Microparticles in MF59, a potent adjuvant combination for a recombinant protein vaccine against HIV-1

Novel adjuvant formulations involving PLG microparticles with entrapped rec ombinant protein antigens (env gp120 and p24 gag) from human immunodeficien cy virus type-1 (HIV-1), dispersed in the emulsion adjuvant MF59 were evalu ated as potential HIV-1 vaccine candidates in mice and baboons. In mice, th e adjuvant combination induced significantly enhanced antibody responses in comparison to either adjuvant used alone. In addition, the polylactide co- glycolide polymer (PLG) microparticles and MF59 combination induced CTL act ivity against HIV-1 p24 gag. In baboons, the adjuvant combination induced s ignificantly enhanced antibody titers after a single dose of gp120, but the responses were comparable to gp120 in MF59 alone after boosting. Both MF59 + gp120 alone and PLG/gp120 in MF59 induced neutralizing antibodies agains t a T cell line-adapted (TCLA) strain and a primary isolate of HIV-1. In co ntrast to the observations with gp120, immunization in baboons with PLG/p24 in MF59 induced significantly enhanced antibody responses after boosting, in comparison to immunization with MF59 alone + p24. (C) 2000 Elsevier Scie nce Ltd. All rights reserved.