COMPARISON OF THE PROSTAGLANDIN-E (EP) RECEPTOR OF HUMAN NEUTROPHILS AND HL-60 CELLS DIFFERENTIATED WITH DMSO

Human promyelocytic leukaemic HL-60 cells can be differentiated with DMSO to become neutrophil-like. In this study, the prostanoid receptors linked to adenylate cyclase have been compared in human neutrophils and in differentiated HL-60 cells. Both cell types appear to express EP(2) receptors as recognised by the ability of EP(2) agonists and not EP(1) or EP(3) agonists to increase cell cyclic AMP levels, and the finding that the increase in cyclic AMP induced by PGE, was not blocked by the EP(4) receptor antagonist AH 23,848 (30 mu M). Neither cell type appears to express receptors for PGI(2), but human neutrophils and not differentiated HL-60 cells express receptors for PGD(2). In addition, human neutrophils may contain EP(3) receptors linked to a reduction in cyclic AMP levels. The lack of other prostanoid receptors coupled to adenylate cyclase in HL-60 cells suggests that these cells may provide a useful starting point for the cloning of the EP(2) receptor