Conserved complement binding to bacterial porins

与细菌孔蛋白结合的保守补体

• 批准号: 8772309
• 负责人: Daniel J Wozniak
• 金额: $ 23.1万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8772309
• 关键词: Acinetobacter; American; Bacteria; Bacterial Infections; Binding; Biochemical Genetics; Biology; Blood Circulation; Burn injury; C-terminal; Cell surface; Clinical; Complement; Data; Deletion Mutagenesis; Diagnosis; Diffusion; Disease; Epidemiology; Escherichia coli; Event; Genetic Heterogeneity; Goals; Gram-Negative Bacteria; Health; Hospitals; Host Defense; Human; Immune; Infection; Lead; Legionella; Ligands; Link; Lung; Maps; Masks; Mediating; Membrane; Molecular; Mutagenesis; Organism; Pathogenesis; Pathway interactions; Pattern; Phagocytes; Polysaccharides; Prevention; Proteins; Pseudomonas aeruginosa; Publishing; Recombinants; Relative (related person); Research; Resistance; Role; Salmonella; Sepsis; Serum; Structure; Surface; Testing; Therapeutic Agents; Virulence; Work; base; complement C3 precursor; complement system; design; improved; insight; killings; novel therapeutics; pathogen; porin; prevent; public health relevance; research study; small molecule; solute; trait; treatment strategy; vaccine candidate

DESCRIPTION (provided by applicant): This application seeks to define the molecular mechanism of complement C3 binding interactions with bacterial surfaces. Specifically we will evaluate how Pseudomonas aeruginosa C3 binding to an outer membrane porin (OprF) promotes phagocyte interactions and how this may be exploited to enhance opsonophagocytosis and complement-mediated killing. We also discovered that the C-terminal region of P. aeruginosa OprF has high structural identity with the OmpA domain of several other Gram- negative bacteria, one of which is known to bind C3. Therefore, this study will not only contribute to an understanding of P. aeruginosa pathogenesis but also provide insights into the biology of complement interactions in other Gram-negative bacteria. This will, in turn, lead to new and more effective strategies for the treatment or prevention of P. aeruginosa and perhaps other Gram-negative infections. This proposal will use state-of-the art molecular, biochemical, and genetic approaches to probe interactions of complement and Gram-negative porins. To date, the mechanistic basis for resistance to complement-mediated killing of P. aeruginosa is not completely understood. We recently discovered that OprF is one ligand recognized by human complement C3. Aim 1 will evaluate conservation of OprF-C3 binding and Psl masking among P. aeruginosa clinical isolates. The goal of Aim 2 is to determine if OprF levels can be modulated to improve serum-mediated killing. Aim 3 will focus on mapping regions of OprF that are required for C3 interactions. Finally, in Aim 4 we will evaluate conservation of C3 interaction with surface exposed porin domains in other Gram-negative pathogens. Understanding the molecular mechanism of C3 binding to bacterial surfaces offers a potential means for preventing and/or treating diseases caused by these Gram-negative pathogens.

描述（由申请人提供）：本申请旨在定义补体C3与细菌表面结合相互作用的分子机制。具体来说，我们将评估铜绿假单胞菌C3与外膜孔蛋白（OprF）结合如何促进吞噬细胞相互作用，以及如何利用这一点来增强调理吞噬作用和补体介导的杀伤。我们还发现P. aeruginosa OprF的c端区域与其他几种革兰氏阴性细菌的OmpA结构域具有高度的结构一致性，其中一种已知可以结合C3。因此，本研究不仅有助于了解铜绿假单胞菌的发病机制，还将为其他革兰氏阴性菌的补体相互作用的生物学提供见解。反过来，这将导致新的和更有效的策略来治疗或预防铜绿假单胞菌和其他革兰氏阴性感染。本提案将使用最先进的分子，生化和遗传方法来探测补体和革兰氏阴性孔蛋白的相互作用。迄今为止，铜绿假单胞菌对补体介导的杀伤产生耐药性的机制基础尚不完全清楚。我们最近发现OprF是人类补体C3识别的一个配体。目的1将评估铜绿假单胞菌临床分离株中OprF-C3结合和Psl掩蔽的保守性。目的2是确定是否可以调节OprF水平以改善血清介导的杀伤。目标3将侧重于绘制C3相互作用所需的OprF区域。最后，在Aim 4中，我们将评估C3相互作用的守恒性