ObjectivesCytotoxic T-lymphocytes (CTL) appear to be an important defense mechanism against HIV infection. This study proposes to examine the major histcompatibilty complex (MHC)-restricted HIV-1 Env-, Gag-and Pol-specific CTL activities in HIV-infected asymptomatic patients.DesignD4+ and CD8+ CTL were examined to establish whether the same HIV-1 protein (Env, Gag or Pol) was recognized by both CD4+ and CD8+ CTL with MHC antigen restriction.MethodsPeripheral blood mononuclear cells, CD4+ and CD8+ T-cells from 17 HIV-infected asymptomatic patients and 10 HIV-seronegative individuals were examined for HIV-1 Env-, Gag-and Pol-specific MHC-restricted cytotoxicity using autologous and heterologous B-lymphoblastoid cell lines infected with vaccinia recombinant expressing HIV-1 Env, Gag and Pol proteins as targets.ResultsCD4+ and CD8+ CTL specific for the HIV-1 Env, Gag and Pol were demonstrated in the peripheral blood. DR4 and DQw2 were possible sites of MHC class II restriction of CD4+ CTL. Possible MHC class I restriction sites of CD8+ CTL included A2 and B8 for Env, A1 and A2 for Gag, and A2 and B8 for Pol antigen.ConclusionsThese observations should help to define more precisely the nature and elements of protective immunity and to evaluate AIDS vaccine strategies.