Addition of PGE2 to maturing DCs changes their morphology and IL12 production. (A) Morphology of immature DCs (imDCs; IL4/GM-CSF) harvested at day 7, and mature monocyte-derived DC (maDCs) harvested at day 10. Different cytokine combinations were used during the last 72 hours of DC culture: DCs were matured with TNFα and αCD40 (n = 12) or with TNFα and αCD40 in the presence of PGE2 (n = 12). Alternatively, DC maturation was induced by TNFα, IL1β, and IL6 in the presence of PGE2 (n = 3). Photographs were taken by an Olympus digital camera (Tokyo, Japan) connected to a Zeiss Telaval 31 microscope. Representative experiments for each of the culture conditions are shown. (B) IL12 secretion measured in supernatants from different DC populations. Supernatants from imDCs (IL4 + GM-CSF) and maDCs (matured as described in panel A) were harvested 72 hours after the onset of maturation and assessed for p70 IL12 by ELISA, in at least 3 experiments per condition. Black bars represent IL12 production in PGE2-treated DCs; mean ± standard deviation is shown. ^*P < .05. (C) Analysis of cell-surface expression of CD14, CD206, CD11c, CD54, CD80, CD83, CD86, CCR7, and HLA-DR by different DC populations using flow cytometry. At least 12 experiments were performed for each of the conditions, except for the combination of TNFα, IL1β, IL6, and PGE2 (n = 3); a representative experiment for each condition is shown. Isotype controls are shown as gray area underneath the dotted line; specific antibodies are reflected by the black lines.