Defining the Role of WxL Proteins in Enterococcus faecium

定义 WxL 蛋白在屎肠球菌中的作用

• 批准号: 8261417
• 负责人: Jessica Rhea Galloway-Pena
• 金额: $ 2.78万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8261417
• 关键词: Affect; Animal Model; Antibodies; Antibody Formation; Attenuated; Binding; Biochemistry; Biological Assay; C-terminal; Cell Fractionation; Cell Wall; Cell surface; Cells; Clinical; Collection; Communicable Diseases; Data; Disease; Doctor of Philosophy; Electron Microscopy; Endocarditis; Enterococcus; Enterococcus faecalis; Enterococcus faecium; Enzyme-Linked Immunosorbent Assay; Extracellular Matrix Proteins; Extracellular Protein; Flow Cytometry; Future; Gene Deletion; Gene Expression; Genes; Genetic; Goals; Gram-Positive Bacteria; Guanine + Cytosine Composition; Hospitals; Human; Immunization; Immunology; Infection; Integral Membrane Protein; Knowledge; Laboratories; Lactobacillus; Mediating; Membrane Proteins; Microbiology; Modeling; Molecular Biology; Mus; Operon; Organism; Passive Immunization; Pathogenesis; Pathogenicity; Patients; Peritonitis; Prevention; Probability; Proteins; Recombinants; Research; Research Personnel; Role; Serum; Surface; Techniques; Testing; Training; Virulence; Western Blotting; fitness; in vitro Assay; in vitro Model; in vivo; in vivo Model; insight; killings; macrophage; mutant; neutrophil; novel; pathogen; protein E; protein expression; protein protein interaction; public health relevance; research study; structural biology

DESCRIPTION (provided by applicant): Enterococci have become important nosocomial pathogens over the past 25 years, with Enterococcus faecium infections recently increasing from less than ten percent of clinical isolates to causing over one-third of all enterococcal infections. Several surface proteins with a cell wall anchoring LPxTG motif are associated with enterococcal infection. Recently, researchers have indicated the probability of a new cell wall binding motif, designated the WxL domain. Proteins containing this domain have been implicated as important in peritonitis infections caused by Enterococcus faecalis and aggregation in Lactobacillus coryniformis. My preliminary data have shown that the WxL proteins of E. faecium exist in putative operons containing a transmembrane protein and an LPxTG protein, indicating the possibility of a novel form of surface assembly. The long term goal of this proposal is to better understand cell wall associated proteins and their possible contribution to colonization and virulence in Enterococcus faecium. The goals of this study concentrate on proteins containing the newly identified WxL domain at the C-terminal region. The specific aims of the proposed study will first investigate the role of WxL proteins in E. faecium pathogenesis by looking at mutants in a number of in vitro models of virulence related functions and in vivo models of typical infections caused by Enterococcus faecium. Second, the function of the WxL domain will be defined, the localization of the proteins examined, and an initial understanding of the interactions between the proteins within the putative operons will be gained. Lastly, the in vivo expression of these proteins will be analyzed, their antigenicity determined, and the possibility of protecting against E. faecium infection using WxL proteins will be explored. This proposal encompasses the microbiology and infectious disease fields, specifically concentrating on the emerging pathogen E. faecium. This study will contribute to the knowledge of this normally commensal organism, as well as explore future options for immunization. The proposed study includes a variety of techniques used in numerous fields including molecular biology, genetics, biochemistry, immunology, and structural biology and should cover the duration of the last three years of Ph.D. training. PUBLIC HEALTH RELEVANCE: Although Enterococcus faecium is an important hospital-associated pathogen, research on how this normally commensal organism initiates disease and interacts with the host is lacking when compared to the information known about other gram positive pathogens. Assessment of the importance of putative surface proteins with the "WxL" motif in virulence, identification of the binding domains involved in cell wall association, possible protein-protein interactions between proteins encoded in the same operon, expression of the genes encoding WxL proteins within the host, and the possibility of using the WxL proteins in immunization for E. faecium infections will enhance the very limited knowledge of the mechanisms for pathogenicity of this organism, and may provide for possible immunization candidates for the prevention of enterococcal infections.

描述（由申请人提供）：肠球菌在过去 25 年中已成为重要的医院病原体，最近粪肠球菌感染从临床分离株的不到 10% 增加到占所有肠球菌感染的三分之一以上。几种具有细胞壁锚定 LPxTG 基序的表面蛋白与肠球菌感染相关。最近，研究人员指出了一种新的细胞壁结合基序（称为 WxL 结构域）的可能性。含有该结构域的蛋白质在粪肠球菌引起的腹膜炎感染和棒状乳杆菌聚集中发挥着重要作用。我的初步数据表明，屎肠球菌的 WxL 蛋白存在于含有跨膜蛋白和 LPxTG 蛋白的推定操纵子中，这表明存在一种新型表面组装的可能性。该提案的长期目标是更好地了解细胞壁相关蛋白及其对屎肠球菌定植和毒力的可能贡献。本研究的目标集中在 C 末端区域含有新鉴定的 WxL 结构域的蛋白质。本研究的具体目的是首先通过观察一些毒力相关功能的体外模型和屎肠球菌引起的典型感染的体内模型中的突变体来研究WxL蛋白在屎肠球菌发病机制中的作用。其次，将定义 WxL 结构域的功能，检查蛋白质的定位，并初步了解推定操纵子内蛋白质之间的相互作用。最后，将分析这些蛋白质的体内表达，确定其抗原性，并探索使用 WxL 蛋白质预防屎肠球菌感染的可能性。该提案涵盖微生物学和传染病领域，特别关注新出现的病原体屎肠球菌。这项研究将有助于加深对这种通常共生生物的了解，并探索未来的免疫选择。拟议的研究包括分子生物学、遗传学、生物化学、免疫学和结构生物学等众多领域使用的各种技术，并且应涵盖博士学位最后三年的时间。训练。 公共卫生相关性：尽管屎肠球菌是一种重要的医院相关病原体，但与其他革兰氏阳性病原体的已知信息相比，缺乏对这种正常共生生物如何引发疾病以及与宿主相互作用的研究。评估具有“WxL”基序的推定表面蛋白在毒力中的重要性，鉴定参与细胞壁关联的结合域，同一操纵子中编码的蛋白质之间可能的蛋白质-蛋白质相互作用，编码 WxL 蛋白质的基因的表达宿主，并且使用 WxL 蛋白进行屎肠球菌感染免疫的可能性将增强对该生物体致病性机制的非常有限的了解，并可能为预防肠球菌提供可能的免疫候选者感染。