猪源ETEC的黏附素基因克隆与原核表达

目的]克服传统方法制备黏附素抗原的缺点。方法]应用PCR对猪源性产肠毒素性大肠杆菌(ETEC)的黏附素F4、F5和F6的质粒中扩增出faeG、fanC和fasG基因片段,克隆测序并与pET 32a(+)构建重组表达载体。将重组表达载体转化E.coli表达菌株BL21(DE3),并分析其免疫原性。结果]重组表达载体经IPTG诱导获得高效表达。血凝抑制试验表明,鼠抗血清能抑制标准的ETEC强毒株凝集红细胞,抑制效价在1∶128以上。这说明克隆表达的猪源ETEC黏附素蛋白具有良好的免疫原性。结论]该研究可为进一步开发抗体制剂奠定基础。

Gene Cloning and Prokaryotic Expression of Adhesin in Enterotoxigenic Escherichia coil from Swine

Objective] The research aimed to overcome the disadvantages of the traditional preparation method of adhesion.Method] The gene fragments of faeG,fanC and fasG were amplified by PCR from the plasmid of adhesin(F4,F5 and F6)of enterotoxigenic E.coli(ETEC)and sequenced to construct the recombinant expression vectors with pET 32a(+).The recombinant expression vectors were transferred into E.coli BL 21(DE3) to analyze their immunogenicity.Result] The recombinant expression vectors were highly expressed by IPTG induction.The results of hemagglutination inhibition assay showed mice antiserum could inhibit the standard agglutinate erythrocyte of highly virulent strain of ETEC and the titer was above 1∶128,which indicated that the cloned and expressed adhesion protein of swine ETEC had a good immunogenicity.Conclusion] The research could lay the foundation for further development of antibody preparation.