FIG. 4.

Synergistic effect of Nod agonists with TLR agonists on induction of IL-12 p70 and IFN-γ production and on upregulation of membrane-bound IL-15, CD40, CD80, and CD86 expression on DCs. DCs were stimulated for 72 h at 37°C with MDP (10 μg/ml), FK565 (10 μg/ml), lipid A (10 ng/ml), Pam3CSSNA (1 μM, 1.27 μg/ml), poly(I:C) (10 μg/ml), or CpG DNA (2 μM). The amounts of IL-12 p70 (A) and IFN-γ (B) in the culture supernatants were analyzed by ELISA. Data are expressed as mean values ± SD, and significant differences are shown. ** and *, P < 0.01 and P < 0.05, respectively, versus medium alone; ## and #, P < 0.01 and P < 0.05, respectively, versus the respective TLR agonist alone. Cells were stained with anti-human IL-15 (C), -CD40 (D), -CD80 (E), and -CD86 (F) or with matched isotype MAbs and analyzed by flow cytometry. The results indicate the mean fluorescence intensities (MFI). The results are representative of three independent experiments.