Cytokine secretion and IDO activity of mature DCs. (Left panel) DCs were matured for 24 hours with CC or CD40L in the presence or absence of LTC4 or PGE2. Supernatants were harvested and secretion of IL-10, IL-12p70, and IL-12p40 were analyzed by ELISA. To determine IDO enzyme activity in mature DCs, conversion of tryptophan into kynurenine was determined. The data shown are the mean ± SEM of triplicate cultures and represent 1 of 2 experiments that yielded similar results. (Right panel) Stability of mature DC phenotype in the absence of IL-4 and GM-CSF. DCs were matured for 2 days with CD40L in the presence of LTC4. Cells were then frozen, thawed and cultured for another 2 days in the absence of any cytokines and the expression of HLA-DR and maturation markers CD25, CD83, and CD86 was analyzed by FACS. The data presented are from 1 of 3 experiments that all yielded similar results.
