MOLECULAR ANALYSIS OF T. DENTICOLA-HOST INTERACTIONS

描述：与龈下菌斑相关的螺旋体占优势 严重的牙周病变提示在牙周疾病中起重要作用 发病机制。这项研究的目标是描述 齿密螺旋体与龈下组织在分子水平上。通过 重点分析直接影响宿主的表面表达蛋白 细胞，我们将深入了解牙周细胞病理学的机制。 齿状毛滴虫主要外膜蛋白(MSP)与细胞和细胞外基质结合 成分，具有成孔细胞毒活性。MSP是由基因决定的 在许多口腔螺旋体中保守，但显示出相当大的菌株间 异质性，提示它是一种重要的免疫原。整体而言 假设MSP是牙周组织中一个重要的毒力决定因素 疾病，是外膜蛋白复合体的关键成分，介导 螺旋体与龈下组织的相互作用。 拟议研究的具体目标，以及将提出的个别假设 测试内容如下：1)鉴定与MSP相关的齿状毛滴虫蛋白 表情。本机需要MSP以外的外膜组件 MSP天然外膜复合体的表达和组装。同基因 突变体和重组表达系统将被用来表征这些 流程。2)确定MSP的免疫优势结构域和功能结构域。 MSP抗原异质性是口腔宿主抗体识别的一个因素 螺旋体。将对存档的血清样本进行筛查，以检测其反应性 特定的MSP。将在患者斑块中发现编码新MSPs的基因 样本。3)研究MSP在细胞病变反应中的作用。 齿纹夜蛾T.denticola亲本和MSP突变株结合宿主细胞的能力， ECM和血清成分，并激活促炎细胞反应 将会被化验。上皮细胞表面一种可能的MSP受体 将被描述为。 这些研究同时涉及遗传和生化分析，包括 旨在为理解微生物宿主做出重大贡献 牙周病病因学中的相互作用，以及 致病螺旋体的分子生物学。

DESCRIPTION: The predominance of spirochetes in subgingival plaque associated with severe periodontal lesions suggests an important role in periodontal pathogenesis. The goal of this research is to characterize interactions of Treponema denticola with subgingival tissues at the molecular level. By focusing on analysis of surface-expressed proteins that directly affect host cells, insights will be gained into mechanisms of periodontal cytopathology. The major outer membrane protein (Msp) of T. denticola binds to cells and ECM components, and has pore-forming cytotoxic activity. Msp is genetically conserved in many oral spirochetes, yet shows considerable inter-strain heterogeneity, suggesting that it is an important immunogen. The overall hypothesis is that Msp is a significant virulence determinant in periodontal disease, and is a key component of an outer membrane protein complex mediating interactions of the spirochete with subgingival tissue. Specific Aims of the proposed research, and the individual hypotheses to be tested are: 1) to characterize T. denticola proteins associated with Msp expression. Outer membrane components other than Msp are required for native Msp expression and assembly of the native outer membrane complex. Isogenic mutants and recombinant expression systems will be used to characterize these processes. 2) to identify immunodominant and functional domains of Msp. Antigenic heterogeneity of Msp is a factor in host antibody recognition of oral spirochetes. Archived serum samples will be screened for reactivity with specific Msps. Genes encoding novel Msps will be identified in patient plaque samples. 3) to characterize the role of Msp in cytopathic cellular responses to T. denticola. The ability of parent and msp mutant strains to bind host cells, ECM and serum components, and to activate pro-inflammatory cellular responses will be assayed. A putative Msp receptor identified on epithelial cell surfaces will be characterized. These studies, which involve both genetic and biochemical analyses, are intended to contribute significantly to the understanding of microbe-host interactions in the etiology of periodontal diseases, and to basic knowledge of the molecular biology of pathogenic spirochetes.