Experimental study of immune responses in mice induced by nucleic acid vaccine of gag gene of Chinese HIV-1 strains / 解放军医学杂志

ABSTRACT

Objective To construct the nucleic acid vaccine(DNA vaccine) plasmid of the gag gene of the prevalent HIV-1 strains in China so as to develop a therapeutic AIDS vaccine against the HIV-1 strains, and to investigate the immune responses induced by HIV-1 DNA vaccine in mice. Methods The recombinant expression vector pCI-neo GAG was constructed by inserting HIV gag gene into the eukaryotic expression vector pCI-neo, which was identified by restrictive enzymes (Xba Ⅰ/Sal Ⅰ) digestion analysis and DNA sequencing. Balb/c mice were immunized with pCI-neo GAG or pCI-neo. Their sera were collected for the assay of the titer of anti-HIV antibody and IFN-? level by ELISA, and their splenic cells were isolated for detecting antigen-specific lymphoproliferative responses and specific cytotoxic T lymphocyte(CTL) response by MTT assay and LDH assay, respectively. Results Restrictive enzymes digestion analysis and DNA sequencing results revealed that the recombinant expression vector pCI-neo GAG had been constructed successfully. Both the anti-HIV antibody titer and the IFN-? level of mice immunized with the pCI-neo GAG were higher than those of mice immunized with pCI-neo (P