Co-inoculating DNA Vaccine of HIV-1 gag-gp120 and IL-2

Eukaryotic expression plasmid pVAXIL2 was constructed by inserting IL-2 gene into the downstream of CMV (cytomegalovirus) promotor in the vector pVAX1. BALB/c mice were co-inoculated muscularly by this plasmid and the nucleic acid vaccine plasmid pVAXGE expressing the HIV-1 (Human immunodeficiency virus type I) gag-gp120 protein. The level of serum antibodies after immunization showed that the specific antibodies against HIV-1 appeared at the second week and raised to the peak level at the sixth week for the co-immunization group. The specific CTL cytotoxicity activities examined by non-radioactive lactate dehydrogenase release cytotoxity assays demonstrated that the specific CTL cytotoxicity activities in co-immunization group were significantly higher than those in pVAXGE immunization group(P0.05) and pVAX1 control group(P0.01). These results manifested that specific humoral and cellular immune response can be induced by co-inoculating DNA vaccine of HIV-1 gag-gp120 and IL-2, and the level of immune response in co-immunization group was higher than pVAXGE immunization group, which shows that IL-2 augments the immunogenicity of the nucleic acid vaccine as the immunoadjuvant.