Figure 2.

AMD3100 interferes with CLL cell trafficking. (A) Intracellular F-Actin was measured using FITC-labeled phalloidin in CD19-pre-labeled CLL cells after the addition of SDF-1α (100 ng/mL) at different time points without any drugs, in the presence of AMD3100 (5 μg/mL) or in the presence of pertussis toxin (200 ng/mL) as control. All time points are plotted relative to the mean fluorescence of the sample before addition of the chemokine. (B) CLL cells were pre-treated or not with AMD3100 for 30 min before being plated onto 5-μm Transwell microporous membranes for the migration assay. Results are expressed as the mean ± SEM migration index of 8 experiments. Migration index was calculated as the number of cells transmigrating in the presence of the chemoattractant divided by the number of transmigrating cells in the absence of the chemoattractant. (C) 5×10⁶ untreated or AMD3100-treated cells were added to stromal layers, and after a 3-h incubation, cells that had migrated to the stromal layer were counted as described in the Online Supplementary Appendix.