Abstract: | A variant strain of HL-60, which is positive for HLA-DR antigen, was induced to express HLA-DQ antigen following treatment with phorbol esther. It was preceded by cell cycle arrest in the G1 phase and was accompanied by augmented phagocytosis. This differential expression of HLA class II antigens on this subline may contribute to understanding the functional role of HLA class II antigens in the hematopoietic differentiation of macrophage cells. |