Mechanisms of Gut Microbiota-Driven Paneth Cell Regulation

项目总结 潘氏细胞(PC)是一种特殊的小肠上皮细胞，控制肠道中的微生物种群 通过分泌抗菌肽(AMPs)。重要的是，个人电脑功能障碍正在成为 几种胃肠道(GI)疾病的发展，包括克罗恩病，坏死性肠炎， 以及移植物抗宿主病。这些疾病的治疗选择有限，这往往会带来显著的 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 针对这些疾病的新的治疗策略。要做到这一点，需要进一步了解监管机制- 对正常PC生物学负责的反常现象是必需的。为此目的，本研究试图在过去的基础上-- 这位申请人的实验室发表的研究表明，肠道微生物区系显著影响- ENCE PC生物学。具体地说，这项申请的目的是阐明 驻留的肠道微生物区系对PC起着调节作用。这项工作的临床原理是 所获得的知识将支持设计有针对性的策略，以增强PC功能，以推定地治疗 胃肠道疾病谱。这项研究的中心假设是肠道微生物区系增加了PC普查 并通过上皮下组织(即肠道下面的组织)发出信号促进AMP的产生 上皮细胞)。这一假设将通过两个独立的目标进行检验，这两个目标分别侧重于宿主和微生物 个人电脑监管的要素。在目标1中，我们试图确定特定的内皮下组织因子如何能够 规范PC功能。在我们初步数据的指导下，我们将结合(A)以IL22为重点的针对性研究， 通过(B)更广泛的合理选择的附加分子(IL17A、Retnlb、JChain、S100A9、CXCL5)的屏幕到 确定上皮下组织调节PC生物学的新机制。在目标2中，微生物方面 这些相互作用中的一部分将被探索。这将由一种新型的PC报告鼠标(Defa6-cre；td-to- Mato)我们已经开发，将在传统和无菌住房条件下进行研究。指定- 从理论上讲，这些小鼠将被用来：(A)确定细菌是否与克罗恩病的发病机制有关 (已与PC功能障碍有关)以不同的方式调节PC生物学；以及(B)确定PC功能是否可以 使用已确定的临床益生菌VSL#3-在动态平衡和炎症期间均可增强疗效。在……里面 结合起来，这些目标有望确定宿主(目标1)和微生物(目标2)可以调节 PC功能。本申请中提出的研究具有创新性，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 先前研究的概念框架，这些研究表明腔细菌直接与PC相互作用 模拟抗菌功能。这些预期的发现意义重大，因为它们将提供科学依据。 为临床增强PC功能的新型药物的开发和未来测试提供了阳离子。这有 为治疗选择有限的患者提供治疗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.