Regulation of Intestinal Innate Immunity by Speckled Protein 140

项目摘要 炎症性肠病(IBD)是一种由多种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。这项拟议研究的长期目标是 以了解肠道炎症的机制基础。更具体地说，我试图确定 免疫细胞的表观遗传学改变如何促进IBD开发新的治疗策略。我们的中央 假设表观基因组维持免疫细胞和共生体之间的动态平衡串扰。 微生物区系。全基因组关联研究(GWARs)发现了 Sp140与IBD子集克罗恩病(CD)有关。斑点蛋白140(Sp140)是一种 转录调节因子仅在免疫细胞中表达，并含有预测的染色质“阅读器” 结构域，包括植物同源域和溴域。染色质“阅读器”蛋白与组蛋白对接 它们可以通过招募其他染色质因子来调节转录的修饰，立体地阻止 转录，或主动重塑染色质。我们之前的工作确定了Sp140与CLOSED 巨噬细胞染色质区域控制谱系不适当转录因子的转录。我的 初步数据显示，Sp140调节暴露于低密度脂蛋白的小鼠巨噬细胞细胞因子的产生 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，该链接 染色质结合和细胞因子调节之间的关系仍未解决。我们将描述通过什么机制 Sp140与巨噬细胞中的染色质相互作用，决定巨噬细胞的效应功能。 我们之前已经证明了CD相关的Sp140 SNPs会导致mRNA剪接的改变和总体上 Sp140蛋白丢失。以前发表的使用基因敲除方法的数据和我使用基因敲除方法的初步数据 小鼠证明，Sp140的缺失会加剧上皮屏障损伤后的肠道炎症。 巨噬细胞是肠道固有层内的前哨天然免疫细胞，有助于体内平衡。 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物失调。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反应所必需的。目前对IBD的治疗是有限的 在控制复发性肠炎方面常常变得无效。确定分子和 支持微生物先天免疫反应的细胞机制可能会改善IBD的治疗 设计。这些研究将有助于我们了解肠道宿主对致病入侵者和先天免疫的免疫。 促进与微生物群落共生的动态平衡的免疫反应。这项研究和 这份申请表中列出的培训计划将使我成为一名创新而有效的消化系统疾病患者 研究员。我的赞助商、共同发起人和合作者将提供必要的反馈和支持 完成我成为一名独立的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.