Molecular interactions: oral bacteria & matrix proteins

分子相互作用：口腔细菌

• 批准号: 6334259
• 负责人: KEITH Peter MINTZ
• 金额: $ 18.75万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6334259
• 关键词: Actinobacillus actinomycetemcomitans; Bacteroides gingivalis; bacteria infection mechanism; bacterial genetics; bacterial proteins; binding proteins; cell adhesion molecules; cell type; collagen; epithelium; extracellular matrix proteins; fibronectins; genetic library; genome; human tissue; mutant; oral bacteria; periodontitis; periodontium; polymerase chain reaction; protein purification; protein sequence; protein structure; transposon /insertion element

Gram-negative bacteria are associated with periodontal diseases, which are a group of chronic inflammatory diseases of the gingiva and the supporting structures of the periodontium. Actinobacillus actinomycetemcomitans (Aa) is a Gram-negative, facultative coccobacillus that colonizes the human oral cavity and upper respiratory tract. This bacterium is closely associated with periodontitis in young individuals and with cases of adult periodontitis. This pathogen has been associated with other serious human infections such as endocarditis, soft tissue abscesses, and more recently cardiovascular disease. Although the periodontium is believed to be the source of these extraoral infections, little is known about the tropisms used by Aa to maintain itself within the oral cavity and to infiltrate and disseminate in tissues. Pathogens have evolved diverse strategies to be successful in colonization of the host tissue. A common theme amongst these pathogens is the ability to initiate infection by adhesion to specific host macromolecules under stringent or hostile conditions. These molecules include proteins that are secreted by host cells that form the extracellular matrix. This matrix is usually composed of collagen and specific noncollagenous proteins, e.g. fibronectin. The major protein found in the periodontium is collagen and we have demonstrated that Aa binds to both collagen and fibronectin. In this proposal, we plan to identify the genes coding for matrix binding proteins and determine the amino acid sequences of these proteins required for binding. It is our hypothesis that the synthesis of matrix binding proteins is involved in Aa colonization of the periodontal pocket and underlying tissues. In order to realize these goals, we propose to 1) isolate the genes coding for collagen and fibronectin binding proteins by constructing a transposon mutagenesis and a phage display library; 2) determine the gene sequences and generate isogenic mutants; 3) determine the regions(s) of the protein essential for binding activity; 4) determine the immunoreactivity of LJP patient sera to these proteins. This information can be used for the development of therapeutic agents of vaccines for periodontal disease.

革兰氏阴性菌与牙周病有关，牙周病是牙龈和牙周支持结构的一组慢性炎症性疾病。伴放线放线杆菌 (Aa) 是一种革兰氏阴性、兼性球杆菌，定植于人类口腔和上呼吸道。 这种细菌与年轻人的牙周炎和成人牙周炎密切相关。 这种病原体与其他严重的人类感染有关，例如心内膜炎、软组织脓肿以及最近的心血管疾病。 尽管牙周组织被认为是这些口外感染的来源，但人们对 Aa 在口腔内维持自身以及在组织中渗透和传播的趋向性知之甚少。病原体已经进化出多种策略来成功地在宿主组织中定殖。 这些病原体的一个共同主题是能够在严格或敌对条件下通过粘附到特定宿主大分子来引发感染。 这些分子包括由形成细胞外基质的宿主细胞分泌的蛋白质。 该基质通常由胶原蛋白和特定的非胶原蛋白组成，例如胶原蛋白。纤连蛋白。 牙周组织中发现的主要蛋白质是胶原蛋白，我们已经证明 Aa 与胶原蛋白和纤连蛋白结合。 在本提案中，我们计划鉴定编码基质结合蛋白的基因，并确定结合所需的这些蛋白质的氨基酸序列。 我们假设基质结合蛋白的合成参与牙周袋和下面组织的 Aa 定植。为了实现这些目标，我们建议1）通过构建转座子诱变和噬菌体展示库来分离编码胶原蛋白和纤连蛋白结合蛋白的基因； 2)确定基因序列并产生等基因突变体； 3) 确定结合活性所必需的蛋白质区域； 4)确定LJP患者血清对这些蛋白质的免疫反应性。 该信息可用于牙周病疫苗治疗剂的开发。