Identification of a differentiation-specific cell surface antigen on HL60 cells that is associated with proliferation

We have produced a murine IgM monoclonal antibody (Y201) that recognizes a cell surface antigen present on HL60 cells. Seventy percent of uninduced HL60 cells expressed Y201 antigen, while the remainder did not. There were no morphological differences between HL60 cells that expressed Y201 antigen and cells that did not express Y201 antigen. Cells with the greatest number of antigenic sites were found to have greater proliferative capacity in liquid culture and in soft agar than did HL60 cells deficient in this marker. Expression or lack of expression of the Y201 antigen is not constant over a prolonged period in that both subpopulations ultimately reproduced the original pattern of antigenic expression when grown in liquid culture. The antigen identified by Y201 was lost with terminal differentiation of HL60 cells using a variety of inducers. Loss of Y201 antigen during differentiation was associated with a decrease in proliferative capacity in soft agar. Loss of Y201 antigen by greater than 95% of differentiated HL60 cells was associated with loss of proliferative capacity. These data suggest that HL60 cells are heterogeneous in regard to proliferative capacity and that this heterogeneity is associated with expression of the cell surface antigen identified by Y201.