Chemotactic response of NK cells in response to chemerin. Freshly purified NK cells were isolated and used in Transwell-chemotactic assays (A) or in endothelial transmigration experiments (B). CXCL8 was used as reference NK cell chemotactic agonist. Checkerboard analysis was performed using 300 nM chemerin in the lower, upper, or both lower and upper wells (C). (D) NK cells were preincubated with different concentrations of Bordetella pertussis toxin (PTox) at 37°C for 3 hours and then tested in chemotaxis assays (300 nM chemerin, 10 nM CXCL8). Results are expressed as percent of migrated cells; values are the mean ± SE of 3 (A-C) or 2 (D) independent experiments. * P < .05 by paired Student t test versus control cells. Dotted lines (A-B) represent basal cell migration.