Fig. 3: huCD26mAb exhibited ADCC against CD26+ MM cell lines.

a Cell viability was determined usingct effects on the growth of CD26− MM cell lines cultured alone (left panel), but it dose-dependently inhibited the proliferation of CD26+ MM cells in co-culture with OCs primarily at higher concentrations >10 μg/ml (right panel). The data represent the mean ± SE of three independent experiments (*p < 0.05, **p < 0.01). b ADCC assay was performed by co-culture of calcein-AM-labeled MM target cell lines with human NK effector cells in various effector–target (E/T) ratios, at a huCD26mAb concentration of 10 μg/ml. Specific lysis percentage (%) was calculated, and the data represent three experiments conducted with three different human NK effector cell donors. huCD26mAb-triggered CD26-specific lysis of CD26+ MM cell lines co-cultured with OCs in an effector–target (E/T) ratio-dependent manner by ADCC. c huCD26mAb induced lysis of CD26+ MM cell lines co-cultured with OCs with human NK effector cells at an E/T ratio of 20:1 in the presence of indicated concentrations of huCD26mAb (0.0001–10 μg/ml) or iso IgG₁. The data represent the mean ± SE of triplicate wells (*p < 0.05)