乙肝核酸疫苗接种小鼠后特异性抗原表达及CTL应答的动态观察

The Serial Observation of Specific Antigen Expression and CTL Responses Induced by A Hepatitis B Virus DNA Vaccine in BALB/c Mice

目的:观察乙肝病毒(hepatitis B virus,HBV)核酸疫苗pCMV-S2S免疫小鼠后,接种局部HBV preS2S抗原的表达及特异性细胞毒性T淋巴细胞(CTL)应答的动态变化。方法:将pCMV-S2S接种到BALB/c小鼠胫前肌,分别以免疫组化法检测接种局部肌肉HBV preS2S抗原表达的动态变化,乳酸脱氢酶(LDH)释放法检测特异性CTL活性的动态变化。结果:小鼠接种pCMV-S2S后,局部肌肉细胞3d后已有少量目的抗原HBV preS2S蛋白表达,4周时表达最强,至6月时仍可检出有preS2S蛋白表达,但表达强度明显减弱。小鼠接种pCMV-S2S3天后,特异性CTL活性平均值最高为21·67%,12周时CTL活性平均值最高为35·14%,6月时仍可检出较弱的CTL活性。结论:HBV核酸疫苗pCMV-S2S能在小鼠体内持续表达特异性抗原及诱生特异性CTL应答。

Objective：To observe the dynamic changes of specific antigen expression and cytotoxicity T lymphocyte （CTL） responses induced by a hepatitis B virus DNA vaccine pCMV-S2S in BALB/c mice.Methods：BALB/c mice were intramuscularly injected with pCMV-S2S.The expression of HBV specific antigen preS2S in the muscles were detected by immunohistochemistry assays.The specific CTL activities induced by mice were measured by lactate dehydrogenase （LDH） release assays.Results：HBV preS2S antigen expression in the mice muscles was detected 3 days after the injection of pCMV-S2S,increased to the peak 4 weeks after injection,and still could be detected 6 months later with weaker expression.Relative lower level of HBV preS2S-specific CTL lysis activities in pCMV-S2S mice was detected 3 days after injection.The average HBV preS2S-specific CTL lysis values achieved the peak by 35.14% 12 weeks after injection,and still kept at low level 6 months after injection.Conclusion：The hepatitis B virus DNA vaccine pCMV-S2S vaccination may elicit substantial HBV preS2S expression and HBV preS2S-specific CTL responses in vivo,and lasted for a relatively long time.