含CpG基元的SARS冠状病毒S-1基因片段DNA疫苗的构建及动物试验

设计了3对含不同数目CpG基元(CpGmotifs)的引物,用SARS冠状病毒(SARSCoV)S1基因片段作为靶基因,通过PCR扩增出目的片段,插入真核表达载体pVAX1中。用电击法把构建好的不同质粒注入相应组BALB/c小鼠的股四头肌,2周后再加强免疫一次。每周分别测定血清IgG1和IgG2a抗体水平。结果,免疫组IgG1和IgG2a抗体浓度以及IgG2a与IgG1的比值均显著增加(P<0.001)。表明所构建的SARSCoVS基因S1片段的真核表达质粒可诱导小鼠产生很强的免疫反应。

Construction of DNA vaccine against S-1 gene fragments containing-CpG motif of SARS coronavirus in BALB/c mice and its application to animals

To construct the DNA vaccine against S-1 genefragments containing-CpG motif of SARS coronavirus and investigate immune responses in BALB/c mice, S-1 fragmentsof SARS-CoV S gene, containing different number of CpG motifs introduced by PCR, were inserted into eukaryotic expression vector pVAX1. The recombinant plasmid was injected into quadriceps femoris of BALB/c mice via electroporation and boosting with the same plasmid on week 2 after first immunization. IgG1 and IgG2a were measured weekly. The data indicated that the plasmid can elicit immune system to produce high levels of bothIgG1 and IgG2a significantly (P<0.001). The increased ratios of IgG2a to IgG1 indicated that they can elicitan intense Th1 immune response.The constructed eukaryoticexpression plasmid can induceintense immune response, which suggested that DNA vaccination may open up a new avenue for prevention against SARS.