PERSISTING HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 GP160-SPECIFIC HUMAN T-LYMPHOCYTE RESPONSES INCLUDING CD8+ CYTOTOXIC ACTIVITY AFTER RECEIPT OF ENVELOPE VACCINES

Mononuclear leukocytes (MNL) were obtained from vaccinia-naive, non-human immunodeficiency virus (HIV) infected subjects who were vaccinated with HIV-1-derived recombinant (r) live vaccinia-gp160, 4 of whom were boosted 1-2 years later with purified rgp160. MNL obtained after receipt of the vaccinia-gp160 alone showed persisting (greater-than-or-equal-to 1 year) gp160-specific lymphocyte proliferative responses and production of immune-specific interferon (IFN)-gamma. All 4 subjects who were boosted with rgp160 responded to the boost, including 2 whose cellular responses had waned prior to the boost. MNL from these 4 exhibited gp160-specific proliferative responses, IFN-gamma production, and cytotoxic T lymphocyte activity. The gp160-specific cytolysis was severely reduced or abolished by depletion of CD8+ cells and was not detected using HLA class I-mismatched target cells. Persisting (greater-than-or-equal-to 15 months after boost) HIV gp160-specific T cell recognition and functional responses can be induced by HIV-derived envelope vaccines.