摘要目的 构建含有SIVgag基因的DNA疫苗和重组腺病毒疫苗,为后期在SIV感染的猴模型中进行多载体疫苗联合免疫策略的治疗效果评价奠定基础.方法 将SIV gag基因按照哺乳动物偏嗜密码子进行优化并构建至pVR载体,作为DNA疫苗.以Western Blot方法比较优化前后gag基因表达水平.将优化后的gag基因插入重组腺病毒载体,构建rAd5-SIVgag疫苗.在BALB/c小鼠中分别比较DNA疫苗及rAd5-SIV.gag疫苗单独及联合免疫的效果.结果 密码子优化的SIVgag基因的表达水平远高于野生型SIVgag基因.重组腺病毒疫苗免疫一次或两次诱导的细胞免疫反水平分别高于DNA疫苗免疫一次或两次.两种疫苗联合免疫的反应水平与腺病毒疫苗免疫两次的水平相当,高于DNA疫苗单独免疫及腺病毒疫苗单独免疫一次的结果.结论 成功优化了SIV gag基因,使其不依赖Rev高水平表达；成功构建了表达优化后SIV gag基因的DNA疫苗和rAd5疫苗,可以在小鼠体内诱导较强的gag基因特异性CTL应答.

abstractsObjective To construct DNA and recombinant adenovirus vector vaccines containing SIV gag gene for future evaluation of therapeutic effects of combined immunization strategy in SIV-infected macaque models.Methods The modified SIV gag gene was cloned into pVR vector to get DNA vaccine.The wild type and codon-modified SIV gag gene expression was analyzed by Western Blot assay.Then rAdSSIVgag vaccine expressing modified SIV gag was constructed using AdmaxTM system.BALB/c mice were immunized with DNA or rAd5 vaccine once or twice alone or in DNA prime/rAd5 boost strategy.Gag specific cellular immune responses were detected by IFN-γ ELISPOT assay two weeks post the last immunization.Results The codon modification increased the expression of Gag protein significantly.The cellular immune responses in mice immunized with rAd5 vaccine alone once or twice were higher than that of DNA vaccine.And the immune responses elicited by DNA prime/rAd5 boost were comparative with that of immunization with rAd5 twice.Conclusion The codon modification of SIV gag gene was successful.DNA and rAd5 vaccines encoding codon-modified SIV gag were constructed and both can induce strong Gag-specific CTL responses in mice.