镰形扇头蜱免疫球蛋白结合蛋白的表达及免疫保护分析

Gene expression of the immunoglobulin binding protein of Rhipicephalus haemaphysaloides tick and its immune protective effect

为在大肠杆菌中高效表达镰形扇头蜱免疫球蛋白结合蛋白(immunoglobulin binding protein,IGBP),并对表达产物进行免疫保护效果测定,将IGBP基因克隆到pGEX-4T-1载体,转化到感受态细胞BL21,在IPTG诱导下进行表达;表达产物3次免疫家兔,剂量为500μg/只。3次免疫后进行攻蜱试验,观察免疫保护效果。结果发现在IPTG的诱导下,重组质粒pGEX-4T-1-IGBP在大肠杆菌中获得高效表达,产生GST-IGBP融合蛋白,用融和蛋白免疫家兔后,试验组与对照组成蜱饱血重量和死亡率差异显著(P<0.05)。表明重组质粒pGEX-4T-1-IGBP能在大肠杆菌中高效表达,且表达蛋白能够对家兔产生一定程度的抗蜱保护性免疫力。

To subclone and express the gene encoding the immunoglobulin binding protein （IGBP） of Rhipicephalus haemaphysaloides tick and analyze its immune protective effect, the IGBP gene was cloned into vector pGEX-4T-1, then transformed to Escherichia coli BL21 cells and expressed by the induction with IPTG. The expressed product was purified and used as antigen to immunize rabbits in order to evaluate its immune protective effect. The rabbits in the vaccinated group were immunized with 500μg of the recombinant protein emulsified with 206- adjuvant, while those in the control group injected with PBS emulsified with 206 adjuvant. The immunization consisted of the triple injections at weeks 0, 2 and 4, respectively. All the rabbits were challenged with R. haenaphysaioides ticks 2 weeks after the final injection in order to evaluate the immune effect. It was found that the fusion protein GST-IGBP was highly expressed in E. coli in the form of the inclusion bodies. There were significant differences in tick weights and mortalities between the vaccinated and control groups. It is evident that the IGBP gene can be highly expressed in E. coli and the fusion proteins GST-IGBP can produce the anti-tick protective immunity to a certain degree.