induce a downmodulation of C-C chemokine receptor type 5 (CCR5) surface expression on monocyte-derived microglial-like cells (MDMis). Cells were either left untreated (continuous lines) or treated with 10 ng/ml of (A) LTB4 or (B) LTC4 (dotted lines) for 24 h before labeling with a phycoerythrin (PE)-conjugated anti-CCR5 antibody or PE-conjugated irrelevant control antibody (gray areas). Expression levels of CCR5 were determined by flow cytometry. Results shown are from one donor representative of three. (C) MDMis were either left untreated or treated with increasing concentrations of LTs for 24 h before labeling with a PE-conjugated anti-CCR5 antibody. To compensate for donor-to-donor variations, the results shown represent the mean percentage of CCR5 positive cells ± SD calculated from three independent experiments and are expressed as percentages of control (Ctrl) (*P < 0.05).