Figure 2.

Binding stability of CD20 mAbs to human primary B cells. Binding of 60 nM Ofatumumab (OFA), Rituximab (RTX) or Obinutuzumab (OBI) to primary human B cells isolated from blood of healthy donors was recorded until equilibrium was approached (not shown) and then mAb dissociation was measured either in plain cell culture medium or in presence of 60 nM of the respective unlabeled antibody. (A) One out of three independent measurements shown. (B) Signal intensities were normalized to 100% at the beginning of the dissociation. The remaining signal after 1 h (black) and 2 h (gray) dissociation both in plain media (solid) and in presence of unlabeled antibody (shaded) are plotted. Bars show mean ± standard deviation of n=3 experiments using cells from different donors. For statistical analysis of signal intensities in plain media and in presence of unlabeled antibody for individual time points, two-way ANOVA and Tukey´s multiple comparison test were applied. *p<0.05, n.s. not significant.