Effect of cyclosporin A on the production of interferon by human peripheral blood leukocytes in vitro.

Cyclosporin A (CsA) was assessed for its effect on the production of antiviral activity by human peripheral blood leukocytes (PBL). CsA markedly reduced the production of interferon-gamma (IFN-gamma) in response to stimulation with lectin mitogens, bacterial products, alloantigens, or Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL). CsA-mediated suppression of IFN-gamma secretion was dose-dependent and did not result from a shift of kinetics of the production of antiviral activity. The production of IFN-alpha in response to stimulation with Corynebacterium parvum (CP), viruses, and synthetic polynucleotides was not affected by the addition of CsA. These findings confirm earlier observations that CsA predominantly acts on T lymphocyte function. CsA may prove a valuable agent to study the role of IFN-gamma in the pathogenesis of virus-associated malignant lymphoproliferative disease.