CCR5 internalization is rapidly induced by CCL3 but not by U83A or U83A-N. Results are representative of 3 sets each. (A) Dose effect of CCL5, U83A, and U83A-N on U373-MAGI-CCR5E CCR5 surface expression after 5 minutes and monitored by flow cytometry. (B) CCR5 internalization kinetics over 2 hours induced by 50 nM CCL5, 100 nM U83A or U83A-N. (C) Quantification of CCR5 internalization induced by 100 nM CCL3 and inhibited by U83A and U83A-N. Mean ± SDs of triplicates.