Linking Receptor-Mediated Phagocytosis and cAMP Pathways in Macrophage Responses to Tuberculosis

项目摘要/摘要 结核分枝杆菌(M.tb)是结核病的病原体，也是导致死亡的主要原因。 来自单一的感染源。据估计，2017年有1000万人患上了结核病，这表明 迫切需要新的治疗方法，包括宿主定向治疗(HDT)以阻止感染和 活动性结核病的进展。巨噬细胞通常是抵御入侵病原体的第一道防线。 然而，结核分枝杆菌调节巨噬细胞的信号通路，以诱导有利于其 细胞内存活。结核分枝杆菌采用的战略是一个活跃的调查领域。的总目标是 该实验室将识别炎症和代谢中间产物的细胞内主要调节因子 决定人巨噬细胞对结核分枝杆菌的反应。我们实验室之前的工作表明，结核分枝杆菌与 巨噬细胞甘露糖受体(MR)激活过氧化体增殖物激活受体γ(PPARγ) 一种转录因子，可抑制炎症反应，并与结核分枝杆菌生长增加有关。这个 拟议的研究计划将调查结核分枝杆菌mr连接启动cAMP信号的假设。 导致PPARγ激活的途径，从而提高结核分枝杆菌在巨噬细胞中的存活率。具体目标 目的是：1)确定磷酸二酯酶(PDE)通过cAMP调节PPARγ活性的作用 结核分枝杆菌感染hMDM过程中的信号通路，2)决定蛋白激酶A(PKA)和 CAMP-1直接激活的交换蛋白对结核分枝杆菌诱导的PPARγ活性的调节作用 HMDM中cAMP的产生，以及3)MR/cAMP/PKA/Epa1/PPARγ信号对结核分枝杆菌的影响 发病机制。拟议的项目将进一步阐明MR连接下游的信号通路(S) 由M.TB进行，这是一个只进行过最低限度调查的地区。此外，这个项目使用了一个创新的，新开发的 人源化小鼠模型研究体内人类MR缺乏小鼠MR，这是一个混杂因素 数据分析。对cAMP途径的研究有望为HDT寻找新的可用药的宿主细胞靶点 抗结核病。这项研究计划让我有能力学习新的科学技术，新的研究模式 传染病，详细的数据分析和培训，塑造了这个项目的方向和我的职业生涯。 培训计划概述了职业发展活动，包括提高我的科学能力的机会 演讲和沟通技巧、资助人精神、指导和教学技能。研究和培训 将在德克萨斯生物医学研究所举行，致力于科学培训， 无数的杂志俱乐部、研讨会和德克萨斯生物学院学员协会的全力支持都证明了这一点。 德州生物科技拥有各种核心设施，在体外和小鼠体内研究结核分枝杆菌的高度封闭的研究实验室 和国家卫生计划，以及优秀科学培训所需的所有资源。在团契结业时，我会做好准备 以独立科学家的身份领导宿主/病原体相互作用的研究项目。

PROJECT SUMMARY/ABSTRACT Mycobacterium tuberculosis (M.tb) is the causative agent of tuberculosis (TB) and the leading cause of death from a single infectious agent. An estimated 10 million people developed TB disease in 2017, demonstrating an urgent need to new therapeutic approaches, including host-directed therapy (HDT) to halt infection and progression of active TB. Macrophages often serve as the first line of defense against invading pathogens. However, M.tb modulates macrophage cell signaling pathways to induce an environment beneficial to its intracellular survival. The strategies employed by M.tb are an active area of investigation. The overall goal of the laboratory is to identify intracellular master regulators of inflammation and metabolic intermediates that dictate human macrophage responses to M.tb. Previous work in our lab revealed that M.tb interaction with the macrophage mannose receptor (MR) activates peroxisome proliferator-activated receptor gamma (PPARγ), a transcription factor that dampens the inflammatory response and is associated with increased M.tb growth. The proposed research plan will investigate the hypothesis that MR ligation by M.tb initiates the cAMP signaling pathway leading to PPARγ activation, resulting in enhanced survival of M.tb in macrophages. The Specific Aims are to: 1) Determine the role of phosphodiesterases (PDEs) in regulating PPARγ activity through the cAMP signaling pathway during M.tb infection of hMDMs, 2) Determine the role of Protein Kinase A (PKA) and Exchange Protein Directly Activated by cAMP 1 (Epac1) in regulating PPARγ activity following M.tb-elicited cAMP production in hMDMs, and 3) Determine the effects of MR/cAMP/PKA/Epac1/PPARγ signaling on M.tb pathogenesis. The proposed project will further elucidate the signaling pathway(s) downstream of MR ligation by M.tb, an area only minimally investigated. In addition, this project uses an innovative, newly developed humanized mouse model to study human MR in vivo devoid of the murine MR which is a confounding factor to data analysis. Investigation of the cAMP pathway is expected to identify new, druggable host cell targets for HDT against TB. This research plan affords me the ability to learn new scientific techniques, new models to study infectious diseases, detailed data analysis and the training to shape the direction of this project and my career. The training plan outlines career development activities including opportunities to improve my scientific presentation and communication skills, grantsmanship, mentoring and teaching skills. The research and training will take place at the Texas Biomedical Research Institute with a deep commitment to scientific training, evidenced by numerous journal clubs, seminars and full support of the Texas Biomed Association for Trainees. Texas Biomed has various core facilities, high containment research labs for M.tb work both in vitro and in mice and NHPs, and all resources needed for excellent scientific training. At fellowship completion, I will be prepared to lead a research program in host/pathogen interaction as an independent scientist.