Identity, function and control of Francisella effectors encoded outside its pathogenicity island

弗朗西斯菌致病岛外编码的效应子的身份、功能和控制

基本信息

批准号：
10187513
负责人：
SIMON L DOVE
金额：
$ 68.87万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-01 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10187513
关键词：
1-Phosphatidylinositol 3-Kinase Aerosols Aggressive course Animals Bacteria Biochemical Bioinformatics Biology Cell membrane Cells Data Disease Distal Distant Dose Elements Enzymes Family Francisella Francisella tularensis Gene Expression Genes Genetic Genetic Screening Genome Gram-Negative Bacteria Growth Human Infection Lead Legionella Life Style Link Location Manuscripts Mediating Modeling Molecular Mutagenesis Names Organism Paper Pathogenesis Pathogenicity Pathogenicity Island Pathway interactions Phosphatidylinositols Phosphotransferases Play Protein Secretion Proteins Publishing Regulation Reporting Research Research Personnel Rickettsia Role Route System Testing Tularemia Variant Vesicle Vibrio Virulence Virulence Factors Virulent Work experimental study fitness guided inquiry human pathogen in vivo insight member pathogen pathogenic bacteria phosphatidylinositol 3-phosphate promoter protein function response screening trafficking

项目摘要

Summary The Francisella constitute a genus of Gram-negative bacteria that occupy intracellular niches within a wide range of metazoan hosts. This group includes Francisella tularensis subsp. tularensis, a highly virulent human pathogen that has been classified as a Tier 1 select agent due to its low infectious dose, aerosol route of inoculation, and aggressive course of infection. Several studies have suggested that the key virulence factor of these bacteria is the Francisella pathogenicity island (FPI), which encodes a variant of the bacterial type VI secretion system (T6SS). However, the FPI is conserved among Francisella spp with diverse host ranges and variable capacity to cause disease. In preliminary data accompanying this proposal, we demonstrate that genes encoding substrate effector proteins of the FPI T6SS can be found at distal locations in the genome. We further find that although these effectors are variably present in Francisella spp, they play important, direct roles in promoting the virulence strategies of the bacteria that harbor them. These findings lead us to hypothesize that the FPI-encoded T6SS serves as a versatile platform for the delivery of diverse effector molecules encoded elsewhere within the genome. In our first aim we will define the molecular mechanism by which one T6SS effector of F. tularensis, OpiA, facilitates intracellular replication. Importantly, the mode of action of an FPI effector protein has not been identified to date. We show herein that OpiA is the founding member of a family of bacterial phosphatidylinositol kinases with representatives in diverse pathogens including Vibrio, Legionella, and Rickettsia spp. These data and additional preliminary findings suggest that OpiA acts by manipulating host cell membrane trafficking. In our second aim, we seek to identify the proteins required for targeting effectors to the T6SS in Francisella, as well as to define the mechanism by which the secretory apparatus and its substrates are coordinately regulated. Finally, in the third aim we propose to identify additional substrates of FPI-encoded T6SSs belonging to multiple F. tularensis subspecies and to characterize their contribution to the pathogenesis of F. tularensis subsp. tularensis. Collectively, the proposed research will provide insight into the virulence mechanisms of an important group of human and animal pathogens.

概括 Francisella构成了革兰氏阴性细菌的属，该属属于宽阔的细胞内壁细菌多宗宿主范围。该组包括francisella tularensis subsp。 Tularensis，高度毒性的人由于其低传染剂量，气溶胶途径接种，感染的积极进程。几项研究表明，这些细菌是Francisella致病岛（FPI），它编码细菌型VI的变体分泌系统（T6SS）。但是，FPI在Francisella spp中保存，宿主范围各不相同引起疾病的可变能力。在此提案随附的初步数据中，我们证明了这一点编码FPI T6S的底物效应蛋白的基因可以在基因组的远端位置找到。我们进一步发现，尽管这些效应子在Francisella spp中都有多样化，但它们发挥着重要的，直接的在促进藏有细菌的毒力策略中的作用。这些发现使我们进入假设FPI编码的T6Ss是提供不同效应器的多功能平台分子在基因组中其他地方编码。在我们的第一个目标中，我们将通过这是F. toarlensis，Opia的T6SS效应子，可促进细胞内复制。重要的是，迄今为止尚未确定FPI效应蛋白的作用。我们在这里表明Opia是创始细菌磷脂酰肌醇激酶的一家族成员，具有多种病原体的代表包括Vibrio，Legionella和Rickettsia spp。这些数据和其他初步发现表明 OPIA通过操纵宿主细胞膜贩运来行动。在我们的第二个目标中，我们试图识别蛋白质将效应子靶向Francisella中的T6S，以及定义的机制分泌仪及其底物进行协调。最后，在第三个目标中，我们建议确定属于多个F. tularensis亚种的FPI编码的T6SS的其他底物和表征了它们对f。tularensissubsp的发病机理的贡献。 tularensis。共同提议研究将提供对重要人类和动物群体的毒力机制的见解病原体。