Tumor specific immune response induced by three tandem repeats of CEA mini gene DNA vaccine and safety evaluation / 中国免疫学杂志

ABSTRACT

Objective:To observe the specific killing effect on tumor cells of the spleen cells in mice immunized with three tandem repeats of CEA minigene DNA vaccine pcDNA-triCEA625-667 and to evaluate the safety of the vaccine. Methods: The BALB/c mice were randomly divided into blank vector group ( pcDNA3. 0 ) , haploid vaccine group ( pcDNA-CEA625-667 ) and tandem repeats vaccine group (pcDNA-triCEA625-667). The mice received a total of 4 intramuscular immunization every 10 days once. The changes of body weight,survival state were recorded and the levels of serum ALT and serum creatinine were detected. The specific CTL killing activity of spleen cells in accinated mice on mouse hepatoma cells(H22-CEA+),gastric cancer cells(MFC-CEA+),colorectal cancer cells ( CT26-CEA+) with high expression of CEA and mouse hepatoma cells ( H22-CEA-) without expression of CEA was detected. Results:The two vaccines had strong killing activity on CEA positive liver cancer,gastric cancer and colon cancer cells,and the difference was statistically significant ( P<0. 01 ) compared with the PcDNA3. 0 group. And they had almost no effect on CEA negative tumor cells (H22-CEA-). The killing activity on liver cancer cell(H22-CEA+) and gastric cancer cell(MFC-CEA+) induced by pcDNA-triCEA625-667 was stronger than that induced by pcDNA-triCEA625-667(P<0. 05). The survival status,change of body weight and function of liver and kidney of the mice were not affected by the vaccine. Conclusion:There was no adverse reaction in the course of vaccine immunization. The minigene DNA vaccine derived from CEA can induce tumor specific CTL effect and the immune response level elicited by three tandem repeats of minigene DNA vaccine was superior to that elicited by haploid vaccine.