Fig. 5.

Cross-linking of CD46 to CD40 inhibits NF-κB activation. (A) Electromobility shift assay analysis of nuclear NF-κB complexes from the human B-cell line Ramos stimulated for 2 h with mAb to CD40 in the absence or presence of mAb to CD46 or CD21 followed by cross-linking with GAMIG. The shifted band represents nuclear NF-κB complexed to a radiolabeled NF-κB-binding oligonucleotide derived from the Ig κ light chain enhancer. Results of densitometry scans of the gel bands are shown as fold increase over the intensity band in control cells incubated with GAMIG alone. Similar results were obtained in another experiment. (B) Inhibition of CD40-mediated phopshorylation of IκBα by cross-linking with CD46 in primary B cells. Actin was used as loading control. The vertical line denotes where irrelevant lanes were deleted.