扎伊尔型埃博拉重组糖蛋白GP-Fc基因疫苗构建及免疫原性研究

Construction and Immunogenic Research of a Recombination Zaire Ebola Virus Glycoprotein GP-Fc DNA Vaccine

本实验将基于埃博拉病毒表面糖蛋白抗原GP基因序列,按照哺乳动物密码子使用频率优化,并与人IgG恒定区构建融合蛋白GP-Fc基因序列,重组蛋白序列插入基因疫苗载体pVR中,构建重组蛋白基因疫苗pVRmodGP-Fc。通过基因疫苗导入系统免疫小鼠,用间接ELISA和间接免疫荧光对抗体效价进行评估。实验结果显示,重组蛋白GP-Fc的基因疫苗可以很好的刺激小鼠产生特异性抗体,免疫周期结束后,小鼠血清中结合效价终点达到高剂量组1∶300 000及低剂量组1∶180 000,同时血清中的抗体可以很好地结合表达GP抗原的细胞表面,表现出很强的荧光信号。通过该研究我们验证重组蛋白基因疫苗pVR-modGP-Fc可以很好地诱导BALB/c小鼠产生较高滴度的抗原特异性IgG,具有较好的免疫原性。

We constructed the recombination protein gene vaccine pVR-modGP-Fc.The gene code of modGP-Fc（in which the Ebola glycoprotein（GP）extracellular domain is modified by the codon frequency of humans and fused with the human IgG Fc code at the 3′terminal）was synthesized and inserted into a pVR vector.BALB/c mice were vaccinated thrice（0,3,and 6weeks）at two doses.During the immunization period,serum antibody titers were evaluated by an indirect enzyme-linked immunoassay（ELISA）.Immunofluorescences were applied to manifest the bond efficiency of serum antibodies to cell-expressed Ebola-virus GPs.Specific antibodies were found 1week after the first dose in each vaccination group.At the end of the immunization period,serum ELISA titers increased to 1∶300 000 at a high dose and 1∶180 000 at a low dose.Specific serum antibodies were well bonded to the surface of GP-expressed HEK 293 Tcells,and fluorescence was not detected in controls.These data suggest that the DNA vaccine pVR-modGP-Fc can induce BALB/c mice to generate high-efficiency combination IgG,and that it shows good immunogenicity.Our study could be the basis for development of a vaccine against the Ebola virus.