Stepwise adaptation of murine cytomegalovirus to cells of a foreign host for identification of host range determinants
Stepwise adaptation of murine cytomegalovirus to cells of a foreign host for identification of host range determinants
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DOI：
10.1007/s00430-015-0400-7
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发表时间：
2015-03
影响因子：
5.4
通讯作者：
E. Ostermann;Kerstin Pawletko;D. Indenbirken;U. Schumacher;W. Brune
中科院分区：
文献类型：
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作者：
E. Ostermann;Kerstin Pawletko;D. Indenbirken;U. Schumacher;W. Brune
自从60年前首次分离出巨细胞病毒以来，人们就认为巨细胞病毒具有高度的物种特异性。它们只在自身或近亲宿主的细胞中复制，而系统发育较远的宿主的细胞通常不允许病毒复制。例如，人类巨细胞病毒可以在人类和黑猩猩的成纤维细胞中复制，但不能在啮齿动物细胞中复制；小鼠巨细胞病毒（MCMV）可以在小鼠和大鼠细胞中复制，但不能在灵长类动物细胞中复制。然而，决定巨细胞病毒宿主范围狭窄的病毒和细胞因素在很大程度上仍然未知。我们发现MCMV可以逐步适应在培养的人视网膜色素上皮细胞（RPE-1）和人成纤维细胞中复制。用于初始适应步骤的人RPE-1细胞在巨细胞病毒感染后表现出明显的接触抑制，并产生非常低水平的干扰素-β转录物，这表明这些细胞为适应提供了特别有利的环境。通过对几个适应突变体的230 kbp病毒基因组进行全基因组测序，检测到有限数量的突变。比较几种人类细胞适应的MCMV克隆和通过位点定向诱变将特异性突变引入野生型MCMV基因组，可以鉴定病毒宿主范围决定因素，并为阐明巨细胞病毒宿主物种特异性的分子基础提供基础。
Ever since their first isolation 60 years ago, cytomegaloviruses have been recognized as being highly species specific. They replicate only in cells of their own or a closely related host species, while cells of phylogenetically more distant hosts are usually not permissive for viral replication. For instance, human cytomegalovirus replicates in human and chimpanzee fibroblasts but not in rodent cells, and murine cytomegalovirus (MCMV) replicates in cells of mice and rats but not in primate cells. However, the viral and cellular factors determining the narrow host range of cytomegaloviruses have remained largely unknown. We show that MCMV can be adapted stepwise to replicate in cultured human retinal pigment epithelial (RPE-1) cells and human fibroblasts. The human RPE-1 cells used for the initial adaptation step showed a pronounced contact inhibition and produced very low level of interferon-β transcripts upon cytomegalovirus infection, suggesting that these cells provide a particularly favorable environment for adaptation. By whole genome sequencing of the 230 kbp viral genomes of several adapted mutants, a limited number of mutations were detected. Comparison of several human cell-adapted MCMV clones and introduction of specific mutations into the wild-type MCMV genome by site-directed mutagenesis allows for the identification of viral host range determinants and provides the basis for elucidating the molecular basis of the cytomegalovirus host species specificity.