ADCP of type I and II antibodies. (A) Transgenic hCD20 murine B cells were carboxyfluorescein diacetate succinimidyl ester–labeled and opsonized with 0.01 to 100 µg/mL anti-CD20 mAbs (N = 5). Opsonized B cells were cocultured with murine bone marrow–derived macrophages (BMDMs) for 30 minutes to permit phagocytosis and then analyzed by flow cytometry. (B) Levels of ADCP when target hCD20 murine B cells were opsonized with 10 µg/mL mAbs and cocultured with murine BMDMs. Statistical analyses were carried out using 1-way ANOVA with multiple comparisons and significance was accepted at *P < .05. (C) Primary human CLL samples were carboxyfluorescein diacetate succinimidyl ester–labeled and opsonized with 0.01 to 10 µg/mL anti-CD20 mAbs (N = 3). Opsonized CLL B cells were cocultured with human marrow-derived macrophages (MDMs) for 60 minutes to permit phagocytosis and then analyzed by flow cytometry.