MICROBIAL ANTIGENS ASSOCIATED WITH SPECIFIC ADHERENCE

与特异性粘附相关的微生物抗原

• 批准号: 3939937
• 负责人: J O CISAR
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3939937
• 关键词: Actinomyces; Escherichia; Streptococcus sanguis; affinity chromatography; antibody specificity; bacterial DNA; bacterial antigens; bacterial genetics; cell adhesion; dental caries; dental plaque; gene expression; gingiva; gingivitis; host organism interaction; hybridomas; immune complex; immunochemistry; microorganism immunology; molecular cloning; monoclonal antibody; oral bacteria; periodontium disorder; phosphodiesterases; pilus; saliva; structural genes; surface antigens; tooth

Studies are continuing to define the fimbriae of Actinomyces viscosus and A. naeslundii that mediate the adherence of these oral bacteria to various cells and oral tissue surfaces and thereby contribute to microbial colonization, dental plaque formation and the initiation of gingivitis and periodontal disease. The type 1 fimbriae of A. viscosus are involved in bacterial attachment to the acquired salivary pellicle to teeth. The amino acid sequence of the type 1 fimbrial subunit has now been deduced from the nucleotide sequence of the cloned gene. Certain anti-type 1 fimbrial antibodies were previously shown to block bacterial adsorption to saliva-treated hydroxyapatite; however, antibodies directed against the 59 Kd fimbrial subunit appear to be poor inhibitors of adsorption even though they reacted with the type 1 fimbriae on actinomyces. Thus, the fimbrial subunit may not be directly involved in the adhesive interaction. Type 2 fimbriae of A. Viscosus and A. naeslundii have been associated with a Gal/GalNAc specific lectin activity. The type 2 fimbrial subunit of A. naeslundii was identified as a 60 kD protein by cloning and expression of the corresponding gene in Escherichia coli. DNA- DNA hybridization was observed between the genes for A. naeslundii and A. viscosus type 2 fimbrial subunits as well as those for A. naeslundii type 2 and A. viscosus type 1 subunits. Thus, the different fimbriae of Actinomyces sp. may be composed of subunits encoded by genes derived from a common ancestor. The receptor for type 2 Actinomyces fimbriae on S. sanguis 34 has been identified as a linear polysaccharide formed by identical hexasaccharide units linked through phosphodiester bridges. Different structural features of the hexasaccharide appear to be involved in lectin and antibody recognition since the specificity of bacterial coaggregation is strikingly different from that of antibody against the polysaccharide. These studies have begun to provide a structural basis for understanding the specificity of oral microbial adherence and mechanisms by which oral bacteria resist the immune system.

放线菌菌毛的研究仍在继续 viscosus和A.介导这些粘附的内氏菌 口腔细菌到各种细胞和口腔组织表面， 有助于微生物定植、牙菌斑形成和 引发牙龈炎和牙周病。 类型1 A.粘多糖参与细菌附着到 获得性唾液膜到牙齿。 氨基酸序列 1型菌毛亚基的结构现在已经从 克隆基因的核苷酸序列。 某些抗1型抗体 菌毛抗体以前被证明可以阻断细菌 吸附到唾液处理的羟基磷灰石;然而，抗体 针对59Kd菌毛亚基的表达似乎很差 吸附抑制剂，即使它们与类型1反应 放线菌菌毛。 因此，菌毛亚基可能不是 直接参与粘合剂的相互作用。 2型菌毛 a. Viscossus和A.内氏菌与一种 Gal/GalNAc特异性凝集素活性。 2型菌毛亚单位 曲霉通过克隆鉴定，naeslundii为60 kD蛋白， 相应基因在大肠杆菌中的表达。 DNA- 在A. naeslundii和A.粘性2型菌毛亚基以及那些 对于. naeslundii 2型和A.粘多糖1型亚基。 因此 放线菌的不同菌毛可由以下组成 由来自共同祖先的基因编码的亚基。 的 2型菌毛放线菌受体。sanguis 34已经 被鉴定为由相同的 通过磷酸二酯桥连接的六糖单元。 六糖的不同结构特征似乎是 参与凝集素和抗体识别，因为 细菌的共聚集与 抗多糖抗体。 这些研究已经开始 为理解口腔粘膜的特异性提供了结构基础 微生物粘附和口腔细菌抵抗的机制 免疫系统.