P. gingivalis Capsule in Cell Inflammation

描述：牙龈卟啉单胞菌是一种革兰氏阴性、厌氧、口腔病原体，是成人牙周病的主要病原。最近的报道表明，包封的牙龈卟啉卟啉菌比未包封的菌株毒性更强。然而，牙龈假单胞菌荚膜多糖在疾病发病中的确切作用，以及这种毒力因子的作用机制，在很大程度上是未知的。我们假设牙龈卟啉单胞菌的荚膜多糖促进了牙龈卟啉单胞菌感染的细胞炎症反应特征，并有助于在牙龈卟啉单胞菌介导的成人牙周病中观察到的病理。我们的初步体外研究表明，这种抗原与宿主细胞结合并刺激先天免疫反应，这是允许PMN趋化的。体内观察证实了我们的体外数据，并证明纯化的牙龈假单胞菌荚膜多糖刺激宿主炎症细胞反应，模拟活的牙龈假单胞菌全细胞挑战。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的结合动力学。我们将描述1-剂量和时间依赖的结合动力学，2-结合特异性，并采用阻断研究来确定纯化的牙龈假单胞菌荚膜多糖对宿主细胞的附着。2)：研究上皮细胞及相关白细胞群对牙龈假单胞菌荚膜多糖的先天免疫反应。细胞因子分泌、细胞粘附分子产生和中性粒细胞募集将被检查。我们将描述受激细胞产生的细胞因子、趋化因子和细胞粘附分子库，这些分子与PMN迁移的刺激和表征有关。3)：在小鼠气袋模型中明确牙龈卟啉单胞菌荚膜多糖反应后发生的细胞炎症事件。我们将描述宿主细胞对纯化牙龈假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.