Objective: To determine whether B7-2 could improve hepatitis B virus (HBV)-specific immunity induced by inoculation of a plasmid encoding HBV preS2+S HBV DNA vaccine.
Methods: B7-2 expression plasmids were inoculated with the DNA vaccine in the gastrocemius muscles. Then the cytolytic T Lymphocyte activity (CTL), the delayed-type hypersensitivity (DTH) response and the titers of anti-HBs were analysed.
Results: The DTH response and CTL activity were significantly enhanced when B7-2 expression plasmids were coinoculated with the DNA vaccine (P<0.01), but the titers of anti-HBs were unaffected (P>0.05).
Conclusions: The results suggest that B7-2 expression plasmid could improve HBV specific cell-mediated immunity induced by HBV DNA vaccine, and the gene-based coinoculation strategy using HBV viral antigen and B7-2 costimmulating could be a powerful means of combating HBV infection.