Figure 6.

Complement dependent lysis and C3b deposition on B cell lines. Ramos, Daudi, P493.6 and LCL1.11 B cell lines were treated with 20 µg/ml (A, C) or 2 µg/ml (B, D) anti-CD20 mAb and 20% human serum (white bars) for 30 min at 37°C. As controls, cells were treated with heat-inactivated serum (black bars) or with serum in absence of anti-CD20 mAb. (A, B) Dead cells were quantified by flow cytometry analysis of DAPI stained cells. (C, D) Quantification of C3b/iC3b deposition on B cells. Bars show statistical mean ± standard deviation of n=3–5 independent experiments each using three to seven human serum samples (A, C) or n=2–3 independent experiments each using three to four human serum samples (B, D) per cell line. For statistical analysis, two-way ANOVA and Tukey´s multiple comparison test were applied. *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001.