Metabolic regulation of macrophage function during M. tuberculosis infection

项目摘要 结核分枝杆菌(Mtb)感染了全球20亿人，每年导致的死亡人数比以往任何时候都多。 其他单一病原体。大多数感染结核分枝杆菌的人能够终生控制感染，这表明 存在能够成功控制感染的免疫机制。确定这些机制是 对于开发能够增强免疫力不足患者免疫力的治疗方法至关重要。 巨噬细胞既是结核分枝杆菌感染的宿主细胞，又是主要受感染的细胞。 负责通过激活有效杀死细菌的杀菌机制来控制感染。在……里面 此外，巨噬细胞通过产生促炎症反应和抗感染反应来影响感染的炎症反应。 炎症因子。这个项目的长期目标是了解巨噬细胞如何代谢 影响抗菌活性和炎症的调节。我们之前的工作主要是围绕 干扰素-γ激活巨噬细胞，这是一种对结核分枝杆菌免疫控制至关重要的细胞因子。我们发现一个 连接有氧糖酵解、一氧化氮和转录因子HIF-1α的免疫代谢环在 体外感染巨噬细胞的抗菌药控制和调节炎症平衡。在……里面 此外，我们还证明了巨噬细胞中的缺氧诱导因子-1α对于控制小鼠感染是必不可少的。然而，它 目前尚不清楚缺氧诱导因子-1α和一氧化氮在体内的重要性是否源于细胞的内在控制 巨噬细胞，调节炎症，或两者兼而有之。此外，来自几个实验室的最新数据表明 干扰素-γ虽然很重要，但可能不是巨噬细胞控制巨噬细胞感染的唯一因素。 体内感染。事实上，有几个研究小组报告说，CD4T细胞也可以介导干扰素-γ的非依赖性 体内感染的控制。我们已经开发了一种体外培养系统，可以重现CD4T细胞 依赖但干扰素-γ独立控制感染，这为机制研究提供了一个模型系统。 有趣的是，我们的初步数据表明，由干扰素-γ激活的巨噬细胞是独立的机制。 激活有氧糖酵解和缺氧诱导因子-1α，而不产生NO。最后，人们对此知之甚少。 巨噬细胞通过调节代谢物的运输来支持代谢的大规模变化。在这里我们 建议加深我们对干扰素-γ依赖和独立巨噬细胞控制的理解。 结核分枝杆菌感染的三个目的：1)确定NO/HIF-1α在结核分枝杆菌感染的细胞内控中的重要性 体内实验证明干扰素-γ对结核分枝杆菌感染的独立控制需要有氧糖酵解和缺氧诱导因子-1α 3)证明溶质载体蛋白在调节HIF-1α依赖的感染控制中起作用 支持代谢物跨细胞膜的运输。

Project Summary Mycobacterium tuberculosis (Mtb) infects 2 billion people worldwide, and kills more people every year than any other single pathogen. Most people infected with Mtb are able to contain infection for their lifetimes, suggesting the existence of immune mechanisms that can successfully control infection. Identifying these mechanisms is crucial for the development of therapeutics that can bolster immunity in patients with insufficient immunity. Macrophages serve the dual role as both the host cell for Mtb infection, and the cell that is primarily responsible for controlling infection by activating microbicidal mechanisms that effectively kill bacteria. In addition, macrophages influence the inflammatory response to infection by producing both pro-and anti- inflammatory factors. The long-term goal of this project is to understand how macrophage metabolism influences both antimicrobial activity and the regulation of inflammation. Our previous work centered around activation of macrophages by IFN-γ, a cytokine that is critical for immune control of Mtb. We found that an immuno-metabolic loop linking aerobic glycolysis, nitric oxide, and the transcription factor HIF-1α is crucial for both antimicrobial control and regulating the balance of inflammation in macrophages infected ex vivo. In addition, we demonstrated that HIF-1α in macrophages in essential for control of infection in mice. However, it remains unclear whether the importance of HIF-1α and nitric oxide in vivo result from cell intrinsic control by macrophages, regulation of inflammation, or both. Furthermore, recent data from several labs has suggested that IFN-γ, while clearly important, may not be the only factor required for macrophage-based control of infection in vivo. Indeed, several groups have reported that CD4 T cells can also mediate IFN-γ independent control of infection in vivo. We have developed an ex vivo culture system that recapitulates CD4 T cell dependent but IFN-γ independent control of infection, which provides a model system for mechanistic studies. Intriguingly, our preliminary data suggest that macrophages activated by IFN-γ independent mechanisms activate aerobic glycolysis and HIF-1α without producing NO. Finally, very little is known about how macrophages support large scale changes in metabolism via regulated metabolite transport. Here we proposed to further our understanding of both IFN-γ dependent and independent macrophage based control of Mtb infection in three aims: 1) Determine the importance of NO/HIF-1α for cell intrinsic control of Mtb infection in vivo 2) Demonstrate that IFN-γ independent control of Mtb infection requires aerobic glycolysis and HIF-1α 3) Demonstrate that solute carrier proteins play a role in regulating HIF-1α dependent control of infection by supporting metabolite transport across cell membranes.