Figure 1.
BHK-derived FVIII possesses higher levels of the αGal antigen than does CHO-derived FVIII. (A) BHK or CHO cells were incubated with FITC-IB4 lectin, followed by examination of IB4 binding by flow cytometric analysis. Blue lines represent IB4 binding, and gray shaded areas indicate no stain control. (B) Mass spectrometry analysis for αGal bearing N-glycans from BHK-derived FVIII (Helixate) or CHO-derived FVIII (ADVATE). Highlighted peaks correspond to biantennary N-glycans decorated with 1 or 2 αGal residues. (C) Schematic diagram of microarray construction, interrogation, and analysis for examining possible lectin and antibody interactions with BHK-derived or CHO-derived FVIII. (D) Quantitative analysis of IB4 binding following incubation with a microarray populated with ADVATE and Helixate. ****P < .0001, Student t test. FSC, forward scatter; RFU, relative fluorescence unit; SSC, side scatter.