GOBLET CELLS IN INTESTINAL IMMUNE HOMEOSTATSIS

描述(申请人提供)：小肠固有层(LP)DC群体主要由两个不同的亚型组成：具有稳态/耐受特性的CD103+DC和具有炎症特性的CD103-DC。这些观察结果表明，向适当的LP-DC亚型递送抗原以引导免疫反应走向动态平衡或免疫的关键作用。近年来发现，杯状细胞(GCs)是一种向CD103+Lp-DC递送可溶性管腔抗原的通道。这一发现表明，GCs在诱导和维持肠道免疫动态平衡方面发挥着以前未被认识到的重要作用。然而，对于这种GC功能是如何调节的，以及GC介导的抗原递送如何有助于粘膜免疫动态平衡，缺乏机制细节。我们观察到，胆碱能刺激诱导杯状细胞相关抗原通道(GAP)，GCs对胆碱能刺激的敏感性是通过感知管腔菌群来调节的。此外，在缺乏GCs的情况下，细胞的肠道免疫隔间会发生变化，这表明GCs在塑造肠道免疫系统方面发挥着额外的作用。因此，我们假设GCs通过招募和调节LP-DC，以及通过调节抗原递送来响应肠道微生物区系来促进体内平衡，在塑造肠道免疫中起着至关重要的作用。在目标1中，我们将通过对格氏菌小鼠、无特定病原体的小鼠和诱导突变小鼠品系的体内成像和体外研究，评估感知管腔微生物区系如何改变GC对胆碱能刺激的敏感性。在目标2中，我们将使用体外方法和诱导细胞类型特异性乙酰胆碱产生缺陷的突变小鼠，评估乙酰胆碱诱导GAP的细胞来源和它是如何调节的。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在对鲁米那蛋白抗原的动态平衡免疫反应中的作用。这些研究还将评估地方政府在招募和印记低收入区议会方面的作用。了解GAP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，并为优化口服疫苗提供途径。

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.