Modulation of epithelial cell response by P. gingivalis

描述（由申请人提供）：牙龈假单胞菌是一种革兰氏阴性厌氧菌，被认为是与严重慢性牙周病相关的口腔细菌之一，是口腔组织的成功定植菌，可以侵入并在原发性牙龈上皮细胞（GECs）中长时间存活。牙龈卟啉卟啉能够在细胞内复制并调节gec的许多表型和信号传导特性。与许多对宿主有害的细胞内病原体不同，牙龈假单胞菌不会诱导gec细胞凋亡或坏死死亡。此外，牙龈卟啉卟啉感染可保护gec免受强效促凋亡药物诱导的凋亡。然而，牙龈假单胞菌对GECs细胞死亡信号通路和关键上游介质以及诱导的生化和形态学改变的抑制机制尚未明确。此外，微生物在上皮内增殖和传播感染的能力不断增强，其长期侵入gec的后果以及感染细胞的命运仍有待确定。本项目的总体目标是描述牙龈卟啉单胞菌感染对宿主细胞状态的长期影响。具体来说，感染细胞的最终命运将通过检查整个感染过程中的细胞死亡-存活标记和表型事件来研究。研究人员将对牙龈假单胞菌介导的细胞凋亡反应调控的潜在机制进行描述，并确定这种微生物在上皮内随时间繁殖和扩散的能力及其与宿主细胞存活的关系。流式细胞术、荧光显微镜、磷酸化特异性Western印迹活化试验、RNA干扰和基于微阵列的方法将被用于实现这些目标。牙周病是影响大多数美国人口的最普遍的多微生物疾病之一，对卫生保健系统造成了重大负担。此外，与牙龈卟啉卟啉菌相关的口腔感染已被视为心血管疾病、糖尿病、中风和早产等主要系统性健康问题的潜在危险因素。对所提出的Aims的研究将有助于建立牙龈假单胞菌与宿主细胞相互作用的概念框架，并确定更有针对性的方法来控制牙龈假单胞菌相关疾病。

DESCRIPTION (provided by applicant): P. gingivalis, a Gram-negative anaerobe identified as one of the putative oral bacteria associated with severe, chronic forms of periodontal disease, is a successful colonizer of oral tissues, and can invade and remain viable for extended periods in primary gingival epithelial cells (GECs). P. gingivalis is capable of intracellular replication and modulates many phenotypic and signaling properties of GECs. Unlike many intracellular pathogens that are harmful to their host, P. gingivalis does not induce apoptotic or necrotic death in GECs. Furthermore, P. gingivalis infection protects GECs against apoptosis induced by potent pro-apoptotic agents. Nevertheless, the mechanisms of inhibition of GECs cell death-signaling pathway(s) and the key upstream mediators along with biochemical and morphological alterations induced by P. gingivalis have not been characterized. In addition, the consequences of prolonged invasion of GECs by the microorganism with respect to its increasing ability to multiply and disseminate the infection within epithelium, and the fate of infected cells remain to be determined. Overall goal of this project is to delineate the long-term outcomes of P. gingivalis infection on host cell status. Specifically, ultimate fate of infected cells will be investigated by examining cell death-survival markers and phenotypic events throughout the infection. Underlying mechanism(s) of the modulation of apoptotic cell responses mediated by P. gingivalis will be characterized and the microorganism's ability to multiply and spread within epithelium over time and its relation to host cell survival will be determined. Flow cytometry, fluorescence microscopy, phospho-specific Western blotting-activation assays, RNA interference, and microarray based approaches will be employed to achieve these goals. Periodontal diseases are among the most prevalent polymicrobial diseases affecting a majority of U.S. population and impose a significant burden on the health care system. Moreover, oral infections associated with P. gingivalis have been linked as potential risk factors to major systemic health problems such as cardiovascular disease, diabetes mellitus, stroke and premature births. Investigations of proposed Aims will contribute to the conceptual framework of the P. gingivalis interaction with host cells and define more targeted approaches to control P. gingivalis associated diseases.