中文摘要：

目的构建多房棘球绦虫（Em）重组双歧杆菌（Bb）-Em14-3-3疫苗，并研究Em14-3-3分子在春肠埃希菌BL21（DE3）中的表达效率。方法通过PCR扩增Em14-3-3抗原编码基因；将该基因定向克隆于含有谷胱甘肽-S-转移酶（GST）基因的大肠埃希菌-双歧杆菌穿梭表达载体pGEX-1λT，构建重组质粒pGEX-Em14-3-3；用电穿孔法将该质粒导入Bb，构建多房棘球绦虫重组Bb-Em14-3-3疫苗。经PCR和酶切鉴定后以IPTG诱导表达Em14-3-3／GST融合蛋白；SDS-PAGE及Western blot对表达产物进行鉴定。结果PCR成功扩增出530bp的Em14-3-3基因；双酶切证实Em14-3-3基因插入pGEX-1λT中；PCR证实重组Bb-Em14-3-3疫苗构建成功；SDS-PAGE及Western blot分析显示重组质粒转化宿主菌在IPTG诱导下高效表达了Em14-3-3／GST融合蛋白，表达效率为23％。结论成功构建了多房棘球绦虫重组Bb-Em14-3-3疫苗，重组质粒pGEX-Em14-3-3在大肠杆菌中获得了高效表达，Western blot结果提示表达出的Em14-3-3重组蛋白具有特异抗原性。

英文摘要：

Objective To construct recombinant Bb-Em14-3-3 vaccine of Echinococcus multilocularis and to investigate expression efficiency of Em14-3-3 antigen encoding gene in Escherichia coli BL21（DE3）. Methods Em14-3-3 antigen gene was amplified by PCR. Then the gene was cloned into Escherichia coli-Bifidobacteria shuttle plasmid pGEX-1λT containing gluathione-S-transferaze（GST） gene to construct pGEX-Em14-3-3. The recombinant plasmid was electroporated into Bifidobacteria bifidum （Bb） to construct rBb-Em14-3-3 vaccine. The vaccine was identified with PCR and restriction-endonuclease digestion. The expression of pGEX-Em14-3-3 was induced with isopropyl-β-D-thiogalactopyranosid （IPTG） and fusion protein Em14-3-3/GST was examined by SDS-PAGE and Western blot techniques, Results 530 bp gene of Em14-3-3 was successfully amplified by PCR and cloned into pGEX-1λT by restriction analysis, rBb-Em14-3-3 vaccine was successfully constructed by PCR and restrictionendonuclease digestion. It was demonstrated with SDS-PAGE and Western blot that the fusion protein Em14-3-3/ GST was expressed in E. coli, BL21. The expression efficiency is 23%. Conclusion rBb-Em14-3-3 vaccine of Echinococcus multilocularis was successfully constructed. The plasmid pGEX-Em14-3-3 was highly expressed in E. coli in fused form with GST and this kind of protein shows specific antigenicity.