不同EV71毒株的免疫保护差异性研究

The research on the immunoprotection difference among five EV71 virus

目的 对用MRC-5细胞分离的5株EV71疫苗候选株进行差异性研究,旨在筛选出符合疫苗制备需要的病毒株.方法 将5株单克隆化的EV71疫莳候选株制备成试验苗,腹腔接种ICR雌性小鼠,加强免疫两周后,雌雄配对,饲养2周,对雌鼠再加强免疫1次,并对出生24 h内的乳鼠进行颅腔攻毒,观察乳鼠生存状况;用ELISA法检测母鼠和乳鼠血清IgG滴度;用巢式PCR检测攻毒乳鼠肠道EV71载量;用MRC-5细胞培养法检测免疫血清对病毒的中和能力;用SPSS16.0对实验数据进行统计分析.结果 5株病毒免疫的雌鼠血清抗体水平随免疫次数增加而提高、抗体对病毒的中和能力存在差别;致死株攻毒的乳鼠存活状况存在差别,非致死株攻毒的乳鼠肠道EV71载量也存在差别.结论 从分子水平、细胞水平和个体水平上证实5株病毒的免疫原性和免疫保护性存在差别,123株是免疫保护力最好的一株。

Objective To screen the 5 EV71 vaccine candidates which were isolated from MRC-5 cells to find one as the vaccine virus. Methods The ICR mother mouse were immunized by intraperitoneal injection with the 5 vaccine candidates which were made from monoclonal EV71 virus. Two weeks after booster immunization, the animals were allowed to mate, another booster was given after 2 weeks, and then attracted the milk mouse within 24 h with different types of virus by cranial cavity injection. The survival condition were recorded everyday, and the antibody titre（IgG） were detected by ELISA, the virus titre of intestine were detected by nest-PCR, and neutralizing antibodies were determined using a microassay with MRC-5 cells, and then the data were analyzed by SPSS16.0. Results The antibody titre of 5 virus immunized ICR mouse were improved with the increase in the immune times, and they got difference in neutralization capacity, the survival rate after fatal attract and the virus titre of the intestine. Conclusion It proved that the five vaccine candidates were different at the molecular level, cellular level and individual level. 123 strain was the best one in immunogenicity and immunoprotective property, which agreed with the vaccine requirement.