Efficient activation of viral genomes by levels of herpes simplex virus ICP0 insufficient to affect cellular gene expression or cell survival
Efficient activation of viral genomes by levels of herpes simplex virus ICP0 insufficient to affect cellular gene expression or cell survival
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DOI：
10.1128/jvi.75.7.3391-3403.2001
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发表时间：
2001-04-01
影响因子：
5.4
通讯作者：
DeLuca, NA
中科院分区：
文献类型：
--
作者：
Hobbs, WE;Brough, DE;DeLuca, NA
单纯疱疹病毒（HSV）ICP 0可以有效地激活基因表达，否则沉默的启动子上持续存在的病毒基因组。然而，如来自ICP 4（-）HSV 1型（HSV-1）载体的高水平ICP 0的表达导致显著的毒性。我们已经分析了从E1（-）E4（-）腺病毒载体（AdS.11E4ICP0）表达ICP 0的结果，其中ICP 0表达由内源性腺病毒E4启动子控制。在该系统中，ICP 0的表达水平相对于HSV-1载体的表达水平降低超过1，000倍。通过基因表达阵列分析比较HSV和腺病毒载体菌株的作用，评估了这种低水平的ICP 0不影响细胞分裂或极大地扰乱细胞代谢。然而，如通过早幼粒细胞白血病免疫荧光所测量的，该量的ICP 0足以定量破坏ND 10结构。腺病毒表达的ICP 0水平足以激活静止的病毒基因组的反式和促进持续的转基因表达的顺式。此外，用AdS.11E4ICP0感染补充细胞促进了病毒生长，并导致d109的噬斑效率增加了20倍，d109是一种对所有5个立即早期基因都有缺陷的病毒。因此，来自E1（-）E4（-）腺病毒载体的ICP 0的低水平表达可以增加腺病毒载体的效用，并且还提供了有效定量和可能繁殖ICP 0缺陷的HSV载体的手段。重要的是，结果表明，ICP 0的激活功能可能不是由细胞基因表达的变化引起的，而是可能是蛋白质固有的酶功能的直接结果，该酶功能可能涉及其在ND 10的作用，导致病毒基因组的优先激活。
Herpes simplex virus (HSV) ICP0 can effectively activate gene expression from otherwise silent promoters contained on persisting viral genomes. However, the expression of high levels of ICP0, as from ICP4(-) HSV type 1 (HSV-1) vectors, results in marked toxicity. We have analyzed the results of ICP0 expressed from an E1(-) E4(-) adenovirus vector (AdS.11E4ICP0) in which ICP0 expression is controlled from the endogenous adenoviral E4 promoter. In this system, the expression level of ICP0 was reduced more than 1,000-fold relative to the level of expression from HSV-1 vectors. This low level of ICP0 did not affect cellular division or greatly perturb cellular metabolism as assessed by gene expression array analysis comparing the effects of HSV and adenovirus vector strains. However, this amount of ICP0 was sufficient to quantitatively destroy ND10 structures as measured by promyelocytic leukemia immunofluorescence. The levels of adenovirus-expressed ICP0 were sufficient to activate quiescent viral genomes in trans and promote persistent transgene expression in cis. Moreover, infection of complementing cells with AdS.11E4ICP0 promoted viral growth and resulted in a 20-fold increase in the plaquing efficiency of d109, a virus defective for all five immediate-early genes. Thus, the low level expression of ICP0 from the E1(-) E4(-) adenovirus vector may increase the utility of adenovirus vectors and also provides a means to efficiently quantify and possibly propagate HSV vectors defective in ICP0. Importantly, the results demonstrate that the activation function of ICP0 may not result from changes in cellular gene expression, but possibly as a direct consequence of an enzymatic function inherent to the protein that may involve its action at ND10 resulting in the preferential activation of viral genomes.