IFN-Is at the interface of Innate and Adapative Immunity

描述(由申请人提供)：干扰素(IFN)，最初被鉴定为其有效的抗病毒活性，可分为两大类。其中，II型或免疫性干扰素(又名干扰素-γ)已经赢得了很多恶名，但I型干扰素(干扰素-是；例如，干扰素-α，干扰素-β等)代表着一个更大更复杂的家庭。与此一致的是，病毒已经进化出许多策略来抑制干扰素-I的活性。最近，干扰素-IS也获得了一些知名度，人们认识到它们是由浆vtoid树突状细胞(PDCs，又名)分泌的主要效应细胞因子。“天然产生干扰素-I的细胞”)。然后这些干扰素调节先天免疫和获得性免疫的各个方面。也有有趣的新证据表明，干扰素-IS和pDC在系统性红斑狼疮(SLE)的发病机制中发挥着重要作用。 像其他细胞因子一样，干扰素-1通过诱导新的基因来诱导它们的有效活性。对干扰素-α快速诱导基因的能力的表征导致了前两个STAT转录因子STAT1和STAT2的发现。这些STATs通过未知的机制被招募到I型干扰素受体(IFNAR)，然后它们被激活(通过酪氨酸磷酸化)，二聚体，移位到细胞核并激活基因。相反，干扰素-伽马只通过STAT1传递其信号，尽管动力学不同。 为了确定Stat2在干扰素-IS的生物学反应中所起的独特作用，我们建立了Stat2基因敲除小鼠。这些小鼠对病毒感染高度敏感，对干扰素-IS没有部分反应。出乎意料的是，它们在干扰素-I刺激STATL激活和主要组织相容性复合体II(MHC-II)的正常调节方面表现出组织特异性差异。这些观察结果突出了I型干扰素在调节先天免疫和获得性免疫方面发挥的重要作用。为了了解干扰素-是如何调节它们的许多有效作用的，我们建议： 1.确定I型干扰素受体的STATS是如何激活的，包括组织特异性差异。 2.确定Stat2在调节巨噬细胞MHC-II表达中的独特作用 3.探讨SUMO化在调节干扰素刺激的STATS动力学中的作用。

DESCRIPTION (provided by applicant): Interferons (IFNs), first identified for their potent antiviral activity, can be divided into two major classes. Of these, type II or immune IFN (a.k.a. IFN-gamma) has earned much notoriety, but the type I IFNs (IFN-Is; e.g., IFN-alpha, IFN-beta, etc.) represent a much larger and complex family. Consistent with this, viruses have evolved numerous strategies to thwart IFN-I activity. More recently, IFN-Is have also achieved some celebrity with the recognition that they are the major effector cytokine secreted by plasmacvtoid dendritic cells (pDCs, a.k.a. "Natural IFN-I Producing Cells"). These IFN-Is then regulate aspects of both innate and adaptive immunity. There is also intriguing new evidence that IFN-Is and pDCs play an important role in the pathogenesis of Systemic Lupus Erythematosis (SLE). Like other cytokines, IFN-Is induce their potent activity through the induction of new genes. Characterization of the ability of IFN-alpha to rapidly induce genes led to the identification of Stat1 and Stat2, the first two STAT transcription factors. These STATs are recruited to the type I IFN receptor (IFNAR) by unknown mechanisms, whereupon they become activated (by tyrosine phosphorylation), dimerize, translocate to the nucleus and activate genes. In contrast, IFN-gamma transduces its signals solely through Stat1, albeit with differing kinetics. To determine the unique role Stat2 plays in the biological response to IFN-Is, Stat2 knockout mice were generated. These mice were highly susceptible to viral infection and partially unresponsive to IFN-Is. Unexpectedly, they exhibited tissue-specific differences in IFN-I stimulated Statl activation and a loss in the normal regulation of the Major Histocompatibility Complex class II (MHC-II). These observations highlight the important role type I IFNs play in regulating innate and adaptive immunity. To understand how IFN-Is mediate their many potent effects we propose to: 1. Determine how STATs are activated at the type I IFN receptor, including tissue specific differences. 2. Determine the unique role Stat2 exhibits in regulating MHC-II expression in macrophages 3. Explore the role SUMOylation may play in regulating the kinetics of IFN stimulated STATs.