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

Abstract

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.