The differential inhibitory effects exerted by cyclosporine and hydrocortisone on the activation of human cytotoxic lymphocytes by recombinant interleukin-2 versus allospecific CTL.

Two immunosuppressive drugs, cyclosporine (CsA) and Hydrocortisone (Hy) were examined in parallel for their effect on the generation of cytolytic T lymphocytes (CTL). Peripheral blood lymphocytes (PBL) were stimulated with allogeneic cells to produce allospecific CTL, or with purified recombinant Interleukin 2 to activate lymphokine activated killer cells (LAK). CTL and LAK activity were measured in a 4 hr chromium release assay after 7 days of activation. Lysis by CTL was tested against stimulator PBL (not blasts) and LAK against fresh sarcoma tumor cells. At pharmacologic doses, CsA inhibited only CTL generation, and Hy inhibited only LAK. This greater understanding of the selective role, or roles, in vitro of CsA and Hy provides a basis by which to consider selective immune suppression--and, alternatively, the possibility of combining modalities for a more thorough immune suppression.