O型口蹄疫病毒VP1 T细胞与B细胞表位基因双拷贝串联表达产物的免疫应答

The immune responses of the fusion protein including two copies of T cell and B cell epitopes of Food-and-mouth disease VP1

以一株O型口蹄疫病毒(FMDV)外壳蛋白VP1基因为模板,合成与细胞免疫及体液免疫相关抗原表位肽基因:21-40肽(20AA)和141-160肽(20AA)基因序列,运用基因工程技术构建了含有串联结构21-40(20AA)～141-160(20AA)～21-40(20AA)～141-160(20AA)的2020-2020VP1融合基因表达载体r2020-2020,转化宿主菌BL21(DE3)RIL后诱导表达,表达产物经SDS-PAGE及Western Blot分析显示重组融合蛋白的分子量约为18Ku.动物实验表明,较小剂量的融合蛋白就能诱导豚鼠产生特异性T淋巴细胞增殖反应及抗FMDV中和抗体,证明该融合蛋白可同时激活细胞免疫及体液免疫反应,具有开发成为抗FMDV疫苗的应用价值.

It is usually thought that the 21-40 peptide of VP1 of food-and-mouth disease（FMDV） Type O is related with cellular immunity and the 141-160 peptide is related with humorlar immunity. According to the sequences of epitopes of 21-40（20AA）and 141- 160（20AA） peptides of VPl of FMDV Type O and biased codons in E. coli, the nucleotides fragment （ 198 bp）containing the 21-40 and 141-160 peptides codons was synthesized.The recombined expression vector r2020-2020 was correcdy constructed, which expressing fusion protein of tandem sequence of 21-40（20AA） - 141-160（20AA） - 21-40（20AA）-141-160（20AA） peptides. The fusion protein was successfully expressed in BL21 （DE3） RIL and confirmed by SDS-PAGE and Western Blot. The molecular weight of the fusion protein is about 18 Ku. The fusion protein was purified and used to vaccinate guinea pigs, whose immune responses were then observed. The fusion protein could induce proliferation of spleen T ceils of vaccinated guinea pigs and elicit high levels of neutralizing antibody. It could be concluded that the fusion protein could activate cellular immune-response and humoral immune-response simultaneously and it has potential to be FMDV vaccine.