Fig 1: Effect of IFN-γ on indoleamine 2,3-dioxygenase expression in cultured chorionic villi. Chorionic villous explants from term placenta were cultured with 1000 unit/ml IFN-γ or vehicle for 36 hours. (A) RT-PCR. The relative abundance of indoleamine 2,3-dioxygenase-1 (IDO1), indoleamine 2,3-dioxygenase-2 (IDO2), and glyceraldehyde phosphate 3-dehydrogenase (GAPDH) mRNA were analyzed by RT-PCR as described in the section “Materials and Methods.” The results presented are representative of 3 separate experiments performed with 3 placentas yielding similar results. (B) Relative quantitation. IDO1, IDO2, and GAPDH mRNA expression were analyzed by quantitative RT-PCR as described in the section “Materials and Methods.” Data represent the mean ± SD of 3 separate experiments performed with 3 placentas. *Significantly different from values for villous explants cultured with vehicle alone (P < .05). (C) Immunocytochemistry. Cultured villous explant stained for IDO1 and IDO2 as described in the section “Materials and Methods.” The results presented are representative of 3 separate experiments performed with 3 placentas. Scale bars represent 100 µm.