摘要The immune efficiency of a recombinant adenovirus type 5 with type 35 fiber containing HIV-1 gag gene (rAd5/F35-mod.gag) was investigated in BALB/c mice, in which the rAd5/F35-mod. gag was firstly identified with PCR, then transfected to 293 cells and the in vitro expression level of Gag protein was determined by Western blotting and indirect immuno-fluorescent assay. Mice were immunized with intramuscular injections of rAd5/F35-mod. gag, rAd5-mod. gag or DNA and were boosted after 3 weeks.To test the effect of pre-existing anti-viral immunity on immunization, mice were also injected with Ad5-GFP vector and then immunized 4 and 7 weeks later with Ad5/F35-mod. gag vector. The P24-specific IgG antibody in sera of immunized mice was determined by ELISA and the specific cytotoxic T lymphocyte (CTL) response was assayed by intracellular cytokine staining. It was demonstrated that the rAd5/F35-mod. gag vector could express efficiently the HIV Gag protein in 293 cells in vitro and induce strong HIVspecific immune responses in vivo. The strongest CTL and serum IgG response occurred when mice were immunized twice with injection of rAd5/F35 alone, but the anti-Ad5 antibody after primary infection with adenovirus could inhibit the specific immune responses induced by rAd5/F35 vector. It is concluded that single immunization with recombinant adenovirus rAd5/F35-mod. gag can induce specific CTL and serum IgG antibody responses in mice, but the immunogenicity of rAd5/F35 is comparably weaker than that of rAd5.