Molecular mechanisms of host cell escape by Mycobacterium tuberculosis

结核分枝杆菌逃逸宿主细胞的分子机制

基本信息

批准号：
10080702
负责人：
VOLKER BRIKEN
金额：
$ 60.81万
依托单位：
UNIV OF MARYLAND, COLLEGE PARK
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-01-10 至 2023-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10080702
关键词：
Adult Aerosols Apoptosis Autophagocytosis Bacteria Bone Marrow CRISPR/Cas technology Cavia Cell Communication Cell Death Cell Death Inhibition Cell Wall Cell surface Cells Cessation of life Cytolysis Data Drug resistance in tuberculosis Effector Cell Escape Mutant Event Genetic Transcription Granuloma Growth Human Immunotherapeutic agent Individual Infection Innate Immune Response Integration Host Factors Investigation Knock-in Mouse Knock-out Knockout Mice Lead Lipids Lung Manuscripts Mediating Mediator of activation protein Membrane Lipids Mitochondria Modeling Molecular Multi-Drug Resistance Mus Mycobacterium tuberculosis Natural Immunity Necrosis Necrosis Induction Pathway interactions Phagosomes Phenotype Phosphotransferases Production Proteins Proteomics Proto-Oncogene Proteins c-akt Publications Publishing Pulmonary Pathology Pulmonary Tuberculosis Reactive Oxygen Species Regulation Regulon Reporting Research Role Signal Pathway Signal Transduction Signaling Protein Testing Therapeutic Therapeutic Uses Transcription Repressor Tuberculosis Tuberculosis Vaccines Vaccines Virulence Virulence Factors Western Blotting drug development in vivo innovation macrophage mouse model mutant new therapeutic target novel overexpression porcine model protein kinase inhibitor targeted treatment transcriptome

项目摘要

Abstract Mycobacterium tuberculosis (Mtb) causes pulmonary tuberculosis (TB) in humans. In 2015 alone,10.4 million new cases were reported, leading to approximately 1.4 million deaths. There are no effective vaccines for TB and only sub-optimal chemotherapeutics exist. Mtb, after a period of intracellular replication and inhibition of host cell apoptosis, leaves the phagosome and triggers cell lysis in order to exit the host cell. There is a gap in our understanding of how Mtb exploits host cell signaling in order to mediate these events. We have discovered a novel transcriptional repressor, Rv3167c, that is important for suppression of phagosomal escape, host cell necrosis and of macroautophagy (autophagy) induction. This activity is mediated via suppression of gene transcription of genes encoding for synthesis and transport of the outer cell membrane lipid phthiocerol dimycocerosates (PDIM). In the current application we propose to utilize a unique set of Mtb mutants discovered in our lab to elucidate the molecular mechanisms of Mtb-mediated host cell necrosis induction. In AIM1 we will characterize the host cell necrosis and autophagy signaling pathways engaged after phagosomal exit of Mtb. AIM1.1. will test how Mtb mediates the regulation of the host kinase AKT. The Aims 1.2 and 1.3 will explore cell signaling events downstream of AKT leading to necrosis or autophagy induction, respectively. These approaches will be used to identify central signaling hubs within the signaling network that will be most interesting for host directed therapeutic approaches. In AIM2 we will characterize the relevance of host cell escape pathway for virulence of Mtb and its potential as a target for therapeutic approaches. In Aim 2.1, knock-out or knock-in mice will be used to corroborate the ex vivo findings of the importance of select host cell signaling proteins during in vivo infection. In Aim 2.2 our discovery of host cell necrosis signaling components will be exploited to test their relevance for Mtb virulence during aerosol infection of mice and thus determine their potential as novel candidates for host-targeted therapeutics using the mouse model of tuberculosis. We believe that our findings will have great translational potential since inhibition of Mtb-mediated necrosis should reduce virulence of the bacteria and decrease host lung pathology.

抽象的结核分枝杆菌 (Mtb) 会导致人类肺结核 (TB)。仅2015年一年，就有1040万报告了新病例，导致约 140 万人死亡。没有有效的结核病疫苗并且只有次优的化疗药物存在。 Mtb，经过一段时间的细胞内复制和宿主抑制细胞凋亡，离开吞噬体并触发细胞裂解以退出宿主细胞。我们之间存在差距了解 Mtb 如何利用宿主细胞信号传导来介导这些事件。我们发现了一个新型转录抑制因子 Rv3167c，对于抑制宿主细胞吞噬体逃逸非常重要坏死和巨自噬（自噬）诱导。该活性是通过抑制基因介导的编码外细胞膜脂质苯硫酚合成和运输的基因的转录二霉菌角酸酯（PDIM）。在当前的应用中，我们建议利用发现的一组独特的 Mtb 突变体我们的实验室旨在阐明 Mtb 介导的宿主细胞坏死诱导的分子机制。在 AIM1 中，我们将描述吞噬体吞噬后参与的宿主细胞坏死和自噬信号通路 Mtb 出口。 AIM1.1。将测试 Mtb 如何介导宿主激酶 AKT 的调节。目标 1.2 和 1.3 将探索 AKT 下游分别导致坏死或自噬诱导的细胞信号转导事件。这些将使用方法来识别信令网络内最有趣的中央信令枢纽用于宿主定向的治疗方法。在 AIM2 中，我们将描述宿主细胞逃逸途径的相关性了解 Mtb 的毒力及其作为治疗方法靶标的潜力。在目标 2.1 中，淘汰或淘汰小鼠将用于证实体外研究结果，即选择宿主细胞信号蛋白在体内感染。在目标 2.2 中，我们将利用宿主细胞坏死信号成分的发现来测试它们的小鼠气溶胶感染期间 Mtb 毒力的相关性，从而确定其作为新型药物的潜力使用结核病小鼠模型进行宿主靶向治疗的候选者。我们相信，由于抑制 Mtb 介导的坏死，我们的研究结果将具有巨大的转化潜力应降低细菌的毒力并减少宿主肺部病理。