Expression of leukocyte differentiation antigens during the differentiation of HL-60 cells induced by 1,25-dihydroxyvitamin D3: comparison with the maturation of normal monocytic and granulocytic bone marrow cells.

1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] induces monocytic differentiation of the HL-60 leukemic cell line. The present study investigated whether and to what extent this differentiation resembles the normal maturation of monocytic cells in the bone marrow. Multidimensional flow cytometry was used to identify changes in antigen expression that occur in normal bone marrow cells at distinct stages of monocytic and granulocytic maturation. HL-60 cells were analyzed in the same manner after exposure to 1,25-(OH)2D3 to determine whether the hormone induces a similar sequence of phenotypic changes. In the leukemic cells, monocytic features were sequentially induced and several maturational steps could be resolved. CD14, CD32, CD53, CD15, CDw65, CD29, CD16, and CD66b were modulated in 1,25-(OH)2D3-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 therefore suggest that 1,25-(OH)2D3 induces a differentiation program in HL-60 cells that in many ways resembles that of normal monocytic cells in the bone marrow but also carries elements of the granulocytic pathway.