GOBLET CELLS IN INTESTINAL IMMUNE HOMEOSTATSIS

描述（由申请人提供）：小肠固有层（LP） DC种群主要由两种不同的亚型组成；具有稳态/耐受性特性的CD103+ dc和具有炎症特性的CD103- dc。这些观察结果表明，将抗原递送到适当的LP-DC亚型，以指导免疫反应达到稳态或免疫的关键作用。近年来，人们发现杯状细胞（GCs）可作为将可溶性腔内抗原传递到CD103+ lp - dc的通道。这一发现表明，GCs在诱导和维持肠道免疫稳态中发挥着重要的作用，而这一作用以前未被认识到。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促进粘膜免疫稳态，机制细节尚不清楚。我们观察到胆碱能刺激诱导杯状细胞相关抗原通道（GAPs），并且GCs对胆碱能刺激的敏感性是通过感知腔内菌群来调节的。此外，在缺乏GCs的情况下，细胞肠道免疫区被改变，这表明GCs在塑造肠道免疫系统中发挥了额外的作用。因此，我们假设GCs通过lp - dc的募集和调节，以及根据肠道微生物群调节抗原递送以促进体内平衡，在塑造肠道免疫中起着至关重要的作用。在目的1中，我们将通过体内成像和体外研究来评估感知肠道微生物群如何改变GC对胆碱能刺激的敏感性，研究对象包括非生物小鼠、特异性无病原体小鼠和诱导突变小鼠菌株。在目标2中，我们将评估乙酰胆碱诱导gap的细胞来源以及它是如何被调节的，使用离体方法和诱导具有乙酰胆碱产生特异性细胞类型缺陷的突变小鼠。在目标3中，我们将利用诱导和挑战口服耐受的方案来评估GCs和GAPs在对腔内蛋白抗原的稳态免疫应答中的作用。这些研究还将评估GCs在lp - dc的招募和印迹中的作用。了解GAP调控及其在肠道免疫稳态中的作用可能为肠道炎症性疾病的治疗提供新的干预措施，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.