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

项目总结/摘要 结核分枝杆菌（Mycobacterium tuberculosis，M.tb）是结核病（TB）的病原体，也是导致死亡的主要原因 一种传染性病原体据估计，2017年有1000万人患上结核病， 迫切需要新的治疗方法，包括宿主导向治疗（HDT），以阻止感染， 活动性TB的进展。巨噬细胞通常作为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信号传导途径，以诱导有利于其生长的环境。 细胞内存活结核分枝杆菌采用的策略是一个活跃的研究领域。的总目标 该实验室的目标是确定炎症和代谢中间体的细胞内主要调节因子， 决定了人类巨噬细胞对结核杆菌的反应。我们实验室以前的工作表明，结核分枝杆菌与 巨噬细胞甘露糖受体（MR）激活过氧化物酶体增殖物激活受体γ（PPAR γ）， 结核分枝杆菌是抑制炎症反应并与结核分枝杆菌生长增加相关的转录因子。的 拟议的研究计划将调查结核分枝杆菌的MR连接启动cAMP信号传导的假设 通过导致过氧化物酶体增殖物激活受体γ激活的途径，导致结核分枝杆菌在巨噬细胞中的存活增强。具体目标 目的：1）确定磷酸二酯酶（PDE）通过cAMP调节PPAR γ活性的作用， 2）确定蛋白激酶A（PKA）的作用， cAMP 1直接激活的交换蛋白Epac 1对结核分枝杆菌诱导的过氧化物酶体增殖物激活受体γ活性的调节 hMDM中cAMP的产生，以及3）确定MR/cAMP/PKA/Epac 1/PPAR γ信号传导对结核分枝杆菌的影响 发病机制拟议项目将进一步阐明MR连接下游的信号通路 结核分枝杆菌，一个领域只有最低限度的研究。此外，该项目采用了创新的，新开发的 人源化小鼠模型，以在体内研究缺乏鼠MR的人MR，鼠MR是一种混杂因素， 数据分析对cAMP途径的研究有望为HDT确定新的、可药物化的宿主细胞靶点 对抗结核病。这个研究计划使我有能力学习新的科学技术，新的模型来研究 传染病，详细的数据分析和培训，以塑造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，演讲，指导和教学技巧。研究和培训 将在德克萨斯生物医学研究所举行，并致力于科学培训， 众多的期刊俱乐部，研讨会和德克萨斯州生物医学协会的全力支持证明了这一点。 德克萨斯生物医学公司拥有各种核心设施，高遏制性结核病研究实验室，包括体外和小鼠实验室 和NHP，以及优秀科学培训所需的所有资源。在奖学金结束时，我会准备好 作为一名独立的科学家，领导一个宿主/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.