利用体内电穿孔的免疫途径来研究不同的真核表达载体和免疫剂量对DNA疫苗M.RCAg-1和D10的免疫应答的影响。分别将M.RCAg-1和D10基因克隆到VR1012和pVAX1表达载体中,用质粒免疫小鼠,采用ELISA和IFA法比较这两种载体的免疫效果,并对基因疫苗免疫小鼠的剂量进行摸索。D10基因免疫大白兔,检测纯化IgG体外对疟原虫生长的影响。结果表明,接种抗原基因疫苗的小鼠都产生了较高滴度的抗重组蛋白抗体,并且都识别培养的恶性疟原虫天然蛋白。pVAX1-D10免疫效果优于VR1012-D10。低、中剂量组产生的抗体水平比高剂量组高。D10基因免疫大白兔后,总IgG的GIA水平为45%。pVAX1表达载体的免疫效果比VR1012表达载体好。M.RCAg-1和D10的DNA疫苗均可诱导识别恶性疟的抗体。通过电穿孔的免疫途径低剂量的DNA疫苗即可诱导高水平的抗体,并且使D10基因在家兔模型中诱导抗恶性疟原虫抑制性抗体。
This study is aimed to compare immune responses induced by different eukaryotic expression vector and immune doses of DNA vaccines M.RCAg-1 and D10 by in vivo electroporation.M.RCAg-1 and D10 were cloned into VR1012 and pVAX1 vector.Mice were immunized with plasmids.ELISA and IFA were used to compare the immune effects of these two vectors.Optimal dose of the DNA vaccine was investigated.White rabbits were immunized with D10 gene,then the impact of purified IgG on the P.falciparum growth was tested in vitro.Results showed that specific antibodies were detected in mice serum after the inoculation and recognized blood stage parasites.Immune effect of pVAX1-D10 was better than VR1012-D10.Antibody levels of low-dose and middle-dose group were higher than that of high-dose group.The level of GIA using total IgG from rabbit immunized with D10 gene was 45%.pVAX1 expression vector was more effective than VR1012 expression vector.Both antibodys induced by M.RCAg-1 and D10 DNA vaccine could recognize blood stage parasites.Moreover,low-dose DNA vaccine could lead to high levels of antibody by in vivo electroporation,which makes it possible for D10 gene to induce inhibitory antibodies against Plasmodium falicparum in rabbits.