不同基因融合方式对HIV-1AE2f Tat、Rev和Nef蛋白免疫原性的影响

目的 构建表达HIV-1 AE2f gp145-tat-rev-nef融合基因的DNA疫苗,并比较gp145-tat-rev-nef(AE-Gp145TRN)和tat-rev-integrase(c-half)(AE-TRIVN)两种不同基因融合方式对Tat、Rev和Nef蛋白免疫原性的影响.方法 按人源密码子使用频率对HIV-1 AE2f的gp145、tat、rev和nef基因序列进行优化并构建DNA疫苗.经Western blot进行体外表达检测后,利用小鼠模型比较AE-Gp145TRN与AE-TRIVN的免疫原性.结果 限制性酶切及DNA测序结果表明AE-Gp145TRN融合基因表达重组质粒构建正确;Western blot结果显示其能够在体外表达相应的融合蛋白.小鼠免疫后IFN-γ ELISPOT检测结果显示:AE-TRIVN所活化的针对Tat、Rev和Nef蛋白的总T细胞反应强度(148±91)SFCs/106脾细胞]显著高于Gp145TRN(55±28)SFCs/106脾细胞,P=0.017].T细胞反应分布情况显示:AE-TRIVN所活化的T细胞反应主要集中在Rev蛋白上;而Gp145TRN则可以显著提高对Nef蛋白的免疫识别.结论 AE-TRIVN与Gp145TRN在小鼠体内所活化的T细胞反应特征有明显区别,提示不同的抗原融合方式可能影响融合基因DNA疫苗的免疫结果.

Abstract：

Objective To construct DNA vaccine expressing HIV-1 AE2f gp145-tat-rev-nef fusion gene( AE-Gp145TRN) and to compare the immunogenicities of DNA vaccines expressing Tat, Rev and Nef in gene fusion formulations of tat-rev-integrase(c-half)-vif-nef( AE-TRIVN) and AE-Gpl45TRN. Methods DNA vaccine was constructed by inserting the codon optimized HIV-1 AE2( gp145-tat-rev-nef fusion gene into mammalian expression DNA vector. In vitro expression efficiency of the constructed DNA vaccine was determined by Western blot and the immunogenicities of AE-Gpl45TRN and AE-TRIVN were compared by immunizing female BALB/c mice. IFN-r ELISPOT assay was used to read out the specific T cell immunity. Results Western blot assay showed the constructed DNA vaccine could be expressed efficiently in vitro. After vaccination, AE-TRIVN mounted significantly higher T cell responses against Tat, Rev and Nef(148±91)SFCs/106 splenocytes]than Gpl45TRN(55±28) SFCs/106 splenocytes]. Specific T cell responses elicited by AE-TRIVN predominantly targeting Rev, whereas Gpl45TRN could significantly enhance T cell responses against Nef. Conclusion AE-TRIVN and Gpl45TRN induced distinct T cell response modalities, which implied different gene fusion formulations may affect the immunogenicity of specific DNA vaccines.

Immunogenicity comparison of DNA vaccines encoding HIY-1 AE2f Tat, Rev and Nef in different gene fusion formulations

Objective To construct DNA vaccine expressing HIV-1 AE2f gp145-tat-rev-nef fusion gene( AE-Gp145TRN) and to compare the immunogenicities of DNA vaccines expressing Tat, Rev and Nef in gene fusion formulations of tat-rev-integrase(c-half)-vif-nef( AE-TRIVN) and AE-Gpl45TRN. Methods DNA vaccine was constructed by inserting the codon optimized HIV-1 AE2( gp145-tat-rev-nef fusion gene into mammalian expression DNA vector. In vitro expression efficiency of the constructed DNA vaccine was determined by Western blot and the immunogenicities of AE-Gpl45TRN and AE-TRIVN were compared by immunizing female BALB/c mice. IFN-r ELISPOT assay was used to read out the specific T cell immunity. Results Western blot assay showed the constructed DNA vaccine could be expressed efficiently in vitro. After vaccination, AE-TRIVN mounted significantly higher T cell responses against Tat, Rev and Nef(148±91)SFCs/106 splenocytes]than Gpl45TRN(55±28) SFCs/106 splenocytes]. Specific T cell responses elicited by AE-TRIVN predominantly targeting Rev, whereas Gpl45TRN could significantly enhance T cell responses against Nef. Conclusion AE-TRIVN and Gpl45TRN induced distinct T cell response modalities, which implied different gene fusion formulations may affect the immunogenicity of specific DNA vaccines.