title: Dependence of highly enriched human bone marrow progenitors on hemopoietic growth factors and their response to recombinant erythropoietin.
abstract: Human bone marrow cells were sequentially fractionated by three negative selection steps to remove adherent cells and Fc receptor-bearing cells, followed by immune adsorption (panning) to deplete maturing cells that react with a panel of monoclonal antibodies. This nonadherent Fc receptor and antibody negative fraction could be further enriched by a positive selection "panning" step, using an antibody to HLA-DR antigen; 12-27% of the cells formed erythroid burst-forming unit (BFU-E), erythroid colony-forming unit, granulocyte-monocyte colony-forming unit, and erythroid and granulocyte and/or monocyte colony-forming unit-derived colonies with recovery of 0.5-1% of the cells and 20-100% of the colony-forming cells. Sequential fractionation resulted in increasing dependence of a subset of BFU-E-derived colonies on exogenous burst-promoting activity (BPA) for proliferation in culture, but the most enriched progenitor fraction still contained a proportion of accessory cell or BPA-independent BFU-E that responded to either natural or biosynthetic erythropoietin when added to cultures on day 0 in the absence of BPA. If the addition of erythropoietin was delayed until day 3, the data suggest that this population of BFU-E either died or became unresponsive to erythropoietin. Delayed addition of erythropoietin to cultures of enriched progenitors provided a sensitive BPA assay, since BPA-independent but erythropoietin-responsive BFU-E were eliminated. The surviving BFU-E that were dependent for their proliferation on the presence of both BPA and erythropoietin showed a characteristic dose response to increasing BPA concentrations.
mesh_terms: D000328:Adult; D001854:Bone Marrow Cells; D002469:Cell Separation / Q000379:methods; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D004920:Erythropoiesis; D004921:Erythropoietin / Q000494:pharmacology* / Q000652:urine; D005870:Giant Cell Tumors / Q000378:metabolism; D006133:Growth Substances / Q000494:pharmacology*; D006410:Hematopoiesis / Q000187:drug effects*; D016298:Hematopoietic Cell Growth Factors; D006412:Hematopoietic Stem Cells / Q000145:classification / Q000166:cytology / Q000502:physiology*; D006801:Humans; D011994:Recombinant Proteins
chemical_list: D003115:Colony-Stimulating Factors; D003470:Culture Media; D006133:Growth Substances; D016298:Hematopoietic Cell Growth Factors; D011994:Recombinant Proteins; D004921:Erythropoietin