Time-dependent internalization of CP-870,893. A. Profile of surface CD40 expression on peripheral blood B cells and monocytes before and after CP-870,893 infusion. Cells were stained with FITC labeled anti-CD40 clone 5C3, CP-870,893, or isotype control (red histogram). B. Monocyte-derived dendritic cells were labeled with CP-870,893 FITC or a non-agonistic FITC-conjugated anti-CD40 antibody (clone 5C3) followed by incubation with recombinant CD40L trimer. Images were taken at 0, 15, 30, and 60 minutes.