Fig. 4.

Additive effect of anti-GD2 and stimulation by pDC for NK cell degranulation and the killing of autologous patient’s neuroblastoma cells. a Large spectrum of GD2 expression on P004′s NB cells. SJ-N-TQ42 cells were stained with anti-GD2 mAb and analyzed by flow cytometry. b NK cell cytotoxic assays against autologous patient’s NB cells. Purified NK cells from P004 were incubated with or without TLR9-activated pDC (a-pDC) for 20 h prior to cytotoxic assays against autologous SJ-N-TQ42 NB cells in the presence or not of anti-GD2 mAb (ch14.18). Specific lysis of are represented for E:T ratio of 2:1 and 5:1. Due to the low amount of peripheral blood from very young patient, only two E:T ratios were performed and the results of one (E:T 5:1) or two (E:T 2:1) experiments are displayed. c NK cell degranulation assays against autologous patient’s NB cells. Unstimulated NK (unst) and stimulated NK cells (a-pDC, anti-GD2 mAb, or anti-GD2 mAb + a-pDC) were incubated with target cells at a ratio of 1:1 and stained with the anti-CD107a antibody. CD107a MFI are presented for CD56^brightCD16^low/− and CD56^dimCD16⁺ NK cells