Inhibitory effect of 3'-azido-3'-deoxythymidine on proliferative responsiveness of CD8+ lymphocytes to interleukin-2

Although several studies have shown that 3'-azido-3'-deoxythymidine (AZT) is not toxic for CD4+ lymphocytes, its effect on CD8+ cells has never been studied in a systematic way. We purified CD8+ cells from the peripheral blood mononuclear cells of both human immunodeficiency virus (HIV)-seronegative and HIV-infected individuals by means of magnetic beads that had been coated with monoclonal antibodies. We report that AZT, but not two other nucleosides tested, inhibited the interleukin-2-dependent proliferation of CD8+ lymphocytes in a dose-dependent manner. No such effect was observed with regard to CD4(+)-enriched populations. The AZT-mediated antiproliferative effect did not appear to be related to either the CD4+ count or to prior treatment with this drug in the case of HIV-seropositive subjects.