Fig. 2.

Co-ligation of CD40 and CD46 on B cells inhibits CD40 up-regulation of CD23 expression. Purified peripheral blood B-cell populations (>96% CD20⁺ cells) were stimulated with mAb to CD40 in the absence or presence of mAb to CD46 or to CD21, followed by cross-linking with GAMIG and analyzed as described for PBMCs in Fig. 1. Percentages of CD20⁺ cells that are CD23⁺ are given in the inset. Numbers in parentheses refer to MFI. Results are representative of three experiments.