Impact of glycosylation status on whole blood ADCC and contribution of PMNs. Tumor cell lysis at various antibody concentrations was analyzed with whole blood from healthy (A) or G-CSF–primed donors (C) as a physiologic combination of different effector cell populations. A431 cells served as target cells. To analyze PMN involvement in target cell killing in whole blood, ADCC assays were performed in the presence of F(ab′)2 fragments of FcγRII blocking antibody AT10, or control F(ab′)2-fragments (both at10 μg/mL). 2F8 antibody concentrations were0.4 μg/mL. Blocking experiments with blood from healthy donors (B), or from G-CSF–primed donors (D). 2F8-C (●), 2F8-H (○), or human IgG1 control antibody (Δ). Data from experiments with 5 (healthy donors) and 3 (G-CSF–primed donors) different volunteers, respectively, are presented as means plus or minus SEM. *Significant difference in killing between 2F8-C and 2F8-H. #Significant blockade compared with control treated samples (P < .05).
