Suppression of NF-κB activity by miR-146a and miR-146b. (A) Luciferase reporter assay for miR-146a– or miR-146b–dependent regulation of NF-κB. Luciferase activity was measured in HEK293T cells transfected with a control empty vector, miR-146a, or miR-146b expression vector (with or without 50 ng/mL PMA). Data are presented as the mean ± SEM. Two independent experiments were performed, and similar results were obtained. +, 5 ng; ++, 75 ng. (B) Luciferase reporter assays in 293FT cells transfected with pcDNA-miR-146a (miR-146a), pcDNA-miR-146b (miR-146b), or an empty vector (Ctrl). MCS, pLuc2-KAP-MCS (multicloning site as an empty reporter). Data are presented as the mean ± SEM; n = 3. (C) Western blot analysis of TRAF6 protein expression in nonstimulated WT and miR-146a or miR-146b KO splenic B cells and those stimulated with LPS or anti-CD40 antibody. Two mice per genotype were analyzed; representative results are shown. *P < .05, **P < .01.