EV71-VP1抗原在双歧杆菌中表达的免疫效果检测

Detection of Immune Effect of EV71-VP1 Antigen Expressed in Bifidobacteria

目的检测表达肠道病毒71型(enterovirus 71,EV71)VP1基因的重组双歧杆菌免疫后小鼠Ig G、Ig A表达变化,并对免疫的孕鼠产下的新生小鼠注射EV71病毒,以检测免疫保护作用可否从母代传给子代。方法 ELISA法检测免疫小鼠血清Ig G、Ig A抗体效价;用EV71毒株对免疫孕鼠所产下的新生小鼠攻毒。结果两种抗体效价都有明显升高(P<0.01);实验组受病毒攻击新生小鼠存活率明显高于对照组。结论口服表达VP1蛋白的双歧杆菌能够激活体内免疫系统产生特异性抗体,重组双歧杆菌可通过免疫孕鼠而使新生幼鼠获得保护性抗体。为研制EV71亚单位口服活疫苗奠定了研究基础。

Objective To constructe a bifidobacterium recombinant carrying the VP1 gene from enterovirus71 to create an oral vaccine to prevent EV71 infection. To detect the futher protective effect of the recombinant using ELISA in vovo. Methods We studied the efficacy of an orally administered vaccine candidate developed using recombinant baculovirus displaying VP1 （Bac-VP1） in a murine model. Gastrointestinal delivery of Bac-VP1 significantly induced VP1-specific humoral （IgG） and mucosal （IgA） immune responses. Results Bifidobacterium recombinant with the VP1 gene from enterovirus71 was constructed. The virus-neutralizing titer of anti-EV71-VP1 significantly increased than the control group. Expression of IgA and IgG increased after oral treatment. A lethal challenge test indicated that the survival rate of bac-VP1 and VP1 group was significantly higher than the control group during 14days. Conclusion Bac-VP1 could be a promising oral vaccine candidate against EV71 infections. Thus, Bac-VP1 may provide a needle free, painless approach for immunization against EV71, thereby increasing patient compliance and consequently increasing vaccination coverage.