Equine CCL11 induces eosinophil cytoskeletal reorganization and activation

To assess the biological effects of purified recombinant equine CCL11 on equine eosinophil function. Following stimulation of eosinophils from normal horses, the polymerised form of actin was measured by flow cytometry using fluorescently labelled phalloidin. Migration was determined in a 96 well plate chemotaxis assay using 8 microm pore membranes, and adherence of eosinophils to serum-coated plastic was assessed using a colorimetric assay for eosinophil peroxidase. Superoxide generation was measured by the reduction of cytochrome C in a colorimetric assay. Equine CCL11 induced significant (p < 0.001), concentration-dependent actin polymerisation and migration of equine eosinophils. Stimulation with CCL11 did not induce significant adherence to serum coated plastic, or superoxide production. Equine CCL11 stimulates cytoskeletal reorganization and migration of equine eosinophils, suggesting that it may be involved in the regulation of eosinophil trafficking in horses.