CD40 forms complexes with c-Rel on the promoters of proliferation and survival genes in LBCL cells. (A) Supershift analysis of c-Rel and CD40 proteins binding to the NF-κB site. LBCL cell (MS) nuclear extracts were incubated with the NF-κB cold probe or antibody against c-Rel and CD40 or both. A 32P-labeled NF-κB probe was then added to the reaction mixtures, and samples were analyzed by electrophoretic mobility shift assay (EMSA). comp indicates competition. Arrow indicates the supershift complex. (B) ChIP analysis was performed on 2 LBCL cell lines (MS and McA). The indicated antibodies were used to precipitate chromatin after cross-linking. PCR to detect the BLyS, CD154, Bfl1/A1, and β-actin promoter regions was performed on the precipitated DNA. IgG was used as a nonspecific antibody control.
