Contribution of CdiA to Pseudomonas aeruginosa pathobiology

CdiA 对铜绿假单胞菌病理学的贡献

• 批准号: 10437887
• 负责人: Jonathan P Allen
• 金额: $ 36.91万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-24 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10437887
• 关键词: Affect; Alleles; Antibiotic Resistance; Area; Attenuated; Bacteremia; Bacteria; Bacterial Toxins; C-terminal; Cell Survival; Cells; Characteristics; Clinical; Code; Common Core; Complex; Data; Defect; Disease; Disease Progression; Escherichia coli; Eukaryotic Cell; Exotoxins; Genes; Genome; Genomic approach; Goals; Grant; Growth; Health Care Costs; Healthcare; Hela Cells; Immune system; In Vitro; Incidence; Infection; Inflammation; Laboratories; Lactate Dehydrogenase; Length of Stay; Luciferases; Measures; Mediating; Modeling; Molecular; Multi-Drug Resistance; Mus; Mutation; Organism; Outcome; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Pneumonia; Prokaryotic Cells; Property; Proteins; Pseudomonas aeruginosa; Pseudomonas aeruginosa infection; Public Health; Pyocyanine; Reporter; Reporting; Research; Role; Sampling; Surface; System; Tertiary Protein Structure; Testing; Therapeutic; Therapeutic Agents; Therapeutic Intervention; Toxic effect; Toxin; Transfer RNA; Type III Secretion System Pathway; Virulence; Virulence Factors; Virulent; Work; alpha Toxin; antagonist; bacterial resistance; base; combat; comparative genomics; cytotoxicity; enhancing factor; health organization; high risk; immune activation; insight; interest; microorganism; mortality risk; multidrug-resistant Pseudomonas aeruginosa; mutant; new therapeutic target; novel; novel therapeutics; programs; rational design; resistant strain; stem; targeted treatment; trait

Project Summary/Abstract Pseudomonas aeruginosa is a leading cause of healthcare-acquired infections worldwide. Many globally- distributed high-risk strains are emerging due to an increase in antibiotic resistance and acquisition of novel virulence traits. With diminishing treatment options for many of these severe P. aeruginosa infections, studies aimed at uncovering the virulence strategies used by these aggressive clinical strains should help to identify new targets for therapeutic intervention. Our research program aims to elucidate virulence strategies that enhance the pathogenicity of P. aeruginosa. We recently employed a comparative genomics approach to interrogate the accessory genomes of 100 clinical isolates for potential factors that augment the virulence of P. aeruginosa. By comparing virulence in a mouse infection model with the presence or absence of genes in the accessory genome, we identified several virulence determinants enriched among highly virulent P. aeruginosa strains that were absent from less virulent strains. From this work we identified an accessory virulence factor that spanned a portion of two genes encoding products involved in contact-dependent growth inhibition (CDI). CDI is one type of competitive mechanism microorganisms use to antagonize their immediate neighbors by delivering protein toxins directly into targeted cells. This antagonism is executed by CdiA, a large multidomain exoprotein that sits at the surface of an attacking cell and delivers a self-contained toxin domain into the targeted cell. The importance of this proposal stems from our discovery that: (i) CdiA contains a toxin domain that has tRNAse activity against prokaryotic and eukaryotic substrates, (ii) mutations that abrogate the in vitro tRNAse activity attenuate both CDI and virulence in mice, (iii) the CdiA-toxin domain has cytopathic effects on eukaryotic cells dependent upon its tRNase activity. To our knowledge this dule role for CdiA in both interbacterial completion and virulence within a mammalian host has not yet been investigated for P. aeruginosa. From this preliminary work we hypothesize that P. aeruginosa can utilize CdiA to intoxicate host cells for overcoming barriers to infection. Our proposal seeks to answer a number of outstanding questions at the molecular (Aim 1), cellular (Aim 2), and organismal (Aim 3) level. Successful completion of these aims will provide detailed insight into how CdiA contributes to P. aeruginosa pathobiology.

项目摘要/摘要 铜绿假单胞菌是全球医疗保健获得感染的主要原因。许多全球 - 由于抗生素耐药性的增加和新颖的获取，分布式高风险菌株正在出现 毒力特征。由于许多严重的铜绿假单胞菌感染的治疗选择减少，研究 旨在发现这些积极的临床菌株使用的毒力策略应有助于确定新的 治疗干预的目标。我们的研究计划旨在阐明增强的毒力策略 铜绿假单胞菌的致病性。我们最近采用了一种比较基因组学方法来询问 100个临床分离株的辅助基因组，以增加铜绿假单胞菌的毒力。经过 比较小鼠感染模型中的毒力与辅助基因组中存在或不存在基因的毒力， 我们确定了在高毒的铜绿假单胞菌菌株中富集的几种毒力决定因素 缺乏较少的毒素菌株。从这项工作中，我们确定了一个跨越a的附件毒力因子 两个基因的一部分编码涉及接触依赖性生长抑制（CDI）的产物。 CDI是一种类型 竞争机制微生物通过传递蛋白质来拮抗其直系邻居 毒素直接进入靶细胞。这种拮抗作用是由CDIA执行的 在攻击细胞的表面，并将一个独立的毒素结构域运送到靶细胞中。这 该提议的重要性源于我们发现：（i）CDIA包含一个具有TRNase的毒素域 对原核生物和真核底物的活性，（ii）消除体外TRNase活性的突变 （iii）CDIA-TOXIN结构域对小鼠的CDI和毒力均衰减，对真核细胞具有细胞质作用 取决于其TRNase活性。据我们所知，CDIA在两个细分间完成 尚未对铜绿假单胞菌进行哺乳动物宿主内的毒力。从这个初步 工作我们假设铜绿假单胞菌可以利用CDIA陶醉于宿主细胞，以克服障碍 感染。我们的建议旨在在分子（目标1）上回答许多未悬而未决的问题 （AIM 2）和生物（目标3）水平。这些目标的成功完成将提供详细的见解 CDIA有助于铜绿假单胞菌病理生物学。