. Levels of IgE and IgG1 antibodies were also impaired in serum from these mice. The inhibitory activity of PAS-I was also observed in IL-12(-/-) mice, but not in IFN-gamma(-/-) and IL-10(-/-) animals. These data show that IFN-gamma and IL-10, but not IL-12, play an important role in the PAS-1 modulatory effect. (C) 2008 Elsevier Ltd. All rights reserved.

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All-trans-retinoic acid (atRA) appears to affect Th1-Th2 differentiation and its effects on immune responses might also be mediated by dendritic cell (DC). Nonetheless, studies have been showing contradictory results since was observed either induction or inhibition of DC differentiation. Our aim was to investigate atRA action on human monocyte derived DC differentiation. For this purpose we tested pharmacological and physiological doses of atRA with or without cytokines. Cell phenotypes were analyzed by flow cytometry and function was investigated by phagocytosis and respiratory burst. DC, positive control group, was differentiated with GM-CSF and IL-4 and maturated with TNF-alpha. We demonstrated that atRA effects depend on the dose used as pharmacological doses inhibited expression of all phenotypic markers tested while a physiological dose caused cell differentiation. However, atRA combined or not with cytokines did not promote DC differentiation. In fact, atRA was detrimental on IL-4 property as a DC inductor. (C) 2009 Elsevier Inc. All rights reserved.

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Introduction Antigen-presenting cells, like dendritic cells (DCs) and macrophages, play a significant role in the induction of an immune response and an imbalance in the proportion of macrophages, immature and mature DCs within the tumor could affect significantly the immune response to cancer. DCs and macrophages can differentiate from monocytes, depending on the milieu, where cytokines, like interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF) induce DC differentiation and tumor necrosis factor (TNF)-alpha induce DC maturation. Thus, the aim of this work was to analyze by immunohistochemistry the presence of DCs (S100+ or CD1a+), macrophages (CD68+), IL-4 and TNF-alpha within the microenvironment of primary lung carcinomas. Results Higher frequencies of both immature DCs and macrophages were detected in the tumor-affected lung, when compared to the non-affected lung. Also, TNF-alpha-positive cells were more frequent, while IL-4-positive cells were less frequent in neoplastic tissues. This decreased frequency of mature DCs within the tumor was further confirmed by the lower frequency of CD14-CD80+ cells in cell suspensions obtained from the same lung tissues analyzed by flow cytometry. Conclusion These data are discussed and interpreted as the result of an environment that does not oppose monocyte differentiation into DCs, but that could impair DC maturation, thus affecting the induction of effective immune responses against the tumor.

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 The main focus of the PhD studies was the identification and characterization of a peptide antagonist which inhibited and/or down-regulated the binding of Interleukin-4 receptor to its cytokines IL-4 and IL-13 for allergy treatment. In addition, dietary components were tested for their ability to reduce inflammatory pathways of allergy, including fatty acids, resolvins and coenzyme Q10. Lastly, the Deakin AIRwatch project was undertaken which included the collection of ryegrass pollen data from 2012-2014 and its correlation with meteorological variables in regional Victoria.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Immunity against the intracellular protozoan Leishmania species is highly dependent on Th1 development. We have previously shown that IL-12 is a powerful and probably obligatory factor for Th1 cell generation and proliferation. We also observed that the experimental infection of C3H and BALB/c mice with Leishmania major is associated with IL-12 production in vivo. Now we demonstrate that metacyclic L. major promastigotes are poor inducers of IL-12 in vitro in fresh human PBMC and monocytes. In addition, we show that the ability of this pathogen to induce IL-12 and other cytokines is modulated by the metacyclogenic process, which had previously not been recognized. In contrast to the infective parasites (metacyclic promastigotes), the procyclic promastigotes collected at the logarithmic phase of the culture displayed a striking ability to induce IL-12, IFN-γ, TNF-α, and IL-10. Despite this differential effect of procyclic and metacyclic parasites in terms of IL-12 induction, both stages were inhibitory for IL-12 production induced by Staphylococcus aureus. The ability of procyclic promastigotes and, to a much lesser extent, that of metacyclic promastigotes to induce IL-12 were enhanced by pretreatment of monocytes in a cytokine milieu containing IFN-γ, IL-4, IL-13, or granulocyte-macrophage CSF or. by neutralization of endogenous IL-10. Our results suggest the development of an evasion mechanism as the Leishmania promastigotes mature to infectious forms and the possi-bility of using Ags derived from procyclic promastigotes for immunization procedures. Copyright © 1997 by The American Association of Immunologists.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)