PATHOGENIC FIBER FORMATION IN BACTERIA: STRUCTURAL BASIS

细菌中致病纤维的形成：结构基础

• 批准号: 8602779
• 负责人: SCOTT J. HULTGREN
• 金额: $ 38万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2016-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8602779
• 关键词: Adhesives; Age; Amyloid fibers; Antibiotic Resistance; Antibiotic Therapy; Antibiotics; Architecture; Bacteria; Binding; Biochemical; Biogenesis; Biological Assay; Biology; Bladder; Bladder Tissue; C-terminal; Calorimetry; Catheters; Cells; Cellulose; Chronic; Communities; Community Developments; Complex; Confocal Microscopy; Cytoplasm; Development; Disease; Electron Microscopy; Environment; Epithelial; Epithelial Cells; Escherichia coli; Event; Fiber; Fimbriae Proteins; Genetic; Genetic Screening; Genome; Gram-Negative Bacteria; Host Defense; Image; Immune response; Immunoglobulins; In Vitro; Individual; Infection; Intravenous; Invaded; Knowledge; Lead; Mannosides; Mediating; Membrane; Microbial Biofilms; Modeling; Molecular Chaperones; Molecular Weight; Mus; N-terminal; Operon; Organism; Pathway interactions; Pattern; Peptides; Pilum; Plague; Play; Process; Proteins; Proton-Motive Force; Recurrence; Regulation; Regulatory Element; Reporter; Research; Resistance; Role; Signal Transduction; Specificity; Surface; System; Systems Biology; Therapeutic; Time; Tissues; Urinary tract infection; Uropathogenic E. coli; Virulence Factors; Woman; Work; bacterial genetics; base; biophysical techniques; combat; comparative genomics; design; extracellular; genome sequencing; improved; in vitro Model; in vivo; in vivo Model; inhibitor/antagonist; macromolecular assembly; mutant; novel therapeutic intervention; pathogenic bacteria; periplasm; polymerization; programs; protein folding; public health relevance; residence; retinal rods; small molecule; therapeutic target

DESCRIPTION (provided by applicant): Over ten million women suffer from urinary tract infection (UTI) annually. Most UTIs are caused by uropathogenic Escherichia coli (UPEC). Although antibiotics are typically effective, millions of women suffer from chronic recurrences and are often put on long-term suppressive and/or intravenous antibiotic therapy. Clearly, better therapeutic alternatives are critical for improving the lives of those suffering from UTI. Toward this end, studies of how UPEC cause recurrent UTI have revealed that pili assembled by the chaperone/usher pathway (CUP) play a critical role; abolishing the function of CUP pili renders UPEC noninfectious. CUP pili are comprised of multiple subunits with partial immunoglobulin folds. Previous work has shown that these partial folds are completed by adjacent subunits within the assembled pilus. Prior to assembly, a dedicated chaperone protein temporarily completes these folds. These exquisitely specific chaperone-subunit and subunit-subunit interactions are prime targets for treatment of UTI and other pili-related diseases. During infection, CUP pili mediate colonization, tissue invasion, and biofilm formation. Type 1 pili, for example, mediate the binding and invasion of UPEC into bladder epithelial cells, where they replicate rapidly in the cytoplasm. Simultaneously, the expression of type 1 pili facilitates the aggregation of the invaded organisms into a biofilm-like intracellular bacterial community (IBC) that protects the bacteria from host defenses and antibiotics. CUP pili are also important in biofilm formation on catheters and other surfaces in nosocomial settings. Individual E. coli can encode over ten CUP operons that likely are important in UTI or other infections, yet few have been studied. Therefore, an understanding of the contribution of CUP pili to biofilm formation and the regulation of their expression is also central to combating these infections. This proposal outlines a concerted research program to elucidate the complexity of fiber systems biology and its relation to disease. In vitro and in vivo models, genetics, imaging, and biochemical and biophysical techniques will be used to understand: fiber polymerization (aim 1); the role of CUP pili in biofilm formation (aim 2); and the regulation of expression of the multiple CUP operons in the E. coli genome (aim 3). These studies will increase the understanding of the fiber arsenal used by UPEC and other bacteria to cause problematic infections (such as UTI or catheter-associated infections). Knowledge of these pili is leading to the development of small molecules that block pilus assembly and/or function and thereby infection.

描述（由申请人提供）：超过一千万妇女每年患有尿路感染（UTI）。大多数UTI是由肝癌大肠杆菌（UPEC）引起的。尽管抗生素通常是有效的，但数以百万计的女性患有慢性复发，并且经常进行长期抑制和/或静脉内抗生素疗法。显然，更好的治疗替代方法对于改善患有UTI的人的生活至关重要。为此，对UPEC引起的反复UTI的研究表明，由伴侣/Usher途径（杯）组装的Pili起着至关重要的作用。废除杯子的功能使UPEC非感染。杯pili由多个具有部分免疫球蛋白折叠的亚基组成。先前的工作表明，这些部分折叠是由组装pilus中的相邻亚基完成的。在组装之前，专用的伴侣蛋白暂时完成了这些褶皱。这些精确的特异性伴侣 - 亚基和亚基 - 亚基相互作用是治疗UTI和其他Pili相关疾病的主要靶标。在感染期间，杯pil介导定殖，组织侵袭和生物膜形成。例如，1型PILI介导UPEC的结合和侵袭到膀胱上皮细胞中，它们在细胞质中迅速复制。同时，1型pili的表达促进了被入侵的生物的聚集成生物膜样细胞内细菌群落（IBC），可保护细菌免受宿主防御和抗生素的影响。 pili在医院环境中的导管和其他表面的生物膜形成中也很重要。大肠杆菌可以编码在UTI或其他感染中可能很重要的十个杯子操纵子，但很少有人研究。因此，了解pili对生物膜形成的贡献及其表达的调节对于打击这些感染也是至关重要的。该提案概述了一项协同的研究计划，旨在阐明纤维系统生物学的复杂性及其与疾病的关系。体外和体内模型，遗传学，成像以及生化和生物物理技术将用于理解：纤维聚合（AIM 1）； pili在生物膜形成中的作用（AIM 2）；以及大肠杆菌基因组中多杯操纵子表达的调节（AIM 3）。这些研究将增加对UPEC和其他细菌引起有问题感染的纤维砷的理解（例如UTI或导管相关感染）。这些pili的知识导致了阻断菌毛组装和/或功能并因此感染的小分子的发展。