D-2-HG reduces intracellular IL-12 levels and mRNA expression in DCs. (a) Monocyte-derived immature dendritic cells (iDCs) were activated with 100 ng/mL LPS with or without D-2-HG in the presence of monensin. Intracellular levels of IL-12 p35 and IL-12 p40 were analyzed by flow cytometry. One representative experiment out of three is shown. (b,c) Monocyte-derived iDCs were activated with 100 ng/mL LPS with or without D-2-HG or L-2-HG for 4 h (b,c) or 24 h (d,e). RNA was isolated from cell lysates. After reverse transcription, the samples were analyzed by RT-qPCR. Gene expression of IL-12p70 subunits IL-12A and IL-12B relative to 18S RNA are shown. Data represent the median of three independent experiments. Statistical analysis was tested using an Ordinary One-Way Test with Dunnet’s multiple comparison test (* p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001).