DIFFERENTIAL EXPRESSION OF QA-M2 ALLOANTIGEN ON MURINE HEMATOPOIETIC PROGENITOR CELLS - SELECTIVE ENRICHMENT FOR MEGAKARYOCYTE PROGENITORS

Abstract

The selective expression of Qa-m2 antigen on murine megakaryocyte colony-forming cells (MEG-CFC) has been demonstrated. A monoclonal antibody defining the Qa-m2 alloantigen has been shown to inhibit, in the presence of complement, in vitro formation by murine bone marrow cells of megakaryocyte colonies, but not granulocyte-macrophage, erythroid or eosinophil colonies. Inhibition of megakaryocyte colony formation was shown, by mixing and other experiments, to be due to C-mediated lysis of MEG-CFC rather than lysis of accessory cells. B-lymphocyte colony formation was reproducibly decreased by approximately 50%, demonstrating the presence of Qa-m2+ and Qa-m2- subsets of B-lymphocyte colony-for..