Impact of modulation on ADCC and ADCP effector mechanisms. (A-B) Surface levels of CD20 after incubation with type I and II mAbs. Target murine hCD20 (A) or primary human CLL (B) B cells were opsonized with 10 µg/mL anti-CD20 mAbs for 30 minutes or 6 hours; samples were then stained for 30 minutes with anti-mouse (A) or anti-human (B) Fc PE and assessed by a flow cytometer, using BD QuantiBRITE beads to calculate mean number of PE molecules/cell (N = 3). (C-D) Impact on ADCC, murine hCD20 (C), or primary human CLL (D) B cells were loaded with calcein-AM and incubated with anti-CD20 mAbs for either 30 minutes or 6 hours with 10 µg/mL anti-CD20 mAbs. Samples were then cocultured for either 2 hours with mNK cells (C) or 4 hours with human peripheral blood mononuclear cells (D) at an E:T ratio 10:1 and 50:1, respectively. Sample supernatant was assessed for fluorescence at 495 nm. (E-F) Impact on ADCP, murine hCD20 (E), or primary human CLL (F) B cells were stained with CFSE and incubated with 10 µg/mL anti-CD20 mAbs for either 30 minutes or 6 hours. Samples were then cocultured for 30 minutes with murine BMDMs (E) or 1 hour with human MDMs (F) and then assessed by flow cytometer. Statistical analyses were carried out using 2-way ANOVA with multiple comparisons and significance was accepted at *P < .05, **P < .01, ***P < .001, and ****P < .001.