Characterization of a novel chemotactic factor for neutrophils in the bronchial secretions of patients with cystic fibrosis

Abstract

Chronic airway inflammation is a hallmark of cystic fibrosis (CF). Biological products with chemotactic activity are essential for neutrophil recruitment to sites of inflammation. The presence of a factor with chemotactic activity higher than that of interleukin (IL)-8 in the bronchial secretions of patients with CF has recently been reported. This article reports that the chemotactic activity of this factor remained unaffected by a variety of physical treatments and could be distinguished from those of IL-8, formylmethionylleucylphenylalanine, leukotreine B4, and platelet-activating factor. The factor induced chemotaxis and chemokinesis locomotion of neutrophils, and its chemotactic activity was sensitive to pertussis toxin and thapsigargin. Semi-purified preparation of the chemotactic factor increased transiently intracellular Ca2+ concentration but failed to stimulate the release of neutrophil primary granules and the production of superoxide, suggesting that the semipurified chemotactic factor is a Ca2+-dependent chemoattractant of neutrophils, acting via pertussin toxin-sensitive G protein-coupled surface receptors, that directs neutrophil movement toward the airway epithelium.