Epigenetic modulation of T cell tolerance in Multiple Sclerosis autoimmunity

项目总结/摘要 多发性硬化（MS）是年轻人非创伤性残疾的主要原因， 疗效和没有治愈。在MS及其小鼠模型实验性自身免疫性脑脊髓炎（EAE）中， 炎性辅助性T（Th）1和Th17 T细胞促进致病性炎性神经环境， Th2和调节性T细胞（Treg）是有益的。抑制甲基化反应的策略抑制 炎症和实验性自身免疫性脑脊髓炎（EAE）。这些影响归因于 抑制蛋白质精氨酸甲基转移酶（PRMT），一种调节基因表达的酶家族 以及通过催化组蛋白和其他蛋白质上的精氨酸甲基化而具有活性。然而，缺乏理解 PRMT如何调节T细胞效应子功能和缺乏选择性精氨酸 甲基转移酶抑制剂迄今阻碍了该领域的进一步发展， 这些发现的临床应用。我们已经开发出一流的PRMT5特异性抑制剂。这些 抑制剂抑制EAE和促炎性Th1/Th17细胞应答，同时维持/增加 Treg/Th2应答。我们假设PRMT5介导的对称二甲基化反应 通过促进和维持炎性T细胞应答来促进自身免疫。以 在T细胞表型和EAE的分子机制方面独特的专业知识组合的优势 自身免疫（Guerau）、PRMT5特异性抑制剂药物/信号通路（Baiocchi）和新型CRISPRi 技术（Han），我们提出通过解剖来鉴定甲基化促进的自身免疫的机制， PRMT5在驱动T细胞炎症反应的特定途径上的作用。使用体外和 在髓磷脂特异性T细胞驱动的MS疾病的临床前体内模型中，我们提出：1）定义信号， 在CD4 T细胞活化/分化为CD4 T细胞期间控制PRMT5表达的调节机制 炎症表型与调节表型，2）确定PRMT5活性对炎症的机制性后果， 3）确定T细胞特异性PRMT5调节对临床炎症T细胞应答的影响。 这些实验将确定在MS的过继转移EAE小鼠模型中的作用。 PRMT 5在导致CNS的髓鞘特异性T细胞反应的发展和致病潜力中的作用 自身免疫在完成这些目标后，我们将了解PRMT5催化的精氨酸是如何在细胞中表达的。 甲基化塑造T细胞的表型和扩增，以及这些效应如何塑造适应性免疫 对髓鞘抗原的反应。这些实验将是第一个解决PRMT5在炎症反应中的作用的实验。 自身免疫性T细胞反应和疾病与新的特异性药物。由于小鼠和人PRMT5都是 这些药物高度保守和靶向，这些研究可以转化为新的治疗策略， 治疗MS和其他自身免疫性疾病。

PROJECT SUMMARY/ABSTRACT Multiple Sclerosis (MS) is the leading cause of non-traumatic disability in young adults, therapies have limited efficacy and there is no cure. In MS and its mouse model Experimental Autoimmune Encephalomyelitis (EAE), inflammatory T helper (Th)1 and Th17 T cells promote a pathogenic inflammatory neural environment while Th2 and regulatory T cells (Treg) are beneficial. Strategies that inhibit methylation reactions suppress inflammation and Experimental Autoimmune Encephalomyelitis (EAE). These effects have been attributed to inhibition of Protein Arginine Methyl Transferases (PRMT), a family of enzymes that regulate gene expression and activity by catalyzing arginine methylation on histones and other proteins. However, lack of understanding of which and how PRMTs modulate T cell effector function and lack of selective arginine methyltransferase inhibitors has so far prevented further advancement in the field, as well as the clinical application of these findings. We have developed first-in-class PRMT5-specific inhibitors. These inhibitors suppressed EAE and pro-inflammatory Th1/Th17 cell responses while maintaining/increasing Treg/Th2 responses. We hypothesize that PRMT5-mediated symmetric dimethylation reactions contribute to autoimmunity by promoting and sustaining inflammatory T cell responses. Taking advantage of the unique combination of expertise in molecular mechanisms of T cell phenotype and EAE autoimmunity (Guerau), PRMT5-specific inhibitor drugs/signaling pathways (Baiocchi) and novel CRISPRi technology (Han), we propose to identify a mechanism for methylation-promoted autoimmunity by dissecting the role of PRMT5 on specific pathways that drive T cell inflammatory responses. Using both in vitro and preclinical in vivo models of myelin-specific T cell driven MS disease, we propose to: 1) define the signals and regulatory mechanisms governing PRMT5 expression during CD4 T cell activation/differentiation into inflammatory vs. regulatory phenotypes, 2) determine the mechanistic consequences of PRMT5 activity on inflammatory T cell responses and 3) determine the impact of T cell-specific PRMT5 modulation on clinical disease activity in the adoptive transfer EAE mouse model of MS. These experiments will determine the role of PRMT5 in the development and pathogenic potential of myelin-specific T cell responses that lead to CNS autoimmunity. At the completion of these aims, we will have learned how PRMT5-catalyzed arginine methylation shapes the phenotype and expansion of T cells and how these effects shape the adaptive immune response to myelin antigens. These experiments will be the first to address the role of PRMT5 in inflammatory autoimmune T cell responses and disease with novel specific drugs. Since both mouse and human PRMT5 are highly conserved and targeted by these drugs, these studies could translate to novel therapeutic strategies to treat MS and other autoimmune diseases.