The inhibitory effects of the DNA vaccine co-expressing CEA tandem repeat epitopes and FL on the in vivo growth of heptocarcinomas in mice.

Objective:To observe inhibitory effects of DNA vaccine co-expressing CEA tandem repeat epitopes and FL on cancer cells in mice.Methods:The encoding sequences for CEA tandem repeats and FL were inserted into plasmid pcDNA3.0 using gene recombinant technique.BALB/c mice were immunized intramuscularly with the co-expressing DNA vaccine.The survival time and tumor size were measured and specific CTL cytotoxicity was detected by 125 I-UdR release method.Results:Compared with that of the control,the survival time was prolonged(P0.01)and the tumors were significantly inhibited in the mice immunized with the vaccine pcDNA-triCEA625-667-sFL(P0.01).The splenic cells from mice immunized with the vaccine pcDNA-triCEA625-667-sFL induced strongly cytotoxicity against tumor cells H22-CEA+(P0.01).Conclusion:The recombinant DNA vaccine co-expressing pcDNA-triCEA625-667-sFL can suppress the growth of tumor expressing CEA in mice and enhance CTL response against CEA antigen.