Expression of IDO-specific transcripts in nonadherent CD123⁺/CCR6⁺ DCs from healthy donors and MS patients before and after treatment with IFN-γ. Immature DCs (iDCs) obtained from healthy donors (A) or MS patients with or without MBP loading (B) were cultured overnight with medium containing maturation factors, supplemented or not with IFN-γ. Total RNA was isolated and reverse transcribed into cDNA. PCR was performed using IDO-specific primers, and the products were analyzed by agarose gel electrophoresis. The positive control (+) consisted of material extracted from IDO transgene expressing 293 cells, whereas negative control “a” (-a) was water instead of RNA for reverse transcription and negative control “b” (-b) was water instead of cDNA template for PCR; M indicates DNA molecular marker. One representative example for healthy donors and MS patients is shown. A faint IDO band occurred in 2 of 9 tested DCs.