INDUCTION OF POTENT HUMORAL AND CELL-MEDIATED IMMUNE-RESPONSES FOLLOWING DIRECT-INJECTION OF DNA ENCODING THE HIV TYPE-1 ENV AND REV GENE-PRODUCTS

DNA vaccines have the potential of giving rise to a potent cell-mediat ed immune response by inducing intracellular synthesis and subsequent antigenic presentation of encoded antigens. We have tested a DNA vacci ne specific for human immunodeficiency virus type 1 (HIV-1) by the inj ection of animals with expression plasmids encoding the HIV-1 envelope protein and the Rev regulatory protein, Injection of both plasmids in to mice, rabbits, or macaques was found to induce high levels of speci fic antibodies capable of efficiently inhibiting both HIV-1 infection and envelope-mediated cell fusion, A readily detectable delayed-type h ypersensitivity (DTH) response was demonstrable in injected mice and l ymphocytes derived from these mice proliferated in response to an HIV- 1 envelope V3 loop-specific peptide. Interestingly, the injected mice or macaques also developed a strong cytotoxic T lymphocyte (CTL) respo nse against target cells pulsed with the V3 peptide. Taken together, t hese data demonstrate that injection of HIV-1 gene expression plasmids can induce potent humoral and cell-mediated immune responses and sugg est that DNA vaccines may prove to be significantly beneficial as a me ans of immunizing against HIV-1.