Multilineage differentiation potential of Mpl-expanded bone marrow cells.

Flow cytometric analysis was performed on 2 subclones (A and B) derived from single-cell plating from a pool of F1Mpl-transduced bone marrow cells. Before derivation of the subclones, the pool had been maintained in culture in the presence of FK1012 for more than 3 months. Flow cytometry was performed using antibodies directed against erythroid (Ter119), monocytic (CD11b), and granulocytic (Gr-1) cells in the presence of FK1012 alone (controls) or after 6 days of culture using conditions designed to elicit erythroid (SCF/Epo) or granulocyte–macrophage differentiation (IL-3–GM-CSF). Cells cultured in the presence of FK1012 alone (blue-shaded curves) provided controls for antibody staining. Culture in SCF/Epo produced 35% to 40% Ter119-positive cells, whereas culture in IL-3–GM-CSF resulted in 60% of cells expressing CD11b and 25% to 30% of cells expressing Gr-1.