FIG. 8.

(A) Opposite effects of AMD3451 and AMD3100 on the binding of anti-CXCR4 (12G5) MAb to Molt-4 cells. After preincubation for 30 min on ice with or without the compounds at the indicated concentrations, the cells were stained with phycoerythrin-conjugated 12G5 MAb and analyzed by flow cytometry. The upper panel shows the aspecific background fluorescence of Molt-4 cells, as determined by an isotype control MAb. The second panel shows Molt-4 cells stained with the antibody in the absence of any compound. The MFI of the cell population is indicated in each histogram. The data shown are from one representative experiment out of four. (B) Effect of AMD3451 on competition binding of anti-CXCR4 antibody 12G5. The binding assay was performed with COS-7 cells transfected with wild-type (wt) CXCR4 with ¹²⁵I-12G5 as a radioligand. The data are shown as means ± standard errors of the means (n = 3).