FIG. 5.

Nitric oxide contributes to the maturation of MDDC induced by cAMP-elevating agonists through the elevation of cGMP. (A) Nitric oxide production by MDDC. MDDC were incubated with 10 μM DAF-2 diacetate with or without 1 μg/ml LPS, 1 μg/ml CT, or 1 mM d-cAMP. Twenty hours later, the cells were assayed by flow cytometry. Stimulated MDDC (solid histograms) are compared to untreated MDDC (dotted histograms). Data are representative of one experiment of three performed with similar results on MDDC derived from different donors. (B) Dibutyryl-cGMP and YC-1 activate MDDC to mature. Cell surface expression of the indicated markers on untreated MDDC (dotted histograms) or stimulated MDDC (solid histograms) is shown. MDDC were incubated with 1 mM d-cAMP (as a control) or the indicated concentrations of dibutyryl-cGMP or YC-1 for 20 h. Cells were then harvested and stained for four-color flow cytometry with PE-labeled anti-CD80, FITC-labeled anti-CD83, Cy-Chrome-labeled anti-CD86, and APC-labeled anti-HLA-DR. Data are representative of one experiment of three performed with similar results on MDDC derived from different donors.