B GINGIVALIS POLYSACCHARIDES--STRUCTURE AND FUNCTION

细菌的包裹经常与一种 毒力增强。微囊化大肠埃希菌 大肠埃希菌、脑膜炎奈瑟菌和流感嗜血杆菌 表现出更强的侵袭性并导致严重疾病， 而其未封装的对应物通常要少得多 致命的。在美国，胶囊多糖疫苗是 可用于预防II疾病的商业用途。 乙型流感、肺炎链球菌等胶囊化 细菌。牙龈类杆菌是厌氧革兰氏阴性菌 与牙周病有关的细菌。 以前的研究已经证明了胶囊的存在 并将其抗吞噬特性归因于 这个胶囊。这项提案将研究这一能力 多糖类对该微生物的毒力和 这种多糖作为免疫原的能力和 诱导保护性抗体的形成，从而导致 保护免受这种细菌的感染。 这项提议试图表征来自于 不同菌株的B_3菌株。牙周炎，使用这些多糖 作为免疫原，并研究它们的生物学效应。 将从不同的菌株和 化学和免疫化学特征。免疫原性 这些多糖的含量将通过以下方法进行评估：修饰 多糖衍生物、多糖蛋白结合物 疫苗、不同的免疫佐剂和可以 刺激或抑制不同的T细胞群，这些T细胞群 参与对多糖类抗原的免疫反应。这个 这些多糖类免疫原修饰细胞的能力 实验性小鼠毒力模型感染的研究进展 然后将接受调查。多糖之间的相互作用 与血清补体系统的关系及其对吞噬功能的影响 中性粒细胞将会被检测出来。最后，未被包裹的菌株 将通过自然选择或 转座子诱变及其毒力特性的研究 这些未包裹的菌株将与包裹的菌株进行比较 细菌。这些研究的结果应该会大大提高我们的 对细菌多糖免疫原性的认识 抗原和衣壳对毒力的贡献 观察是否有牙龈假单胞菌。

Bacterial encapsulation is frequently correlated with an enhancement of virulence. Encapsulated strains of Escherichia coli, Neisseria meningitidis, and Haemophilus influenzae demonstrate enhanced invasive properties and cause serious disease, while their unencapsulated counterparts are generally much less virulent. In the USA, capsular polysaccharide vaccines are commercially available for the prevention of disease by Ii. influenza type b, Streptococcus pneumoniae, and other encapsulated bacteria. Bacteroides gingivalis is an anaerobic gram-negative bacteria associated with periodontal disease. Previous studies have demonstrated the presence of a capsule on B. gingivalis and have attributed antiphagocytic properties to this capsule. This proposal will study the ability of this polysaccharide to contribute to this microorganism's virulence and the ability of this polysaccharide to function as an immunogen and induce the formation of protective antibodies, thus resulting in protection from infection with this bacteria. This proposal seeks to characterize the polysaccharides from different strains of B_. gingivalis, to use these polysaccharides as immunogens, and to study their biological effects. Polysaccharides will be isolated from different strains and chemically and immunochemically characterized. The immunogenicity of these polysaccharide will then be assessed by using: modified polysaccharide derivatives, polysaccharide-protein conjugate vaccines, different immunological adjuvants, and agents that can either stimulate or suppress different T cell populations which are involved in the immune response to polysaccharide antigens. The ability of these polysaccharide immunogens to modify the development of infection in an experimental mouse virulence model will then be investigated. The interaction of the polysaccharide with the serum complement system and its effect on phagocytosis by neutrophils will be determined. Finally, unencapsulated strains of B. gingivalis will be derived either by natural selection or through transposon mutagenesis and the virulence properties of these unencapsulated strains will be compared with the encapsulated bacteria. The results of these studies should greatly enhance our knowledge of the immunogenicity of bacterial polysaccharide antigens and to the contribution of the capsule to the virulence observed for B. gingivalis.