Bcl-3-deficient macrophages are defective in IL-10-mediated suppression of LPS-induced TNF-α production. (A-B) Peritoneal macrophages from wild-type and Bcl-3-deficient mice were pretreated with IL-10 at the indicated concentrations for 18 hours and stimulated with 100 ng/mL LPS for an additional 24 hours. Concentrations of IL-6 (A) and TNF-α (B) in the culture supernatants were measured by ELISA. The experiments were repeated with 3 different animals and produced similar results. Open circles indicate wild-type mice; closed squares, Bcl-3-deficient mice. (C) Peritoneal macrophages from wild-type and Bcl-3-deficient mice were pretreated with 10 ng/mL IL-10 for 18 hours and stimulated with 100 ng/mL LPS for 2 hours. TNF-α mRNA expression was analyzed by Northern blotting.