Listeria monocytogenes physiology and host pathogen interactions

单核细胞增生李斯特氏菌生理学和宿主病原体相互作用

• 批准号: 10330555
• 负责人: Joshua Woodward
• 金额: $ 49.11万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10330555
• 关键词: 4 hydroxynonenal; Actins; Adenosine Monophosphate; Affinity; Aldehydes; Antimicrobial Effect; Antimicrobial Resistance; Bacteria; Bacterial Infections; Binding; Biochemical; Biological Response Modifiers; Bone Marrow; Cells; Cytosol; Detection; Disease; Dissection; Enzymes; Eukaryotic Cell; Exhibits; Exposure to; Funding; Gallbladder; Genes; Genetic; Genetic Transcription; Genetic study; Glean; Grant; Growth; Health; Host Defense; Human; Immune; Immune response; In Vitro; Individual; Infection; Inflammation; Inflammatory Response; Innate Immune Response; Innate Immune System; Listeria monocytogenes; Mediating; Mediator of activation protein; Membrane Transport Proteins; Modeling; Molecular; Mus; NF-kappa B; NFKB Signaling Pathway; Nitric Oxide; Nitric Oxide Synthase; Nucleotides; Organism; Pathogenesis; Pattern recognition receptor; Periodicity; Physiology; Predisposition; Process; Production; Proteins; Public Health; Reactive Nitrogen Species; Resistance; Role; Second Messenger Systems; Signal Transduction; Testing; Toxic effect; Virulence; Whole Organism Analysis; antimicrobial; base; cell motility; fitness; foodborne; foodborne illness; genome-wide; human pathogen; immune activation; in vivo; insight; macrophage; microbial; mouse model; novel; pathogen; pathogenic bacteria; polymerization; resistance factors; resistance mechanism; response; tissue culture; tool; transmission process; transposon sequencing

ABSTRACT Listeria monocytogenes is a gram-positive, opportunistic, intracellular bacterial pathogen that causes food borne illness. Given its well-characterized infection cycle and genetic amenability, L. monocytogenes provides a powerful tool to interrogate the fundamental aspects of intracellular bacterial pathogenesis and the host immune response to invasion by intracellular pathogens. L. monocytogenes that enter into the host cell cytosol secrete the second messenger signaling nucleotide, c-di-AMP, resulting in innate immune activation by the host cell. We recently identified the host protein RECON as a key mediator of this response. RECON is an enzyme whose activity is inhibited by c-di-AMP. C-di-AMP inhibition of RECON results in the accumulation of the ROS byproduct 4-hydroxy-2-nonenal (4-HNE), which augments NF-kB activation, resulting in elevated nitric oxide synthase expression and NO production during infection. Intriguingly, we have revealed that NO produced by the host cell promotes L. monocytogenes intracellular motility, rather than restricting bacterial growth, and that L. monocytogenes exhibits extreme NO resistance. Additionally, preliminary studies have revealed that 4-HNE is ubiquitously induced by eukaryotic cells following exposure to bacteria and that this reactive aldehyde exhibits antimicrobial effects on bacteria analogous to NO. Furthermore, L. monocytogenes exhibits extreme resistance to the antimicrobial effects of 4-HNE and induces a specific transcriptional response to 4-HNE exposure, which we hypothesize promotes survival within the infected host. We have begun in vitro biochemical studies, in vivo forward genetic studies, and the murine models of infection to interrogate the mechanisms by which L. monocytogenes counteracts the antimicrobial effects of NO and 4-HNE and utilizes NO to promote virulence. In Aim I, we will interrogate the mechanisms used by L. monocytogenes to detoxify and counteract the antimicrobial effects of 4-HNE. In Aim II, we propose to detail the molecular mechanisms of NO resistance and the impacts on bacterial virulence. Finally, in Aim III we will detail the mechanism of NO induced L. monocytogenes actin- based motility and explore the in vivo impacts of this process on bacterial invasion and dissemination. Together these studies will define the molecular mechanisms of exquisite antimicrobial innate immune responses employed by L. monocytogenes to promote survival within the eukaryotic host. .

抽象的 单核细胞增生李斯特氏菌是一种革兰氏阳性、机会性、细胞内细菌病原体，可导致食源性疾病 疾病。鉴于其明确的感染周期和遗传适应性，单核细胞增生利斯特氏菌提供了一种 询问细胞内细菌发病机制和宿主免疫的基本方面的强大工具 对细胞内病原体入侵的反应。进入宿主细胞胞浆的单核细胞增生利斯特氏菌分泌 第二信使信号核苷酸 c-di-AMP，导致宿主细胞激活先天免疫。我们 最近发现宿主蛋白 RECON 是这种反应的关键介质。 RECON 是一种酶，其 活性被 c-di-AMP 抑制。 RECON 的 C-di-AMP 抑制导致 ROS 副产物的积累 4-羟基-2-壬烯醛 (4-HNE)，增强 NF-kB 激活，导致一氧化氮合酶升高 感染期间的表达和NO产生。有趣的是，我们发现宿主细胞产生的 NO 促进单增李斯特菌细胞内运动，而不是限制细菌生长，并且李斯特菌。 单核细胞增生李斯特菌表现出极端的NO抵抗性。此外，初步研究表明 4-HNE 暴露于细菌后普遍由真核细胞诱导，并且这种反应性醛表现出 对细菌的抗菌作用类似于NO。此外，单核细胞增生利斯特氏菌表现出极高的耐药性 4-HNE 的抗菌作用，并诱导对 4-HNE 暴露的特异性转录反应，这 我们假设促进受感染宿主的生存。我们已经开始体外生化研究，体内 前瞻性遗传学研究和小鼠感染模型来探究 L. 单核细胞增生李斯特菌抵消 NO 和 4-HNE 的抗菌作用，并利用 NO 增强毒力。在 目标 I，我们将探究单核细胞增生利斯特氏菌解毒和对抗抗菌药物的机制 4-HNE 的影响。在目标 II 中，我们建议详细介绍 NO 耐药性的分子机制及其影响 关于细菌毒力。最后，在目标 III 中，我们将详细介绍 NO 诱导单核细胞增生李斯特氏菌肌动蛋白的机制。 基于运动性并探索该过程对细菌入侵和传播的体内影响。一起 这些研究将定义精致的抗菌先天免疫反应的分子机制 单核细胞增生利斯特氏菌用于促进真核宿主内的存活。 。