Figure 3.

C3d suppresses the BCR induced IL-6 production of human B cells. Resting human B cells were cultured with complexes consisting of either streptavidin-conjugated biotinylated anti-IgG/A/M (control) or streptavidin-linked biotinylated anti-IgG/A/M and biotinylated C3d in different concentrations as indicated. Interleukin (IL)-6 production was measured by ELISA after 48 h. Mean IL-6 concentrations ± SD of triplicate samples of a representative donor are shown (A). Mean IL-6 concentrations of differently treated samples were compared to the control samples taken as 100%. The cumulative results gained in three independent experiments display the mean of the relative values ± SD (B). *p < 0.05, **p < 0.01, ****p < 0.0001.