Molecular mechanisms of persistence in mycobacteria

分枝杆菌持久性的分子机制

• 批准号: 10231221
• 负责人: Sarah M. Schrader
• 金额: $ 5.18万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-11-25
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10231221
• 关键词: Antibiotic Resistance; Antibiotics; Biological Assay; Cause of Death; Cells; Clinical; Communicable Diseases; Dangerousness; Data; Development; Disease; Drug resistance; Drug resistance in tuberculosis; Exposure to; Fostering; Genetic; Genetic Determinism; Genome; Genus Mycobacterium; Goals; Healthcare Systems; Individual; Infection; Knock-out; Length; Methods; Molecular; Mutation; Mycobacterium smegmatis; Mycobacterium tuberculosis; Mycobacterium tuberculosis complex; Nature; Outcome; Pathway interactions; Patient-Focused Outcomes; Patients; Pharmaceutical Preparations; Phenotype; Poly A; Polyphosphates; Population; Regimen; Regulator Genes; Research; Resistance; Role; Source; Stress; Testing; Therapeutic; Time; Treatment Effectiveness; Treatment Efficacy; Treatment Failure; Tuberculosis; Veins; antibiotic tolerance; base; biological adaptation to stress; compliance behavior; cost; design; effective therapy; emerging antibiotic resistance; genome sequencing; global health; improved; mutant; mycobacterial; novel; resistant strain; screening; side effect; stem; transmission process; treatment duration; tuberculosis drugs; tuberculosis treatment; whole genome

PROJECT SUMMARY/ABSTRACT Tuberculosis (TB), caused by the Mycobacterium tuberculosis (Mtb) complex, is the leading cause of death due to infectious disease worldwide. Treatment for drug-susceptible TB requires a multi-drug regimen prescribed for a period of six months, longer than for almost any other drug-susceptible infection. The treatment of increasingly- prevalent drug-resistant TB often demands riskier drugs taken for even longer periods of time. The length of treatment poses major challenges in terms of cost, side effects, and patient adherence. A phenomenon known as phenotypic tolerance to antibiotics, in which phenotypic differences among individual cells in a population allow some of them–known as persister cells–to survive exposure to an antibiotic against which their genomes do not encode resistance, is a main contributing factor to the protracted therapy for TB. In addition to lengthening treatment duration, persister cells also represent a source of treatment failure, contribute to TB reactivation after apparently effective treatment, and constitute a pool of surviving cells from which antibiotic-resistant strains can eventually emerge. Thus, elimination of persisters could reduce treatment times as well as cut rates of treatment failure and disease reactivation and slow emergence of drug resistance. However, in order to effectively target persisters therapeutically, a deeper understanding of how cells enter, maintain, and exit from a persistent state is required. The goal of this proposal is to dissect the molecular mechanisms underlying persistence in Mtb via two complementary approaches. In the first, the project will seek to isolate so-called high persister (hip) mutants, populations of which generate a higher proportion of persister cells than wild type strains, and characterize the molecular mechanisms by which the hip mutations they carry increase the proportion of persisters. These mutants will be isolated using a novel filter-based method that takes into account three parameters–type of antibiotic stress, antibiotic concentration, and time of exposure–to allow for the uncovering of diverse persistence mechanisms. In the second approach, the project will aim to elucidate the role of inorganic polyphosphate (poly(P)) in mycobacterial persistence. Specifically, the project will test the hypothesis that poly(P) acts as a molecular switch to control entry into and exit from a persistent state using a set of genetic knockouts in key poly(P) regulatory genes. Ultimately, this project will contribute to a molecular understanding of persistence in Mtb, which will advance efforts to target persister cells therapeutically.

项目总结/摘要 由结核分枝杆菌（Mtb）复合体引起的结核病（TB）是由于结核病引起的死亡的主要原因。 传染病的威胁药物敏感性结核病的治疗需要多药方案， 六个月的时间，比几乎任何其他药物敏感性感染都要长。越来越多的治疗- 流行的耐药结核病通常需要更长时间服用风险更大的药物。的长度 治疗在成本、副作用和患者依从性方面提出了主要挑战。一种已知的现象 作为对抗生素的表型耐受性，其中群体中单个细胞之间的表型差异 允许其中一些细胞--被称为持久细胞--在暴露于抗生素的情况下存活下来， 不编码耐药性，是结核病治疗拖延的主要因素。除了加长 持续治疗期间，存留细胞也是治疗失败的来源，有助于结核病复发后， 显然有效的治疗，并构成了一个池的存活细胞，从其中耐药菌株可以 最终出现。因此，消除持久性可以减少治疗时间以及降低治疗率 失败和疾病再激活以及耐药性的缓慢出现。为了有效地瞄准 坚持治疗，更深入地了解细胞如何进入，维持和退出持久状态 是必需的.这项建议的目标是通过以下途径剖析结核病持续存在的分子机制： 两种互补的方法。首先，该项目将寻求分离所谓的高持久性（hip）突变体， 其群体比野生型菌株产生更高比例的持留细胞，并表征了 他们携带的髋关节突变增加了持续者的比例的分子机制。这些 突变体将使用一种新的基于过滤器的方法分离，该方法考虑了三个参数： 抗生素压力、抗生素浓度和确定时间--以揭示不同的持久性 机制等在第二种方法中，该项目旨在阐明无机多磷酸盐的作用 （poly（P））在分枝杆菌持久性中的作用。具体来说，该项目将测试假设聚（P）作为一个 一种分子开关，利用一组关键基因的基因敲除来控制进入和退出持久状态 poly（P）调节基因。最终，这个项目将有助于从分子水平上理解持久性， 结核分枝杆菌，这将推动针对持久性细胞的治疗努力。