Selective enhancement of human mononuclear leucocyte cytotoxic function by interferon.

The influence of type I interferon (IFN) on leucocyte-mediated antibody-dependent cellular cytotoxicity (ADCC) has been examined in a system in which differential alloantibody sensitization of human erythrocyte target cells allows discrimination between lymphocyte and monocyte effector function. ADCC mediated by unfractionated mononuclear leucocyte populations was regularly enhanced by interferon pretreatment over a range of concentrations of the sensitizing antibody. The capacity of IFN-augmented reactivity was, however, removed with adherent cell depletion, suggesting that lymphocyte (K-cell) effectors are not modulated by IFN, even though such populations demonstrate IFN-potentiated natural killer (NK) reactivity against K562. These results suggest that monocyte and NK cell function but not K-cell activity was influenced by interferon.