Figure 2.

The effect of IL-18 and IL-18BP on IL-1β-induced PGE₂ and IFN-γ production in PBMC. PBMC were cultured in flat bottom wells at 5 × 10⁶ cells/ml in RPMI containing IL-12 (5 ng/ml) in the presence or absence of IL-1β (100 ng/ml). In addition, PBMC were simultaneously stimulated with either IL-18 (5 nM) or IL-18BP (100 ng/ml). After 48 hr, levels of IFN-γ (A) and PGE₂ (B) were measured. The data represent the fold-increase ±SEM over that of the spontaneous production in unstimulated cells (set at 1). n = 8 donors. (A) *, P < 0.05 compared with IL-1β only. (B) *, P < 0.05 compared with control; **, P < 0.01 compared with the combination of IL-1β plus IL-18.