日本血吸虫中国大陆株26kD GST基因在大肠杆菌中的高效表达

用大肠杆菌高效表达日本血吸虫中国大陆株 2 6k D GST基因 (Sj2 6)并观察表达产物诱导的免疫保护效果 .将 Sj2 6基因亚克隆至 p ET2 8b(+)中构建重组表达质粒 Sj2 6/ p ET,转化大肠杆菌 BL 2 1 (DE3) .Sj2 6在诱导条件下及未诱导条件下均获得高效表达 .表达产物 (r Sj2 6GST)以包含体形式表达 ,分子量为 2 8k D左右 ,能用 6× His亲和层析柱纯化 ,纯化产量为 55～ 60 mg/ L大肠杆菌培养物 .免疫印迹及 ELSA实验证实 r Sj2 6GST具有良好抗原性 .用 r Sj2 6GST不加佐剂直接背部皮下免疫昆明系小鼠 ,获得了 1 9.6% (P<0 .0 5)的减虫率及 31 .9% (P<0 .0 5)的成熟虫体减虫率 ;且免疫组检获的虫体中未成熟虫体的比例为 32 % (66/ 2 0 6) ,明显高于对照组的 1 9.6% (56/2 85) (P<0 .0 1 ) ,说明 r Sj2 6GST免疫不仅可诱导抗日本血吸虫的部分攻击感染作用 ,而且能抑制部分虫体的发育 .

Expression in E.coli of 26 kD GST Gene from Chinese Strain of Schistosoma japonicum

The objective was to express the 26 kD glutathione S transferase(Sj26GST) gene of Chinese strain of Schistosoma japonicum in E.coli and observe the vaccination results of this expression products.The cDNA fragment encoding Sj26GST was cloned into the expression vector pET28b(+)and expressed in E.coli BL21(DE3) in conditions both of non induction and induction with IPTG.The recombinant protein (rSj26GST) was wholly insoluble in aquous solution and could be purified with 6×His chromatography column.Its molecular weight was about 28 kD.The yield was 55～60 mg/L E.coli culture.The immunological tests revealed that rSj26GST had good antigenicity.After vaccination in mice with rSj26GST,19.6% total worm reduction( P <0.05)and 31.9% matured worm reduction( P <0.05) were obtained.The ratio of immature worms in total worms harvested from vaccination group was 32%(66/206),significantly higher than that from control group(19.6%,56/285)( P <0.01).The results showed that vaccination with rSj26GST not only induced partial protection against Schistosoma japonicum infection,but also inhabited the development of Schistosoma japonicum in final host.