Function of MVFR in Pseudomonas aeruginosa virulence

MVFR 在铜绿假单胞菌毒力中的作用

• 批准号: 7394450
• 负责人: LAURENCE G RAHME
• 金额: $ 38.09万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7394450
• 关键词: Anabolism; Animal Model; Animals; Anthranilic Acids; Anti-Infective Agents; Antibiotics; Attenuated; Bacteremia; Bacteria; Bacterial Infections; Binding; Binding Sites; Biochemical; Blood; Burn injury; Cell Communication; Cells; Class; Complex; Cultured Cells; Cystic Fibrosis; Cytochromes; Development; Disease Outbreaks; Doctor of Philosophy; Drosophila melanogaster; Enzymes; Exhibits; Genes; Goals; Growth; HIV; Healthcare; Hospitals; Human; Immune; Immunity; Incidence; Infection; Injection of therapeutic agent; Laboratories; Ligand Binding; Ligand Binding Domain; Ligands; Lung; Magnetic Resonance Imaging; Mammals; Manuscripts; Mediating; Modeling; Molecular Genetics; Multi-Drug Resistance; Mus; Neonatal; Nosocomial Infections; Nucleic Acid Regulatory Sequences; Operon; Organ; Pathway interactions; Patients; Pharmaceutical Preparations; Play; Proteins; Pseudomonas; Pseudomonas aeruginosa; Publishing; Quinolones; Range; Regulation; Regulatory Pathway; Research Personnel; Resistance development; Respiratory Tract Infections; Role; Sepsis; Signal Transduction; Signaling Molecule; Skin; Structure; Testing; Therapeutic; Thick; Time; Tissues; Toxic effect; Transcription Coactivator; Virulence; Virulence Factors; anthranilic acid; bacterial resistance; base; clinically relevant; cystic fibrosis patients; genetic analysis; heat injury; in vivo; inhibitor/antagonist; mortality; mutant; novel; outcome forecast; pathogen; pathogenic bacteria; pressure; prevent; programs; promoter; quorum sensing; research study; respiratory; transcription factor

DESCRIPTION (provided by applicant): Infections caused by Pseudomonas aeruginosa are a significant problem in human healthcare. This bacterial pathogen is the principle agent of sepsis in burn patients; of persistent lung infections and mortality in cystic fibrosis patients; of nosocomial infections in HIV and other immune-suppressed patients; and of the outbreak of deleterious multi-drug resistant infections in hospitals. The long-term goal of this proposal is to provide effective and selective therapies that reduce the incidence and complications of human P. aeruginosa infections. This study proposes this goal can be achieved by drugs that prevent or limit the activation of the MvfR/HAQ pathway, and the development of such anti-infective compounds is the immediate goal of this application. This proposal is based on the hypothesis that MvfR, a P. aeruginosa transcriptional regulator, is a candidate target for anti-infective drugs, as it plays a central role in modulating the expression of many QS-controlled virulence-associated factors; and its activation is mediated by its binding to a specific ligand, which is essential for its function. To identify MvfR-pathway inhibitors, and demonstrate their in vivo anti-infective activity, this study proposes three Specific Aims: 1) to confirm the identity of the MvfR ligand, identify its binding site, and determine its mechanism of action; 2) to identify compounds that inhibit the MvfR/HAQ pathway; and 3) to determine the in vivo efficacy and potential feasibility of these inhibitors to limit P. aeruginosa infection in mammals. These aims will be accomplished via three sets of experiments. First, biochemical, mass spectrometric, and molecular genetic analyses will confirm the identity of the P. aeruginosa MvfR-ligand; define the MvfR ligand binding domain; and determine the pqsA promoter sequence recognized and bound by MvfR and the MvfR-ligand complex. Second, biochemical and mass spectrometric analyses will identify compounds that prevent ligand-mediated MvfR activation by limiting the synthesis and/or binding of its ligand, and that are metabolically stable in P. aeruginosa. Third, each identified inhibitor will be tested in the Drosophila melanogaster, the mouse full-thickness skin thermal injury, and the mouse neonatal respiratory model, to determine their toxicity, their in vivo efficacy to limit P. aeruginosa infection; and their "immunity" to the development of bacterial resistance. Specific inhibition of a pathway that directly mediates virulence is less likely to generate selective pressure to develop resistance to the inhibitor, than for drugs, including most antibiotics, that reduce bacterial viability. Such targeted inhibitors could significantly enhance the long-term prognosis of burn, cystic fibrosis, and HIV patients. To this end, the results here should enable novel therapies to treat and/or prevent P. aeruginosa-human infections.

描述（由申请人提供）：铜绿假单胞菌引起的感染是人类医疗保健中的一个重大问题。这种细菌病原体是烧伤患者败血症的主要病原体。囊性纤维化患者持续性肺部感染和死亡率； HIV 和其他免疫抑制患者的医院感染；以及医院爆发有害的多重耐药性感染。该提案的长期目标是提供有效且选择性的治疗方法，以减少人类铜绿假单胞菌感染的发生率和并发症。本研究提出这一目标可以通过阻止或限制MvfR/HAQ通路激活的药物来实现，而开发此类抗感染化合物是本申请的直接目标。该提议基于这样的假设：MvfR（一种铜绿假单胞菌转录调节因子）是抗感染药物的候选靶点，因为它在调节许多 QS 控制的毒力相关因子的表达中发挥着核心作用；它的激活是通过与特定配体的结合介导的，这对其功能至关重要。为了鉴定MvfR通路抑制剂，并证明其体内抗感染活性，本研究提出了三个具体目标：1）确认MvfR配体的身份，确定其结合位点，并确定其作用机制； 2) 鉴定抑制MvfR/HAQ途径的化合物； 3) 确定这些抑制剂限制哺乳动物铜绿假单胞菌感染的体内功效和潜在可行性。这些目标将通过三组实验来实现。首先，生化、质谱和分子遗传学分析将确认铜绿假单胞菌 MvfR-配体的身份；定义MvfR配体结合域；并确定被MvfR和MvfR-配体复合物识别和结合的pqsA启动子序列。其次，生化和质谱分析将鉴定通过限制其配体的合成和/或结合来防止配体介导的MvfR激活的化合物，并且这些化合物在铜绿假单胞菌中代谢稳定。第三，每种确定的抑制剂将在黑腹果蝇、小鼠全层皮肤热损伤和小鼠新生儿呼吸模型中进行测试，以确定它们的毒性以及限制铜绿假单胞菌感染的体内功效；以及它们对细菌耐药性发展的“免疫力”。与降低细菌活力的药物（包括大多数抗生素）相比，对直接介导毒力的途径进行特异性抑制不太可能产生选择性压力以产生对抑制剂的耐药性。这种靶向抑制剂可以显着改善烧伤、囊性纤维化和艾滋病毒患者的长期预后。为此，这里的结果应该能够提供治疗和/或预防铜绿假单胞菌人类感染的新疗法。