The synergistic effect of TNFα and IL-1β/IL-18 on IκBζ protein expression is partially suppressed with a TNFα-specific Ab, but completely blocked with IL-1β and/or IL-18 neutralization.

<p>KG-1 cells (10⁶/ml) were stimulated with rIL-1β, rIL-18, rTNFα (10 ng/ml each) (A), or the indicated combinations of these cytokines (B and C) for the indicated time points. At selected time points, the cells were incubated with the recombinant proteins in the presence of IL-1ra (100 µg/ml), IL-18R Ab (10 µg/ml), TNFα Ab (10 µg/ml), or different combinations of these neutralizing agents. Protein-matched total cell extracts were analyzed by Western blotting using anti-serum against IκBζ and actin Ab. Results are representative of at least 3 separate experiments.