B.forsythus BsPA protein: role in virulence

B.forsythus BsPA 蛋白：在毒力中的作用

• 批准号: 6824886
• 负责人: Ashu Sharma
• 金额: $ 27.48万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6824886
• 关键词: B.forsythus; BsPA; protein; role; virulence

EXCEED THE SPACE PROVIDED. Bacteroides forsythus is a Gram-negative oral anaerobe implicated in the development of periodontal disease pathogenesis. Although, very little is known about the virulence factors of this organism, based on our recent in vitro and in vivo studies, a surface-associated 98-kDa protein (BspA) has been suggested as a virulence factor. The BspA protein contains homologous sequences belonging to the leucine-rich repeat motif family (LRR), as well as to motifs belonging to the immunoglobulin superfamily (Ig-SF). In vitro, the BspA protein binds to extracellular matrix components fibronectin and fibrinogen, and to epithelial cells, and also induces release of proinflammtory cytokines from monocytic cells. Further, a mutant of B. forsythus defective in BspA expression constructed in our laboratory has been found to be significantly attenuated in its ability to bind to fibronectin, fibrinogen, and epithelial cells. The studies proposed here will address the hypotheses that LRRs and IgSF domains are critical for host cell interactions via binding to specific cellular receptors, and thal the BspA protein plays important roles in pathogenesis via mediating bacterial colonization and triggering of host cellular responses, such as release of cytokines and other mediators. The experimental design will include: (a) studies to determine the specific BspA-domains involved in host cell (epithelial and monocytic cells) interactions (Specific Aim l a), and investigate intracellular signaling events resulting from BspA binding (Aim l b); (b) biochemical characterization of epithelial (Aim 2a) and monocyte receptors (Aim 2b) that bind BspA protein; and (c) assessment of the in vivo role of BspA protein as judged by studies in a mouse model of periodontal disease (Aim 3a), and by evaluating the host immune response against the BspA protein in patients with a history of periodontitis (Aim 3b). The findings will be important in determining the roles of BspA protein, and the underlying contribution of its domains in bacterial pathogenesis. The studies will also be critical from a 'proteomic' standpoint in defining the roles of LRR and lg- like signatures found in other bacterial proteins in general. In the long term, understanding the basic mechanisms of the BspA-mediated pathogenesis of B.forsythus will be vital in developing intervention strategies against periodontal disease. PERFORMANCESITE( ========================================Section End===========================================

超出所提供的空间。 拟杆菌是一种革兰氏阴性的口腔厌氧菌，与牙周病的发生发展密切相关。虽然，很少有人知道这种生物体的毒力因子，根据我们最近在体外和体内的研究，表面相关的98-kDa蛋白（BspA）已被建议作为毒力因子。BspA蛋白含有属于富亮氨酸重复基序家族（LRR）的同源序列，以及属于免疫球蛋白超家族（Ig-SF）的基序。在体外，BspA蛋白与细胞外基质组分纤连蛋白和纤维蛋白原结合，并与上皮细胞结合，还诱导促炎细胞因子从单核细胞释放。此外，还提供了B的突变体。在我们的实验室中构建的BspA表达缺陷的BspA表达载体已经被发现在其与纤连蛋白、纤维蛋白原和上皮细胞结合的能力方面显著减弱。 本文提出的研究将解决以下假设：LRR和IgSF结构域通过与特异性细胞受体结合而对宿主细胞相互作用至关重要，塔尔BspA蛋白通过介导细菌定植和触发宿主细胞反应（如释放细胞因子和其他介质）而在发病机制中起重要作用。 实验设计将包括：（a）确定宿主细胞中涉及的特定BspA结构域的研究（上皮细胞和单核细胞）相互作用（特异性Aim 1 a），并研究由BspA结合引起的细胞内信号传导事件（Aim 1 B）;（B）结合BspA蛋白的上皮（Aim 2a）和单核细胞受体（Aim 2B）的生物化学表征;和（c）通过在牙周病小鼠模型中的研究（目的3a）和通过评价具有牙周炎病史的患者中针对BspA蛋白的宿主免疫应答（目的3b）来判断BspA蛋白的体内作用。 这些发现对于确定BspA蛋白的作用以及其结构域在细菌发病机制中的潜在贡献将是重要的。从蛋白质组学的角度来看，这些研究在确定LRR和Ig样特征在其他细菌蛋白中的作用方面也是至关重要的。从长远来看，了解BspA介导的B. patienthus致病的基本机制将是制定牙周病干预策略的关键。表演现场（=