Kinetics of CCL18 production by differentiated DCs and effect of CCL18 neutralization. Monocytes were purified from nonallergic (NA) or allergic (A) subjects and differentiated for 6 days with different cytokines. (A) GM-CSF plus IL-4–differentiated DCs were analyzed for CCL18 production by ELISA at day 1, 2, 5, and 6 of differentiation and at day 8 after maturation. Evolution of CCL18 production (black line) and flow cytometry DC phenotype (histograms) expressed as mean fluorescence intensity (MFI) for the indicated markers during differentiation. (B) GM-CSF plus IL-4 differentiated DCs from NA or A donors were treated or not with a neutralizing anti-CCL18 antibody, and cytokine production was quantified by ELISA 48 hours after DC maturation and 5 days after coculture with allogenic naive T cells (DC/T). (C) DCs differentiated for 6 days with the indicated combinations of cytokines were evaluated for CCL18 production by ELISA at different time points of differentiation. Results are expressed as mean ± SEM (ng/mL) for CCL18 and mean ± SEM (pg/mL) for the other cytokines. n = 3-6 per condition for panel A, n = 8 NA and 5 A for panel B, and n = 10 or 11 for panel C. *P < .05, NA versus A. ^##P < .01, NA versus A. NS indicates not significant.