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）： 由结核分枝杆菌（Mtb）感染引起的结核病（TB）是世界上主要的公共卫生问题之一，每年造成超过200万人死亡。同时发生的HIV流行加上广泛耐药的结核分枝杆菌菌株的出现，极大地扩大了结核分枝杆菌的影响。结核病感染，造成全球医疗危机。那些负责治疗结核病的人面临的问题之一是，即使是由药物敏感的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分枝杆菌剂在杀死宿主适应性细菌方面效率低下。这项工作的主要目的是确定结核分枝杆菌基因的适应生存在肺，特别是那些没有确定在早期的筛选方法。前提是对感染期间生物体的生理学了解得越多，设计靶向体内必需细菌酶和途径的成功治疗干预的机会就越大。这项工作采用通过气溶胶对豚鼠进行Mtb转座子突变库的全基因组筛选。豚鼠宿主复制人结核病的许多方面，包括在所有模型系统（例如小鼠）中未发现的坏死性缺氧肉芽肿。该提案有两个目标。AIM 1将转座子捕获和测序或TraCS分析应用于现有豚鼠感染源文库。TraCs是一种稳健且高度灵敏的基于深度测序的方法，其允许检测Mtb基因中的突变，所述突变使得杆菌不能在肺环境中存活。第二个AIM是筛选的验证性分析，其中将在原始筛选中鉴定的两个基因中构建单个缺失等位基因。将在低剂量气溶胶豚鼠和小鼠结核病感染模型中检查缺失突变体的体内表型，并将结果与野生型和补充突变菌株感染时观察到的结果进行比较。包括鼠感染队列允许种间比较和验证特定感染的潜在排他性。 在豚鼠模拟的类人肺环境中维持疾病的基因。最终，这项工作将有助于开发针对宿主环境中杆菌生存所必需的途径的治疗方法。 公共卫生相关性：结核病是一种由结核分枝杆菌引起的疾病，自法老时代以来一直困扰着人类，目前是世界人口面临的最严重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所使用的遗传机制。这项工作的一个预期的长期成果是设计改进的治疗方法（抗生素和疫苗），以禁用被确定为对细菌生存和疾病发展至关重要的细菌途径。