BACTEROIDES GINGIVALIS ANTIGENS AND PERIODONTAL DISEASE

牙周病是成年人牙齿脱落的主要原因，也是 仅次于龋齿的男性第二常见感染。革兰氏阴性 牙龈类杆菌是一种优势菌株。 成人牙周炎的病变和血清抗体水平的升高 在成人中始终观察到牙龈类杆菌的特异性 牙周炎。这些发现加上罕见的 生物体和正常个体中发现的低水平抗体，以及 牙龈假单胞菌产生的毒力因子为其提供了证据。 成人牙周炎的病因学作用。提纯和 类杆菌衣壳多糖抗原的特性研究 牙周炎为我们提供了对牙周炎发病机制的新认识。 牙周感染牙龈类杆菌。 荚膜多糖抗原的纯化及其在血吸虫病中的作用 牙龈类杆菌的致病性将是这项研究的目标 研究计划由两个阶段组成。第一阶段将涉及 牙龈类杆菌和牙周杆菌荚膜多糖的分离纯化 它的化学、结构和免疫化学特征。一个 放射性抗原结合法测定抗囊性血药浓度 将开发针对牙龈类杆菌的抗体。抗原会 从大规模生长的细菌中通过酶和 色谱分析方法。常规的化学分析将定义其 化学成分。结构分析将通过甲基化得到 多糖类及其修饰衍生物的气相分析 色质联用。免疫化学特征将是 凝胶扩散、交叉免疫电泳法、定量沉淀法 研究和放射性抗原结合分析。 第二阶段将评估胶囊免疫的效果。 多糖对预防菌血症和走向脓肿的作用 在啮齿动物感染模型中的形成。晶状体囊膜的能力 多糖类修饰牙龈假单胞菌与口腔的粘附性 将对上皮细胞和选定的革兰氏阳性细菌进行评估 试图了解胶囊在黏附中的作用。它的 中性粒细胞影响牙龈假单胞菌吞噬的能力 在旨在评估该病毒潜在毒力作用的实验中进行检查 胶囊中的多糖。血清中抗囊性抗体水平， 唾液和牙周沟液将被测量并与 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 以及被膜多糖所引起的宿主反应。

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.