Wu Yushui, Zhang Fuquan, Ma Wenyu, Song Jianhua, Huang Qingsheng, Zhang Hongyi
Department of Microbiology, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China.
Microbiol Immunol. 2004;48(8):585-90. doi: 10.1111/j.1348-0421.2004.tb03555.x.
A plasmid encoding Japanese encephalitis virus (JEV) prM and E proteins was constructed, and its efficacy as a candidate vaccine against JEV was evaluated in suckling mice. Groups of 10 BALB/c mice (5-7 days old) were immunized twice via muscular injection with this DNA vaccine, an empty vector or PBS at an interval of 3 weeks, and were challenged with a lethal dose of JEV 3 weeks after the second inoculation. Both cellular and humoral immune responses were examined before the challenge. Two animals from each group were sacrificed to detect the JEV-specific cytotoxic T lymphocyte activity. JEV-specific lactate dehydrogenase release in the DNA vaccine, empty vector and PBS groups was 37.5%, 18% and 8.5% respectively. JEV-specific antibody was detected in 8 of 10 animals in DNA vaccine group with a geometrical mean titer of 1: 28.3. The pooled serum from the same group also showed a neutralizing activity. Six of 8 mice in the DNA vaccine group survived the challenge, with a protection rate of 75%, but all the mice died in the two control groups. These results show that this JEV prM and E DNA vaccine is immunogenic and protective against JEV infection in the mouse model.
构建了一种编码日本脑炎病毒（JEV）前膜（prM）和包膜（E）蛋白的质粒，并在乳鼠中评估了其作为JEV候选疫苗的效力。将10只BALB/c小鼠（5 - 7日龄）分为一组，通过肌肉注射分别用该DNA疫苗、空载体或PBS免疫两次，间隔3周，并在第二次接种后3周用致死剂量的JEV进行攻毒。在攻毒前检测细胞免疫和体液免疫反应。每组处死两只动物以检测JEV特异性细胞毒性T淋巴细胞活性。DNA疫苗组、空载体组和PBS组的JEV特异性乳酸脱氢酶释放率分别为37.5%、18%和8.5%。DNA疫苗组10只动物中有8只检测到JEV特异性抗体，几何平均滴度为1:28.3。同一组的混合血清也显示出中和活性。DNA疫苗组8只小鼠中有6只在攻毒后存活，保护率为75%，但两个对照组所有小鼠均死亡。这些结果表明，这种JEV prM和E DNA疫苗具有免疫原性，并且在小鼠模型中对JEV感染具有保护作用。
