Pseudomonas detection and metabolism of sphingosine

假单胞菌检测和鞘氨醇代谢

• 批准号: 8760307
• 负责人: MATTHEW J WARGO
• 金额: $ 27.45万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-11-15 至 2015-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8760307
• 关键词: Acinetobacter; Address; Alcaligenes; Antibiotic Resistance; Area; B-Lymphocytes; Bacteria; Binding; Biological Assay; Biology; Burkholderia; Cells; Chronic Obstructive Airway Disease; Cystic Fibrosis; DNA Binding; Data; Degradation Pathway; Detection; Development; Disease; Enzymes; Escherichia coli; Gene Expression; Gene Expression Regulation; Genes; Genetic Screening; Genetic Transcription; Goals; Health; Healthcare; Human; Immune; Immune response; Immune system; In Vitro; Infection; Inflammatory; Knowledge; Lead; Life; Ligand Binding; Ligands; Link; Lung; Maps; Mechanical ventilation; Metabolic; Metabolic Pathway; Metabolism; Microarray Analysis; Mission; Mus; Mycobacterium tuberculosis; Pathogenesis; Pathway interactions; Patients; Phosphoric Monoester Hydrolases; Physiological; Play; Pseudomonas; Pseudomonas aeruginosa; Regulation; Regulon; Reporter; Reporting; Research; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Specificity; Sphingolipids; Sphingosine; Stenotrophomonas maltophilia; Surveys; System; T-Cell Activation; Testing; Therapeutic Agents; Tight Junctions; United States National Institutes of Health; Virulence; antimicrobial; care burden; co-infection; fitness; improved; in vivo; innovation; insight; interest; macrophage; migration; mouse model; mutant; new therapeutic target; novel; novel therapeutics; pathogen; promoter; response; screening; sphingosine 1-phosphate; sphingosine-1-phosphate phosphatase; therapeutic target; transcription factor

DESCRIPTION (provided by applicant): Pseudomonas aeruginosa lung infections are life threatening and constitute a large health-care burden. Modulation of host immune responses is one paradigm used by pathogens to initiate and prolong infections. Preliminary data demonstrate that P. aeruginosa can degrade the potent immune signaling molecule sphingosine-1-phosphate (S1P) and its precursor sphingosine. S1P degradation would allow P. aeruginosa to alter the host immune response, which could have profound effects on progression of infection and the pathogenesis of disease. Described in this proposal is a previously uncharacterized transcription factor that regulates P. aeruginosa gene expression in response to S1P and sphingosine and is required for their degradation. Deletion of this transcription factor reduces P. aeruginosa virulence in vivo, highlighting the importance of this pathway during infection. Characterization of the detection and metabolism of sphingosine by P. aeruginosa will be a concrete contribution to understanding of sphingosine-related compounds in bacterial biology and pathogenesis. The long term goal is to understand the role of P. aeruginosa S1P and sphingosine metabolism during the course of lung infection. In pursuit of this long-term goal, the overall objectives of this application are to characterize the recognition and degradation system used by P. aeruginosa to respond to S1P and determine the impact of S1P degradation on P. aeruginosa virulence in the lung. The central hypothesis is that P. aeruginosa detection of S1P induces genes necessary for S1P degradation, which promotes virulence. The central hypothesis will be tested by pursuing three specific aims: (1) Characterize S1P and sphingosine-dependent transcription in P. aeruginosa~ (2) Identify the components of the S1P degradation pathway~ and (3) Test the impact of S1P degradation on P. aeruginosa infection. The goals of Aim 1 are to determine the ligand and promoter-binding specificities of the sphingosine-responsive transcription factor by promoter mapping, DNA binding, and reporter assays, and determine its contribution to the sphingosine regulon using microarray analysis. The goal of Aim 2 is to identify the P. aeruginosa S1P phosphatase and the enzymes that degrade sphingosine using genetic screens, metabolite tracking, and in vitro enzymatic assays. Finally, the goal of Aim 3 is to test the hypothesis that the reduced virulence of the transcription factor mutant is due to lack of S1P degradation, versus regulation of genes unrelated to degradation, using a mouse model of lung infection established in the applicant's lab. This proposal is innovative because it will advance understanding of a previously uncharacterized sphingosine detection and metabolic pathway, which may be used by P. aeruginosa to detect the host and interfere with a potent host signaling pathway. The proposed research is significant because it will expand understanding of the metabolic links between bacterial pathogens and the host, perhaps leading to novel antimicrobial or anti-virulence therapies.

描述（由申请人提供）：铜绿假单胞菌肺部感染是危及生命的，构成了巨大的医疗负担。宿主免疫反应的调节是病原体启动和延长感染的一个范例。初步研究表明，P. aeruginosa可以降解免疫信号分子鞘氨醇-1-磷酸（S1P）及其前体鞘氨醇。S1P降解将允许铜绿假单胞菌改变宿主的免疫反应，这可能对感染的进展和疾病的发病机制产生深远的影响。本提案中描述的是一种以前未被表征的转录因子，它调节P. aeruginosa基因表达以响应S1P和鞘氨醇，并且是它们降解所必需的。该转录因子的缺失降低了铜绿假单胞菌体内的毒力，突出了该途径在感染过程中的重要性。P. aeruginosa对鞘氨醇的检测和代谢的表征将为理解鞘氨醇相关化合物在细菌生物学和发病机制中的作用做出具体贡献。长期目标是了解P. aeruginosa S1P和鞘氨醇代谢在肺部感染过程中的作用。为了实现这个长期目标，这个应用程序的总体目标是表征识别