猪圆环病毒2型两种重组多表位蛋白免疫效果的评价

Evaluation of two recombinant multi-epitope proteins against porcine circovirus type 2

Cap蛋白和Rep蛋白是猪圆环病毒2型(porcine circovirus type 2)的2个主要蛋白,其中含有很多表位。本研究合成了由3个Cap蛋白表位和1个Rep蛋白表位组成的2个表位串联体,利用NcoⅠ、SpeⅠ和SalⅠ位点,将Hsp65基因与表位串联体依次克隆到pET30a,把构建的重组表达质粒PHE转化到大肠杆菌BL21(DE3)细胞中,诱导重组蛋白的表达。将表达的两种重组蛋白HSP-e-1和HSP-e-2纯化复性后分别免疫小鼠,结果被免疫的小鼠产生特异性抗体,其中HSP-e-2产生的抗体水平较高,而HSP-e-1的淋巴细胞增殖结果要优于HSP-e-2。结果表明,牛型分枝杆菌Hsp65能够作为多表位肽的载体,而融合蛋白HSP-e-1和HSP-e-2可作为PCV2新型疫苗的候选物。

Cap and Rep,two major proteins of porcine circovirus type 2（PCV2）,contain several epitopes of the virus induces inducing the immune response against PCV infection.We designed and chemically synthesized two recombinatnt DNA fragments which both encoding three epitopes from Cap and one epitope from Rep,and cloned the heat shock protein 65 gene of Mycobacterium bovis into pET30a vector,which was marked as pET30a-HSP.By using the NcoⅠ,SpeⅠ and SalⅠ sites,two recombinant DNA fragments were cloned into pET30a-HSP vector in turn to form two recombinant plasmids pET30a-HSP-e-1 and pET30a-HSP-e-2.Two chimeric proteins,named HSP-e-1 and HSP-e-2,were obtained after separately transforming pET30a-HSP-e-1 and pET30a-HSP-e-2 into Escherichia coli BL21（DE3） host cell and induced by IPTG.After being inoculated with two refolding chimeric proteins,special antibodies were strongly induced,which were higher in mouse induced with HSP-e-2,while the Lymphocyte proliferation showed more advantages in mouse induced by HSP-e-1.The results indicated that the HSP 65 of M.bovis can act as the carrier protein for PCV2 multi-epitope peptides,and HSP-e-1 and HSP-e-2 were potential novel vaccines candidates for the prevention of PCV2 infection.