Leukotriene receptors in HL-60 cells differentiated into eosinophils, monocytes and neutrophils

The expression of leukotriene B-4 (LTB(4)) and leukotriene D-4 (LTD(4)) receptors was determined, by binding assay, in HL-60 cells differentiated into the monocyte/macrophage, neutrophil, and eosinophil lineages. Monocyte/macrophage- and neutrophil-differentiated cells developed specific LTB(4) receptors with high affinities (K-d = 1.27 nM and 2.65 nM, respectively) and low affinities (K-d = 26.41 nM and 55.63 nM, respectively). These receptors were functional and specific as indicated by the ability of LTB(4) to elicit an increase in intracellular calcium concentration antagonised by specific antagonists. Eosinophil-differentiated cells developed mainly LTD(4) receptors (K-d = 41.91 nM), and stimulation with LTD(4) induced an increase in intracellular calcium that was antagonised by a specific LTD(4) antagonist. These results show, for the first time, that eosinophil-differentiated HL-60 cells express specific functional LTD(4) receptors. These cells could be used for the study of the actions of peptidoleukotrienes on eosinophils, and for studies on the molecular mechanisms regulating LTD(4) receptor expression.