Oral Treponema Surface Proteins: Host Cell Interactions

 描述（由申请人提供）：本研究的目的是表征齿垢密螺旋体（Td）表面蛋白在该人类口腔螺旋体与宿主组织相互作用中的作用，从而深入了解这些生物体导致牙周病发生和进展的机制。我们专注于分析Td蛋白复合物，直接影响细胞分离的组织，包括牙周膜（PDL），包括牙齿和牙槽骨之间的连接的牙槽窝：特别是PrtP脂蛋白蛋白酶复合物（牙本质）和寡聚Msp蛋白。我们的总体假设是牙本质素和Msp是牙周病中Td细胞病变行为的主要贡献者。为了表征它们在微生物-宿主相互作用中的特定作用，我们的方法是利用纯化的天然和重组蛋白以及在这些外膜复合物的各个组分中携带定义突变的等基因Td菌株。我们将首先扩展我们正在进行的研究表征牙本质素组装在Td外膜。然后，为了进一步研究宿主细胞对Td攻击的反应，我们将（A）确定牙本质素诱导的pro-MMP-2活化的机制和（B）表征PDL细胞的Td攻击导致的MMP-2依赖性纤连蛋白片段化。这个项目将测试的假设，牙本质是一种效应蛋白，其活动的结果放大的“下游”信号的影响，可能是显着的体内。我们的研究团队在开展这些研究方面具有独特的优势，结合了螺旋体分子生物学，细胞外基质生物学和炎症性疾病细胞病理学方面的专业知识。本计画的完成将有助于螺旋体分子生物学的基础知识，以及了解慢性感染如牙周疾病中微生物与宿主的相互作用。

 DESCRIPTION (provided by applicant): The goal of this research is to characterize the role of Treponema denticola (Td) surface proteins in interaction of this human oral spirochete with host tissue, thereby gaining insight into mechanisms by which these organisms contribute to initiation and progression of periodontal disease. We focus on analysis of Td protein complexes that directly affect cells isolated from tissue comprising the periodontal ligament (PDL) that comprises the junction between the tooth and the alveolar bone of the tooth socket: specifically the PrtP lipoprotein protease complex (dentilisin) and the oligomeric Msp protein. Our overall hypothesis is that dentilisin and Msp are major contributors to Td cytopathic behavior in periodontal disease. To characterize their specific roles in microbe-host interactions, our approach is to utilize purified native and recombinant proteins as well as isogenic Td strains carrying defined mutations in individual components of these outer membrane complexes. We will first extend our ongoing studies characterizing dentilisin assembly in the Td outer membrane. Then, to further studies of host cell responses to Td challenge, we will (A) determine the mechanism of dentilisin-induced activation of pro-MMP-2 and (B) characterize MMP-2-dependent fibronectin fragmentation resulting from Td challenge of PDL cells. This project will test the hypothesis that dentilisin is an effector protein whose activity results in magnified "downstream" signaling effects that are likely to be significant in vivo. Our research team is uniquely positioned to conduct these studies, with combined expertise in spirochete molecular biology, extracellular matrix biology and cytopathology of inflammatory diseases. Completion of this project will contribute to both basic knowledge of spirochete molecular biology and to understanding of microbe-host interactions in chronic infections such as periodontal diseases.