Identification of secreted proteins important for tularemia pathogenesis

描述（由申请人提供）：革兰氏阴性菌土拉菌弗朗西斯菌亚种。土拉菌是土拉菌病的病原体，被认为是一种潜在的危险生物武器。这是由于该生物通过气溶胶途径具有极强的传染性和土拉菌病的严重性。这种细菌的挑剔性质，要求使用生物安全三级（BSL3）容器来处理它，以及遗传工具的缺乏阻碍了对这种生物的研究。因此，与许多其他细菌病原体相比，对土拉菌亚种知之甚少。土拉菌的生理学、遗传学和发病机制。以前的研究使用了来自土拉菌亚种的减毒活疫苗（LVS）。或致病性较低的土拉菌亚种。novicida。本建议的目的是确定在毒力强的土拉菌亚种发病机制中重要的分泌蛋白。土拉杆菌内。我们将使用最近开发的遗传工具来识别和破坏编码分泌蛋白的基因，其直接目标是识别小鼠巨噬细胞细胞内存活和复制所需的蛋白质。我们预计这项工作将确定几个感兴趣的蛋白质，并将使我们能够为进一步的工作奠定基础。本申请中提出的工作将有助于NIAID生物防御研究议程的研究目标，如CDC A类药剂，如土拉菌弗朗西斯菌。这些近期目标包括：1)遗传系统的发展，将致病机制和毒力的差异联系起来；2)增加了土菌病研究的专业知识多样性。

DESCRIPTION (provided by applicant): The Gram-negative bacterium Francisella tularensis subsp. tularensis, the causative agent of tularemia, is considered a potentially dangerous biological weapon. This is due to the organism's extreme infectivity via the aerosol route and the severity of tularemia. The fastidious nature of the bacterium, the requirement that it be handled using biosafety level three (BSL3) containment, and the paucity of genetic tools have hindered research on this organism. Thus, compared to many other bacterial pathogens, little is known about F. tularensis subsp. tularensis physiology, genetics, and pathogenesis. Previous studies have used the attenuated live vaccine strain (LVS) derived from F. tularensis subsp. holarctica, or the rarely pathogenic F. tularensis subsp. novicida. The goal of this proposal is to identify secreted proteins that are important in the pathogenesis of the virulent F. tularensis subsp. tularensis. We will use recently developed genetic tools to identify and disrupt genes encoding secreted proteins with the immediate goal of identifying proteins required for intracellular survival and replication in mouse macrophages. We anticipate that this work will identify several proteins of interest and will allow us to formulate hypotheses for the basis of further work. The work proposed in this application would contribute to the research goals of the NIAID biodefense research agenda for CDC category A agents such as Francisella tularensis. These immediate goals include; 1) the development of genetic systems to correlate differences in pathogenesis and virulence and 2) increased diversity of expertise in the study of tularemia. The research in this proposal will provide additional genetic methods for the study of F. tularensis biology and identify factors important for the pathogenesis of tularemia disease. This work may also contribute to better diagnostics, vaccine and drug development. Because of F. tularensis is a select agent and could be used a biological weapon, this research could potentially have a significant impact on public health in the future.