Innate Immune Responses to Mycobacteria

描述（由申请人提供）：该项目的目的是了解对分枝杆菌的先天免疫反应。结核分枝杆菌比任何其他细菌病原体造成的人类死亡人数都多。它在细菌病原体中是独一无二的，因为它能够破坏宿主的防御并建立持久的潜伏感染。当宿主免疫力减弱时，分枝杆菌可以重新激活并引起疾病。对细菌发病机制或宿主反应的分子理解很少。有效的宿主反应可能取决于对分枝杆菌模式的识别和先天免疫反应的激活。巨噬细胞是分枝杆菌复制的场所，也是宿主防御的中心。我们假设有宿主因素在杀死分枝杆菌中很重要，以及细菌因素使病原体破坏破坏。我们提出功能基因组学和遗传学方法来鉴定和表征对分枝杆菌的先天免疫反应。利用果蝇吞噬细胞系，我们将建立一种基于体外细胞的方法来研究分枝杆菌对巨噬细胞的感染。我们提出了一种全基因组分析，使用基于细胞的测定和基于RNA干扰（RNAi）的方法，来确定分枝杆菌进入吞噬细胞并在吞噬细胞内存活的重要宿主因子。将进行二次分析，以确定宿主因素在感染过程中的作用及其与细菌毒力因素的关系。微阵列实验将用于表征果蝇巨噬细胞对分枝杆菌反应中激活的信号通路。我们将研究我们在RNAi筛选和微阵列分析中发现的宿主因子在果蝇和哺乳动物巨噬细胞分枝杆菌感染中的作用。该项目由哈佛医学院的Norbert Perrimon博士和哈佛公共卫生学院的Eric Rubin博士的实验室进行，将使候选人能够建立一个独立的实验室，研究结核分枝杆菌感染的发病机制，重点是宿主的先天免疫反应。

DESCRIPTION (provided by applicant): The goal of this project is to understand innate immune responses to mycobacteria. Mycobacterium tuberculosis is responsible for more human deaths than any other bacterial pathogen. It is unique among bacterial pathogens in that it is able to subvert host defenses and establish persistent, latent infection. When host immunity wanes, the mycobacteria can reactivate and cause disease. There is little molecular understanding of bacterial pathogenesis or host responses. Effective host responses likely depend upon recognition of mycobacterial patterns and activation of innate immune responses. Macrophages serve as the site for mycobacterial replication but also are central to host defense. We hypothesize that there are host factors important in killing mycobacteria, as well as bacterial factors that enable the pathogen to subvert destruction. We propose functional genomic and genetic approaches to identify and characterize innate immune responses to mycobacteria. Using Drosophila phagocytic cell lines, we will develop an in vitro cell based assay to study mycobacterial infection of macrophages. We propose a genome-wide analysis, using the cell-based assay and an RNA interference (RNAi)-based approach, to identify host factors important in mycobacterial entry into and survival within phagocytes. Secondary assays will be done to characterize the role of the host factors during infection and their relationship to bacterial virulence factors. Microarray experiments will be done to characterize signaling pathways that are activated in Drosophila macrophages in response to mycobacteria. We will examine the host factors that we identify in RNAi screens and microarray analysis for their role in mycobacterial infections in flies and in mammalian macrophages. This project, carried out in the laboratories of Dr. Norbert Perrimon at Harvard Medical School and Dr. Eric Rubin at the Harvard School of Public Health, will enable the candidate to establish an independent laboratory studying pathogenesis of M. tuberculosis infection with a focus on host innate immune responses.