Rigg R J, Carver A S, Dimmock N J
Department of Biological Sciences, University of Warwick, Coventry, U.K.
J Gen Virol. 1989 Aug;70 ( Pt 8):2097-109. doi: 10.1099/0022-1317-70-8-2097.
Even when neutralized by saturating amounts of monoclonal IgG directed against the haemagglutinin, influenza virus attaches to cells with kinetics similar to those of infectious virus. It then enters those cells and is uncoated; its RNA becomes localized within the nucleus and its lipid envelope and associated proteins remain in the cytoplasm. In this report we show that despite the apparent normality of these early stages of virus-cell interaction, neutralized virus underwent no detectable primary transcription. In contrast, there was only a slight inhibition of transcription by neutralized virus in vitro which was insufficient to account for the loss in infectivity, despite using mRNA to measure the production of capped oligonucleotides or to prime the elongation step. To test whether the absence of primary transcription in vivo resulted from non-accessibility of the genome rather than an effect on the transcriptase complex itself, we examined the susceptibility to RNase of virion RNA after inoculation of cells with neutralized virus. Data clearly show that, unlike RNA of infectious virus, RNA of neutralized virus did not become sensitive to RNase and we conclude that neutralization of influenza virus by IgG results in failure of virus to undergo a secondary uncoating process which is necessary for the activity of the virion transcriptase complex. Finally we show that by treatment of virions in vitro with detergent it is possible to produce a core structure which is stable and has some of the properties expected of a structure resulting from primary uncoating.
即使被针对血凝素的饱和量单克隆IgG中和，流感病毒仍以与感染性病毒相似的动力学附着于细胞。然后它进入这些细胞并被脱壳；其RNA定位于细胞核内，而其脂质包膜和相关蛋白质则保留在细胞质中。在本报告中，我们表明，尽管病毒与细胞相互作用的这些早期阶段看似正常，但中和后的病毒未发生可检测到的初级转录。相比之下，体外中和病毒对转录仅有轻微抑制，这不足以解释感染性的丧失，尽管使用mRNA来测量带帽寡核苷酸的产生或引发延伸步骤。为了测试体内初级转录的缺失是由于基因组无法接近还是对转录酶复合物本身的影响，我们在用中和病毒接种细胞后检查了病毒粒子RNA对RNase的敏感性。数据清楚地表明，与感染性病毒的RNA不同，中和病毒的RNA对RNase不敏感，我们得出结论，IgG对流感病毒的中和导致病毒无法经历病毒粒子转录酶复合物活性所必需的二次脱壳过程。最后，我们表明，通过在体外用去污剂处理病毒粒子，可以产生一种稳定的核心结构，该结构具有一些预期的由初级脱壳产生的结构特性。
