Second Messenger Nucleotides of Enterococcus faecalis

粪肠球菌第二信使核苷酸

• 批准号: 10676471
• 负责人: Jose A Lemos
• 金额: $ 28.99万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-17 至 2028-02-29
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10676471
• 关键词: Agonist; Antibiotic Therapy; Antibiotics; Area; Attenuated; Bacteria; Binding; Biological Process; Cell Maintenance; Cell physiology; Cells; Cellular Metabolic Process; Characteristics; Clinical; Complex; Cues; Cyclic Nucleotides; Data; Disease; Disinfectants; Enterococcus; Enterococcus faecalis; Enterococcus faecium; Environment; Exposure to; Functional disorder; Gastrointestinal tract structure; Goals; Growth; Homeostasis; Hospitalization; Hospitals; Human; Immune response; Immune system; Impairment; Infection; Innate Immune Response; Interferon Type I; Investigation; Knowledge; Light; Link; Mechanics; Mediating; Metabolism; Microbial Biofilms; Multi-Drug Resistance; Nosocomial Infections; Nucleotides; Osmoregulation; Pathogenesis; Pathogenicity; Patients; Phase; Physiological; Play; Process; Production; Proteins; Public Health; Regulation; Research; Research Design; Role; Second Messenger Systems; Signal Transduction; Solid; Stimulus; Stress; Surface; Time; Tissues; Virulence; Work; antibiotic tolerance; antimicrobial; bacterial fitness; biological adaptation to stress; catheter associated UTI; cell envelope; cellular targeting; fitness; implantable device; innovation; insight; interest; mouse model; multi-drug resistant pathogen; novel; opportunistic pathogen; pathogen; rational design; resident commensals; resistant strain; response; stress resilience; trait

ABSTRACT Enterococci are the 3rd most common cause of hospital-acquired infections and a major public health threat due to the continuous rise of multidrug-resistant (MDR) isolates. Because the pathogenic potential of enterococci is closely linked to their ubiquitous stress resilience, work in our lab aims to identify and dissect the mechanisms that allow Enterococcus faecalis, the most prevalent enterococcal species of human infections, to survive in the hostile host environment. Second messenger nucleotides such as (p)ppGpp (the effector molecule of the stringent response) and c-di-AMP are produced by bacteria in response to internal or external stimuli, playing major roles in the regulation of processes associated with cell homeostasis and virulence. In addition, cyclic nucleotides such as c-di-AMP act as agonists of the innate immune response of mammalians by stimulating a potent STING-dependent type I interferon response. Of interest, previous investigations have shown that the c-di-AMP and (p)ppGpp signaling networks are interconnected in other bacteria, but a clear understanding of the mechanics and physiological significance of this interaction are still lacking. In previous studies, we discovered that E. faecalis depends on small amounts of (p)ppGpp to maintain a balanced metabolism and to respond to external cues in an accurate and timely manner. We also found that lack of (p)ppGpp greatly increases antibiotic sensitivity and attenuates the virulence of E. faecalis. More recently, we showed that c-di-AMP is also critical to E. faecalis pathophysiology and that either accumulation or lack of c- di-AMP can drastically impair the virulence potential of E. faecalis. The goals of this application are: (i) to probe the multifaceted roles played by c-di-AMP during infection using a catheter-associated urinary tract infection (CAUTI) mouse model that recapitulates many of the clinical characteristics of the disease in humans, (ii) to identify and characterize the c-di-AMP binding/effector proteins in E. faecalis, and (iii) to investigate how integration of the c-di-AMP and (p)ppGpp regulatory networks controls specific processes that promote bacterial fitness and then determine how this association contributes to E. faecalis pathophysiology. This conceptually innovative application builds on our extensive preliminary data and the complementary expertise and solid track record of our research team in each specific area of this application. Significance of the proposed studies lies in unravelling the multifaceted role of c-di-AMP in host-pathogen interactions, uncovering the scope of c-di-AMP regulation in a major MDR pathogen, and shedding new light onto the intricate relationship between c-di-AMP and (p)ppGpp. Given the central role of regulatory nucleotides in bacterial pathogenesis, a better understanding of how they modulate cell physiology based on identification and characterization of their mechanisms of action and effectors can facilitate the rational design of new antimicrobial therapies.

抽象的 肠球菌是医院获得性感染的第三大常见原因，也是主要的公共卫生威胁 由于多重耐药（MDR）菌株的不断增加。因为潜在的致病性 肠球菌与其普遍存在的应激恢复能力密切相关，我们实验室的工作旨在识别和剖析 粪肠球菌（人类感染中最常见的肠球菌）的机制 在恶劣的宿主环境中生存。第二信使核苷酸，例如 (p)ppGpp（效应子 严格反应分子）和 c-di-AMP 由细菌响应内部或外部产生 刺激，在细胞稳态和毒力相关过程的调节中发挥重要作用。在 此外，环核苷酸（例如 c-di-AMP）可通过以下方式充当哺乳动物先天免疫反应的激动剂： 刺激有效的 STING 依赖性 I 型干扰素反应。有趣的是，之前的调查显示 研究表明，c-di-AMP 和 (p)ppGpp 信号网络在其他细菌中是相互关联的，但明确的 对这种相互作用的力学和生理意义的理解仍然缺乏。在之前的 研究中，我们发现粪肠球菌依靠少量的 (p)ppGpp 来维持平衡 新陈代谢并准确及时地响应外部线索。我们还发现缺乏 (p)ppGpp 大大提高抗生素敏感性并减弱粪肠球菌的毒力。最近，我们 表明 c-di-AMP 对粪肠球菌病理生理学也至关重要，并且 c-di-AMP 的积累或缺乏 di-AMP 可以极大地削弱粪肠球菌的毒力潜力。该应用程序的目标是： (i) 使用导管相关尿路探讨 c-di-AMP 在感染过程中发挥的多方面作用 感染（CAUTI）小鼠模型，概括了人类疾病的许多临床特征， (ii) 鉴定和表征粪肠球菌中的 c-di-AMP 结合/效应蛋白，以及 (iii) 研究 c-di-AMP 和 (p)ppGpp 调控网络的整合如何控制促进促进的特定过程 细菌适应性，然后确定这种关联如何影响粪肠球菌的病理生理学。这 概念上的创新应用建立在我们广泛的初步数据和互补的基础上 我们的研究团队在此应用的每个特定领域拥有专业知识和良好的业绩记录。意义 拟议的研究在于揭示 c-di-AMP 在宿主-病原体相互作用中的多方面作用， 揭示了主要 MDR 病原体中 c-di-AMP 调节的范围，并为研究这一问题提供了新的线索 c-di-AMP 和 (p)ppGpp 之间错综复杂的关系。鉴于调节核苷酸的核心作用 细菌发病机制，根据鉴定更好地了解它们如何调节细胞生理学 及其作用机制和效应器的表征可以促进新药物的合理设计 抗菌疗法。