The mAb ligation of CD38 and CD16 induces Ca⁺⁺ currents in CD16⁺ YT and NKL cells.

YT and NKL cells were loaded with the fluorescent indicator Fluo 3-AM and preincubated for 10 minutes at room temperature with agonistic anti-CD38 (panels 1, 2, 7, and 8), anti-CD16 (panels 3, 4, 9, and 10), and anti-gp120 (panels 5 and 11). The cells were then washed and analyzed continuously at 37°C by using a FACSort instrument. RaMIg was added 10 seconds after the analysis began and was by itself unable to mobilize Ca⁺⁺ (panels 6 and 12, left). Appropriate dye loading by the cells was verified by adding the ionophore A23187 (panels 6 and 12, right). Data are presented as a density plot of the shift in the Fluo 3-AM fluorescence (y-axis) during 512 seconds (x-axis) and are from 6 experiments.