EVASION OF ANTIGEN PRESENTATION BY VACUOLAR PATHOGENS

描述（改编自申请人的摘要）：其中最具破坏性的 感染人类的病原体是可以在内吞细胞内复制的细菌， 限制与溶酶体融合的空泡。居住在一个不退化的 空泡会严重削弱细菌决定簇在MHC上的呈递 I类和II类分子。然而，很明显，细胞介导的 适应性免疫应答在宿主防御这些疾病中起着关键作用。 传染源这个项目的目的是解决如何适应 产生针对微生物病原体的反应，该微生物病原体应该具有 通过抗原呈递限制免疫原性表位呈递的能力 细胞所描述的方法使用细菌病原体军团菌 作为一种生物学工具，以确定什么样的影响抑制 吞噬体/溶酶体融合对受感染宿主的能力有影响， 抗原特异性免疫反应。已经建立了系统来调查 体外宿主免疫监视。等基因L.嗜肺菌株已经被 构建的基因中有确定的功能丧失突变， 用于抑制吞噬体/溶酶体融合。分离骨的程序 来自许可小鼠宿主的骨髓源性巨噬细胞和树突状细胞 已经建立。测定L. 嗜肺细胞特异性MHC I类和II类限制性表位 已经开发出专职抗原呈递细胞。这些试剂和 分析将被用来系统地解决是否居住在一个 非降解性液泡提供病原体保护，使其免受抗原处理 并在被巨噬细胞和树突细胞摄取后呈递。 将进行实验，以确定是否居住在一个 非降解性液泡提供病原体保护，使其免受抗原处理 并在被巨噬细胞和树突细胞摄取后呈递。 将进行实验，以确定是否在体外获得的结果， 与体内宿主反应相关。这将通过测量 使用MHC的小鼠感染模型中的抗原特异性T细胞应答 II类四聚体标记。这些实验将提供独特的见解， 驻留在非降解液泡中是否能提供一定程度的保护， 一种来自宿主免疫监视的空泡病原体这些信息应该会有所帮助 指导未来的研究，旨在确定最佳的抗原和交付 用于刺激针对多种免疫缺陷病毒的保护性T细胞免疫的系统， 空泡病原体

DESCRIPTION (Adapted from Applicant's Abstract): Among the most devastating pathogens to infect man are bacteria that can replicate within endocytic vacuoles that restrict fusion with lysosomes. Residence in a non-degradative vacuole should severely diminish presentation of bacterial determinants on MHC class I and class II molecules. It is apparent, however, that cell-mediated adaptive immune responses play a pivotal role in host-defense against these infectious agents. The aim of this project is to resolve how an adaptive response is generated against a microbial pathogen that should have the capacity to restrict presentation of immunogenic epitopes by antigen presenting cells. The described approaches use the bacterial pathogen Legionella pneumophila as a biological tool to determine what effect inhibition of phagosome lysosome fusion has on the ability of an infected host to mount an antigen-specific immune response. Systems have been established to investigate host immune surveillance in vitro. Isogenic L. pneumophila strains have been constructed with defined loss-of-function mutations in genes that are essential for inhibition of phagosome lysosome fusion. Procedures to isolate bone marrow-derived macrophages and dendritic cells from permissive murine hosts have been established. Assays to measure presentation of L. pneumophila-specific MHC class I and class II-restricted epitopes by these professional antigen presenting cells have been developed. These reagents and assays will be used to systematically address whether residence in a non-degradative vacuole affords a pathogen protection from antigen processing and presentation following uptake into macrophages and dendritic cells. Experiments will be conducted to determine whether residence in a non-degradative vacuole affords a pathogen protection from antigen processing and presentation following uptake into macrophages and dendritic cells. Experiments will be conducted to determine whether findings obtained in vitro correlate with in vivo host responses. This will be done by measuring antigen-specific T cell responses in a murine model of infection using MHC class II tetramer labeling. These experiments will provide unique insight on whether residence in a non-degradative vacuole offers a degree of protection to a vacuolar pathogen from host immune surveillance. This information should help guide future research aimed at identifying the best antigens and delivery systems for stimulating protective T cell immunity against a variety of vacuolar pathogens.