GOBLET CELLS IN INTESTINAL IMMUNE HOMEOSTATSIS

描述（由申请人提供）：小肠固有层（LP）DC群主要由两种不同的亚型组成;具有稳态/致耐受特性的CD 103 + DC和具有炎症特性的CD 103-DC。这些观察结果暗示了将抗原递送至适当的LP-DC亚型以引导免疫应答朝向稳态或免疫的关键作用。近年来发现杯状细胞（GCs）作为一个通道将可溶性管腔抗原传递给CD 103 + LP-DCs。这一发现表明，GC在诱导和维持肠道免疫稳态中发挥着重要的和以前未被认识到的作用。然而，机制的细节缺乏如何GC功能的调节和GC介导的抗原递送如何有助于粘膜免疫稳态。我们观察到胆碱能刺激诱导杯状细胞相关抗原通道（GAP），并且GC对胆碱能刺激的敏感性通过感受管腔植物群来调节。此外，在没有GC的情况下，细胞肠道免疫区室被改变，表明GC在塑造肠道免疫系统中发挥额外的作用。因此，我们假设GC通过招募和调节LP-DC以及通过调节抗原递送以响应肠道微生物群来促进稳态，从而在塑造肠道免疫中发挥关键作用。在目标1中，我们将使用对无菌小鼠、无特定病原体小鼠和诱导突变小鼠品系的体内成像和离体研究来评估感测管腔微生物群如何改变GC对胆碱能刺激的敏感性。在目标2中，我们将评估乙酰胆碱诱导GAP的细胞来源及其如何调节，使用离体方法并诱导具有乙酰胆碱产生中的细胞类型特异性缺陷的突变小鼠。在目标3中，我们将使用诱导和挑战口服耐受的方案来评估GC和GAP在对管腔蛋白抗原的稳态免疫应答中的作用。这些研究还将评估GC在招募和印迹LP-DCs中的作用。了解GAP的调节和GAP在肠道免疫稳态中的作用可能为肠道炎症性疾病提供新的治疗干预措施，并优化口服疫苗。 公共卫生相关性：肠的慢性炎性疾病，如炎性肠病，是由对肠腔中物质的不受控制的免疫应答引起的。本研究将研究如何将管腔物质递送到肠道免疫系统，以及改变这一过程的后果。这些研究可能会发现新的治疗慢性炎症性疾病的肠道，并建议如何改善口服疫苗。

DESCRIPTION (provided by applicant): The small intestine lamina propria (LP) DC population is largely comprised of two divergent subtypes; CD103+ DCs with homeostatic/tolerogenic properties and CD103- DCs with inflammatory properties. These observations imply a critical role for delivering antigens to the appropriate LP-DC subtype to guide immune responses toward homeostasis or immunity. Recently it was discovered that goblet cells (GCs) act as a passages to deliver soluble luminal antigens to CD103+ LP-DCs. This discovery suggests that GCs play an important and previously unappreciated role in the induction and maintenance of intestinal immune homeostasis. However, mechanistic details are lacking for how this GC function is regulated and how GC mediated antigen delivery contributes to mucosal immune homeostasis. We observed that cholingeric stimuli induce the goblet cell associated antigen passages (GAPs), and that GCs sensitivity to cholinergic stimuli is regulated by sensing the luminal flora. Moreover in the absence of GCs, the cellular intestinal immune compartment is altered, suggesting that GCs play additional roles in shaping the intestinal immune system. Therefore we hypothesize that GCs play a crucial role shaping intestinal immunity through the recruitment and conditioning of LP-DCs, and by regulating antigen delivery in response to intestinal microbiota to promote homeostasis. In aim 1 we will evaluate how sensing the luminal microbiota alters GC sensitivity to cholinergic stimuli using in vivo imaging and ex vivo studies on gnotobiotic mice, specific pathogen free mice, and induced mutant mice strains. In aim 2 we will evaluate the cellular source of acetylycholine inducing GAPs and how it is regulated, using ex vivo approaches and induced mutant mice with cell type specific defects in acetylcholine production. In aim 3 we will evaluate the role of GCs and GAPs in homeostatic immune responses to luminal protein antigens using regimens to induce and challenge oral tolerance. These studies will also evaluate the role of GCs in recruiting and imprinting LP-DCs. Understandning GAP regulation and the role of GAPs in intestinal immune homeostasis may offer new therapeutic interventions for intestinal inflammatory diseases and avenues to optimize oral vaccines. PUBLIC HEALTH RELEVANCE: Chronic inflammatory diseases of the intestine, such as inflammatory bowel disease, result from uncontrolled immune responses to substances in the intestinal lumen. This study will investigate how delivery of luminal substances to the intestinal immune system is regulated and the consequences of altering this process. These studies may identify new treatments for chronic inflammatory diseases of the intestine and suggest how oral vaccines can be improved.