Regulation of Intestinal Innate Immunity by Speckled Protein 140

项目摘要 炎症性肠病（IBD）是一种由基因突变组合形成的复杂疾病， 环境变量、微生物组和表观基因组。拟议研究的长期目标是 了解肠道炎症的机制基础。更具体地说，我想确定 免疫细胞的表观遗传改变如何促进IBD发展新的治疗策略。我们的中央 一种假说认为，表观基因组维持免疫细胞和免疫细胞之间的稳态串扰， 微生物群落全基因组关联研究（GWAS）确定了单核苷酸多态性（SNP）， Sp140与克罗恩病（CD）（IBD的一个子集）相关。斑点蛋白140（Speckled protein 140，Sp140）是一种 仅在免疫细胞中表达并含有预测的染色质“阅读器”的转录调节因子 结构域，包括植物同源结构域和布罗莫结构域。染色质“阅读器”蛋白质与组蛋白对接 它们可以通过招募其他染色质因子来调节转录的修饰， 转录或主动重塑染色质。我们以前的工作确定Sp140与封闭的 巨噬细胞中的染色质区域，以控制谱系不适当的转录因子的转录。我 初步数据表明，Sp140调节暴露于 微生物配体这种调节依赖于染色质阅读器结构域的存在。然而，链接 染色质结合和细胞因子调节之间的关系仍然没有解决。我们将描述 Sp140与巨噬细胞中的染色质相互作用并决定巨噬细胞效应子功能。 我们先前已经证明CD相关的Sp140 SNP导致mRNA剪接改变， Sp140蛋白缺失。先前发表的数据使用敲除方法和我的初步数据敲除 小鼠证实Sp140的耗尽加剧了上皮屏障损伤后的肠道炎症。 巨噬细胞是肠道固有层内的哨兵先天性免疫细胞，其有助于维持体内平衡。 细胞因子反应和对微生物入侵者的反应。我们将确定Sp140在维持 肠道中的免疫-微生物相互作用和防止生态失调。我们还将确定Sp140是否 在细菌诱导的结肠炎期间有效的免疫应答所必需的。目前IBD的治疗方法有限 并且在控制复发性肠道炎症时常常变得无效。确定分子和 对微生物的先天免疫应答的细胞机制可能改善IBD治疗 设计这些研究将为我们了解肠道宿主对致病性入侵者的免疫和先天免疫提供信息。 免疫反应，促进体内微生物群群落的稳态。研究与 培训计划概述在此应用程序将使我成为一个创新和有效的消化系统疾病 研究员我的赞助商、共同赞助商和合作者将提供必要的反馈和支持， 完成我成为一名独立学术研究科学家的目标。

Project Abstract Inflammatory bowel disease (IBD) is a complex disease shaped by a combination of genetic mutations, environmental variables, the microbiome, and the epigenome. The long-term goal of the proposed research is to understand the mechanistic underpinnings of intestinal inflammation. More specifically, I seek to determine how epigenetic alterations in immune cells can promote IBD to develop novel therapeutic strategies. Our central hypothesis is that the epigenome maintains homeostatic crosstalk between immune cells and the commensal microflora. Genome-wide association studies (GWAS) identified single nucleotide polymorphisms (SNPs) within Sp140 that associate with Crohn’s disease (CD), a subset of IBD. Speckled protein 140 (Sp140) is a transcriptional regulator expressed exclusively in immune cells and contains predicted chromatin “reader” domains, including a plant homeodomain and bromodomain. Chromatin “reader” proteins dock to histone modifications where they can modulate transcription by recruiting other chromatin factors, sterically preventing transcription, or actively remodeling chromatin. Our previous work determined that Sp140 associates with closed chromatin regions in macrophages to control the transcription of lineage-inappropriate transcription factors. My preliminary data demonstrate that Sp140 regulates cytokine production in murine macrophages exposed to microbial ligands. This regulation is dependent on the presence of chromatin reader domains. However, the link between chromatin binding and cytokine regulation remains unsolved. We will delineate the mechanism by which Sp140 interacts with chromatin in macrophages and dictates macrophage effector functions. We have previously shown that CD-associated Sp140 SNPs lead to altered mRNA splicing and an overall loss of Sp140 protein. Prior published data using knockdown approaches and my preliminary data with knockout mice demonstrate that depletion of Sp140 exacerbates intestinal inflammation after epithelial barrier injury. Macrophages are sentinel innate immune cells within the intestinal lamina propria that contribute to homeostatic cytokine responses and respond to microbial invaders. We will determine the role of Sp140 in maintaining immune-microbe interactions in the intestine and preventing dysbiosis. We will also determine whether Sp140 is necessary for effective immune responses during bacteria-induced colitis. Current treatments for IBD are limited and often become ineffective in controlling relapsing intestinal inflammation. Determining the molecular and cellular mechanisms that underlie innate immune responses to microorganisms may improve IBD treatment design. These studies will inform our understanding of intestinal host immunity to pathogenic invaders and innate immune responses that promote homeostasis with commensal microbiota communities. The Research and Training Plans outlined in this application will enable me to become an innovative and effective digestive disease researcher. My Sponsor, Cosponsor, and collaborators will provide the necessary feedback and support to complete my goal of becoming an independent academic research scientist.