Fig. 1.

MAB273 binds CD40 and activates human B cells and MDCs with a similar potency as CP-870,893 in vitro. A Surface expression levels of CD40 were evaluated by flow cytometry after exposure with MAB273 or CP-870,893. n = 3, mean ± SEM. B Flow cytometry (left) and ELISA (right) results show the signal of competitive CD40L-biotin-streptavidin conjugate after culture with MAB273 or CP-870,893 or CD40L. n = 3, mean ± SEM. C–D Human PBMCs were stimulated with MAB273, CP-870,893 or TLR7/8L (positive control). Costimulatory markers CD80, CD70 and LN homing marker CCR7 on B cells (C) and MDCs (D) were evaluated by flow cytometry. n = 3, mean ± SEM. E Human PBMCs were stimulated with MAB273, CP-870,893 or CpG (positive control) for 5 days. B cell proliferation is displayed as the number of CellTrace Violet negative B cells per 10⁶ B cells. Representative flow cytometry plots are shown. n = 3 + 3, mean ± SEM