Leveraging humoral immunity to promote commensal microbial protection from T1D

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。尽管在预测谁是 由于存在患T1D的风险，目前还没有有效的治疗方法来预防这种疾病。无论是遗传还是 环境因素增加了发生T1D的风险。某些人类白细胞抗原(HL A) 单倍型主要阻止T1D的发生，但这一机制值得注意 对自身免疫的保护还没有被很好地理解。NOD小鼠，最广泛使用的T1D模型，不 表达主要组织相容性复合体(MHC)II类E分子。MHCII E基因的转基因表达 NOD小鼠中的分子(Eα16/NOD)完全阻止T1D，反映了对T1D的显性保护 人类。利用这些Eα16/NOD小鼠作为T1D显性遗传保护的模型，我们最近 证明MHC/HLA对自身免疫的遗传保护作用是通过免疫系统选择 在生命早期保护糖尿病的共生微生物区系，进而影响发育中的免疫系统 系统。因为我们发现肠道Tregs和一个明显的早期微生物群的比例增加了 Ea16/NOD小鼠，我们的中心假设是特定的微生物通过促进 开发抗糖尿病的CD4+调节性T细胞(Tregs)。人类白细胞抗原II类优势模型的建立 在小鼠模型中对T1D的保护可能为支持我们发展的长期目标提供关键的见解 以微生物群为基础的疗法以预防人类的T1D。由于其复杂性和高度的可变性， 肠道微生物群，决定教育免疫系统的特定微生物菌株是 这是个问题。建立在已建立的抗体包被共生微生物流式细胞术技术的基础上 微生物，我们开发了一种名为mflow-SEQ的创新方法来识别刺激 T1D遗传保护模型中的CD4+T细胞隔间。AIM 1利用我们的创新mflow- SEQ方法鉴定可诱导CD4+Treg细胞并预防T1D的共生微生物。AIM 2用途 确定早期生命的Treg细胞在基因上阻止自身免疫的程度的遗传模型 保护Eα16/NOD小鼠。成功完成这些目标将提供关键信息，说明哪些早期- 生命微生物影响免疫系统的发育，以预防T1D，并进一步影响早期生命的Tregs 提供针对T1D的保护。此外，mflow-SEQ是一种创新的工具，用于识别 调节小鼠的免疫系统。作为未来的发展方向，我们设想将mflow-SEQ应用于人类 帮助根据人类白细胞抗原单倍型为人类患者生成个性化微生物区系疗法的样本，请访问 T1D的风险。

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 human leukocyte antigen (HLA) haplotypes dominantly protect against the development of T1D, yet the mechanism of this remarkable protection from autoimmunity is not well-understood. NOD mice, the most widely used model of T1D, do not express a major histocompatibility complex (MHC) class II E molecule. Transgenic expression of the MHCII E molecule in NOD mice (Eα16/NOD) completely prevents T1D, mirroring dominant HLA protection from T1D in humans. Using these Eα16/NOD mice as a model of dominant genetic protection from T1D, we recently demonstrated that MHC/HLA genetic protection from autoimmunity operates via immune system selection of diabetes-protective commensal microbiota early in life, which in turn, influences the developing immune system. Since we find an increased proportion of intestinal Tregs and a distinct early-life microbiome in Ea16/NOD mice, our central hypothesis is that specific microbes prevent T1D by promoting development of diabetes-protective CD4+ regulatory T cells (Tregs). Modeling of HLA class II dominant protection from T1D in murine models 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 educate the immune system is problematic. Building upon established techniques of microbial flow cytometry of antibody-coated commensal microbes, we developed an innovative approach called mFLOW-SEQ to identify microbes that stimulate the CD4+ T cell compartment in a model of genetic protection from T1D. Aim 1 leverages our innovative mFLOW- SEQ approach to identify commensal microbes that induce CD4+ Treg cells and prevent T1D. Aim 2 uses genetic models to determine the extent to which early-life Treg cells prevent autoimmunity in genetically protected Eα16/NOD mice. Successful completion of these aims will provide critical information on which early- life microbes impact the development of the immune system to prevent T1D and further whether early-life Tregs provide protection from T1D. In addition, mFLOW-SEQ is an innovative tool for identifying microbes that modulate the immune system in mice. As a future direction, we envision applying mFLOW-SEQ to human samples to help generate personalized microbiota therapies based on HLA haplotypes for human patients at risk for T1D.