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菌是一种革兰氏阳性，机会性的，细胞内细菌病原体，导致食物内 疾病。鉴于其特征良好的感染周期和遗传性不适，单核细胞增生乳杆菌提供了 询问细胞内细菌发病机理和宿主免疫的基本方面的强大工具 细胞内病原体对侵袭的反应。进入宿主细胞胞质分泌的单核细胞增生 第二信使信号传导核苷酸C-DI-AMP导致宿主细胞的先天免疫激活。我们 最近将宿主蛋白重新确定为该反应的关键介体。侦察是一种酶 C-DI-AMP抑制活性。 C-DI-AMP抑制侦察会导致ROS副产品的积累 4-羟基-2-非烯酸（4-HNE），增强NF-KB激活，导致一氧化氮合酶升高 在感染过程中表达且无生产。有趣的是，我们已经透露，宿主细胞没有产生 促进单核细胞增生的细胞内运动，而不是限制细菌的生长，而L. 单核细胞增生剂表现出极端的耐药性。此外，初步研究表明4-HNE是 暴露于细菌后，由真核细胞诱导的普遍诱导，这种反应性醛表现出 抗菌对细菌的作用类似于NO。此外，L。单核细胞增生表现出极端的抗性 4-HNE的抗菌作用并诱导对4-HNE暴露的特定转录反应，这 我们假设促进感染宿主内的生存。我们已经开始体外生化研究，体内 正向遗传研究和感染的鼠模型，以询问L. 单核细胞增生剂抵消了NO和4-HNE的抗菌作用，并利用NO来促进毒力。在 目的I，我们将询问单核细胞增生乳杆菌使用的机制，以排毒和抵消抗菌剂 4-HNE的影响。在AIM II中，我们建议详细说明无电阻的分子机制和影响 关于细菌毒力。最后，在AIM III中，我们将详细详细介绍无诱导的单核细胞增生李斯特菌肌动蛋白的机理 基于运动和探索该过程对细菌侵袭和传播的体内影响。一起 这些研究将定义精致的抗微生物先天免疫反应的分子机制 由单核细胞增生李斯特氏菌雇用来促进真核宿主内的生存。 。