Role of Type 2 Immunity in Innate Protection from C. difficile

项目摘要 假设：2型先天免疫保护肠道免受C。艰难梭菌感染（CDI）通过协调 先天性淋巴细胞2型（ILC 2），嗜酸性粒细胞和交替激活的巨噬细胞（AAM）的作用。 进展：5 R 01 AI 124214的前5年支持表明，微生物群引起的2型 免疫力保护CDI。它在两个阶段发挥作用，在急性CDI期间保护上皮屏障， 促进愈合。我们发现该过程中的关键步骤是：（i）由IL-25和IL-33的产生， 肠对肠道微生物的反应;（ii）IL-25和IL-33对ILC 2的激活;和（iii）通过 下游2型细胞效应细胞嗜酸性粒细胞和AAM。关键的知识差距是ILC 2，嗜酸性粒细胞 和AAM采取行动保护。 显著性：C. difficile是CDC的“紧急抗生素耐药性威胁”，是医院获得性 北美感染。目前的抗生素治疗是不够的，因为复发率高达20%， 死亡率为6%。通过确定先天免疫如何保护，拟议的研究提供了 免疫疗法作为目前治疗方法的补充和作为粪便移植的替代。 研究人员：PI William Petri在过去5年中发现了2型免疫在CDI中的作用。 支持.主要人员包括Maureen Carey（系统生物学），Stacey Burgess（光谱流式细胞术）， Katia Sol-Church（scRNAseq）和Pankag Kumar（生物信息学）。 创新方面首先是假设2型先天免疫保护免受C。艰难， 免疫系统可以用来治疗CDI 方法：我们将在CDI过程中描述ILC 2 (Aim 1）、嗜酸性粒细胞（Aim 2）和AAM（Aim 3）在鼠模型中对CDI应答。我们将确定共同的 通过这3种细胞效应子的协调作用保护2型先天免疫缺陷病毒的潜在机制 免疫力这些研究将包括在存在或不存在以下物质的情况下的单细胞转录组学（scRNAseq）： 肠上皮细胞因子IL-25和IL-33的保护性上游激活，以及干预性研究 以直接测试先天免疫效应细胞对保护的贡献。 工作环境是高度互动的所有关键人员位于几分钟内 佩特里博士的C.艰难的研究实验室。 这些研究的成功完成将确定细胞2型反应的机制， 保护免受CDI的侵害，并为CDI作为抗生素的辅助治疗和作为免疫治疗的基础奠定基础。 粪便微生物群移植（FMT）。

Project Summary Hypothesis: Type 2 innate immunity protects the gut from C. difficile infection (CDI) via the coordinated actions of innate lymphoid cell type 2 (ILC2), eosinophils and alternatively-activated macrophages (AAM). Progress: The first 5 years of support from 5R01AI124214 demonstrated that microbiota-elicited type 2 immunity protects from CDI. It does so at two stages, protecting the epithelial barrier during acute CDI, and promoting healing. We discovered that key steps in this process are: (i) IL-25 and IL-33 production by the intestine in response to commensal microbes; (ii) IL-25 and IL-33 activation of ILC2; and (iii) protection by downstream type 2 cellular effectors eosinophils and AAM. The key knowledge gap is how ILC2, eosinophils and AAM act to protect. Significance: C. difficile is a CDC “Urgent Antibiotic Resistance Threat” as the number one hospital-acquired infection in North America. Current therapy with antibiotics is inadequate, as relapse occurs in up to 20% and death in 6%. The proposed studies, by identifying how innate immunity protects, offer the promise of immunotherapy as an addition to current approaches to treatment and as a replacement for fecal transplant. Investigators: The PI William Petri discovered the role of type 2 immunity in CDI in the prior 5 year period of support. Key personnel include Maureen Carey (systems biology), Stacey Burgess (spectral flow cytometry), Katia Sol-Church (scRNAseq) and Jennie Ma and Pankag Kumar (bioinformatics). Innovative aspects are foremost the hypothesis that type 2 innate immunity protects from C. difficile and that the immune system can be harnessed to treat CDI. Approach: We will describe during the course of CDI the individual and collective mechanisms by which ILC2 (Aim 1), eosinophils (Aim 2) and AAM (Aim 3) respond to CDI in the murine model. We will identify common underlying mechanisms of protection by the coordinated action of these 3 cell effectors of type 2 innate immunity. The studies will include single cell transcriptomics (scRNAseq) in the presence or absence of protective upstream activation by the intestinal epithelial cytokines IL-25 and IL-33, and interventional studies to directly test the contributions of innate immune effector cells on protection. The environment for the work is highly interactive with all of the key personnel located within a few minutes walk of Dr. Petri’s C. difficile research lab. Successful completion of these studies will identify the mechanisms by which cellular type 2 responses protect from CDI and lay the foundation for immunotherapy for CDI as an adjunct to antibiotics and as a replacement for fecal microbiota transplant (FMT).