摘要
分别对SA14 - 14- 2 (PHK8代 )疫苗株及其原野毒株SA14 和另 2个疫苗传代株 [SA14 - 14- 2 (PHK17代 )和SA14 - 14- 2 (鼠脑 1代 ) ]的E区基因进行了序列测定。结果表明 ,乙脑病毒减毒活疫苗SA14 - 14- 2在PHK细胞上连传至 17代时 ,发现 2个氨基酸突变 (E - 331、E - 398) ,但不是回复突变。虽然在毒力最容易返祖的乳鼠脑内传 1代后发生E - 10 7个氨基酸回复 ,但与野毒株毒力相比仍然相差很大 ,无毒力返祖现象。在疫苗的实际质控工作中 ,对上述与毒力相关的基因进行监测 ,可能有助于发现减毒活疫苗的毒力水平 ,为疫苗安全性提供更可靠的检测手段。
The Japanese encephalitis live attenuated virus strain SA 14 -14-2 has been used for production of live vaccine in China for ten years.However,the possibility of reverse mutation of the vaccine has not been elaborated on molecular level.In this study,we sequenced E genes of the parent wild-type strain SA 14 ,two PHK cell passaged viruses SA 14 -14-2(PHK-8),SA 14 -14-2(PHK-17),and another one ,the SA 14 -14-2(SM-1)that had been passaged once in suckling mice brain.The results indicated that there were twelve nucleotides and eight amino acids differences between SA 14 and SA 14 -14-2(PHK-8).The SA 14 -14-2(PHK-17)showed two additional mutations(E-331 and E-398)in the E protein which were not reverse mutations.Although one reverse mutation(E-107)was found in SA 14 -14-2(SM-1),its neuroattenuation was stable when tested in mice.It indicates that the genotypic characteristics of the attenuated vaccine virus SA 14 -14-2 is stable,that is consistent with the neuroattenuation stability tested in mice.
出处
《病毒学报》
CAS
CSCD
北大核心
2002年第1期39-47,共9页
Chinese Journal of Virology
关键词
流行性乙型脑炎
传代
E基因序列
基因稳定性
减毒活疫苗
Japanese encephalitis
viruses of different passages
E gene sequence
stability of neuroattenuation
