Turning Mycobacterium tuberculosis appetite for fatty acids against itself

结核分枝杆菌对脂肪酸的需求与自身相悖

• 批准号: 10592602
• 负责人: SABINE EHRT
• 金额: $ 21.19万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-11-14 至 2024-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10592602
• 关键词: Acetylcysteine; Acute; Address; Affect; Affinity; Antibiotic Therapy; Antioxidants; Antitubercular Antibiotics; Bacillus; Biology; Bone Marrow; C3HeB/FeJ Mouse; Carbon; Catabolism; Cell physiology; Cholesterol; Chronic; Clinical; Clinical Trials; Complement; Culture Media; Cyclic AMP; Cytochrome c Reductase; Data; Desire for food; Diet; Doxycycline; Drug Targeting; Drug Tolerance; Electrons; Energy Metabolism; Environment; Enzymes; Etiology; Fatty Acids; Gene Expression; Genes; Genetic; Genetic Determinism; Genus Mycobacterium; Goals; Growth; Heat shock proteins; Infection; Knock-out; Knowledge; Label; Laboratories; Lead; Lesion; Libraries; Lipid Peroxidation; Lipids; Macrophage; Malate Synthase; Measures; Membrane; Metabolism; Modeling; Morbidity - disease rate; Mus; Mutate; Mutation; Mycobacterium tuberculosis; NADH; NADH oxidase; Names; Oleic Acids; Operon; Outcome Measure; Oxidative Stress; Oxidoreductase; Oxygen Consumption; Pathogenesis; Pathogenicity; Pathway interactions; Persons; Pharmaceutical Preparations; Phase; Phenotype; Physiological; Physiology; Play; Predisposition; Proteins; Protons; Reactive Oxygen Species; Regimen; Research; Respiration; Respiratory Chain; Role; Serine; Signal Transduction; Source; Supplementation; System; Testing; Therapeutic; Time; Toxic effect; Treatment Protocols; Tuberculosis; Work; adenosine cyclic-3' ,5' -monophosphate binding proteins; alpha Tocopherol; attenuation; bactericide; caseating granulomas; folic acid metabolism; host colonization; improved; inhibitor; knock-down; long chain fatty acid; metabolomics; minimal inhibitory concentration; mortality; mouse model; mutant; new therapeutic target; novel strategies; nucleotide metabolism; oxidation; pathogen; prevent; response; screening; transposon sequencing; tuberculosis drugs; uptake

Project summary Tuberculosis (TB) remains a leading cause of morbidity and mortality worldwide. In 2020, it is estimated that 1.5 million people died from TB. This calls for improved treatment regimens, which will greatly benefit from the identification of novel strategies to sterilize infections. The overarching idea of this line of research is to subvert highly adaptive strategies employed by the etiological agent of TB Mycobacterium tuberculosis (Mtb). There is a large body of work in support of Mtb exploiting host fatty acids as a carbon source. However, although important for growth and survival, fatty acids can also be toxic for Mtb. Previous work from our laboratory showed that mutants devoid of malate synthase (glcB), type-2 NADH dehydrogenase (ndh/ ndhA) and EtfD (etfD) render a fatty acid sensitive phenotype associated with attenuation in the mouse model of TB. This showed that it is possible to turn Mtb’s optimized metabolism to oxidize host fatty acids against the bacilli. Beyond these specific cases, there is a gap in knowledge on the genetic determinants necessary for Mtb to avoid fatty acid toxicity. To address this issue, we have performed transposon sequencing (Tn-seq) and compared transposon mutant libraries generated in medium with and without oleic acid (a long-chain fatty acid commonly used in mycobacteria culture media, and likely a carbon source during infection). This screening identified ndh and etfD transposon mutants as being sensitive to oleic acid, which is consistent with our previous findings. In this proposal we will do a “deep dive” on the physiological function of the top hit of our Tn-seq screening. Preliminary data indicates that an interplay between cAMP signaling, fatty acid catabolism and respiration impacts Mtb drug susceptibility and pathogenicity. Understanding how these different cell processes interact will not only lead to a better understanding of the pathogen’s biology, but it will unveil new strategies to sterilize Mtb infections.

项目概要 结核病 (TB) 仍然是全世界发病和死亡的主要原因。 2020年预计为1.5 数百万人死于结核病。这就需要改进治疗方案，这将大大受益于 确定消除感染的新策略。这一系列研究的总体思想是颠覆 TB 结核分枝杆菌 (Mtb) 病原体采用的高度适应性策略。有一个 支持结核分枝杆菌利用宿主脂肪酸作为碳源的大量工作。然而，虽然重要 对于生长和生存来说，脂肪酸对结核分枝杆菌也可能有毒。我们实验室之前的工作表明 缺乏苹果酸合酶 (glcB)、2 型 NADH 脱氢酶 (ndh/ndhA) 和 EtfD (etfD) 的突变体导致 与小鼠结核病模型减毒相关的脂肪酸敏感表型。这表明它是 可能会改变结核分枝杆菌的优化代谢，氧化宿主脂肪酸来对抗杆菌。除了这些具体的 在某些情况下，对于结核分枝杆菌避免脂肪酸毒性所需的遗传决定因素的了解存在差距。到 针对这个问题，我们进行了转座子测序（Tn-seq）并比较了转座子突变体 在含有和不含油酸（分枝杆菌中常用的长链脂肪酸）的培养基中生成的文库 培养基，并且可能是感染期间的碳源）。该筛选鉴定了 ndh 和 etfD 转座子 突变体对油酸敏感，这与我们之前的发现一致。在本提案中，我们将 对我们 Tn-seq 筛选的热门产品的生理功能进行“深入研究”。初步数据表明 cAMP 信号传导、脂肪酸分解代谢和呼吸之间的相互作用影响 Mtb 药物敏感性 和致病性。了解这些不同的细胞过程如何相互作用不仅会带来更好的结果 了解病原体的生物学，但它将揭示消除结核分枝杆菌感染的新策略。