Aoki K, Kawakita M
Department of Physiological Chemistry, Tokyo Metropolitan Institute of Medical Science (Rinshoken), Japan.
Arch Virol. 1996;141(10):1847-62. doi: 10.1007/BF01718199.
Had-2, a mouse mutant cell line derived from FM3A, constitutively releases interferon-alpha and beta and acquires resistance to Newcastle disease virus (NDV) and other viruses. However, Had-2 was found as susceptible to Sendai virus (HVJ) as FM3A. Even when Had-2 cells were infected simultaneously with NDV and HVJ, only the replication of NDV was inhibited, while that of HVJ was not. Northern blot hybridization analysis indicated that accumulation of NDV-specific primary transcripts was somewhat reduced in Had-2, but the reduction was insufficient to critically suppress the viral replication. Moreover, this decrease was not observed in the presence of cycloheximide, and a closely comparable amount of the primary transcripts was detected in both Had-2 and FM3A cells. The mRNA accumulated in the presence of cycloheximide was translated efficiently on removal of the inhibitor in FM3A cells, but not at all in Had-2 cells. Thus the translation of NDV mRNA was the major target of interferon in Had-2 cells. The fact that the synthesis of HVJ proteins was unaffected in Had-2 cells may imply that a host-cell component that distinguishes between NDV and HVJ mRNAs is involved in their translation.
Had-2是一种源自FM3A的小鼠突变细胞系，可组成性释放α和β干扰素，并获得对新城疫病毒（NDV）和其他病毒的抗性。然而，发现Had-2对仙台病毒（HVJ）的敏感性与FM3A相同。即使Had-2细胞同时感染NDV和HVJ，也只有NDV的复制受到抑制，而HVJ的复制不受影响。Northern印迹杂交分析表明，Had-2中NDV特异性初级转录本的积累有所减少，但减少程度不足以严重抑制病毒复制。此外，在环己酰亚胺存在的情况下未观察到这种减少，并且在Had-2和FM3A细胞中检测到的初级转录本数量相当。在FM3A细胞中，去除抑制剂后，在环己酰亚胺存在下积累的mRNA能够有效翻译，但在Had-2细胞中则完全不能翻译。因此，NDV mRNA的翻译是Had-2细胞中干扰素的主要作用靶点。Had-2细胞中HVJ蛋白的合成未受影响这一事实可能意味着，区分NDV和HVJ mRNA的宿主细胞成分参与了它们的翻译过程。
