Two-component system interactions as uropathogenic Escherichia coli drug targets

作为尿路致病性大肠杆菌药物靶标的两组分系统相互作用

• 批准号: 8816807
• 负责人: Maria Hadjifrangiskou
• 金额: $ 35.87万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-12-01 至 2019-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8816807
• 关键词: Accounting; Acute; Address; Adhesives; Antibiotics; Area; Attenuated; Bacteria; Bacterial Infections; Biological Assay; Bladder; Cells; ChIP-seq; Chimera organism; Chronic; Communities; Cytoplasm; Deterioration; Development; Disease; Drug Targeting; Drug usage; Electrophoretic Mobility Shift Assay; Environment; Escherichia coli Infections; Female; Fiber; Fostering; Frequencies; Gene Expression; Genes; Genetic Transcription; Goals; Gram-Negative Bacteria; Human; Immunoprecipitation; In Vitro; Infection; Iron; Kinetics; Lead; Link; Metabolism; Microbial Biofilms; Microscopy; Modeling; Molecular; Mus; Mutagenesis; Operon; Outcome; Pathogenesis; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Physiological; Pilum; Population; Quality of life; Recurrence; Research; Resistance; Resources; Role; Series; Signal Transduction; Source; System; Testing; Therapeutic; Universities; Urinary tract; Urinary tract infection; Uropathogenic E. coli; Vacuole; Virulence; Woman; Work; attenuation; bacterial resistance; base; drug discovery; experience; extracellular; fitness; in vivo; inhibitor/antagonist; insight; molecular array; mouse model; mutant; novel; pathogen; prevent; promoter; public health relevance; response; sensor; small molecule libraries; tool

DESCRIPTION (provided by applicant): Urinary tract infections (UTIs) are among the most frequent bacterial infections afflicting humans and have a high degree of recurrence. With rising resistance to front-line antibiotics, there is a pressing need for the development of targeted strategies aimed at preventing and/or treating UTIs. Uropathogenic Escherichia coli (UPEC) account for the majority of UTIs and can form robust extracellular biofilms, as well as biofilm- like intracellular bacterial communities (IBCs). Among the factors impacting IBC formation is the QseC sensor kinase, the disruption of which diminishes IBC formation and attenuates UPEC virulence. We have shown that QseC is required for the de-phosphorylation and deactivation of its cognate response regulator QseB, which becomes constitutively activated in the absence of QseC. Constitutively active QseB leads to the dysregulation of >500 genes, interferes with core metabolic processes and downregulates virulence gene expression. Investigating the source of QseB phosphorylation in the absence of QseC identified the PmrAB two-component system (TCS) as the primary QseB activator. We went on to show that in wild-type UPEC, signal reception by PmrB can also activate the non-cognate partner QseB, indicating a potential overlap between QseBC and PmrAB signaling. These results lead to two hypotheses: 1) There is robust cross-talk between non-cognate TCS partners that is of physiological significance during UPEC pathogenesis and, 2) We can target QseC function as a means to attenuate virulence. This proposal will engage fundamental questions about the regulatory interactions between QseBC and PmrAB and their role in UTI pathogenesis, and endeavor to harness this information to treat/prevent UTIs. Aims 1 and 2 will elucidate the molecular mechanisms underlying the cross-talk between UPEC QseBC and PmrAB. Aim 3 will probe the role of QseBC-PmrAB interactions during infection and will identify compounds that target the QseC phosphatase function, and/or bias cross-talk between QseB and PmrB. We have developed an extensive array of molecular tools that we are using in our studies, including non-polar deletion mutants, as well as inactive or constitutively active point mutants. Combined with the well-established murine model of UTI we are using, our microscopy capabilities to track infection in the bladder, and the impressive facilities and resources of Vanderbilt University, we are confident that we will harness information that will elucidate the QseBC-PmrAB molecular interplay within and outside the host. Our long-term goal is to leverage the outcomes of the herein proposed studies to develop better therapies against UPEC infection.

描述（由申请人提供）：尿路感染（UTI）是困扰人类的最常见的细菌感染之一，并且复发很高。随着对前线抗生素的抵抗力增加，迫切需要开发旨在防止和/或治疗UTI的目标策略。尿道病性大肠杆菌（UPEC）占大多数UTI的占多数，并且可以形成强大的细胞外生物膜以及类似生物膜的细胞内细菌群落（IBC）。影响IBC形成的因素之一是QSEC传感器激酶，其破坏IBC形成并减轻了UPEC毒力。我们已经表明，QSEC是其同源响应调节剂QSEB的去磷酸化和失活所必需的，该QSEB在没有QSEC的情况下被组成式激活。组成性活性QSEB导致> 500个基因的失调，干扰核心代谢过程并下调毒力基因表达。在没有QSEC的情况下，研究QSEB磷酸化的来源将PMRAB两组分组（TC）识别为主要QSEB激活剂。我们继续表明，在野生型UPEC中，PMRB的信号接收也可以激活非认知伴侣QSEB，表明QSEBC和PMRAB信号传导之间存在潜在的重叠。这些结果导致了两个假设：1）在UPEC发病机理期间，非认知TCS伴侣之间具有生理意义，并且2）我们可以将QSEC作为减轻毒力的一种手段。该提案将引入有关QSEBC与PMRAB之间的调节性相互作用及其在UTI发病机理中的作用，并努力利用此信息来治疗/预防UTI的基本问题。目标1和2将阐明UPEC QSEBC和PMRAB之间串扰的基础机制。 AIM 3将探测感染过程中QSEBC-PMRAB相互作用的作用，并将识别靶向QSEC磷酸酶功能的化合物，以及/或QSEB和PMRB之间的偏置串扰。我们已经开发了广泛的分子工具，这些工具包括非极性缺失突变体，以及非活性或组成性活性点突变体。结合我们正在使用的公认的UTI鼠模型，我们的显微镜能力跟踪膀胱感染的能力以及范德比尔特大学的令人印象深刻的设施和资源，我们有信心我们将利用QSEBC-PMRAB分子的信息主机内外的相互作用。我们的长期目标是利用此处提出的研究的结果来开发针对UPEC感染的更好疗法。