title: Enrichment of pluripotent hemopoietic progenitor cells from human bone marrow.
abstract: Pluripotent hemopoietic progenitor cells (CFU-GEMM, cells forming mixed hemopoietic colonies in methylcellulose) from human bone marrow were enriched 90-fold by positive selection on the fluorescence-activated cell sorter using monoclonal antibody RFB-1. Bone marrow cells were separated by cell size, using log 90 degrees light scatter, and the cell fraction containing CFU-GEMM was further separated by relative fluorescence intensity for the RFB-1 antigen. Further enrichment, up to 150-fold, was achieved by depleting bone marrow of T cells and mature myeloid cells prior to RFB-1 selection. These procedures yield a cell fraction containing 51% blast cells, 2% promyelocytes, and 47% undifferentiated (lymphocyte-like) mononuclear cells, although only 1% of the cells formed a mixed colony. CFU-GEMM are strongly positive for the RFB-1 antigen, whereas morphologically identifiable erythroblasts, myeloblasts, and promyelocytes are weakly RFB-1+. This suggests that the relative concentration of the RFB-1 antigen on bone marrow cells is inversely related to their maturity. The greatly increased recovery of CFU-GEMM after the separation of bone marrow by log 90 degrees light scatter and the removal of T cells and mature myeloid cells suggested that accessory cells that normally regulate the cloning efficiency of CFU-GEMM were removed.
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D001854:Bone Marrow Cells; D002452:Cell Count; D002469:Cell Separation; D003114:Colony-Forming Units Assay; D006098:Granulocytes / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D008027:Light; D012542:Scattering, Radiation; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal