M. tuberculosis strain-dependent interactions with host cells

结核病是一种多方面的疾病，其临床表现具有广泛的多样性。 结核分枝杆菌感染一种单一病原体的产物。中国丰富的遗传多样性 导致临床结果差异的人类和结核分枝杆菌基因组代表 宿主-病原体相互作用的修饰是发病机制的关键。了解这些问题的基础 异质性反应将揭示毒力和耐药性的新机制，并将影响治疗 和诊断学。不幸的是，研究感染不同结局的机制面临的挑战 在人类中，不仅包括鉴定宿主/病原体基因类型与表型之间的相关性 以及随后对引起疾病的机制的识别，这些疾病 要求在没有病原体自然寄主的情况下在实验室进行研究。此计划需要 独特的、正在进行的全基因组关联研究(GWAS)的优势，这些研究已经确定了人类和 在两个不同的人群中与不同的临床反应相关的病原体变异。 为了确定这些变异背后的机制，我们将采用一套强大的实验 检测，包括新的基于蛋白质组学的扫描平台，用于探测实验期间的宿主反应 巨噬细胞感染，与传统的信使核糖核酸图谱垂直，以便广泛地寻找 宿主与这些临床菌株相关的疾病结局的先天免疫途径。 根据我们的初步数据，我们假设其中许多相互作用发生在感染和感染的早期 是由结核分枝杆菌分泌的蛋白质介导的。在本提案中，我们主要关注相关性 在两组独特的临床细菌变异之间，与更大程度上传播 肺结核病和更容易扩散到身体远端部位的菌株。一个 这两组菌株出人意料的主题是ESX分泌的结核蛋白的流行 用结核分枝杆菌表达的系统。结核分枝杆菌的ESX-1和ESX-5分泌系统都是 细胞内生长和激发不同的天然免疫反应所需的关键毒力决定因素 在巨噬细胞感染期间。一个中心假设是影响疾病的一组细菌蛋白质 结果丰富了介导病原菌和宿主之间相互作用的分泌蛋白 巨噬细胞。为了验证这一假设，我们将与内核A和内核B合作，使用一种综合方法 将来自结核分枝杆菌Gwas数据集的遗传数据与遗传和蛋白质组筛选相结合以鉴定 调节与巨噬细胞相互作用的因果基因。我们将使用这些相同的技术进行协作 项目2和项目3确定与宿主抗性和细菌有关的蛋白质/途径 传播。

Tuberculosis (TB) is a multifaceted disease that has extensive variation in clinical manifestations despite being the product of infection with a single pathogen, Mycobacterium tuberculosis. The extensive genetic diversity in human and Mycobacterium tuberculosis genomes responsible for differences in clinical outcomes represent modifications of host-pathogen interactions that are key to pathogenesis. Understanding the basis for these heterogenous responses will uncover new mechanisms of virulence and resistance and will impact treatment and diagnostics. Unfortunately, the challenges of studying the mechanisms of differential outcomes of infection in humans not only includes identification of correlations between host/pathogen genotypes with phenotypes in human populations, but also the subsequent identification of the mechanisms that are causal for disease which require studying them in the laboratory without the pathogen’s natural host organism. This Program takes advantage of unique, ongoing genome-wide association studies (GWAS) that have identified both human and pathogen variants that are associated with heterogenous clinical responses in two different human populations. To determine the mechanisms underlying these variations, we will employ a powerful set of experimental assays, including new proteomics-based scanning platform to probe host responses during experimental macrophage infection that is orthogonal to traditional mRNA profiling, in order to broadly search for changes in host innate immune pathways that correlate with disease outcomes associated with these clinical strains. Based on our preliminary data, we hypothesize that many of these interactions occur early during infection and are mediated by proteins secreted by M. tuberculosis. In this proposal, we focus primarily on correlations between two unique sets of clinical bacterial variants, strains that are associated greater transmission of pulmonary TB disease and strains that are more prone to dissemination to distal sites in the body. An unexpected theme from both of these sets of strains is the prevalence of TB proteins secreted by the ESX systems expressed in M. tuberculosis. Both the ESX-1 and ESX-5 secretion systems of M. tuberculosis are key virulence determinants required for intracellular growth and for eliciting distinct innate immune responses during macrophage infection. A central hypothesis is that the set of bacterial proteins that influence disease outcomes are enriched for secreted proteins that mediate interactions between pathogen and host macrophages. To test this hypothesis, we will collaborate with Cores A and B to use an integrative approach to combine genetic data from the M. tuberculosis GWAS datasets with genetic and proteomic screen to identify causal genes that mediate interactions with macrophages. We will use these same technologies to collaborate with Projects 2 and 3 to identify proteins/pathways responsible for host resistance and bacterial dissemination.