EVASION OF MACROPHAGE LYSOSOMES BY L PNEUMOPHILA

（改编自申请人摘要）被巨噬细胞摄取后， 膜结合嗜肺军团菌逃避融合 溶酶体，与内质网，并复制到高 号码 因此，嗜肺军团菌与分枝杆菌， 弓形虫，衣原体和相关的艾滋病毒的能力，以破坏一个 对体液免疫和细胞免疫都起重要作用宿主细胞。 因此，对控制细菌的宿主和细菌因素的了解， 嗜肺军团菌细胞内命运可能提示新的治疗方法 各种人类疾病的治疗方法。 这项工作的目标是 为了了解嗜肺军团菌吞噬体如何避免与 溶酶体 L.嗜肺细胞因子是细胞内 生存将通过两个基因和分子分析来确定， 先前表征的在溶酶体中降解的突变体。 这些突变体鉴定的基因座将通过遗传学方法分离。 补充其细胞内生长缺陷。 克隆的 基因将用于确定互补组的数量 通过突变体鉴定，构建非极性无效等位基因，并 确定每个基因座的预测氨基酸序列。细菌 逃避溶酶体所需的因素也将通过一个 功能获得的补充策略。 巨噬 A/J小鼠骨髓细胞递送L.嗜肺菌转化为溶酶体， 细菌被杀死。 安湖嗜肺菌 pneumophila的分子生物学特性和生化特性。 逃避溶酶体所需的嗜肺因子应 阐明控制吞噬体命运的细胞机制。 为了深入了解L.来颠覆 内吞途径，细菌吞噬体的组成。 将不同成熟阶段与吞噬体进行比较， 遵循更传统的路径。 以确定是否 L.嗜肺菌吞噬体以囊泡形式存在， 介导的膜成分的再循环，标记的 质膜蛋白和磷脂双层将被跟踪 显微镜下。 这项研究将作为未来的基础 分析宿主和细菌之间的相互作用， 巨噬细胞中吞噬体的命运

(Adapted from the applicant's abstract) After uptake by macrophages, membrane-bounded Legionella pneumophila evade fusion with lysosomes, associated with endoplasmic reticulum, and replicate to high numbers. Thus, L.pneumophila shares with Mycobacterial, Toxoplasma, Chlamydia and associate HIV the capacity to subvert a host cell that is central to both humoral and cell-mediated immunity. Therefore, knowledge of the host and bacterial factors that govern the intracellular fate of L.pneumopila will likely suggest novel therapeutic approaches to a variety of human diseases. The goal of this work is to understand how L.pneumophila phagosomes avoid fusion with lysosomes. L. pneumophila factors that are required for intracellular survival will be identified by genetic and molecular analysis of two previously characterized mutants that are degraded in the lysosomes. The loci identified by these mutants will be isolated by genetic complementation of their intracellular growth defects. The cloned genes will be used to determine the number of complementation groups identified by the mutants, to construct non-polar null alleles, and to determine the predicted amino acid sequence of each locus. Bacterial factors required for evasion of lysosomes will also be sought by a complementary gain-of - function strategy. Macrophages derived from A/J mouse bone marrow cells deliver L. pneumophila to lysosomes, and the bacterial are killed. An L. pneumophila genomic L. pneumophila molecular, and biochemical characterization of the L. pneumophila factors required for evasion of he lysosomes should elucidate the cellular mechanisms that govern the fate of phagosomes. To gain insight to the strategy used by L. pneumophila to subvert the endocytic pathway, the composition of bacterial phagosomes at different stages of maturation will be compared to the phagosomes that follow the more conventional pathway. To determine whether biogenesis of the L. pneumophila phagosome occurs by vesicle- mediated recycling of membrane components, the fate of labeled plasma membrane proteins and phospholipid bilayers will be followed microscopically. This study will serve as a foundation for future analysis of the interactions between host and bacterial that determine the fate of phagosomes in macrophages.