title: Isolation and analysis of primitive hemopoietic progenitor cells on the basis of differential expression of Qa-m7 antigen.
abstract: In the presence of the hemopoietic growth factor CSF-1, the later committed cells of the macrophage lineage can be detected by their ability to form small colonies in clonal agar culture (CFCCSF-1). Synergistic factors have been described that in combination with CSF-1 stimulate developmentally early hemopoietic progenitor cells of high proliferative potential (HPP-CFC). By using a monoclonal antibody to the Qa-m7 antigenic determinant, we investigated and compared the expression of Qa-m7 on CFCCSF-1 and on HPP-CFC of two types that grow in response to either 1) CSF-1 plus synergistic factor from human placenta-conditioned medium (HPP-CFCHplac+CSF-1) or 2) CSF-1 plus synergistic factor from conditioned medium of the WEHI-3 myelomonocytic cell line (HPP-CFCW+CSF-1). We have shown that HPP-CFC of both types express relatively more Qa-m7 antigen than CFCCSF-1 and can be separated and enriched on this basis by discontinuous buoyant density centrifugation and fluorescence-activated cell sorting of normal bone marrow. Significant enrichments of HPP-CFCHPlac+CSF-1 (43.5-fold) and HPP-CFCW+CSF-1 (28.8-fold) have been achieved with cloning efficiencies of HPP-CFC in the most enriched fractions reaching 4 to 5%. These results clearly illustrate the fact that there are populations of progenitor cells from normal, unperturbed bone marrow that strictly require a combination of two hemopoietic growth factors (CSF-1 plus synergistic factor) in order to be detected.
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000032:analysis* / Q000276:immunology; D002454:Cell Differentiation; D002469:Cell Separation / Q000379:methods; D002499:Centrifugation, Density Gradient; D003114:Colony-Forming Units Assay; D003601:Cytotoxicity Tests, Immunologic; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000145:classification* / Q000276:immunology; D006649:Histocompatibility Antigens / Q000032:analysis* / Q000276:immunology; D015395:Histocompatibility Antigens Class I; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains
chemical_list: D000954:Antigens, Surface; D006649:Histocompatibility Antigens; D015395:Histocompatibility Antigens Class I; C032907:Q surface antigens