The Role of p. gingivalis Capsule in Cell Inflammation

描述：牙龈卟啉单胞菌，一种革兰氏阴性，厌氧，口腔病原体是成人牙周病的主要病原体。最近的报道表明，封装的牙龈卟啉单胞菌比未封装的菌株更具毒性。然而，牙龈卟啉单胞菌荚膜多糖在疾病发病机制中的确切作用以及这种毒力因子的作用机制在很大程度上是未知的。我们认为牙龈卟啉单胞菌的荚膜多糖促进牙龈卟啉单胞菌感染的细胞炎症反应特征，并有助于牙龈卟啉单胞菌介导的成人牙周病的病理学观察。我们的初步体外研究表明，这种抗原结合宿主细胞，并刺激先天性免疫反应，这是允许中性粒细胞趋化。体内观察证实了我们的体外数据，并证明纯化的牙龈卟啉单胞菌荚膜多糖刺激宿主炎性细胞应答，其模拟活的牙龈卟啉单胞菌全细胞攻击。提出了三个具体目的：1）：确定纯化的牙龈卟啉单胞菌荚膜多糖与上皮细胞和相关免疫细胞群体的结合动力学。我们将表征1-剂量和时间依赖性结合动力学，2-结合特异性，并采用阻断研究来确定纯化的牙龈卟啉单胞菌荚膜多糖与宿主细胞的附着。2）研究牙龈卟啉单胞菌荚膜多糖对牙龈上皮细胞及相关白细胞的天然免疫应答。将检查细胞因子分泌、细胞粘附分子产生和中性粒细胞募集。我们将描绘细胞因子，趋化因子和细胞粘附分子库的细胞相关的刺激和表征的中性粒细胞迁移的挑战。3）：确定在鼠气囊模型中响应于牙龈卟啉单胞菌荚膜多糖而发生的细胞炎症事件。我们将描述宿主细胞对纯化的牙龈卟啉单胞菌荚膜多糖的炎症反应，并开始定义控制白细胞募集的先天性免疫反应。

DESCRIPTION: Porphyromonas gingivalis, a Gram-negative, anaerobic, oral pathogen is the primary etiologic agent of adult periodontal disease. Recent reports indicate that encapsulated P. gingivalis are more virulent then unencapsulated strains. Nevertheless, the precise role of P. gingivalis capsular polysaccharide in disease pathogenesis, and the mechanism by which this virulence factor acts, are largely unknown. We posit that the capsular polysaccharide of Porphyromonas gingivalis promotes a cellular inflammatory response characteristic of P. gingivaIis infection, and contributes to the pathology observed in P. gingivalis-mediated adult periodontal disease. Our preliminary, in vitro studies demonstrate that this antigen binds to host cells and stimulates an innate immune response, which is permissive for PMN chemotaxis. In vivo observations confirmed our in vitro data, and demonstrate that purified P. gingivalis capsular polysaccharide stimulates a host inflammatory cell response, that mimics live, P. gingivalis whole cell challenge. Three Specific Aims are proposed: 1): To define the binding kinetics of purified Porphyromonas gingivalis capsular polysaccharide to epithelial cells and defined populations of relevant immune cells. We will characterize 1- dose-and time-dependent binding kinetics, 2- binding specificity, and employ blocking studies to define the attachment of purified P. gingivalis capsular polysaccharide to host cells. 2): To characterize the innate immune response of epithelial cells and relevant leukocyte populations to P. gingivalis capsular polysaccharide. Cytokine secretion, cell adhesion molecule production and neutrophil recruitment will be examined. We will delineate the cytokine, chemokine and cell adhesion molecule repertoire produced by cells challenged as related to stimulation and characterization of PMN transmigration. 3): To define the cellular inflammatory event that occurs in response to Porphyromonas gingivalis capsular polysaccharide in a murine air pouch model. We will characterize the host cellular inflammatory response to purified P. gingivalis capsular polysaccharide and begin to define the innate immune responses that govern leukocyte recruitment.