REVERSIBLE MACROPHAGE DIFFERENTIATION-INDUCED IN A NEW HUMAN MYELOID CELL-LINE BY GAMMA-INTERFERON

A new cell line was established from the bone marrow of a patient with chronic myeloid leukemia. The cells were attributed art intermediate myeloid phenotype on the basis of their cytochemical features and memb rane antigen expression. These cells respond to both chemical and phys iological activators of the signal transduction pathways with growth a rrest and phenotype changes. Macrophage maturation can be induced in a fraction of the cells by gamma-interferon (gamma-IFN). Cells are howe ver recruited again into the cell cycle by recultivation in gamma-IFN- free medium. variants unresponsive to gamma-IFN, and others which show either reversible or irreversible differentiation were isolated from the original cell line by cloning and sib-selection. These clones cart be used to investigate the relationship between gamma-IFN response pa thways and cell proliferation.