Figure 2. IL-4 increases IFN-γ-induced IDO protein expression.
Cellular expression of the IDO protein was examined by immunofluorescence using anti-IDO antibody in EOC13.31 cells. Cells were either untreated, or treated with IFN-γ, IL-4 or IFN-γ+IL-4. (A) Increased numbers of cells had detectable IDO when treated with IFN-γ + IL-4 as compared to IFN-γ alone. Mean and SEM of 5 different fields, data are representative of two independent experiments. (B) Untreated (i) and cells treated with IL-4 alone (ii) did not show any positive staining for IDO. IDO was present in cells treated with IFN-γ alone (iii), and increased in cells treated with IFN-γ+IL-4 (iv).