Microscopy images of PMNs cocultured with CLL B cells and anti-CD20 OBZ or CET control antibody. (A) Live-cell time-lapse microscopy experiments were performed with purified PMNs and CLL B cells at a 1:2 E:T ratio, cultured at 37°C in X-VIVO medium (Lonza) in the presence of 10 µg/mL of anti-CD20 OBZ-GE or CET control antibody. Time point 0 (T = 0): image taken at the start of the experiment before all CLL B cells had settled down to the bottom of the well. The other representative images were taken at ∼15, 30, 60, and 180 minutes after adding the indicated antibodies. Asterisks mark selected PMNs that repeatedly contacted the CLL B cells (indicated by arrowheads of the same color). Colored circles mark selected PMNs that made brief contact with CLL B cells in the control (CET) experiment. Original magnification ×400. The full videos of representative experiments in the presence of OBZ-GE (supplemental Video 1), CET (supplemental Video 2), RTX-WT (supplemental Video 3), RTX-GE (supplemental Video 4), and control beads (supplemental Video 5) are available on the Blood Web site. (B) Confocal microscopy images of PKH26-labeled PMNs (red) and PKH67-labeled CLL B cells (green) cocultured for 3 hours in the presence of 10 µg/mL of RTX-WT or CET control antibody. The yellow arrows indicate a representative red PMN that trogocytosed green PKH67 dye from CLL B cells. Original magnification ×630. Additional images are available (supplemental Figure 1).