Effect of recombinant human interferon gamma and interleukin 2 on CFU-GM

Human bone marrow CFU-GM were cultured with rHu-GM-CSF and varying concentrations of rHu-gamma-IFN. Concentration-dependent suppression of CFU-GM precursors by gamma-IFN was demonstrated. This suppression was, in part, reversible by addition of rHu-IL-2. Reversal was also concentration-dependent. Both immune-regulatory T-cell mediators seem to act on a more primitive stage of committed progenitor cell development.