修饰的ORF5基因增强猪繁殖与呼吸综合征DNA疫苗的体液免疫

Enhanced Humoral Immune Response of DNA Vaccine Composing a Modified ORF5 Gene of Porcine Reproductive and Respiratory Syndrome Virus

为了提高猪繁殖与呼吸综合征病毒 (PRRSV) ORF5基因 DNA疫苗的免疫效力 ,将通用型辅助性 T淋巴细胞表位 (PADRE)插入 ORF5的中和表位和覆盖表位间 ,获得修饰后的 ORF5基因 ORF5 M。在此基础上 ,进一步构建了ORF5 M的真核表达质粒 p CI- 5 2 M。间接免疫荧光证实体外表达后 ,免疫 BAL B/c小鼠 ,检测免疫后的 EL ISA抗体和中和抗体 ,并与未经修饰的 ORF5基因真核表达质粒 p CI- 5 2进行比较。结果表明 ,修饰后的 DNA疫苗 p CI- 5 2 M诱导的 EL ISA抗体和中和抗体均明显优于未经修饰的 DNA疫苗 p CI- 5 2 ,是一种具有良好开发前景的

To enhance the immunogenicity of DNA vaccines encoding the GP5 of porcine reproductive and respiratory syndrome virus(PRRSV),the universal helper T-cell antigenic epitope(PADRE) was introduced into the neutralization epitope and the decoy epitope of the ORF5 gene,resulting in a modified ORF5 gene(ORF5M).The modified ORF5M was further cloned into the eukaryotic expression vector pCI-neo and the expression was confirmed by indirect immunofluorescence assay.BALB/c mice were immunized with either the modified expression plasmid pCI-52M or non-modified expression plasmid pCI-52 and the humoral immune responses were elevated at various time points after primary immunization.Results showed that both ELISA and neutralization antibody titers induced by the modified DNA vaccine pCI-52M were higher significantly than those elicited by non-modified DNA vaccine pCI-52,indicating that the modified DNA vaccine pCI-5M may enhance the potency of PRRSV DNA vaccines and can be considered as a promising vaccine against PRRS.