Bacterial Factors that Regulate Ocular Host-Pathogen Interactions and Microbial Keratitis

调节眼部宿主-病原体相互作用和微生物角膜炎的细菌因素

• 批准号: 9910406
• 负责人: ROBERT M SHANKS
• 金额: $ 44.44万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9910406
• 关键词: Address; Animal Model; Antibiotics; Bacteria; Bacterial Antibiotic Resistance; Bacterial Eye Infections; Bacterial Proteins; Biology; Blindness; Bulla; Cell Death; Cell Line; Cells; Centers for Disease Control and Prevention (U.S.); Chemicals; Clinic; Clinical; Communities; Community-Acquired Infections; Complement; Complication; Contact Lenses; Cornea; Corneal Diseases; Cytolysins; Cytolysis; Data; Defect; Dextrans; Disease; Enterobacteriaceae; Epithelial Cells; Escherichia coli; Event; Eye; Eye Infections; Family suidae; Foundations; Genes; Genetic Transcription; Goals; Hospitals; Human; Human Biology; In Vitro; Individual; Infection; Inflammation; Keratitis; Knock-out; Laboratories; Mediating; Membrane; Microscopy; Modeling; Molecular; Morbidity - disease rate; Multi-Drug Resistance; Nosocomial Infections; Oryctolagus cuniculus; Pain; Pathogenesis; Pathogenicity; Pathway interactions; Prevention strategy; Production; Productivity; Protein Inhibition; Proteins; Pseudomonas aeruginosa; Regulation; Reporting; Research; Resolution; Role; Serratia marcescens; Societies; Sterility; Stress; Surface; System; Tertiary Protein Structure; Testing; Therapeutic; Transcriptional Regulation; Type III Secretion System Pathway; United States; Virulence; Virulence Factors; Vision; Work; carbapenem-resistant Enterobacteriaceae; cell injury; corneal epithelium; cost; cytotoxicity; effective therapy; experience; human morbidity; human mortality; improved; in vivo; member; microbial; mortality; mutant; novel; ocular surface; pathogen; prevent; programs; tool; transcriptome sequencing; translational impact; treatment strategy

7. Project Summary / Abstract The overall goal of our research program is to develop better treatment strategies for the prevention of vision loss due to microbial keratitis, as well as increasing our understanding of ocular biology through host-pathogen interaction analysis. This specific study will elucidate a novel host-pathogen interaction important for bacterial infection of the ocular surface. We are focusing on a class of bacteria that frequently cause ocular infections and multidrug resistant hospital infections, the Enterobacteriaceae, that is understudied with respect to ocular infections. Importantly, we will be using recent clinical isolates derived from contact lens associated keratitis event rather than non-ocular laboratory strains that may not share ocular virulence factors. Using the member of the Enterobacteriaceae that most commonly causes keratitis as a model organism, Serratia marcescens, we have uncovered a novel host-pathogen interaction that we will define in this study. Namely, a step in bacteria-mediated ocular cell death is the formation of a distinct type of membrane bleb. Preliminary data indicates the mechanism underlying bleb induction by S. marcescens requires a bacterial type V secretion system, a cytolysin, and a conserved but unstudied stress regulator we are calling GumB. Taking advantage of our state of the art microscopy facility, molecular tools, tunable expression systems, and ocular infection models, we are poised to complete our research goals. Our aims will: 1) address the hypothesis that a type V secretion system involving cytolysin proteins ShlB and ShlA is necessary and sufficient to induce membrane blebs in human ocular cells. This will introduce a completely new mechanism by which bacteria influence corneal cells; 2) determine the mechanism by which GumB regulates bleb formation and cytotoxicity to corneal epithelial cells. This aim will uncover the role of GumB as a virulence factor regulator, which is a conserved bacterial protein found in many species associated with ocular host-pathogen interactions; 3) establish the role of GumB in ocular virulence using a rabbit contact lens keratitis model. This work will show that GumB is a novel master regulator of ocular virulence factors, and will identify those factors. These studies have the potential to discover an entirely new mechanism by which bacteria impact human cells and corneal disease. The long-term implication is that CL-associated keratitis is due, at least in part, to this host-pathogen interaction. The resolution of this mechanism could establish the foundation for more effective infection treatments, such as through chemical inhibition of the proteins studied here.

7。项目摘要 /摘要 我们的研究计划的总体目标是制定更好的治疗策略来预防视力 由于微生物性角膜炎而丧失，并通过宿主生病来增加我们对眼生物学的理解 相互作用分析。这项具体研究将阐明一种新型的宿主 - 病原体相互作用，对细菌很重要 眼表的感染。我们专注于经常引起眼部感染的细菌 和多药耐药的医院感染，肠杆菌科，相对于眼部已研究 感染。重要的是，我们将使用来自隐形眼镜相关角膜炎的近期临床分离株 事件而不是可能无法共享眼毒力因素的非眼实验室菌株。 使用肠杆菌科的成员，最常见地导致角膜炎作为模型生物， Serratia marcescens，我们发现了一种新型的宿主 - 病原体相互作用，我们将在这项研究中定义。 也就是说，细菌介导的眼部细胞死亡的一步是形成了独特的膜爆炸。 初步数据表明链球菌诱导的基础机制需要细菌类型 v分泌系统，细胞辛蛋白酶和一个保守但未研究的压力调节剂，我们称为gumb。 利用我们的最先进的显微镜设施，分子工具，可调表达系统和 眼部感染模型，我们准备完成我们的研究目标。我们的目标将：1）解决 假设涉及细胞溶蛋白蛋白SHLB和SHLA的V型分泌系统是必要的，并且 足以在人眼细胞中诱导膜爆炸。这将引入一个全新的 细菌影响角膜细胞的机制； 2）确定牙齿的机制 调节对角膜上皮细胞的BLEB形成和细胞毒性。这个目标将揭示 牙齿作为一种毒力因子调节剂，这是在许多相关物种中发现的保守细菌蛋白 与眼科宿主 - 病原体相互作用； 3）使用兔子确定口感在眼毒力中的作用 隐形眼镜角膜炎模型。这项工作将表明Gumb是眼部毒力的新型主调节器 因素，并将确定这些因素。这些研究有可能发现一种全新的机制 细菌会影响人类细胞和角膜疾病。长期的影响是CL相关 角膜炎至少部分归因于这种宿主病原体的相互作用。该机制的解决方案可能 建立更有效的感染治疗的基础，例如通过化学抑制 在这里研究的蛋白质。