Modulation of epithelial cell response by P. gingivalis

描述(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殖者，可以在原代牙龈上皮细胞(GECs)中入侵并长期存活。牙龈假单胞菌能够在细胞内复制，并调节GEC的许多表型和信号特性。与许多对宿主有害的细胞内病原体不同，牙龈假单胞菌不会导致GEC的凋亡或坏死性死亡。此外，牙龈假单胞菌感染可保护GECs免受强大的促凋亡剂诱导的细胞凋亡。然而，牙龈假单胞菌抑制细胞死亡信号通路(S)及其上游关键介质以及引起的生化和形态改变的机制尚不清楚。此外，微生物对GEC的长期入侵对其在上皮内繁殖和传播感染的能力日益增强的后果，以及感染细胞的命运仍有待确定。这个项目的总体目标是描绘牙龈假单胞菌感染对宿主细胞状态的长期结果。具体地说，将通过检查细胞死亡-生存标记和感染过程中的表型事件来调查感染细胞的最终命运。我们将研究牙龈假单胞菌调节细胞凋亡反应的潜在机制(S)，并将确定微生物随时间在上皮细胞内繁殖和扩散的能力及其与宿主细胞生存的关系。为了实现这些目标，将使用流式细胞术、荧光显微镜、磷酸化的蛋白印迹-激活分析、RNA干扰和基于微阵列的方法。牙周病是影响大多数美国人的最常见的多菌疾病之一，给医疗保健系统带来了巨大的负担。此外，与牙龈假单胞菌相关的口腔感染已被认为是主要系统性健康问题的潜在危险因素，如心血管疾病、糖尿病、中风和早产。对拟议的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.