Characterization of F. tularensis Virulence Genes

土拉弗朗西斯毒力基因的表征

• 批准号: 6912409
• 负责人: Karl E Klose
• 金额: $ 22.64万
• 依托单位: UNIVERSITY OF TEXAS SAN ANTONIO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6912409
• 关键词: Francisella tularensis; bacterial genetics; bacterial vaccines; biotechnology; bioterrorism /chemical warfare; functional /structural genomics; gene expression profiling; genetic mapping; genetic regulatory element; genetic screening; host organism interaction; laboratory mouse; microarray technology; molecular cloning; pathologic process; polymerase chain reaction; transcription factor; vaccine development; virulence

DESCRIPTION (provided by applicant): Francisella tularensis is considered a Category A bioweapon due to the ease of transmission, the low infectious dose and high mortality associated with pneumonic tularemia, and the fact that it has been intensively studied and developed in bioweapons programs in several countries. Virtually nothing is known about virulence of aerosolized forms of the most likely bioweapon, F. tularensis subsp. tularensis. The focus of this research effort is to identify all the essential and virulence genes of F. tularensis subsp. tularensis through a genomics based approach. This will dramatically increase our understanding of F. tularensis pathogenesis, and facilitate the development of subunit and live-attenuated vaccines. First, we will utilize a genomics based technique termed GAMBIT to mutagenize every gene of F. tularensis subsp. tularensis, and then recombine them back onto the chromosome. This will allow for the identification of essential genes, which are potential therapeutic targets. The viable mutant bacteria will be combined in pools and inoculated via aerosol into mice, and those mutants that cannot survive within the host will be identified by a microarray-based technique. This technique will identify all genes important for F. tularensis virulence via the aerosol route, some of which may be potential subunit vaccine candidates. Next, the attenuated F. tularensis subsp. tularensis strains will be tested for markers of virulence: ability for intramacrophage survival and growth, resistance to antimicrobial compounds, and ability to invade nonphagocytic cells. This will allow for the identification and characterization of critical virulence determinants of F. tularensis. Finally, we will characterize the virulence regulatory factors identified by microarray analysis of transcription, including the transcriptional activator MgIA, which should illuminate virulence regulons within Francisella, allowing a better understanding of the molecular mechanisms of pathogenesis. Our research plan involves a multidisciplinary approach and high levels of integration with the other projects that compose this program project. Our combined expertise will propel our knowledge of F. tularensis pathogenesis and immunity and allow for the development of novel therapeutic and preventive measures.

描述（由申请人提供）：土拉热弗朗西丝菌被认为是A类生物武器，因为它易于传播，与肺炎土拉菌病相关的感染剂量低，死亡率高，并且在几个国家的生物武器计划中已经进行了深入研究和开发。事实上，我们对最有可能的生物武器F.土拉热亚种土拉热。本研究的重点是鉴定F.土拉热亚种tularensis通过基因组学为基础的方法。这将大大增加我们对F的理解。土拉热病的发病机制，并促进亚单位和减毒活疫苗的发展。首先，我们将利用基因组学技术GAMBIT对F.土拉热亚种tularensis，然后将它们重新组合到染色体上。这将允许鉴定作为潜在治疗靶点的必需基因。将活的突变细菌合并在池中，并通过气溶胶接种到小鼠体内，并鉴定那些不能在宿主体内存活的突变体 通过微阵列技术。该技术将鉴定所有对F. tularensis 毒力通过气溶胶途径，其中一些可能是潜在的亚单位疫苗候选者。其次，研究了衰减F.土拉热亚种将测试土拉菌菌株的毒力标志物：巨噬细胞内存活和生长的能力、抗微生物化合物的抗性和侵入非吞噬细胞的能力。这将有助于识别和表征F.的关键毒力决定因素。土拉热。最后，我们将表征的毒力调控因子的微阵列分析的转录，包括转录激活剂MgIA，这应该照亮毒力调节内弗朗西斯菌，允许更好地了解致病的分子机制。我们的研究计划涉及多学科方法和与组成该计划项目的其他项目的高度整合。我们的综合专业知识将推动我们对F。土拉热病的发病机理和免疫，并允许开发新的治疗和预防措施。