Fig. 1. ADCC activities of anti-β₂M mAbs against MM cells.

Myeloma cells were incubated with ⁵¹Cr for 1 hour, washed, and incubated with different numbers of PBMCs and anti-β₂M mAbs D1 or mIgG1 for 4 hours. Shown is ADCC killing of (A) ARP-1, (B) different MM cell lines, (C) MSCs, B cells and ARP-1, and (D) CD138⁺ primary MM cells and CD138⁻ nonmyeloma cells from MM patients, mediated by anti-β₂M mAbs at different concentrations (A, C, and D) and at different E:T ratios (A). In B, C and D, an E: T ratio of 40:1 was used. Summarized data from three performed independent experiments are shown. *P < 0.05, **P < 0.01.