(A) Flow cytometry of anti-GD2-BNF (aGD2-BNF) binding to GD2+ neuroblastoma cells, evidenced by fluorescent antihuman IgG (ahu IgG) antibody (tinted histograms), compared with cells treated with ahu IgG antibody alone (heavy contour clear histograms) or cell autofluorescence (autofluor, light contour clear histograms). (B) Flow cytometry of anti-GD2-BNF or anti-GD2 hu14.18K322A alone binding to GD2+ CHLA-20 cells. (C) Immunofluorescence microscopy (400×) of CHLA-20 detecting human IgG (hu IgG) and nuclear DAPI. Cells were pretreated with BNF, anti-GD2-BNF, hu IgG or medium only (upper four panels). Pretreatment with 1A7 anti-idiotype antibody (aID) or with 14.G2a anti-GD2 antibody (aGD2–14.G2a) prevents binding of anti-GD2-BNF to cells (lower two panels). Representative histograms and images, four experimental repeats.
BNF: Bionized NanoFerrite; MFI: Mean fluorescence intensity; RU: Relative units.