Egorov A Iu, Garmashova L M, Lukashok I V, Nevedomskaia G N, Aleksandrova G I, Klimov A I
Vopr Virusol. 1994 Sep-Oct;39(5):201-5.
Phenotypical properties of single-gene reassortants of attenuated cold-adapted strain A/Leningrad/135/47/57 (H2N2) and strain A/PR8/34 virulent for laboratory animals were studied. Only the group of reassortants inheriting NS gene from cold-adapted virus was fully attenuated for various animals species, similarly as reassortants with 6/2 genomic formula containing all the 6 internal protein genes from strain A/Leningrad/134/47/57. Reassortant 25A-1 single-gene for NS was temperature-sensitive (ts) on mammalian cells but formed plaques at 40 degrees C on chicken kidney cells. Reassortants with genomic formula 6/2 were temperature-sensitive in all types of cells used. Reassortant 25A-1 could synthesize normal amounts of polypeptides in MDCK cells at 39 degrees C, whereas protein synthesis of reassortants with 6/2 genomic formula was noticeably reduced at this temperature. Hence, a similar level of attenuation of both reassortant groups appears to be due to various molecular mechanisms. Possible role of NS2 gene mutation in attenuation of strain A/Leningrad/134/47/57 and its reassortants is discussed.
研究了减毒冷适应株A/列宁格勒/135/47/57（H2N2）与对实验动物具有毒力的A/PR8/34株的单基因重配体的表型特性。只有从冷适应病毒继承NS基因的重配体组对各种动物物种完全减毒，与具有6/2基因组公式且包含来自A/列宁格勒/134/47/57株所有6个内部蛋白基因的重配体类似。NS单基因重配体25A-1在哺乳动物细胞上对温度敏感（ts），但在鸡肾细胞上于40℃形成噬斑。具有6/2基因组公式的重配体在所有使用的细胞类型中对温度敏感。重配体25A-1在39℃时可在MDCK细胞中合成正常量的多肽，而具有6/2基因组公式的重配体在此温度下蛋白质合成明显减少。因此，两个重配体组类似水平的减毒似乎是由于各种分子机制。讨论了NS2基因突变在A/列宁格勒/134/47/57株及其重配体减毒中的可能作用。
