IκBζ and IFN-γ expression in human lymphocytes. Human lymphocytes were assessed for the expression of IκBζ and IFN-γ in response to recombinant IL-12 and IL-18 (10 ng/mL each) at 6 and 24 hours. (A) Time course of IκBζ protein expression in human lymphocytes by immunoblot compared with lipopolysaccharide-stimulated monocyte lysate (Control). (B) IκBζ mRNA expression in human lymphocytes assessed by quantitative PCR. (C) IFN-γ release from human lymphocytes in response to IL-12 and IL-18 was determined by ELISA. (D) IFN-γ mRNA expression in human lymphocytes. The immunoblot is representative of 3 independent experiments. Bar values represent mean ± SEM for 3 to 5 experiments. **P < .05 vs controls. RCN indicates relative copy number.