Cell-to-cell interaction in airway mucosa--effect of eosinophils on airway epithelial ion transport

Abstract

We examined the interaction between eosinophil-derived mediators and ion transport in airway epithelial cells. Eosinophils were obtained by peritoneal lavage from polymyxin B-treated guinea-pigs and were purified over discontinuous Percoll density gradients. The activated eosinophil supernatant was prepared with a two-stage method in the presence of A23187. The effects of eosinophil supernatant on the electric properties of cultured epithelial cells from cow trachea were examined in an Ussing chamber under short-circuit conditions. The eosinophil supernatant added to the serosal and mucosal sides increased the short-circuit current (Isc) in an eosinophil number-dependent manner (3 x 10(6), 10(7) eosinophils: delta Isc 9 +/- 1 microA/cm2, 18 +/- 3 microA/cm2). The response was inhibited by treatment of epithelial cells with diphenylamine-2-carboxylate but not by amiloride. The increase in Isc induced by the supermatant from eosinophils treated with indomethacin or the lipoxygenase inhibitor AA861 was significantly less than that induced by untreated eosinophils. These results indicate that activated eosinophils stimulate C1 secretion in airway epithelium via release of metabolites of arachidonic acid.