A HUMAN CELL-LINE ISOLATED FROM FETAL KIDNEY PRODUCES AN APPARENTLY ERYTHROID-SPECIFIC STIMULATING ACTIVITY

The burst formation from human and murine burst forming unit-erythroid (BFU-E) requires the presence of erythropoietin (Epo) in semi-solid c ultures of bone marrow cells, A number of haematopoietic factors are d escribed that increase the burst number: interleukin 3 (IL-3), stem ce ll factor (SCF), granulocyte-macrophage colony-stimulating factor (GM- CSF), IL-9, IL-11, insulin-like growth factor I, and erythroid potenti ating activity (EPA). The authors now show that another activity prese nt in medium conditioned from adult or fetal human kidney cells specif ically stimulates the proliferation of BFU-E, A cell line derived from fetal kidney produced such an activity, which was shown to be differe nt from the previously cited haematopoietins, acted on CD34(+)-enriche d BFU-E and promoted an increase in CFU-E number in the bone marrow of injected animals, could be precipitated using 40% ammonium sulfate, w as destroyed by proteolytic enzymes and was shown to be a glycoprotein by its retention on ConA-Sepharose. The authors propose to cab this a pparently novel activity, which influences only the number of bursts, human erythroid burst-stimulating activity (hEBSA). (C) 1998 Academic Press.