M. tuberculosis genes required for pulmonary survival revealed by TraCS

TraCS 揭示肺存活所需的结核分枝杆菌基因

• 批准号: 8386090
• 负责人: MARY HONDALUS
• 金额: $ 7.43万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8386090
• 关键词: Aerosols; Alleles; Antibiotics; Antimycobacterial Agents; Antitubercular Agents; Bacillus (bacterium); Bacteria; Bacterial DNA; Base Sequence; Biological Models; Cavia; Cessation of life; Complement; Coupled; Deletion Mutation; Detection; Development; Disease; Dose; Drug Resistant Tuberculosis; Environment; Epidemic; Extreme drug resistant tuberculosis; Future; Genes; Genetic; Genome; Goals; Grant; Granuloma; Growth; HIV; Healthcare; Human; Hypoxia; Individual; Infection; Intervention; Libraries; Light; Lung; Maintenance; Methodology; Modeling; Mus; Mutation; Mutation Detection; Mycobacterium tuberculosis; Necrosis; Organism; Outcome; Outcome Study; Pathogenesis; Pathway interactions; Pharmaceutical Preparations; Phenotype; Physiology; Plague; Population; Public Health; Research; Research Project Grants; Resolution; Screening procedure; Sequence Analysis; Therapeutic; Therapeutic Intervention; Time; Tuberculosis; Tuberculosis Vaccines; Vaccines; Validation; Work; arm; attenuation; base; cohort; design; drug development; enzyme pathway; gene discovery; human disease; improved; in vivo; in vivo Model; killings; mouse model; mutant; mycobacterial; novel; pathogen; programs; resistant strain; therapeutic development; vaccine development

DESCRIPTION (provided by applicant): Tuberculosis (TB), caused by infection with Mycobacterium tuberculosis (Mtb) is one of the world's leading public health concerns, responsible for the deaths of more than 2 million people annually. The concurrent HIV epidemic coupled with the emergence of extensively drug resistant strains of Mtb have greatly amplified the impact of M. tuberculosis infection and created a global healthcare crisis. One of the problems facing those tasked with treating tuberculosis is that even infections caused by drug susceptible Mtb strains require long-term treatment in part because the anti-mycobacterial agents used currently are inefficient at killing host adapted bacteria. The primary objective of this work is to identify Mtb genes essential for adaptation to survival in the lung particularly those not identified in earlier screening approaches. The premise is that the more known about the physiology of the organism during infection, the greater is the opportunity to design successful therapeutic interventions which target in vivo essential bacterial enzymes and pathways. This work employs a whole genome screen of an Mtb transposon mutant library administered via aerosol to guinea pigs. The guinea pig host reproduces many aspects of human tuberculosis including the necrotic, hypoxic granuloma not found in all model systems, for example the mouse. The proposal has two AIMS. AIM1 is to apply Transposon Capture and Sequencing or TraCS analysis to existing guinea pig infection derived libraries. TraCs is a robust and highly sensitive deep sequencing based methodology, which allows the detection of mutations in Mtb genes which render the bacilli incapable of survival in the pulmonary environment. The second AIM is a confirmatory analysis of the screen wherein individual deletion alleles will be constructed in two genes identified in the original screen. The in vivo phenotype of the deletion mutants will be examined in the low dose aerosol guinea pig and murine tuberculosis infection models, and results will be compared to those observed with infection of wild type and complemented mutant strains. The inclusion of a murine infection cohort allows interspecies comparison and validation of the potential exclusivity of the particular gene for maintenance of disease in the human-like pulmonary environment modeled by the guinea pig. Ultimately this work will contribute to the development of therapeutics which target pathways essential for bacilli survival in the host environment. PUBLIC HEALTH RELEVANCE: Tuberculosis, a disease caused by the bacterium Mycobacterium tuberculosis, has plagued mankind since the time of the pharaohs and is currently one of the most significant public health threats facing the world's population. This research is implemented to shed light on the genetic mechanisms used by the bacterium to survive in its host. An anticipated long-term outcome of this work is the design of improved therapeutics (antibiotics and vaccines) to disable the bacterial pathways identified as being essential to bacterial survival and disease development.

描述（由申请人提供）：结核病（TB）是由结核分枝杆菌（MTB）感染引起的，是世界上领先的公共卫生问题之一，导致每年超过200万人死亡。并发的HIV流行，以及MTB的广泛抗药性菌株的出现，大大扩大了结核分枝杆菌感染的影响，并造成了全球医疗危机。负责治疗结核病的人面临的问题之一是，即使是由药物易感的MTB菌株引起的感染也需要长期治疗，部分原因是目前使用的抗菌群剂在杀死宿主适应的细菌方面效率低下。这项工作的主要目的是确定适应在肺中生存至关重要的MTB基因，尤其是在较早筛查方法中未发现的MTB基因。前提是，关于感染过程中生物体生理的了解越多，就越有机会设计成功的治疗干预措施，这些干预措施以体内基本细菌酶和途径为目标。这项工作采用了通过气溶胶对豚鼠施用的MTB转座子突变库的整个基因组筛选。豚鼠宿主再现了人类结核病的许多方面，包括所有模型系统中未发现的坏死，低氧肉芽肿，例如小鼠。该提案有两个目标。 AIM1是将转座子捕获和测序或TRACS分析应用于现有的豚鼠感染衍生文库。 TRACS是一种基于强大且高度敏感的深层测序方法，它允许在MTB基因中检测突变，从而使杆菌在肺部环境中无法生存。第二个目的是对屏幕的验证性分析，其中单个缺失等位基因将以在原始屏幕中鉴定的两个基因构建。缺失突变体的体内表型将在低剂量的气溶胶豚鼠和鼠结核病感染模型中进行检查，并将结果与​​野生型和互补突变菌株感染的结果进行比较。包括鼠类感染队列的包含允许种间比较和验证特定的潜在排他性 用于维持疾病的基因在由豚鼠建模的人类肺部环境中。最终，这项工作将有助于开发治疗剂，这些疗法针对宿主环境中杆菌生存至关重要的途径。 公共卫生相关性：结核病是由细菌结核细菌引起的疾病，自法老王时代以来一直困扰着人类，目前是世界人口面临的最重要的公共卫生威胁之一。这项研究的实施是为了阐明细菌在其宿主中生存的遗传机制。这项工作的预期长期结果是设计改进的治疗疗法（抗生素和疫苗），以禁用被确定为细菌生存和疾病发育至关重要的细菌途径。