Bimodal differentiation prospectives for promyelocytes.

In accordance with the long-range goal to demonstrate the direct derivation of blood monocytes from promyelocytes in human bone marrow, the promyelocytic cell line HL-60 in the present study was differently stimulated with various inducers for the purpose of documenting its capability to evolve into granulocytes or monocytes-macrophages. Each differentiation line was monitored with the use of marker enzymes, antigens, and cell-specific monoclonal antibodies. In addition, studies were done on normal human bone marrow and leukemias. The results provided strong evidence for the close cytogeneic relationship of granulocytes and monocytes and for a common progenitor at the maturation stage of promyelocytes-myelocytes for both cell lineages.