Intracellular Pathogens and Innate Immunity

巨噬细胞作为细胞内病原体的宿主、炎症介质和获得性免疫的协调者，在感染性疾病的生物学中发挥关键作用。毫不奇怪，在大多数NIAID优先病原体中，巨噬细胞对感染的结果至关重要。本项目的一个中心假设是，细胞内病原体操纵巨噬细胞的反应，以促进疾病。此外，巨噬细胞对感染的转录反应作为整体反应的基本读出。 本计划项目的目的是使用一组分类学和结构上不同且临床相关的细胞内病原体，使用新开发的新型微阵列（包含所有已知小鼠基因（核心B）的探针）建立巨噬细胞对微生物感染的转录谱。这种转录谱将作为一个基准，以了解宿主的反应是如何操纵每种病原体。通过分析巨噬细胞对微生物突变体的转录反应，这些突变体在与巨噬细胞的致病性相互作用中有缺陷，我们将了解病原体如何操纵宿主细胞以促进感染。通过使用来自基因敲除小鼠的巨噬细胞与微生物突变体的组合，我们将确定决定宿主反应的先天免疫识别途径以及病原体如何操纵这些途径以使其受益。这些研究将阐明巨噬细胞控制先天免疫的基本和保守途径，从而提供治疗干预的潜在靶点以及致病特征，这些特征将有助于揭示微生物致病和宿主反应的基本机制。具体目的是（1）确定影响单核细胞增生李斯特菌、土拉弗朗西斯菌、结核分枝杆菌和荚膜组织胞浆菌中巨噬细胞先天免疫应答的致病微生物决定因素;（2）表征骨髓源性巨噬细胞中微生物突变体的细胞内复制和运输。(3)使用定制合成的DNA微阵列表征宿主基因表达谱，以响应野生型和突变型小鼠巨噬细胞中的野生型和突变型微生物病原体。

Macrophages play pivotal roles in the biology of infectious diseases as hosts to intracellular pathogens, mediators of inflammation, and orchestrators of acquired immunity. It is no surprise that among most of the NIAID priority pathogens, macrophages are critical to the outcome of infection. A central hypothesis of this Program Project is that intracellular pathogens manipulate the response of macrophages to promote disease. Furthermore, the transcriptional response of macrophages to infection serves as a fundamental read-out of the overall response. The purpose of this Program Project is to use a taxonomically and structurally distinct and clinically relevant panel of intracellular pathogens to establish the transcription profile of macrophages in response to microbial infection using a newly developed and novel microarray containing probes for all known mouse genes (Core B). This transcriptional profile will then serve as a benchmark to understand how the host response is manipulated by each pathogen. By profiling the transcriptional response of macrophages to microbial mutants that are defective in their pathogenic interactions with macrophages, we will learn how pathogens manipulate host cells to promote infection. By using macrophages derived from knockout mice in combination with microbial mutants, we will identify the pathways of innate immune recognition that determine the host response and how pathogens can manipulate these pathways for their benefit. These studies will illuminate essential and conserved pathways of macrophage control of innate immunity, thereby providing potential targets of therapeutic intervention as well as pathogenic signatures that will serve to uncover basic mechanisms of microbial pathogenesis and host response. The specific Aims are to (1) Identify microbial determinants of pathogenesis that affect macrophage innate immune responses in Listeria monocytogenes, Francisella tularensis, Mycobacterium tuberculosis and Histoplasma capsulatum; (2) Characterize the intracellular replication and trafficking of microbial mutants in bone marrow-derived macrophages. (3) Characterize host gene expression profiles using custom synthesized DNA microarrays in response to wild-type and mutant microbial pathogens in macrophages from wild-type and mutant mice.