Preston C M, Harman A N, Nicholl M J
Medical Research Council Virology Unit, Glasgow G11 5JR, Scotland.
J Virol. 2001 Oct;75(19):8909-16. doi: 10.1128/JVI.75.19.8909-8916.2001.
Activation of cellular interferon-stimulated genes (ISGs) after infection with herpes simplex virus type 1 (HSV-1) or human cytomegalovirus (HCMV) was investigated. The level of ISG54-specific RNA in human fetal lung (HFL) or human foreskin (BJ) fibroblasts increased substantially after infection with either virus in the presence of cycloheximide. HSV-1 particles lacking glycoprotein D or glycoprotein H failed to induce ISG54-specific RNA synthesis, demonstrating that entry of virus particles rather than binding of virions to the cell surface was required for the effect. A DNA-binding complex that recognized an interferon-responsive sequence motif was induced upon infection with HSV-1 or HCMV in the presence of cycloheximide, and the complex was shown to contain the cell proteins interferon response factor 3 (IRF-3) and CREB-binding protein. IRF-3 was modified after infection with HSV-1 or HCMV to a form of lower electrophoretic mobility, consistent with phosphorylation. De novo transcription of viral or cellular genes was not required for the activation of IRF-3, since the effect was not sensitive to inhibition by actinomycin D. Infection of HFL fibroblasts with HSV-1 under conditions in which viral replication proceeded normally resulted in severely reduced levels of the IRF-3-containing complex, defining the activation of IRF-3 as a target for viral interference with ISG induction. In BJ fibroblasts, however, significant activation of IRF-3 was detected even when the viral gene expression program progressed to later stages, demonstrating that the degree of inhibition of the response was dependent on host cell type. As a consequence of IRF-3 activation, endogenous interferon was released from BJ cells and was capable of triggering the appropriate signal transduction pathway in both infected and uninfected cells. Activation of ISG54-specific RNA synthesis was not detected after infection of human U-373MG glioblastoma cells, showing that the induction of the response by infection is cell type dependent.
研究了1型单纯疱疹病毒（HSV-1）或人巨细胞病毒（HCMV）感染后细胞干扰素刺激基因（ISG）的激活情况。在存在放线菌酮的情况下，用任何一种病毒感染人胎儿肺（HFL）或人包皮（BJ）成纤维细胞后，ISG54特异性RNA的水平显著增加。缺乏糖蛋白D或糖蛋白H的HSV-1颗粒未能诱导ISG54特异性RNA合成，表明病毒颗粒的进入而非病毒体与细胞表面的结合是产生该效应所必需的。在存在放线菌酮的情况下，用HSV-1或HCMV感染可诱导一种识别干扰素反应序列基序的DNA结合复合物，并且该复合物显示含有细胞蛋白干扰素反应因子3（IRF-3）和CREB结合蛋白。感染HSV-1或HCMV后，IRF-3被修饰为电泳迁移率较低的形式，这与磷酸化一致。IRF-3的激活不需要病毒或细胞基因的从头转录，因为该效应不受放线菌素D抑制的影响。在病毒复制正常进行的条件下，用HSV-1感染HFL成纤维细胞会导致含IRF-3复合物的水平严重降低，这将IRF-3的激活定义为病毒干扰ISG诱导的一个靶点。然而，在BJ成纤维细胞中，即使病毒基因表达程序进展到后期阶段，也检测到IRF-3的显著激活，表明反应的抑制程度取决于宿主细胞类型。作为IRF-3激活的结果，内源性干扰素从BJ细胞中释放出来，并且能够在感染和未感染的细胞中触发适当的信号转导途径。在人U-373MG胶质母细胞瘤细胞感染后未检测到ISG54特异性RNA合成的激活，表明感染诱导的反应是细胞类型依赖性的。
