Figure 3

BCR induced signaling is impaired in SLL/CLL and MZL lymphoma B cells. Flow cytometry analysis of BCR-induced phosphorylation of key signaling proteins downstream of BCR. Lymphoma patient samples and PBMCs from healthy donors were stimulated with BCR crosslinking alone (anti-IgM/anti-IgG) or with a combination of BCR crosslinking and hydrogen peroxide (H₂O₂) for 4 or 45 minutes. (A) Scatter plot showing relative MFI for each aBCR- or aBCR+H₂O₂-induced phospho-proteins in CD20⁺ B cells after 4 minutes, normalized to the MFI value in the corresponding unstimulated CD20⁺ B cells from the same individual. SLL/CLL (n = 11), MZL (n = 5) and PBMC (n = 9); * p < 0.05; Mann Whitney test. (B) BCR induced phosphorylation after 4 and 45 minutes. Relative MFI was calculated as in A), and shown is bar charts of mean relative MFI ± SEM, for SLL/CLL (n = 11); MZL (n = 5) and PBMC (n = 9). * p < 0.05; paired t test. (C) Overview of phosphorylated signaling proteins after 4 minutes of BCR stimulation. Phospho-proteins investigated have red color. Pie charts indicate phospho-proteins with significant reduced expression in SLL/CLL or MZL compared to normal B cells. The dark red color in pie charts indicates percentage of relative MFI in SLL/CLL or MZL compared to normal B cells. Phospho-proteins with only light red color indicate no significant change of expression compared to normal B cells.