DNA VACCINATION FOLLOWED BY MACROMOLECULAR MULTICOMPONENT PEPTIDE VACCINATION AGAINST HIV-1 INDUCES STRONG ANTIGEN-SPECIFIC IMMUNITY

The induction of a long-lasting immunity characterized by both a humor al and cell-mediated immune (CMI) response is one of the most importan t considerations in developing an effective HIV vaccine. In previous s tudies, we have independently developed both DNA vaccine and macromole cular multicomponent peptide vaccine (VC1) candidates. In the present study, we attempted to optimize the vaccination protocol using mice, g uinea pigs, rabbits and Macaca fuscata monkeys. Repeated vaccination w ith VC1 induced a substantial level of multivalent antibodies which ne utralized various HIV-1 strains, as determined using a p24 inhibition assay. On the other hand, repeated immunization with DNA vaccine induc ed and sustained high levels of cytotoxic T lymphocytes (CTLs). In add ition, when DNA vaccination was followed by multicomponent peptide vac cination, levels of both humoral immunity and CMI increased, and this effect continued for at least 10 months. These data clearly demonstrat e that for inducing HIV-1 specific immunity, immunization with DNA vac cine followed by VC1 boosting produces better results than immunizing with either vaccine alone. (C) 1997 Elsevier Science Ltd.