不同代次S191株麻疹病毒HA基因的序列分析

HA Gene Sequencing of Different Passages of Measles Virus S191 Strain

目的 考察麻疹S191疫苗株在长期传代过程中HA基因的变化 ,以确定用于生产的最佳代次。方法 对麻疹S191疫苗株鸡胚细胞系 (CEC) 2 0、30代病毒株及S191株羊膜系病毒株 (强毒 )HAM42的血凝蛋白 (HA)基因进行RT—PCR ,克隆到PUC质粒后进行测序。结果 2 0代和 30代疫苗的HA基因的 185 4个碱基序列中未出现核苷酸的变化 ,但二者与HAM42株相比有两个核苷酸的变化 ,分别在 15 17和 1799位 ,并导致 5 0 6位的Gly变为Asp ,6 0 0位的氨基酸由Glu变为Val。结论 麻疹病毒的减毒株与强毒株存在差异。而麻疹减毒株在鸡胚细胞的长期传代中 ,HA基因未出现明显变化 ,没有出现抗原漂移 ,30代毒株与 2

Objective To explore the change of HA gene of measles virus S191 strain during long term culture and select the optimum passage used for production.Methods The HA genes of S191 strain undergone 20 and 30 passages in CEC or 42 passages in HAM were amplified by RT PCR, then cloned into PUC plasmid and sequenced. Results No difference of nucleotide were observed between the 1854 bases of HA genes of CEC20 and CEC 30 strains. However, compared with HAM42 strain, the changes of nucleotides were observed at sites 1517 and 1799 of the 2 strains respectively and further caused the changes of Gly to Asp and Glu to Val at sites 506 and 600 respectively.Conclusion The attenuated measles virus strain is different from strong virus strain. However, during the long term culture of measles virus in CEC, neither significant change of HA gene nor antigen drift is observed.