Effect of anti-CCR4 antibodies on calcium mobilization induced by CCR4-specific ligands CCL22 and CCL17 and by irrelevant ligand CXCL12.

CCR4-positive CCRF-CEM cells, loaded with the Ca2+ sensing dye Fluo-4, were stimulated with either CCR4-specific ligands CCL22 and CCL17 or the irrelevant chemokine CXCL12, in presence or absence of antibodies. Samples were analyzed by FACS and the AUC value, corresponding to CCR4 receptor activation, was recorded over 2 min. Ratios of integrated AUCs expressed as percentage of AUC for stimulation with the ligand alone are shown.