Coxiella burnetii Regulation of Macrophage cAMP/PKA Signaling

描述（由申请人提供）：伯纳蒂克希菌是人类Q热的细胞内细菌病原体，Q热是一种使人衰弱的流感样疾病，也可以表现为严重的慢性心内膜炎。伯纳蒂梭菌通过被污染的气溶胶传播，并在体内靶向肺泡巨噬细胞，在体内病原体调节囊泡运输以建立吞噬溶酶体样寄生液泡（PV）进行复制。真核激酶信号在吞噬体成熟和宿主对细菌病原体的反应中起重要作用；然而，它们与伯纳氏梭菌感染的关系尚未完全确定。目前的研究旨在验证C. burnetii操纵宿主cAMP/PKA信号产生PV并防止宿主细胞死亡的假设。目的1将阐明PKA在PV形成中的作用。本实验将探讨PKA和肌动蛋白相关蛋白运输到PV的需求。目的2将确定PKA在burnetii抗凋亡活性中的作用。这些实验将评估pka依赖的促凋亡Bad失活以及该事件对防止细胞凋亡的要求。目的3将探讨cAMP在PV形成、细菌复制、细胞凋亡抑制和转录调控中的整体作用。总的来说，本提案的目的是探索cAMP/PKA信号在巨噬细胞寄生中的多功能作用。

DESCRIPTION (provided by applicant): Coxiella burnetii is the intracellular bacterial agent of human Q fever, a debilitating flu-like illness that can also present as severe chronic endocarditis. C. burnetii is spread by contaminated aerosols and targets alveolar macrophages in vivo, where the pathogen regulates vesicular trafficking to establish a phagolysosome-like parasitophorous vacuole (PV) in which to replicate. Eukaryotic kinase signaling is heavily involved in phagosome maturation and host responses to bacterial pathogens; however, their involvement in C. burnetii infection has not been fully defined. The current proposal is designed to test the hypothesis that C. burnetii manipulates host cAMP/PKA signaling to generate the PV and prevent host cell death. Aim 1 will elucidate the role of PKA in PV formation. The experiments in this aim will explore the requirement for PKA and actin-related protein trafficking to the PV. Aim 2 will determine the role of PKA in C. burnetii anti-apoptotic activity. These experiments will assess PKA-dependent inactivation of pro-apoptotic Bad and the requirement of this event for prevention of apoptosis. Aim 3 will probe the overall role of cAMP production in PV formation, bacterial replication, apoptosis inhibition, and transcriptional regulation. Collectively, the aims in the current proposal will explore a multi-functional role for cAMP/PKA signaling in C. burnetii parasitism of macrophages.