Coxiella burnetii Regulation of Macrophage cAMP/PKA Signaling

描述（由申请方提供）：贝氏柯克斯体是人类Q热的细胞内细菌因子，Q热是一种使人衰弱的流感样疾病，也可表现为严重的慢性心内膜炎。C.贝氏体通过受污染的气溶胶传播，并以体内肺泡巨噬细胞为目标，在肺泡巨噬细胞中，病原体调节囊泡运输以建立吞噬溶酶体样寄生虫空泡（PV），在其中复制。真核细胞激酶信号转导在很大程度上参与了吞噬体成熟和宿主对细菌病原体的反应;贝氏体感染尚未完全确定。目前的建议是为了测试的假设，C。Burnetii操纵宿主cAMP/PKA信号传导以产生PV并防止宿主细胞死亡。目的1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的必要性。目的2将确定PKA在C. Burnetii抗凋亡活性。这些实验将评估促细胞凋亡Bad的PKA依赖性失活以及该事件对预防细胞凋亡的要求。目的3将探索cAMP的产生在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，本研究的目的是探索cAMP/PKA信号在C.巨噬细胞的贝氏寄生。

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.