Masters P S, Samuel C E
J Biol Chem. 1983 Oct 10;258(19):12026-33.
The effects of a single molecularly cloned subspecies of human leukocyte interferon (IFN-alpha A) on vesicular stomatitis virus (VSV) macromolecular synthesis in human amnion U cells were examined. IFN-alpha A was found to uniformly inhibit VSV protein synthesis to an extent sufficient to account for the overall inhibition of viral infectivity. IFN-alpha A treatment also prevented the shutoff of cellular protein synthesis observed in untreated, VSV-infected U cells. By use of the VSV mutant tsG41, which is competent in RNA transcription but defective in RNA replication at 40 degrees C, it was shown that IFN did not significantly inhibit the accumulation of VSV primary transcripts, although the in vivo translation of primary viral transcripts was greatly impaired as a function of IFN treatment. Thus, the major, and possibly only, effect of IFN-alpha A on VSV replication was translation inhibition. Analysis of RNA, separated by agarose gel electrophoresis after denaturation with glyoxal, with cDNA probes to individual VSV mRNAs, did not reveal any detectable difference in the structural integrity of VSV mRNA isolated from IFN-treated as compared to untreated cells. Likewise, in vitro protein synthesis did not reveal any major difference in the functional integrity of VSV mRNA isolated from IFN-treated as compared to untreated U cells. Viral mRNA isolated from either wild type or tsG41-infected U cells treated with IFN was translated only slightly less efficiently in vitro than viral mRNA from untreated cells. Thus, the principal cause of the IFN-induced inhibition of viral protein synthesis observed in vivo appears to be an alteration of a component of the translational machinery other than the mRNA template.
研究了单一分子克隆的人白细胞干扰素（IFN-αA）对人羊膜U细胞中水泡性口炎病毒（VSV）大分子合成的影响。发现IFN-αA能均匀抑制VSV蛋白合成，其抑制程度足以解释对病毒感染性的整体抑制。IFN-αA处理还可防止在未处理的、VSV感染的U细胞中观察到的细胞蛋白合成的关闭。通过使用VSV突变体tsG41，该突变体在40℃时RNA转录功能正常但RNA复制功能缺陷，结果表明IFN并未显著抑制VSV初级转录本的积累，尽管初级病毒转录本的体内翻译因IFN处理而受到极大损害。因此，IFN-αA对VSV复制的主要（可能也是唯一）作用是抑制翻译。用乙二醛变性后通过琼脂糖凝胶电泳分离RNA，并用针对单个VSV mRNA的cDNA探针进行分析，结果显示，与未处理细胞相比，从IFN处理细胞中分离的VSV mRNA在结构完整性上没有任何可检测到的差异。同样，体外蛋白质合成也未显示从IFN处理的U细胞与未处理的U细胞中分离的VSV mRNA在功能完整性上有任何重大差异。从野生型或tsG41感染的、经IFN处理的U细胞中分离的病毒mRNA在体外的翻译效率仅略低于未处理细胞中的病毒mRNA。因此，体内观察到的IFN诱导的病毒蛋白合成抑制的主要原因似乎是翻译机制的一个组成部分发生了改变，而不是mRNA模板。
