IMMUNE CONTROL AND EVASION IN MURINE CMV INFECTION

描述（由申请方提供）：巨细胞病毒（CMV）编码多个 基因的功能是损害MHC 1类限制性抗原1呈递给 细胞毒性T淋巴细胞（CTL）。据推测，这些基因是 在启动子存在的情况下，使CMV在宿主中持续存在所必需的 免疫反应，但这还没有得到证实。此应用程序使用 小鼠巨细胞病毒感染其天然宿主（小鼠）的模型， 询问免疫逃避基因对MCMV感染过程的影响， 以及它们是如何达到这种效果的。一组突变病毒缺乏每一个 MCMV的免疫逃避基因- m4、m6和m152-单独和组合， 是利用细菌人工染色体技术产生的。这些将是 用于分析免疫逃避基因对CTL应答的影响，和 对病毒持久性和复制的后续影响。为了能够 为了研究CTL应答，H-2b识别的免疫显性MCMV抗原 将首先识别小鼠。包含整个MCMV的表达文库 已经产生了以短DNA片段表达的基因组，并将进行筛选 使用MCMV特异性CTL克隆来鉴定它们识别的抗原。MCMV 感染巨噬细胞和树突细胞以及上皮细胞和其他体细胞 体内细胞专职抗原呈递细胞的抗原呈递是 可能是CTL反应大小的主要决定因素，并且它具有 据报道，免疫逃避基因在免疫系统中不能有效地发挥作用。 巨噬细胞然而，数据表明，免疫逃避基因可能 在某些巨噬细胞中的功能在这里介绍。全面分析 免疫逃避基因在Kb和Db抗原提呈中的作用 原代巨噬细胞和树突状细胞将进行对比 在小鼠胚胎成纤维细胞中观察到这种效果。这些资料 解释小鼠中CTL应答和病毒载量的测量实验 感染野生型病毒和缺乏免疫逃避基因的病毒。

DESCRIPTION (provided by applicant): Cytomegaloviruses (CMVs) encode multiple genes that function to impair MHC class 1-restricted antigen 1 presentation to cytotoxic T lymphocytes (CTL). It has been assumed that these genes are necessary to enable CMV to persist in the host in the presence of a primed immune response, but this has not been demonstrated. This application uses the murine cytomegalovirus model of infection of its natural host (the mouse) to ask what effect the immune evasion genes have on the course of MCMV infection, and how they achieve this effect. A panel of mutant viruses lacking each of the immune evasion genes of MCMV- m4, m6 and m152-alone and in combination, has been generated using bacterial artificial chromosomes technology. These will be used to analyze the effect of the immune evasion genes on the CTL response, and the consequent effect on virus persistence and replication. In order to be able to study the CTL response, the immunodominant MCMV antigens recognized by H-2b mice will first be identified. An expression library containing the entire MCMV genome expressed in short DNA fragments has been generated and will be screened using MCMV-specific CTL clones to identify the antigens they recognize. MCMV infects macrophages and dendritic cells as well as epithelial and other somatic cells in vivo. Antigen presentation by professional antigen presenting cells is likely to be the major determinant of the size of the CTL response, and it has been reported that the immune evasion genes do not function effectively in macrophages. However, data suggesting that the immune evasion genes may function in some macrophages is presented here. A comprehensive analysis of the function of the immune evasion genes on antigen presentation by Kb and Db in primary macrophages and dendritic cells will be carried out and contrasted with the effect seen in mouse embryo fibroblasts. This information will be used to interpret experiments measuring the CTL response and virus load in mice infected with wildtype virus and viruses lacking immune evasion genes.