Innate cytokine responses that regulate autoimmunity

描述（由申请人提供）：本基金资助的研究进展导致发现骨桥蛋白基因通过单个Opn RNA物种的差异翻译指定两种不同的亚型：T细胞中的细胞因子和树突状细胞中表达的关键细胞内蛋白。我们已经证明，在浆细胞样树突状细胞中，Opn的表达对于该细胞的标志性细胞因子- α干扰素的产生至关重要。我们最近发现，强大的Th17应答依赖于新定义的细胞内Opn亚型- Opn-i -抑制DC分泌IL-27的能力。我们还定义了一个依赖于开放蛋白i的相互作用，阻止Th17反应的有效发展。干扰素α / β受体（IFNAR）依赖的Opn-i表达抑制释放IL-27分泌的刹车，抑制Th17对自身肽的反应。IFNAR:Opn-i轴对Th1和Th17反应影响的定义为IFN-I治疗多发性硬化症和其他Th17疾病的基础提供了新的见解，也为利用IFNAR:Opn-i通路的新治疗方法提供了理论基础。我们提出实验(1)来确定导致DC和T细胞中Opn-i和Opn-s表达产生的遗传机制；(2)确定Opn-i与浆细胞样DC中MyD88信号模块之间的相互作用，导致IFN1表达和Th1发育增强；(3)分析常规DC中调节抗原递呈和Th17发育的Opn依赖相互作用；(4)产生选择性表达不同Opn亚型的小鼠，以便我们可以确定实验性自身免疫性脑脊髓炎（ms的EAE mu模型）背景下Opn亚型对外来和自身抗原的免疫反应的贡献。骨桥蛋白（Opn）基因通过与不同细胞类型的相互作用，在多种生物过程中发挥重要作用，包括免疫反应、血管形成和骨形成。我们最近发现了不同的分泌和细胞内的Opn亚型对Th17和Th1亚群的产生的贡献，填补了理解这些亚群在正常和自身免疫反应中的发生的重要空白。我们将产生表达细胞内或分泌的Opn异构体的突变小鼠，用于分析每种对保护再次感染和多发性硬化症小鼠模型的贡献。

DESCRIPTION (provided by applicant): Progress in the research funded by this grant has led to the discovery that the Osteopontin gene specifies two distinct isoforms through differential translation of a single Opn RNA species: a cytokine in T cells and a critical intracellular protein expressed in dendritic cells. We have shown that Opn expression in plasmacytoid dendritic cells is essential for production of this cell's signature cytokine- interferon alpha. We have recently discovered that robust Th17 responses depend on the ability of a newly-defined intracellular Opn isoform- Opn-i - to inhibit secretion of IL-27 by DC. We have also defined an Opn-i-dependent interaction that prevents efficient development of Th17 responses. Interferon alpha/beta receptor (IFNAR)-dependent inhibition of Opn-i expression releases the brakes on IL-27 secretion and inhibits the Th17 response to self-peptides. Definition of the impact of this IFNAR:Opn-i axis on the Th1 and Th17 response has provided new insight into the basis for the therapeutic effects of IFN-I in Multiple Sclerosis and other Th17 diseases, as well as a rationale for new therapeutic approaches that engage this IFNAR:Opn-i pathway. We propose experiments (1) to define the genetic mechanism resulting in generation of Opn-i and Opn-s expression in DC and T cells; (2) to define the interaction between Opn-i and the MyD88 signaling module in plasmacytoid DC leading to IFN1 expression and enhanced Th1 development; (3) to analyze Opn-dependent interactions in conventional DC that regulate antigen presentation and Th17 development and (4) to generate mice that selectively express distinct Opn isoforms so that we may determine the contribution of Opn isoforms to the immune response to foreign and self antigens in the context of Experimental Autoimmune Encephalomyelitis (EAE mu model of MS. PUBLIC HEALTH RELEVANCE: The Osteopontin (Opn) gene is important in diverse biological processes, including immune responses, vascularization and bone formation, through its interaction with different cell types. Our recent discovery of the contribution of distinct secreted and intracellular isoforms of Opn to the generation of Th17 and Th1 subsets fills an important gap in understanding the genesis of these subsets in normal and autoimmune responses. We will generate mutant mice that express the intracellular or secreted Opn isoform for analysis of the contribution of each to protection again infection and in a murine model of Multiple Sclerosis.