大肠杆菌热稳定肠毒素Ⅰ和卵清蛋白融合蛋白的表达及免疫原性分析

摘要

To evaluate the immunogenicity of 3 × STa-ovalbumin fusion protein,the 3 × STa-ovalbumin was expressed in E.coli BL21 and verified by SDS-PAGE and Western blot.The titers of anti-STa antibody ofserum from the mice immunized with 3 × STa-ovalbumin fusion protein were detected by ELISA,and the neutralization activity of anti-STa antibody was tested by STa neutralization assay.SDS-PAGE result showed that the fusion protein was proved to be approximately 42 ku of molecular mass.Western blot assayindicated that the fusion protein could be specifically recognized by anti-STa serum.Furthermore,anti-STa serum titers were detected at 2.33 from the immunized mice,and the anti-STa antibodies possessed neutralization activity in vitro.The results indicated the expressed fusion protein had a good immunogenicity,which could be a candidate for ETEC subunit vaccine.%为探究大肠杆菌热稳定肠毒素Ⅰ (Heat-stable toxin type Ⅰ,STa)和鸡卵清蛋白(Chicken ovalbumin)串联表达的3×STa-ovalbumin重组融合蛋白的免疫原性,原核表达融合蛋白后,经SDS-PAGE和Western blot方法鉴定,将表达的融合蛋白纯化后免疫小鼠,利用ELISA方法测定免疫小鼠血清中抗STa抗体的滴度,应用体外中和试验检测抗体对STa毒素的中和作用.SDS-PAGE检测结果显示,融合蛋白分子质量约42 ku;Western blot分析结果显示,融合蛋白可被STa阳性血清特异性识别.小鼠免疫试验结果表明,融合蛋白具有较强的免疫原性,诱导机体产生的抗STa抗体滴度达到2.33,并且产生的抗体能在体外中和STa的毒性作用.以上结果表明,3×STa-ovalbumin融合蛋白具有良好的免疫原性.