Implications for Speckled proteins 110 and 140 in adaptive immunity

斑点蛋白(SP)家族的核体蛋白最近引起了人们的兴趣，因为他们的作用(S) 在特定免疫中介导基因沉默或激活的转录程序的染色质调节剂 细胞群。人类SP家族由4个成员组成--SP100、SP110、SP140和SP140L，而 鼠标SP系列包括Sp100、Sp110和Sp140。也包括先天免疫细胞和获得性免疫细胞 由于非免疫细胞表达SP100和SP110，而SP140完全受免疫限制。结果来自 RNA测序分析表明，人SP家族成员在发育和发育过程中高度表达 成熟的B细胞，活化的CD4和CD8T细胞，以及髓系血统。SP也被鉴定为干扰素 (干扰素)刺激基因(ISGs)，涉及病原体诱导免疫、自身免疫和感染。 事实上，所有人类SP家族成员的突变都与自身免疫、炎症、 免疫缺陷和传染病，突出了这一蛋白家族在免疫细胞中的重要作用 动态平衡和对感染的反应。然而，目前在免疫细胞的背景下对SP的研究还不够深入。 调节，特别是在适应性免疫细胞中，它们在其中大量表达，知识是 完全缺乏。我们最近确定SP110和SP140是两个新的候选下游介体 转录因子干扰素调节因子5(IRF5)通过T细胞受体(TCR)的scRNAseq- 刺激来自IRF5/和IRF5-/-小鼠的原代小鼠CD4T细胞。IRF5是这两个先天的关键调节因子 和获得性免疫以及与多种炎症性疾病易感性相关的遗传风险因素 和自身免疫性疾病；研究最充分的是系统性红斑狼疮(SLE)。的前提是 这一应用是SP110和SP140作用于IRF5下游，介导B和T细胞失调 常见于SLE患者，如T细胞活化增加，循环血浆水平升高 细胞和致病性自身抗体。在这个提议中，我们将1)检验SP110和SP140起作用的假设 以调节T和B细胞的激活、增殖和效应器功能，以及2)确定是否 SLE患者免疫细胞中SP110和SP140表达异常及其与IRF5的相关性 表达和/或激活、自身抗体产生和疾病活动性。成功完成这些任务 研究将为SP110和SP140在获得性免疫细胞中的功能(S)提供新的机制见解。 其中完全缺乏知识。此外，我们还将了解这些因素是如何 有助于免疫紊乱，这将为设计新的假定的疾病疗法提供理论基础 与SP丢失或过度激活有关，因为SP为驯服提供了一种新的、更精细的治疗途径 过度活跃的免疫反应。

The Speckled protein (SP) family of nuclear body proteins has recently garnered interest for their role(s) as chromatin regulators that mediate transcriptional programs of gene silencing or activation in specified immune cell populations. The human SP family consists of 4 members - SP100, SP110, SP140 and SP140L, whilst the mouse SP family comprises Sp100, Sp110, and Sp140. Both innate and adaptive immune cell lineages as well as non-immune cells express SP100 and SP110, whereas SP140 is entirely immune-restricted. Results from RNA sequencing analysis revealed that human SP family members are highly expressed in developing and mature B cells, activated CD4+ and CD8+ T cells, and myeloid lineages. SPs were also identified as interferon (IFN)-stimulated genes (ISGs), implicating them in pathogen-induced immunity, autoimmunity and infection. Indeed, mutations in all human SP family members are associated with autoimmune, inflammatory, immunodeficiency, and infectious diseases, highlighting essential roles for this family of proteins in immune cell homeostasis and response to infections. However, SPs are currently understudied in the context of immune cell regulation, and particularly in adaptive immune cells, in which they are abundantly expressed, and knowledge is completely lacking. We recently identified SP110 and SP140 as two new candidate downstream mediators of the transcription factor interferon regulatory factor 5 (IRF5) through scRNAseq of T cell receptor (TCR)- stimulated primary murine CD4+ T cells from Irf5+/+ and Irf5-/- littermate mice. IRF5 is a key mediator of both innate and adaptive immunity and a genetic risk factor associated with susceptibility to a wide variety of inflammatory and autoimmune diseases; the most well-studied being systemic lupus erythematosus (SLE). The premise of this application is that SP110 and SP140 act downstream of IRF5 to mediate B and T cell dysregulation commonly seen in patients with SLE, such as increased T cell activation, elevated levels of circulating plasma cells and pathogenic autoantibodies. In this proposal, we will 1) test the hypothesis that SP110 and SP140 act downstream of IRF5 to mediate T and B cell activation, proliferation, and effector function and 2) determine if SP110 and SP140 are dysregulated in immune cells of SLE patients and if expression correlates with IRF5 expression and/or activation, autoantibody production, and disease activity. Successful completion of these studies will provide new mechanistic insight into the function(s) of SP110 and SP140 in adaptive immune cells, in which knowledge is completely lacking. Further, we will provide an understanding of how these factors contribute to immune disorders that will provide rationale for the design of new putative therapies for diseases associated with SP loss or over-activation, as SPs offer a novel and more refined therapeutic avenue for taming hyper-active immune responses.