Separation of functionally distinct human granulocyte-macrophage colony-stimulating factors

Abstract

Human placental conditioned medium (HPCM) contains colony-stimulating factors (CSFs) required for the growth in vitro of neutrophilic granulocyte-macrophage (GM) and eosinophilic (EO) progenitor cells from human bone marrow. Fractionation of CSFs in HPCM was achieved by manipulation of the elution conditions on a column of phenyl-Sepharose. After equilibration of the phenyl-Sepharose column at high ionic strength (1M ammonium sulfate), all of the CSF bound; one species of GM-CSF (α) and all of the elutable EO-CSF were eluted from the column simply by reducing the salt concentration, whereas the second species of GM-CSF (β) was free of EO-CSF and was eluted only by increasing the concentratio..