Project 1: Listeria metabolites and innate immunity

项目概要/摘要（项目1，Portnoy） 该提案是P01更新中的项目1，标题为“先天免疫和适应性免疫的交叉点， 细胞内病原体”我们要解决的一个中心问题是如何识别细胞内病原体 宿主先天免疫系统以及多种信号如何整合以诱导适当的 反应，以及相反，病原体如何避免和/或操纵宿主反应，以促进其 发病机制在项目1中，我们选择通过继续详细分析 单核细胞增生李斯特菌，一种兼性细胞内，食源性病原体，已被研究了几十年 作为一个模型系统来剖析感染和免疫的基本方面。此前，我们发现 那个L。单核细胞增多症分泌c-di-AMP，其结合并激活宿主STING，导致I型 干扰素应答在目标1中，我们利用了一种新开发的口腔粘膜炎模型，我们发现， 细菌分泌的c-di-AMP诱导STING依赖性宿主保护性应答。我们建议 分析STING如何提供保护，并测试STING也促进传播的假设， 胎盘和大脑在目标2和3中，我们开始探索c-di-AMP可能只是一种 小细菌代谢物在形成宿主免疫力方面发挥重要作用的原理的例子。L. 单核细胞增多症是一种需要核黄素的微生物，我们探讨了这一假设， 营养需求允许细菌避免激活粘膜相关的不变T细胞（MAIT 细胞），其是由核黄素生物合成的修饰中间体刺激的先天性T细胞。在 初步研究结果表明，我们将5个枯草芽孢杆菌基因（ribDEAHT）导入L.单核细胞增多症将其 现在我们准备测试我们的假设，并了解 MAIT细胞在细菌感染和免疫过程中的作用。我们还建议探索激活的 人类中的显性γ δ T细胞（Vg 9Vd 2 T细胞）。这些细胞被一种中间体激活， 细菌类异戊二烯生物合成（HMBPP）。我们的最终目标是确定这种先天的重要性， 在灵长类动物（人和非人）感染期间的免疫途径。在这里，我们建议构建 细菌突变体不能产生HMBPP或产生更多的HMBPP，以检查细菌HMBPP是如何产生的。 在组织培养模型中感染期间检测到。我们还提议与考克斯实验室合作 （项目2）探讨HMBPP在M.结核病感染和免疫力。

Project Summary/Abstract (Project 1, Portnoy) This proposal is Project 1 within a P01 renewal, entitled “The intersection of innate and adaptive immunity to intracellular pathogens.” A central problem that we address is how intracellular pathogens are recognized by the host innate immune system and how multiple signals are integrated to induce an appropriate response, and conversely, how pathogens avoid and/or manipulate host responses to promote their pathogenesis. In Project 1, we have chosen to approach this problem by continuing a detailed analysis of Listeria monocytogenes, a facultative intracellular, food-borne pathogen that has been studied for decades as a model system with which to dissect basic aspects of infection & immunity. Previously, we discovered that L. monocytogenes secretes c-di-AMP which binds to and activates host STING leading to a type I interferon response. In Aim 1, we exploit a newly developed oral model of listeriosis where we find that bacterially secreted c-di-AMP induces a STING-dependent host protective response. We propose to analyze how STING provides protection and test the hypothesis that STING also promotes dissemination to the placenta and brain. In Aims 2 and 3, we begin to explore the idea that c-di-AMP might be just one example of the principle that small bacterial metabolites play important roles in shaping host immunity. L. monocytogenes is a riboflavin requiring microorganism, and we explore the hypothesis that that this nutritional requirement allows the bacteria to avoid activation of mucosal-associated invariant T-cells (MAIT cells), which are innate T-cells stimulated by a modified intermediate of riboflavin biosynthesis. In preliminary data, we introduced five Bacillus subtilis genes (ribDEAHT) into L. monocytogenes converting it into a riboflavin-synthesizing bacterium and are now poised to test our hypothesis and learn about the role of MAIT cells during bacterial infection and immunity. We also propose to explore the activation of the dominant gamma delta T-cell in humans (Vg9Vd2 T-cells). These cells are activated by an intermediate of bacterial isoprenoid biosynthesis (HMBPP). Our ultimate goal is to determine the importance of this innate immune pathway during infection of primates (human and non-human). Here we propose to construct bacterial mutants that either fail to make HMBPP or make more of it to examine how bacterial HMBPP is detected during infection in tissue culture models. We further propose to collaborate with the Cox lab (Project 2) to explore the importance of HMBPP during M. tuberculosis infection and immunity.