Figure 5.

CD32 triggering does not affect interleukin-4/anti-CD40 monoclonal antibody (mAb)-induced B-cell proliferation. Tonsillar B cells were cultured with IL-4 or anti-CD40 mAb separately (open bars) or with IL-4 and increasing concentrations of anti-CD40 mAb, as shown on the x-axis. A total of 10 µg/ml mouse immunoglobulin G (IgG) (mIgG) or IV.3 mAb was added at the start of the culture. DNA synthesis was measured on day 4 by [³H]thymidine incorporation (upper panel). Other cell aliquots were cultured further until day 9 after which immunoglobulin E (IgE) concentrations were quantified in the cell supernatants (lower panel). The data were analysed for statistical significance by using the Student's t-test (*P < 0·05, **P < 0·01).