ObjectiveTo evaluate specific anti-HIV cytotoxic T-lymphocyte (CTL) activity in relation to basic clinical and laboratory parameters used to follow HIV infection.MethodsLymphocytes from HIV-1-infected subjects with different clinical and immunologic features of HIV infection were tested for circulating and inducible anti-HIV CTL activity using autologous B-lymphoblastoid cells infected with recombinant vaccinia viruses expressing the HIVgag, polandenvgenes as targets. Anti-HIV CTL were induced by stimulation with HIV-infected autologous lymphoblastsin vitro.ResultsWe detected circulating anti-HIV CTL in asymptomatic subjects exclusively and found a significant association (PP<0.001), but there was no significant difference in mean CD4+ lymphocyte count. CD8+ human histocompatibility leukocyte antigen (HLA) class l-restricted anti-HIV CTL were induced in all HIV-infected subjects tested following stimulation with HIV-infected autologous lymphoblastsin vitro.In subjects without detectable circulating anti-HIV CTL, circulating HLA-DR+ cells contributed to anti-HIV CTL activity induced by stimulation with HIV or concanavalin Ain vitro.ConclusionsCirculating anti-HIV CTL activity is associated with CD8+ lymphocyte counts ≥900/μl. Anti-HIV CTL retain proliferative and functional capacity followingin vitrostimulation with HIV and interleukin-2 through all stages of HIV infection. Persistent inducible anti-HIV CTL activity in subjects with advanced HIV disease and without circulating CTL suggests impaired activation and/or proliferation of the CTLin vivo.