2型猪链球菌srtBCD菌毛岛SSU2100基因的克隆表达与免疫学特性

【目的】研究2型猪链球菌(Streptococcus suis serotype 2,S.suis 2)野毒株05ZYH33的srtBCD菌毛岛菌毛亚蛋白SSU2100的免疫保护性作用。【方法】通过PCR扩增出SSU2100基因片段,将目的基因克隆到表达载体pET28a上,转化入E.coli BL21感受态中表达,亲和层析法纯化目的蛋白;Western blot检测SSU2100蛋白的免疫原性,重组蛋白免疫BALB/c小鼠,ELISA法检测多抗血清的效价及IgG亚型,研究重组蛋白的免疫保护作用。【结果】在原核系统成功表达出了SSU2100蛋白;ELISA结果显示重组蛋白能够刺激小鼠产生高效价的免疫抗体;动物实验表明该蛋白具有良好的免疫保护作用。【结论】菌毛亚蛋白SSU2100可以作为S.suis 2亚单位疫苗的候选分子,为系统地阐释srtBCD菌毛岛在S.suis 2致病机制中的作用奠定基础。

Molecular cloning and immunological characterization of SSU2100 gene from srtBCD pilus island of Streptococcus suis 2

[Objective] To investigate the immunoprotection of pilus subunit SSU2100 which was encoded by srtBCD pilus island presented in the Chinese strain 05ZYH33 of S. suis 2. [Methods] The SSU2100 gene was amplified by PCR, then cloned into prokaryotic expression plasmid pET28a, and expressed the recombinant SSU2100 in E. coli BL21. The SSU2100 protein was purified by affinity chromatography and analyzed by Western blotting. The mice anti-SSU2100 serum was prepared by immunizing mice with recombinant SSU2100 protein and analyzed by ELISA. [Results] The high titer of the serum were obtained, Western blot result indicated that the recombinant protein can react with mice anti-SSU2100 serum. Animal test showed that vaccinating mice with recombinant SSU2100 protein conferred a significant protection. [Conclusion] SSU2100 could serve as a vaccine candidate of S. suis 2, it provides the foundation for system-atically illustrating the role that srtBCD pilus island plays in pathogenicity of S. suis 2.