Mechanisms of Gut Microbiota-Driven Paneth Cell Regulation

项目摘要 潘氏细胞（PC）是专门的小肠上皮细胞，控制肠道中的微生物种群 通过分泌抗菌肽（AMP）。重要的是，PC功能障碍正在成为 在几种胃肠道（GI）疾病中的疾病发展，包括克罗恩病、坏死性肠病、 炎和移植物抗宿主病。这些疾病具有有限的治疗选择，其通常携带显著的 免疫抑制和/或手术风险。最终，开发增强PC功能的疗法可能会提供 一种新的治疗策略。为了实现这一目标，进一步了解监管机制- 负责正常PC生物学的anisms是必需的。为此，本研究试图建立在一个基础上， 来自本申请人实验室的公开的工作，其证明了肠道微生物群显著地影响肠道微生物。 计算机生物学。具体地，本申请的目的是阐明精确的机制， 常驻肠道微生物群对PC发挥其调节作用。这项工作的临床原理是， 获得的知识将支持有针对性的策略的设计，增强PC功能，以治疗抑郁症。 胃肠道疾病谱。本研究的中心假设是肠道微生物群增加PC普查 并通过上皮下组织（即肠上皮下的组织）的信号传导促进AMP产生 上皮）。这一假设将通过两个独立的目标进行测试，分别侧重于宿主和微生物 PC的规则。在目标1中，我们试图确定特异性上皮下组织因子如何能够 调节PC功能。根据我们的初步数据，我们将联合收割机结合（A）以IL 22为重点的靶向研究， 与（B）合理选择的额外分子（Il 17 a、Retnlb、Jchain、S100 a9、Cxc 15）的更宽筛选， 确定新的机制，其中皮下组织调节PC生物学。在目标2中，微生物方面 这些互动将被探索。这将通过一种新的PC-报告小鼠（Defa 6-cre;td-To- mato），将在常规和无菌饲养条件下进行研究。具体- 通常，这些小鼠将用于：（A）确定与克罗恩病的发病机制有关的细菌 （其与PC功能障碍有关）差异性调节PC生物学;和（B）确定PC功能是否可以 使用已建立的临床益生菌VSL#3 -在稳态和炎症期间均得到增强。在 结合，这些目标预计将确定宿主（目标1）和微生物（目标2）的元素，可以调节 PC功能。在这项申请中提出的研究是创新的，因为它探索了新的假设 上皮下组织需要介导微生物对PC生物学的影响。这大大扩展了 以前研究的概念框架，这表明腔细菌直接与PC相互作用， 模拟抗菌功能。预期的结果是重要的，因为它们将提供科学依据- 阳离子的发展和未来的测试新的代理，可以在临床上增加PC功能。这 为治疗选择有限的患者提供治疗其疾病的新方法的潜力。

PROJECT SUMMARY Paneth cells (PC) are specialized small intestinal epithelial cells that control microbial populations in the gut through the secretion of antimicrobial peptides (AMPs). Importantly, PC dysfunction is emerging as a driver of disease development in several gastrointestinal (GI) disorders, including Crohn’s disease, necrotizing enterocol- itis, and graft-versus-host disease. These disorders have limited therapeutic options, which often carry significant immunosuppressive and/or surgical risks. Ultimately, developing therapies to enhance PC function may provide a novel treatment strategy for these diseases. To accomplish this, further understanding of the regulatory mech- anisms responsible for normal PC biology is required. To this end, the present study seeks to build upon previ- ously published work from this applicant’s lab, which demonstrates that the enteric microbiota significantly influ- ence PC biology. Specifically, the objective of this application is to elucidate the precise mechanisms by which the resident gut microbiota exert their regulatory effects on PCs. The clinical rationale for this work is that the knowledge obtained will support the design of targeted strategies that augment PC function to putatively treat a spectrum of GI disease. The central hypothesis of this study is that the enteric microbiota increase PC census and promote AMP production via signaling through the subepithelial tissue (i.e. tissue underlying the intestinal epithelium). This hypothesis will be tested via two independent aims that respectively focus on host and microbial elements of PC regulation. In Aim 1, we seek to determine how specific subepithelial tissue factors are able to regulate PC function. Directed by our preliminary data, we will combine (A) targeted studies focused on IL22, with (B) a broader screen of rationally-selected additional molecules (Il17a, Retnlb, Jchain, S100a9, Cxcl5) to identify novel mechanisms by which the subepithelial tissue regulates PC biology. In Aim 2, the microbial side of these interactions will be explored. This will be facilitated by a novel PC-reporter mouse (Defa6-cre;td-To- mato) we have developed, which will be studied in both conventional and germ-free housing conditions. Specif- ically, these mice will be used to: (A) determine if bacteria implicated in the pathogenesis of Crohn’s disease (which has been linked to PC dysfunction) differentially regulate PC biology; and (B) ascertain if PC function can be enhanced using the established clinical probiotic, VSL#3 – both at homeostasis and during inflammation. In combination, these aims are expected to identify host (Aim 1) and microbial (Aim 2) elements that can regulate PC function. The research proposed in this application is innovative because it explores the novel hypothesis that the subepithelial tissue is required to mediate microbial influences on PC biology. This substantially expands the conceptual framework of previous studies, which suggest that luminal bacteria directly interact with PCs to simulate antimicrobial function. The expected findings are significant because they will provide scientific justifi- cation for the development and future testing of novel agents that can clinically augment PC function. This has the potential to offer patients with limited therapeutic options new approaches for the treatment of their disease.