FIG. 3.

Inhibition of calcium mobilization into CCR5⁺ cells by anti-CCR5 MAbs. L1.2-CCR5⁺ cells were loaded with Indo-1AM and stimulated sequentially with an anti-CCR5 MAb or PBS, followed by RANTES (a). Fluorescence changes were measured with a spectrofluorometer, and the tracings are from a representative experiment. Calcium flux inhibition by PA14 and 2D7 was tested for a wide range of MAb concentrations (b). Results are plotted as percent inhibition of calcium influx = [1 − (peak relative fluorescence in the presence of MAb/peak relative fluorescence in the absence of MAb)] × 100% and are means of values from three independent experiments.