PMN ADCC against LA-N-1 neuroblastoma cells with hu14.18 alone, hu14.18 mixed with GM-CSF, and hu14.18/GM-CSF.

Calcein-AM–labeled neuroblastoma cells (10 000 cells per well) were incubated with PMN (20:1 E/T ratio) and with anti-GD2 mAb hu14.18 alone, hu14.18 mixed with GM-CSF (100 ng/mL), or hu14.18/GM-CSF. Retained calcein fluorescence was quantified after 4 hours with DIMSCAN, and results are expressed as the tumor cell viability index (percent) calculated as described in “Materials and methods.” Each point is the mean ± SD for 6 replicate wells. Data are from 1 of 4 experiments that gave similar results.