The myelosuppressive effect of recombinant interferon gamma in short-term and long-term marrow cultures

The effect of a highly purified human gamma IFN (r-gamma-IFN) on the growth of haemopoietic progenitors was examined in soft agar assays and in long-term bone marrow cultures. r-gamma-IFN reduced colony formation by progenitor cells of the granulocyte/macrophage lineage (GM-CFC), the erythroid lineage (BFU-E) and multipotent cells (GEMM-CFC), and suppressed haemopoiesis in long-term culture in a dose-related fashion. At high doses (1000 units/ml) r-gamma-IFN appeared to be toxic to the stromal cells of the bone marrow.