乳酸乳球菌介导的细粒棘球绦虫重组LL-Eg95疫苗的构建、鉴定及表达

Construction,Identification,and Expression of Lactococcus lactis-Based Recombinant Vaccine for Echinococcus granulosus

目的 构建乳酸乳球菌(Lactococcus lactis, LL)为载体的细粒棘球绦虫(Echinococcus granulosus, Eg)重组LL-Eg95(rLL-Eg95)疫苗,并研究其表达效率。方法 以pCD-Eg95为模板扩增Eg95基因,采用XbaⅠ和HindⅢ双酶切后插入pMG36e,构建重组质粒pMG36e-Eg95,转化大肠埃希菌BL21(DE3)感受态细胞,抽提质粒进行双酶切鉴定;电穿孔转化乳酸乳球菌MG1363株,构建细粒棘球绦虫重组LL-Eg95疫苗,抽提质粒进行PCR鉴定。结果 重组质粒用双酶切鉴定可切出预期大小的片段,以具有罗红霉素抗性的重组LL中抽提的质粒为模板进行PCR可扩增出471 bp的Eg95基因;SDS-PAGE显示重组LL可表达相对分子质量为16.5×10~3的Eg95蛋白,表达蛋白约占菌体总蛋白的17%;免疫印迹表明表达蛋白可被细粒棘球蚴感染的鼠血清识别。结论 成功构建了细粒棘球绦虫重组LL-Eg95疫苗,表达的Eg95具有特异的抗原性。

Objective To construct Lactococcus lactis(LL)-based recombinant LL-Eg95(rLL-Eg95)vaccine for Echinococcus granulosus(Eg)and to examine its expression efficiency.Methods Eg95 gene was obtained by PCR from the template of pCD-Eg95.Then,pMG36e was inserted in the Eg95 gene after double cleaving with restriction endonucleases XbaⅠand HindⅢto construct recombinant plasmid pMG36e-Eg95,which was transformed into E.coli BL2(DE3)competent cells.The recombinant plasmid was extracted and identified by double restriction endonuclease digestion and was then electroporated into LL MG1363 to construct rLL-Eg95 vaccine.Then,the plamid was extracted and identified by PCR.Results Examination of the recombinant plasmid by double restriction endonuclease digestion showed that the segment was of the expected length.PCR showed that 471 base pairs of Eg95 gene were amplified when the plasmid extracted from roxithromycin-resistant recombinant LL was used as the template.Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)showed that the relative molecular mass of the Eg95 protein expressed was approximately 16.5×103 and that the amount of the expressed protein was 17%of the total bacterial proteins.Western blot findings suggested that the expressed protein could be recognized by mice serum infected with hydatid cyst.Conclusion The rLL-Eg95 vaccine was successfully constructed,expressing Eg95 protein that has specific antigenicity.