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: 9172228
• 负责人: Maria Hadjifrangiskou
• 金额: $ 39.43万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 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/9172228
• 关键词: 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; Female; Fiber; Fostering; Frequencies; Gene Expression; Genes; Genetic Transcription; Goals; Gram-Negative Bacteria; Human; Immunoprecipitation; Impairment; In Vitro; Infection; Iron; Kinetics; Lead; Link; Metabolism; Microbial Biofilms; Microscopy; Molecular; 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; 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）是人类最常见的细菌感染之一，并且复发率很高。随着对一线抗生素的耐药性不断增加，迫切需要制定旨在预防和/或治疗尿路感染的有针对性的策略。泌尿道致病性大肠杆菌 (UPEC) 占尿路感染的大部分，可以形成强大的细胞外生物膜以及生物膜样细胞内细菌群落 (IBC)。影响 IBC 形成的因素之一是 QseC 传感器激酶，其破坏会减少 IBC 形成并减弱 UPEC 毒力。我们已经证明，QseC 是其同源反应调节因子 QseB 去磷酸化和失活所必需的，在 QseC 不存在的情况下，QseB 会被组成型激活。持续活跃的 QseB 会导致超过 500 个基因失调，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，确定 PmrAB 双组分系统 (TCS) 是主要的 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同源伙伴 QseB，表明 QseBC 和 PmrAB 信号传导之间存在潜在重叠。这些结果引出了两个假设：1）非同源 TCS 伙伴之间存在强大的串扰，这在 UPEC 发病机制中具有生理意义；2）我们可以将 QseC 功能作为减弱毒力的一种手段。该提案将探讨有关 QseBC 和 PmrAB 之间的监管相互作用及其在 UTI 发病机制中的作用的基本问题，并努力利用这些信息来治疗/预防 UTI。目标 1 和 2 将阐明 UPEC QseBC 和 PmrAB 之间串扰的分子机制。目标 3 将探讨感染过程中 QseBC-PmrAB 相互作用的作用，并将鉴定针对 QseC 磷酸酶功能和/或 QseB 与 PmrB 之间的偏置串扰的化合物。我们开发了一系列广泛的分子工具，用于我们的研究，包括非极性缺失突变体，以及非活性或组成型活性点突变体。结合我们正在使用的完善的 UTI 小鼠模型、我们追踪膀胱感染的显微镜能力以及范德比尔特大学令人印象深刻的设施和资源，我们有信心利用信息来阐明 QseBC-PmrAB 分子宿主内部和外部相互作用。我们的长期目标是利用本文提出的研究结果来开发更好的针对 UPEC 感染的疗法。