Major Histocompatibility Complex Shapes Early Life Microbial Events to prevent Autoimmunity

项目总结： 1型糖尿病(T1D)是一种影响数百万人的衰弱自身免疫性疾病。不幸的是， T1D的发病率正在上升。T1D中最强的遗传因素是MHC II类基因座。一些MHC单倍型 与T1D风险较高相关，而其他则提供主要保护。然而，这种机制仍然存在。 未知。最近的研究表明，环境因素，如微生物组，也有助于 T1D的发病率增加。虽然遗传因素和环境因素都会导致罹患 T1D，对MHC II遗传因素如何与微生物因素相互作用知之甚少。非肥胖型糖尿病(NOD) 小鼠模型概括了人类T1D的许多特征，包括与以下相关的显性保护 MHC II类基因座。NOD小鼠自发发生T1D，但自身免疫可通过转基因预防 MHCIIE等位基因的表达(Eα16/NOD小鼠)。最近发表的研究和新的初步数据来自 我们的实验室表明，微生物群对这种保护至关重要。这项提案的目标是确定 可用于预防T1D的免疫调节细菌和免疫系统途径 针对遗传高危患者的治疗 为了严格研究早期的微生物区系，我们开发了一个由9个可培养细菌组成的新联合体。 (我们称之为PedsCom)，代表了断奶前糖尿病保护性Eα16/NOD中90%以上的细菌 老鼠。为了研究特定细菌的免疫调节机制，我们正在应用诺生菌技术。 使用PedsCom联盟和使用Eα16/NOD小鼠的疾病遗传模型。这些实验 将阐明MHC II分子与肠道相互作用的机制 预防T1D的微生物。在目标1中，我将调查MHC II E的表达是否影响早期生活事件的形成 细菌定植动态和对共生细菌体液反应的比较 由PedsCom财团定植的NOD和Eα16/NOD小鼠。在目标2中，我将确定PedsCom是否 早期微生物的联合足以预防T1D以及外周调节性T细胞是否能防止 通过研究PedsCom、无特定病原体(SPF)和无菌定植小鼠，对Eα16/NOD小鼠进行了T1D。 在此期间，这些调查将扩大我的技术技能，提高我的能力 实验设计和分析，并提高我与科学界沟通的能力。 我将在宾夕法尼亚大学完成这项奖学金，该大学提供课程、课程和结构化的 对我的职业发展有帮助的导师。此外，我将利用 免疫学研究生小组和医学科学家培训计划，以提高我作为一个 教育家和临床医生。根据我所掌握的资源，我将探索基础和临床相关的 这项建议中的问题，以获得成为一名成功的内科科学家所必需的技能。

Project Summary: Type 1 diabetes (T1D) is a debilitating autoimmune disease that affects millions. Unfortunately, the incidence of T1D is rising. The strongest genetic factor in T1D is the MHC class II locus. Some MHC haplotypes are associated with higher risk to T1D, while others provide dominant protection. Yet, the mechanism remains unknown. Recent studies suggest that environmental factors, such as the microbiome, also contribute to the increasing incidence of T1D. While both genetic and environmental factors contribute to the risk of developing T1D, little is known of how MHC II genetic factors interact with microbial factors. The non-obese diabetic (NOD) murine model recapitulates many features of T1D in humans including the dominant protection associated with the MHC class II locus. NOD mice spontaneously develop T1D, but autoimmunity can be prevented by transgenic expression of the MHCII E allele (Eα16/NOD mice). Recent published studies and new preliminary data from our laboratory suggests that microbiota are critical for this protection. The goal of this proposal is to identify immunomodulatory bacteria and immune system pathways that can be used to develop preventative T1D therapies for genetically at-risk patients To rigorously study the early-life microbiota, we developed a novel consortium of 9 culturable bacteria (which we call PedsCom) that represent over 90% of the bacteria in pre-weaning diabetes-protected Eα16/NOD mice. To investigate immunomodulatory mechanisms of specific bacteria, we are applying gnotobiotic techniques using the PedsCom consortium and genetic models of disease utilizing Eα16/NOD mice. The experiments outlined in this proposal will elucidate the mechanisms by which MHC II molecules interact with intestinal microbes to prevent T1D. In Aim 1, I will investigate if MHC II E expression impacts early-life events to shape microbial colonization by comparing colonization dynamics and humoral responses to commensal bacteria in the NOD and Eα16/NOD mice colonized by the PedsCom consortia. In Aim 2, I will determine if the PedsCom consortia of early-life microbes are sufficient to prevent T1D and whether peripheral regulatory T cells prevent T1D in Eα16/NOD mice by studying PedsCom, specific pathogen free (SPF), and germ-free colonized mice. During this fellowship, these investigations will expand my technical skills, improve my aptitude for experimental design and analysis, and enhance my ability to communicate findings to the scientific community. I will complete this fellowship at the University of Pennsylvania, which offers programs, courses, and structured mentorships that will aid my career development. In addition, I will take advantage of opportunities offered by the Immunology Graduate Group and the Medical Scientist Training Program to enhance my abilities as an educator and a clinician. With the resources available to me, I will explore the fundamental and clinically relevant questions in this proposal to gain the skills necessary to become a successful physician scientist.