Interleukin 12 affects immunization of hepatitis B DNA vaccine in mice

AIM To observe the immune responses to gene vaccines coding HBV surface antigen and interleukin 12 in BALB/c (H-2d) 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 Chromiun release assay. RESULTS Eight weeks after immunization, the serum of mice A value in 450 nm codelivried IL-12 vaccine (1.67±0.15) was significantly higher than that of mice injected HBV-S DNA vaccine (0.87±0.1). CTLs activity of the mice injected HBV-S DNA vaccine and codelivried 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 codelivried IL-12 vaccine was (48.3± 5.9 )% and (75.6±9.1)% respectively. CTLs activity was (10.6±1.4)% and (16.9±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 was performed by CD8+ cells. DNA vaccine against HBV may be useful for both prophylactic and therapeutic purposes.