BACTEROIDES GINGIVALIS ANTIGENS AND PERIODONTAL DISEASE

牙周病是成年人牙齿脱落的主要原因， 在人类中仅次于龋齿的第二常见感染。 革兰氏阴性 芽孢杆菌，牙龈拟杆菌，是一种主要的分离物， 成人牙周炎的病变和血清抗体水平的增加 在成人中始终观察到牙龈拟杆菌特异性 牙周炎 这些发现加上很少发生的 该生物体，以及正常个体中发现的低水平抗体，以及 B产生的毒力因子。gingivalis提供证据， 成人牙周炎的病因作用。 纯化和 类杆菌荚膜多糖抗原的鉴定 牙龈炎应该为我们提供新的见解的发病机制， 牙龈拟杆菌引起的牙周感染。 荚膜多糖抗原的纯化及其在免疫中的作用 牙龈拟杆菌的致病性将是本研究的目的 研究计划由两个阶段组成。 第一阶段将涉及 从牙龈拟杆菌中纯化荚膜多糖， 其化学、结构和免疫化学表征。 一 放射性抗原结合法测定抗囊膜抗体 将研制出牙龈拟杆菌的抗体。 抗原将 通过酶法从细菌的大规模生长中纯化， 色谱法 常规化学分析将确定其 化学成分 通过甲基化进行结构分析 多糖及其改性衍生物的气相色谱分析 色谱-质谱法。 免疫化学表征将 通过凝胶扩散、交叉免疫电泳、定量沉淀 研究和放射性抗原结合测定。 第二阶段将评估免疫的效力与胶囊 多糖预防菌血症和脓肿 在啮齿动物感染模型中形成。 囊膜的能力 多糖以改变B的粘附。牙龈至颊 上皮细胞和选定的革兰氏阳性菌进行评价 试图了解胶囊在粘附中的作用。 其 影响B吞噬作用的能力。中性粒细胞引起的牙龈炎将是 在旨在评估潜在毒力作用的实验中进行了检查 荚膜多糖。 血清抗囊抗体水平， 唾液和龈沟液将被测量并与 成人牙周炎患者的疾病状况 纵向研究 因此，第二阶段将评估生物效应 以及由荚膜多糖引起的宿主反应。

Periodontal disease is the major cause of tooth loss in adults and is the second most common infection in man after dental caries. The gram-negative bacillus, Bacteroides gingivalis, is a predominant isolate from advancing lesions of adult periodontitis and an increase in serum antibody levels specfic for Bacteroides gingivalis is consistently observed in adult periodontitis. These findings coupled with the infrequent occurrence of the organism, and low levels of antibody found in normal individuals, and the virulence factors produced by B. gingivalis provide evidence for its etiologic role in adult periodontitis. The purification and characterization of the capsular polysaccharide antigen of Bacteroides gingivalis should provide us with new insight into the pathogenesis of periodontal infection with Bacteroides gingivalis. The purification of the capsular polysaccharide antigen and its role in the pathogenecity of Bacteroides gingivalis will be the objective of this research plan which is composed of two phases. Phase I will involve the purification of the capsular polysaccharide from Bacteroides gingivalis and its chemical, structural, and immunochemical characterization. A radioactive antigen-binding assay for the measurement of anticapsular antibodies to Bacteroides gingivalis will be developed. The antigen will be purified from large-scale growth of bacteria by enzymatic and chromatographic methods. Routine chemical analysis will define its chemical composition. Structural analysis will be obtained by methylation analysis of the polysaccharide and modified derivatives by gas chromatography-mass spectroscopy. Immunochemical characterization will be by gel diffusion, crossed immunoelectrophoresis, quantitative precipitation studies, and radioactive antigen-binding assays. Phase II will evaluate the efficacy of immunization with the capsular polysaccharide toward the prevention of bacteremia and toward abscess formation in rodent models of infection. The ability of the capsular polysaccharide to modify the adherence of B. gingivalis to buccal epithelial cells and to selected gram-positive bacteria will be evaluated in attempts to understand the role of the capsule in adherence. Its ability to affect the phagocytosis of B. gingivalis by neutrophils will be examined in experiments designed to assess the potential virulence role of the capsular polysaccharide. The level of anticapsular antibody in serum, saliva, and gingival crevicular fluid will be measured and correlated to disease status in patients with adult periodontitis enrolled in a longitudinal study. Thus, Phase II will evaluate the biological effects and the host response elicited by the capsular polysaccharide.