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

项目摘要 假设：2型先天免疫通过协调的方式保护肠道免受艰难梭菌感染 天然淋巴样细胞2型(ILC2)、嗜酸性粒细胞和交替激活的巨噬细胞(AAM)的作用。 进展：5R01AI124214的前5年支持表明，微生物区系诱导的类型2 豁免权保护免受CDI的攻击。它分两个阶段进行，在急性CDI期间保护上皮屏障，以及 促进治愈。我们发现这一过程中的关键步骤是：(I)IL-25和IL-33的产生 肠道对共生微生物的反应；(Ii)IL-25和IL-33激活ILC2；以及(Iii)通过 下游的2型细胞效应器嗜酸性粒细胞和AAM。关键的知识缺口是ILC2，嗜酸性粒细胞 而AAM采取行动加以保护。 意义：艰难梭菌是疾控中心的紧急抗生素耐药威胁，成为头号医院获得性肺炎 在北美的感染。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%。拟议中的研究，通过确定先天免疫如何保护，提供了 免疫疗法作为当前治疗方法的补充，并作为粪便移植的替代品。 调查人员：皮威廉·佩里在前5年发现了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(光谱流式细胞仪)、 Katia Sol-Church(ScRNAseq)和Jennie Ma和Pankag Kumar(生物信息学)。 创新方面最重要的是假设2型先天免疫保护艰难梭菌，以及 免疫系统可以被用来治疗CDI。 方法：我们将在CDI过程中描述ILC2通过的个人和集体机制 (Aim 1)、嗜酸性粒细胞(Aim 2)和AAM(Aim 3)在小鼠模型中对CDI有反应。我们将确定共同的 这3种先天2型细胞效应器协同作用的保护机制 豁免权。这些研究将包括存在或不存在单细胞转录组学(ScRNAseq) 肠上皮细胞因子IL-25和IL-33的保护性上游激活及其干预研究 直接检测先天免疫效应细胞在保护中的作用。 工作环境与位于几分钟内的所有关键人员高度互动 佩里博士艰难梭菌研究实验室的漫步。 这些研究的成功完成将确定细胞类型2响应的机制 预防CDI，为CDI作为抗生素的辅助和作为 取代粪便微生物区系移植(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).