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 rgpl60. MNL obtained after receipt of the vaccinia-gp160 alone showed persisting (⩾1 year) gp160-specific lymphocyte proliferative responses and production of immune-specific interferon (IFN)-γ. 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 gp 160-specific proliferative responses, IFN-γ 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 (⩾15 months after boost) HIV gpl60-specific T cell recognition and functional responses can be induced by HIV-derived envelope vaccines.