EXPRESSION OF LEUKOCYTE DIFFERENTIATION ANTIGENS DURING THE DIFFERENTIATION OF HL-60 CELLS INDUCED BY 1,25-DIHYDROXYVITAMIN D-3 - COMPARISON WITH THE MATURATION OF NORMAL MONOCYTIC AND GRANULOCYTIC BONE-MARROWCELLS

1,25-Dihydroxyvitamin D-3 [1,25-(OH)(2)D-3] induces monocytic differen tiation of the HL-60 leukemic cell line, The present study investigate d whether and to what extent this differentiation resembles the normal maturation of monocytic cells in the bone marrow, Multidimensional fl ow cytometry was used to identify changes in antigen expression that o ccur in normal bone marrow cells at distinct stages of monocytic and g ranulocytic maturation, HL-60 cells were analyzed in the same manner a fter exposure to 1,25-(OH)(2)D-3 to determine whether the hormone indu ces a similar sequence of phenotypic changes, In the leukemic cells, m onocytic features were sequentially induced and several maturational s teps could be resolved, CD14, CD32, CD53, CD15, CDw65, CD29, CD16, and CD66b were modulated in 1,25-(OW)(2)D-3-induced HL-60 cells as in the normal monocytic maturational pathway, Differences were observed for CD15s and CDw17. The expression pattern of CD44 during differentiation of HL-60 cells resembled that in granulocytic cells, The results ther efore suggest that 1,25-(OH)(2)D-3 induces a differentiation program i n HL-60 cells that in many ways resembles that of normal monocytic cel ls in the bone marrow but also carries elements of the granulocytic pa thway.