IMMUNE CONTROL AND EVASION IN MURINE CMV INFECTION

描述(申请人提供)：巨细胞病毒(CMV)编码多个 影响MHC-1限制性抗原-1呈递功能的基因 细胞毒性T淋巴细胞(CTL)。据推测，这些基因是 使CMV能够在有PRIMED存在的情况下在宿主中持续存在所必需的 免疫反应，但这一点尚未得到证实。此应用程序使用 小鼠巨细胞病毒模型感染其自然宿主(小鼠) 问免疫逃避基因在MCMV感染过程中有什么作用， 以及他们是如何达到这种效果的。一组突变病毒缺乏每一种 MCMV-M4、M6和M152的免疫逃避基因-单独和组合，有 是使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反应的影响，以及 对病毒持久性和复制的后续影响。为了能够 为了研究H-2b识别的免疫优势MCMV抗原的CTL反应 老鼠将首先被识别。包含整个MCMV的表达文库 以短DNA片段表达的基因组已经产生并将进行筛选 使用MCMV特异性CTL克隆来鉴定它们识别的抗原。小鼠巨细胞病毒 感染巨噬细胞和树突状细胞以及上皮细胞和其他体细胞 体内的细胞。由专业抗原提呈细胞提呈的抗原是 很可能是CTL反应大小的主要决定因素，而且它已经 据报道，免疫逃避基因在 巨噬细胞。然而，数据表明免疫逃避基因可能 这里介绍了一些巨噬细胞的功能。一项全面的分析 免疫逃避基因在Kb和Db提呈抗原中的作用 将进行原代巨噬细胞和树突状细胞的对比 与在小鼠胚胎成纤维细胞中看到的效果相同。此信息将用于 解释测定小鼠CTL应答和病毒载量的实验 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.