The Role of Cell Wall Lipids in Pathogenesis of Rifampin-Resistant TB

细胞壁脂质在利福平耐药结核病发病机制中的作用

基本信息

批准号：
8547236
负责人：
Petros C Karakousis
金额：
$ 20万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-08-19 至 2016-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8547236
关键词：
Actinobacteria class Acute Anabolism Animal Model Attenuated Baltimore Biological Assay C3HeB/FeJ Mouse Cell Wall China Clinical Collaborations Country DNA Sequence DNA-Directed RNA Polymerase Data Defect Development Drug Targeting Environment Exhibits Gene Activation Gene Cluster Gene Mutation Genes Genetic Goals Growth Histologic Human Image Imaging Techniques In Vitro Individual Infection Laboratories Lesion Lipids Liquid Chromatography Lung Lung Inflammation Mediating Metabolic Metabolic Pathway Methods Microbiology Missense Mutation Molecular Target Morphology Multidrug-Resistant Tuberculosis Mus Mutation Mycobacterium tuberculosis Necrosis Nutrient Operon Organism Other Genetics PET/CT scan Parents Pathogenesis Pathway interactions Permeability Pharmaceutical Preparations Polymerase Gene Pulmonary Tuberculosis Relative (related person)Research Personnel Resistance Reverse Transcriptase Polymerase Chain Reaction Rifampicin resistance Rifampin Role Scanning Transmission Electron Microscopy Procedures Simulate Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization Techniques Testing Thick Thin Layer Chromatography Time Universities Virulence Virulence Factors Work base clinically relevant cost cytokine experience fitness innovation interdisciplinary approach isoniazid laser capture microdissection liquid chromatography mass spectrometry macrophage medical schools mouse model mutant novel pathogen polyketide synthase protein expression public health relevance resistant strain tandem mass spectrometry treatment duration tuberculosis treatment

项目摘要

DESCRIPTION (provided by applicant): Multidrug-resistant tuberculosis (MDR-TB), defined as Mycobacterium tuberculosis (Mtb) resistant to the two first-line drugs isoniazid and rifampin, has emerged as a major threat to global TB control. The situation is particularly acute in China, which is one of 27 high-burden MDR-TB countries. In >95% of clinical MDR-TB isolates, rifampin resistance is mediated by mutations in a relatively short segment of the rpoB gene, which encodes the molecular target of rifampin. Although laboratory-derived mutants with a variety of different rpoB gene mutations show slower growth under nutrient-rich conditions, Mtb clinical strains isolated from individuals with TB who developed rifampin resistance during treatment show normal growth compared to their rifampin-susceptible counterparts, despite harboring the same mutation as some of the laboratory-derived strains. Recently, we have found evidence that a known lipid virulence factor, phthiocerol dimycocerosate (PDIM), accumulates in the cell wall of rifampin-resistant TB organisms. Studies using laboratory-generated double mutant strains revealed that PDIM is required for the normal survival of rifampin-resistant strains in activated mouse macrophages. The central hypothesis of this proposal is that the induction of pathways involved in biosynthesis and transport of cell wall-associated lipid virulence factors is a compensatory metabolic adaptation, which serves to enhance the virulence of rifampin-resistant clinical isolates in the infected host. This proposal represents a unique collaboration between investigators at Jiao Tong University School of Medicine in Shanghai, China and Johns Hopkins University School of Medicine in Baltimore, U.S.A. Using a multidisciplinary approach, including the use of a novel mouse model, which develops TB lung lesions resembling their human counterparts, in combination with transcriptional, lipidomic, genetic, and imaging techniques, we will investigate whether PDIM accumulation compensates for the fitness cost associated with Mtb rpoB mutation during host infection. Our data are expected to yield novel drug targets, with the ultimate goal of shortening the duration of MDR-TB treatment in China and worldwide.

描述（由申请人提供）：耐多药结核病（MDR-TB），定义为对两种一线药物异烟肼和利福平具有耐药性的结核分枝杆菌（Mtb），已成为全球结核病控制的主要威胁。作为27个耐多药结核病高负担国家之一的中国，情况尤其严重。在 > 95% 的临床耐多药结核菌株中，利福平耐药性是由 rpoB 基因相对较短的片段突变介导的，该基因编码利福平的分子靶点。尽管实验室衍生的具有多种不同 rpoB 基因突变的突变体在营养丰富的条件下显示出较慢的生长速度，但从治疗期间出现利福平耐药的结核病患者中分离出的 Mtb 临床菌株与利福平敏感菌株相比，显示出正常的生长，尽管具有与一些实验室衍生菌株相同的突变。最近，我们发现有证据表明，一种已知的脂质毒力因子，phthiocerol dimycocerosate (PDIM)，在利福平耐药结核菌的细胞壁中积累。使用实验室产生的双突变菌株的研究表明，PDIM 是利福平耐药菌株在活化的小鼠巨噬细胞中正常生存所必需的。该提议的中心假设是，细胞壁相关脂质毒力因子生物合成和运输相关途径的诱导是一种代偿性代谢适应，有助于增强感染宿主中利福平耐药临床分离株的毒力。该提案代表了中国上海交通大学医学院和美国巴尔的摩约翰霍普金斯大学医学院的研究人员之间的独特合作，采用多学科方法，包括使用一种新型小鼠模型，该模型可产生类似于结核病肺部病变的模型。与人类对应物结合转录、脂质组学、遗传和成像技术，我们将研究 PDIM 积累是否可以补偿宿主感染期间与 Mtb rpoB 突变相关的适应性成本。我们的数据预计将产生新的药物靶点，最终目标是缩短中国和全球耐多药结核病的治疗时间。