Supplement: Vitamin D Fluctuations and the Mucosal Immune Response

学术成就奖 维生素D假说提出，维生素D通过多种途径调节胃肠道稳态， 机制，维生素D状态的变化会影响微生物群的组成， 免疫应答、胃肠道感染的清除和在施用后恢复体内平衡的能力 损伤或感染。在上一个资助周期中，我们确定了几种新的机制， 调节T细胞来控制肠道内的稳态。我们新的初步数据表明， 微生物群会抑制维生素D对免疫功能的调节和宿主对维生素D的代谢。 这些新的研究领域作为本申请的焦点。 胃肠免疫系统是一群异质细胞，其作用是维持无知 食物和微生物群中存在大量抗原。微生物群反过来又塑造了 免疫反应无菌小鼠具有降低的B细胞IgG 1、IgG 2a和伊加应答，但高IgE 抗体的高IgE是生态失调和体内平衡失败的症状。维生素D缺乏症和维生素 D受体敲除小鼠具有高IgE和微生物群的生态失调。此外，受伤后维生素D 部分通过调节微生物群来调节T和B细胞应答。体内平衡紊乱， 胃肠道感染后，维生素D缺乏小鼠的严重性，并与减少 产生抗原特异性抗体应答。维生素D不仅对微生物群有影响， 但微生物群影响了维生素D的代谢。这项提案将集中在维生素D对B细胞的影响 以及控制B细胞反应和微生物调节组织维生素D的微生物相互作用 新陈代谢.我们新的中心假设是“维生素D和微生物群合作调节B细胞 以及宿主对维生素D的反应。” 这三个目标是： 目的1：确定维生素D对体内B细胞的直接和间接靶点，这些靶点对于 维持体内平衡、诱导抗体应答和保护免受GI感染。 目的2：确定维生素D的哪些作用取决于微生物群。 目的3：确定微生物群在B细胞诱导24，25（OH）2D中的作用。 简易行政程序。 这种行政补充将用于在gnotobiotic小鼠中进行一些重要的实验， 直到最近才有可能。我们希望将Cyp 27 B1报告菌株重新衍生为无菌菌株。Cyp 27 B1是 控制1，25（OH）2D产生的关键酶。这些无菌Cyp 27 B1 ko/+和ko/ko报告基因小鼠将 然后用单一微生物（一种微生物和一种病原体）免疫或定殖以确定 所述免疫或微生物信号诱导Cyp 27 B1在B细胞或其它免疫细胞中的表达。在 完成这些实验后，我们将明确地确定在何种条件下B细胞或其他免疫细胞可以被激活。 细胞在体内产生Cyp 27 B1。如果没有这笔额外的补助金，我们将无法做到这些 实验此外，我们希望有足够的雄性和雌性小鼠，这样我们就可以评估性别作为一个指标。 自变量格兰特的父母建议只在无菌野生型小鼠中进行这些实验， 混合性别。除了在Cyp 27 B1 ko/+和ko/ko小鼠中的实验之外，我们希望将数量加倍 雄性和雌性野生型无菌小鼠，这样我们就有足够的雄性和雌性小鼠来确定 性别对Cyp 27 B1表达和维生素D代谢的影响。

SUMMARY PARENT AWARD The vitamin D hypothesis proposes that vitamin D regulates gastrointestinal homeostasis by multiple mechanisms and that changes in vitamin D status affect the composition of the microbiota, the development of the immune response, clearance of gastrointestinal infections and the ability to reinstate homeostasis following injury or infection. During the last grant cycle we determined several novel mechanisms by which vitamin D regulated T cells to control homeostasis in the gut. Our new preliminary data demonstrate that disruptions in the microbiota would inhibit vitamin D regulation of immune function and the metabolism of vitamin D by the host. These novel areas of investigation serve as the focus of the present application. The gastrointestinal immune system is a population of heterogeneous cells whose role is to maintain ignorance of the large number of antigens present in food as well as the microbiota. The microbiota in turn shapes the immune response. Germfree mice have reduced B cell IgG1, IgG2a and IgA responses, but hyper-IgE antibodies. Hyper-IgE is a symptom of dysbiosis and a failure of homeostasis. Vitamin D deficient and vitamin D receptor knockout mice have hyper-IgE and dysbiosis of the microbiota. In addition, following injury vitamin D regulates the T and B cell response in part through regulation of the microbiota. Perturbations of homeostasis, following gastrointestinal infection, of vitamin D deficient mice was severe and associated with the reduced production of antigen specific antibody responses. Not only was there an effect of vitamin D on the microbiota but the microbiota affected vitamin D metabolism. This proposal will focus on the effects of vitamin D on B cells and the microbial interactions that control the B cell response and microbial regulated tissue vitamin D metabolism. Our novel central hypothesis is that “Vitamin D and the microbiota cooperate to regulate B cells and the vitamin D responsiveness of the host.” The three aims are: Aim 1: Determine the direct and indirect targets of vitamin D on B cells in vivo that are important for maintaining homeostasis, induction of antibody responses, and protection from GI infection. Aim 2: Determine which of the effects of vitamin D depend on the microbiota. Aim 3: Determine the role of the microbiota in the induction of 24,25(OH)2D by B cells. SUMMARY ADMINISTRATIVE SUPPLEMENT. This administrative supplement would be used to do some important experiments in gnotobiotic mice that were not possible until recently. We would like to rederive a Cyp27B1 reporter strain as germfree. Cyp27B1 is the key enzyme controlling production of 1,25(OH)2D. These germfree Cyp27B1 ko/+ and ko/ko reporter mice will then be immunized or colonized with a single microorganism (one commensal and one pathogen) to determine which immune or microbial signals induces expression of Cyp27B1 in B cells or other immune cells. At the completion of these experiments we will definitively determine under which conditions B cells or other immune cells produce Cyp27B1 in vivo. Without this additional supplement we would not be able to do these experiments. In addition, we want to have enough male and female mice so that we can evaluate sex as an independent variable. The parent grant proposed to do these experiments only in germfree wildtype mice of mixed sex. In addition to the experiments in Cyp27B1 ko/+ and ko/ko mice; we would like to double the numbers of male and female wildtype germfree mice so that we have enough male and female mice to determine the role of sex on expression of Cyp27B1 and metabolism of vitamin D.