Interleukin 12 potentiates immune response induced by DNA vaccine

Objective:To observe the immune responses to gene vaccines coding HBV surface antigen and interleukin 12 in Balb/c(H 2 d) mice.Methods:The immunization was performed by intramuscular injection in this experiment.Anti HBs in serum was detected by ELISA.HBsAg specific cytotoxic T lymphocytes (CTLs) activity was measured by 51 Cr release assay.Results:8 w after immunization,the serum OD value of the mice coinjected IL 12 vaccine (1.64±0.15) is significantly higher than that of mice injected HBV S DNA vaccine (0.87±0.1) only.CTLs activity of the mice injected HBV S DNA vaccine and coinjected IL 12 vaccine were 50.5%±6.4% and 73.3%±8.8% respectively.After adding anti CD4 + monoclonal antibody in spleen cells,CTLs activity of the mice injected HBV S DNA vaccine and coinjeted IL 12 vaccine were 48.3%±5.9% and 75.6%±9.1% respectively.CTLs activity were 10.6%±1.4% and 16.3%±2.3% respectively after adding anti CD8 + monoclonal antibody in spleen cells.Conclusion:The results showed that the DNA vaccine of pCR3.1 S had strong antigenecity in cellular and humoral immunity which can be promoted by vector coding murine IL 12.CTLs activity were performed by CD8 + cells.DNA vaccine against HBV may be useful for both prophylactic and therapeutic purposes.