Leveraging early-life microbes to prevent type 1 diabetes

项目总结 1型糖尿病(T1D)是一种影响全球数百万人的自身免疫性疾病。的发病率。 T1D正在上升，特别是在年幼的儿童中。尽管在预测谁处于危险中取得了重大进展 对于发生T1D，目前还没有有效的治疗方法来预防这种疾病。遗传的和环境的 影响T1D发病风险的因素有很多。某些主要组织相容性复合体/人类白细胞 抗原(MHC/HLA)II类单倍型主要预防T1D的发生，我们最近 发现保护性MHCII分子塑造早期微生物群落，进而影响免疫 系统开发，预防T1D。在NOD小鼠中模拟T1D的微生物保护作用可能会提供关键的 支持我们开发基于微生物区系的疗法以预防人类T1D的长期目标的见解。到期 针对肠道微生物群的复杂性和高度变异性，确定特定的微生物 驱动免疫系统发育和功能的菌株是有问题的。诺生菌小鼠的研究进展 具有明确的成体微生物群落是该领域的一个重要进展，因为它们简化了 系统的复杂性和可变性，并允许很好地控制，机械的研究。然而，灵知生菌 目前尚缺乏研究儿科疾病的小鼠模型。我们开发了一种新的灵知生菌小鼠模型-早期- 我们称之为儿科社区或“儿科社区”的生命微生物群。PedsCom是由9个细菌组成的联盟 从断奶前糖尿病保护性Eα16/NOD小鼠肠道分离的菌株。值得注意的是，这9- 微生物群落强大地诱导调节性T细胞(Tregs)，并提供从T1D到糖尿病的保护- 易感的NOD小鼠。我们假设特定的PedsCom微生物协同工作来预防T1D 通过提供微生物抗原和代谢产物来诱导外周调节性T细胞(PTregs) 免疫系统发育的关键早期生命窗口。目标1检查了时间、本地化和 由特定的PedsCom成员产生的代谢物，驱动pTreg细胞的发育并防止 自身免疫力。目的2研究PedsCom微生物及其受体诱导pTregs的机制。 蛋白质抗原以及其TCR识别特定微生物抗原的pTregs是否介导了对 T1D。这些目标的成功完成将提供关于早期生命微生物诱导 PTregs，以及微生物抗原和代谢产物共同作用产生糖尿病的程度- 保护性免疫系统。此外，PedsCom小鼠是研究早期宿主的创新工具- 微生物区系相互作用。

PROJECT SUMMARY Type 1 diabetes (T1D) is an autoimmune disease that affects millions of people worldwide. The incidence of T1D is rising, especially in young children. Although significant progress has been made to predict who is at risk for developing T1D, there are no effective therapies to prevent this disease. Both genetic and environmental factors contribute to the risk of developing T1D. Certain major histocompatibility complex/human leukocyte antigen (MHC/HLA) class II haplotypes dominantly protect against the development of T1D, and we recently discovered that protective MHCII molecules shape early-life microbial communities which in turn impact immune system development to prevent T1D. Modeling microbial protection from T1D in NOD mice may provide critical insights to support our long-term goal of developing microbiota-based therapies to prevent T1D in humans. Due to the complexity and high levels of variability of the intestinal microbiome, determining the specific microbial strains that drive immune system development and function is problematic. The development of gnotobiotic mice with defined adult microbial communities has been an important advance in the field because they simplify the complexity and variability of the system and allow for well-controlled, mechanistic studies. However, a gnotobiotic mouse model to study pediatric disease is lacking. We developed a new gnotobiotic mouse model of the early- life microbiome which we call Pediatric Community or “PedsCom”. PedsCom is a consortium of 9 bacterial strains isolated from the intestine of pre-weaning diabetes-protected Eα16/NOD mice. Remarkably, this 9- microbe community robustly induces regulatory T cells (Tregs) and confers protection from T1D to diabetes- susceptible NOD mice. We hypothesize that specific PedsCom microbes work in concert to prevent T1D by providing microbial antigens and metabolites that induce peripheral regulatory T cells (pTregs) during a critical early life window of immune system development. Aim 1 examines the timing, localization, and metabolites produced by specific PedsCom members which drive pTreg cell development and prevent autoimmunity. Aim 2 examines the mechanisms by which pTregs are induced by PedsCom microbes and their protein antigens and whether pTregs whose TCRs recognize specific microbial antigens mediate protection from T1D. Successful completion of these aims will provide critical information on which early-life microbes induce pTregs, and the degree to which microbial antigens and metabolites work together to generate a diabetes- protective immune system. In addition, PedsCom mice are an innovative tool for investigating early-life host- microbiota interactions.