Strong synergistic effects of multicomponent vaccine for human immunodeficiency virus infection.

Several peptides were synthesized, based on sequences of the HTLV-IIIB, HTLV-IIRF, and HTLV-IIIMN strains. These corresponded to the V3 region, the killer T cell activating site, the constant region of env, gag region protein and the helper T cell activating site. Some of these peptides were coupled to keyhole limpet hemocyanin (KLH), and some of them were polymerized with m-maleimido benzoyl-N hydroxysuccinimide ester (MBS). These peptides were used to immunize rabbits and mice. Antisera from immunized animals showed good levels of inhibition of CD4-dependent cell fusion by in vitro HIV infection. The antisera also inhibited the production of p24 protein in the HIV-infected culture system. Interestingly, a strong synergistic HIV growth inhibition by antiserum was observed when we immunized animals with multicomponent vaccine. In addition, substantial levels of HIV antigen-specific IL-2 producing and interferon-gamma (IFN-gamma) producing cells were also observed in lymph node cells from vaccinated mice. These results suggest that immunization with multicomponent vaccine can induce high levels of humoral antibodies as well as activate HIV-specific cellular immunity.