Adenoviral delivery of constitutively active STAT3 in IL-10^-/- BMDCs inhibits cRel recruitment to the IL-12p40 gene promoter without affecting the NF-κB pathway. IL-10^-/- BMDCs were infected with either Ad5STAT3C or Ad5GFP, or preincubated with IL-10 (10 ng/mL) for 12 hours, and then stimulated with LPS (5μg/mL) for 1 or 4 hours. (A) Protein extracts from infected BMDCs were collected after 1 hour, and Western blot analysis was performed using antibodies for IκB, phospho-RelA, and RelA. (B) Cells were treated for 4 hours as described and cRel recruitment to the IL-12p40 promoter was analyzed by ChIP, as described in “Materials and methods.” The results are representative of 2 independent experiments.