Leisenfelder Stacey A, Moffat Jennifer F
Department of Microbiology and Immunology, State University of New York-Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA.
J Virol. 2006 Jun;80(11):5577-87. doi: 10.1128/JVI.00163-06.
In its course of human infection, varicella-zoster virus (VZV) infects rarely dividing cells such as dermal fibroblasts, differentiated keratinocytes, mature T cells, and neurons, none of which are actively synthesizing DNA; however, VZV is able to productively infect them and use their machinery to replicate the viral genome. We hypothesized that VZV alters the intracellular environment to favor viral replication by dysregulating cell cycle proteins and kinases. Cyclin-dependent kinases (CDKs) and cyclins displayed a highly unusual profile in VZV-infected confluent fibroblasts: total amounts of CDK1, CDK2, cyclin B1, cyclin D3, and cyclin A protein increased, and kinase activities of CDK2, CDK4, and cyclin B1 were strongly and simultaneously induced. Cyclins B1 and D3 increased as early as 24 h after infection, concurrent with VZV protein synthesis. Confocal microscopy indicated that cyclin D3 overexpression was limited to areas of IE62 production, whereas cyclin B1 expression was irregular across the VZV plaque. Downstream substrates of CDKs, including pRb, p107, and GM130, did not show phosphorylation by immunoblotting, and p21 and p27 protein levels were increased following infection. Finally, although the complement of cyclin expression and high CDK activity indicated a progression through the S and G(2) phases of the cell cycle, DNA staining and flow cytometry indicated a possible G(1)/S blockade in infected cells. These data support earlier studies showing that pharmacological CDK inhibitors can inhibit VZV replication in cultured cells.
在人类感染水痘带状疱疹病毒（VZV）的过程中，该病毒很少感染处于分裂期的细胞，如真皮成纤维细胞、分化的角质形成细胞、成熟T细胞和神经元，这些细胞均不活跃地合成DNA；然而，VZV能够有效地感染它们并利用其机制来复制病毒基因组。我们推测，VZV通过失调细胞周期蛋白和激酶来改变细胞内环境，以利于病毒复制。在VZV感染的汇合成纤维细胞中，细胞周期蛋白依赖性激酶（CDK）和细胞周期蛋白呈现出非常不寻常的特征：CDK1、CDK2、细胞周期蛋白B1、细胞周期蛋白D3和细胞周期蛋白A的总量增加，同时CDK2、CDK4和细胞周期蛋白B1的激酶活性被强烈诱导。细胞周期蛋白B1和D3在感染后24小时就开始增加，与VZV蛋白合成同时发生。共聚焦显微镜检查表明，细胞周期蛋白D3的过表达仅限于IE62产生的区域，而细胞周期蛋白B1的表达在VZV蚀斑中不规则。CDK的下游底物，包括pRb、p107和GM130，通过免疫印迹未显示磷酸化，感染后p21和p27蛋白水平增加。最后，尽管细胞周期蛋白表达的补充和高CDK活性表明细胞周期通过S期和G2期进展，但DNA染色和流式细胞术表明感染细胞中可能存在G1/S期阻滞。这些数据支持了早期的研究，即药理学CDK抑制剂可以抑制VZV在培养细胞中的复制。
