摘要：将编码登革病毒2型(DV2)氨基末端80％的E蛋白的DNA片段克隆到真核表达载体pCXN2 AG强启动 子下游，构建成DV2E重组真核表达质粒pCXN—E。间接免疫荧光显示其可在COS-7细胞中表达。ELISA法检测 pCxN2一E DNA免疫BALB／c鼠血清中的E抗体变化和维持规律，结果显示三次免疫后2周已有抗体产生，l5周 时仍维持较高的水平；血清空斑减数中和实验显示其中和滴度高于1：640：流式细胞计数仪(FAcs)检测DNA 免疫鼠CD4 、CD8 T淋巴细胞变化情况，与注射空载体pCXN2的阴性鼠相比，CD4 淋巴细胞水平略有上升， CD8+细胞水平有较大升高(p率为60％。以上结果表明：pCXN2．E在实验动物内表达出的DV2E蛋白可以诱导免疫动物的体液免疫和细胞免 疫应答，尤其是MHC．I限制性杀伤性CD8 T淋巴细胞水平的提高对清除病毒是十分有利的。因此，DV2 E DNA 免疫为登革病毒DNA疫苗的发展进行了有益的探索。

The gene encoding a strategically truncated E glycoprotein，approximately 80％ of the N·terminal sequence was cloned into the eukaryotic expressing plasmid pCXN2 to get the recombinant plasmid pCXN2一E．Indirect immune fluorescence assay showed that the recombinant plas mid pCXN2·E Can be expressed in COS一7 cells．Th e specific an tibody against DV2 E was detected by ELISA at 2 weeks after the last inoculation，an d maintained to 1 5 weeks；Plague red uction neutralization test (PRNT)was performed on sera obtained at 2 weeks post inoculation．Th e sera had high PRNT50 titer which was overl"640；Th e percentage of CD4+T—lymphocyte subtype cells in immune mice increased compared with the control group．Th e percentage of CD8 T—lymphocyte subtype cells in the group of pCXN2一E was significantly higher than that of pCXN2 group (p0．01)；Mice protection against challenge showed that 60％ mi ce survived．In conclusion：pCXN2一E Can induce humoral an d celIuar immune response．Especially,the raise of CD8 CTL is importan t to clear virus．