Effect of cyclosporin A on murine natural killer cells

Abstract

In mice, cyclosporin A decreased the natural killer cell-enhancing effect of 2 interferon inducers, infective murine cytomegalovirus and nonreplicating Newcastle disease virus. It also inhibited murine cytomegalovirus replication at doses > 20 mg/kg, but it did not significantly inhibit inteferon induction by Newcastle disease virus. In cell culture, cyclosporin A had no direct effect on the natural killer activity of spleen mononuclear cells derived from normal or murine cytomegalovirus-infected animals. At 50 .mu.g/ml it significantly reduced the ability of interferon to enhance the natural killer activity of normal spleen cell suspensions. The inhibitory effect of cyclosporin A on natural killer cell activity in infected mice may be partly explained by its ability to block the action of interferon.