WT1抗原多表位与热休克蛋白70刺激表位融合基因疫苗的构建、表达及免疫原性研究

本研究用基因工程方法构建一种由WT1抗原多表位与结核分枝杆菌热休克蛋白70(mHSP70)刺激表位组成的融合基因疫苗并检测其表达和病疫原性.根据文献资料,筛选WT1抗原有良好免疫原性的3个受HLA0201与1个受HLA2402限制性的细胞毒性T细胞(CTL)表位及2个辅助性T细胞(Th)表位,加入通用外源性T细胞刺激表位Pan-DR-Th(PADRE)后,以不同的间隔序列相连,蛋白酶体切割软件优化多表位构成,合成1条由732 bp组成的多表位WT1基因片段,并插入真核表达质粒pcDNA3.1(+)中.通过PCR技术从结核分支杆菌基因组(mycobacterium tuberculosis heat shock protein 70,mHSP70)中扩增包含mHSP70刺激表位的DNA片段,亚克隆至pcDNA3.1(+),测序正确后将含有多表位的WT1基因片段亚克隆入该载体上游,构建融合基因疫苗pcDNA3.1-WT1-mHSP70(407-426).用RT-PCR方法检测该基因在293T细胞表达,并免疫C57BL/6小鼠,酶联免疫吸附斑点法(ELISPOT)检测该疫苗的细胞免疫学反应.结果表明:通过蛋白酶体切割工具PAPROC及NETCHOP3.1预测,复合多表位基因工程疫苗各表位可被正确裂解,PCR和酶切鉴定结果表明,构建的重组真核表达质粒pcDNA3.1-WT1-mHSP70(407-426)含有正确编码的融合基因片段,并在真核细胞获得了正确表达.将该基因疫苗免疫小鼠后,可诱导特异性的CTL应答.结论:成功构建含有WT1多表位与热休克蛋白70刺激表位融合基因疫苗.

Construction of Fusion Gene Vaccine of WT1 Multi-epitope Fused with Stimulating Epitope of Mycobacterium Tuberculosis Heat Shock Protein 70 and Its Expression and Immunogenicity

This study was purposed to construct a fusion DNA vaccine containing WT1 multi-epitope and stimulating epitope of mycobacterium tuberculosis heat shock protein 70 and to detect its expression and immunogenicity.On the basis of published data,a multi-epitope gene(Multi-WT1) containing three HLA *0201-restricted CTL epitopes: one HLA*2402-restricted CTL epitope,two Th epitopes and one universal Th Pan-DR epitope(PADRE) was constructed.DNA-coding sequence was modified by Computer-Aided Design(CAD) to optimize ...