日本脑炎病毒DNA疫苗和基因工程亚单位颗粒疫苗的动物保护实验研究  

Prophylaxtic efficacy of genetically-engineered subunit particulate or DNA vaccines against Japanese encephalitis virus in mice

作　　者：吴玉水[1] 张富泉[1] 马文煜[1] 宋建华[1] 肖毅[1] 杨敬[1] 张红毅 

机构地区：[1]第四军医大学微生物学教研室,西安710032 [2]DivisionofBiomedicalSciences,ImperialCollegeofScience,TechnologyandMedicine

出　　处：《中国人兽共患病杂志》2002年第6期3-6,共4页Chinese Journal of Zoonoses

基　　金：英国威康基金会 (TheWellcomeTrust)资助 (课题号 :0 5 5 863 /Z/ 98/Z)

摘　　要：目的　评价 3种日本脑炎病毒 (JEV)新型疫苗 ,即E蛋白病毒样颗粒 (VLPs)、DNA疫苗 (pV/JE)以及E蛋白颗粒 (Eps)的动物免疫效果。方法　BALB/c小鼠经 2次接种疫苗后 ,测定其病毒特异性的CTL活性、结合抗体、中和抗体 ,并以10LD5 0JEV攻击免疫小鼠 ,观察其保护效果。结果　各新型疫苗组的CTL活性为 33%～ 5 6 % ,灭活疫苗组为 2 2 % ,而载体和PBS对照组的CTL活性分别为 17%和 18%。一次免疫后 ,实验组小鼠血清结合抗体阳转率为 90 %。除DNA疫苗组外 ,各组小鼠的二次免疫血清抗体效价高于一次免疫的抗体效价 (P <0 0 5 ) ,且以VLPs加佐剂组小鼠血清抗体效价最高 ,Eps加佐剂组次之 ,均高于 pV/JE组和灭活疫苗组 (P <0 0 5 )。三种疫苗可诱发小鼠产生中和抗体。各实验组小鼠能够抵抗JEV的攻击 ,而对照组小鼠的死亡率为 37 5 %。结论　三种新型疫苗可以正确表达JEV的E蛋白表位 ,可诱发免疫小鼠产生抗JEV的中和抗体并有保护性作用 ,免疫效果优于灭活疫苗 ,有可能成为候选的JEV新型疫苗。Aim To evaluate the prophylactic efficacy of 3 genetically engineered Japanese encephalitis vaccine candidates,i e HIV 1 Gag virus like particulates carrying Japanese encephalitis virus E protein (VLPs)expressed in baculovirus/insect cells,E protein particulates (EPs)expressed in drosophila cells and DNA vaccine (pV/JE) Methods After immunized twice with neonatal vaccines,the cytotoxic T lymphocyte activities,anti JEV antibodies and neutralizing antibodies in the immunized BALB/c mice were detected The immunized mice were challenged with 10 LD50 JEV Results The CTL activities were detected between 33%～56% of mice immunized with 3 neonatal vaccines,compared to 22% in mice immunized with formalin inactivated vaccine (FIV),17% and 18% for the vector and PBS control groups,respectively Seroconversion was 90% (72/80)in vaccine groups after first immunization and 95% (76/80)after the second dose Mice immunized twice with VLPs + complete Freud's adjuvant exhibited the highest specific antibody titre detected by immunofluorescence Except for group pV/JE,twice immunized mice yielded higher anti JEV antibody than that of once immunized(P<0 05) Mice immunized twice with VLPs emulsified with complete Freud's adjuvant (CFA)exhibited highest anti-JEV antibody detected by indirect immunofluorescence assay,and followed by group Eps+CFA Both were significantly higher than that of pV/JE and FIV groups (P<0 05)Neutralizing antibody were also detectable in mice immunized with these neonatal vaccines All immunized mice survived the challenge with 10 LD50 JEV,compared to 37 5% mortality observed in the unimmunized group Conclusion E epitope of JEV has been functionally expressed in these engineered vaccine candidates They induce stronger specific immune responses than a commercialized inactivated vaccine and demonstrated protective efficacy in mice against JEV infection

关 键 词：DNA疫苗 日本脑炎 日本脑炎病毒 疫苗 动物免疫 E蛋白病毒样颗粒 E蛋白颗粒 

分 类 号：R512.32[医药卫生—内科学]