c-MYC expression in M2 macrophages. (A) Expression levels of the c-MYC transcript in human resting macrophages (○; n = 6 independent donors) and after exposure to 20 ng/mL of IFN-γ plus 10 ng/mL of LPS (□; n = 6 independent donors) or 20 ng/mL of IL-4 (■; n = 6 independent donors) at different time points. (B) Expression levels of c-Myc at protein level in human resting macrophages (M0) and after 48 hours of exposure to 20 ng/mL of IFN-γ plus 10 ng/mL LPS (M1) or 20 ng/mL of IL-4 (M2). Results from 1 experiment representative of 3 performed are shown. (C) Immunofluorescence analysis revealing c-MYC translocation to cell nucleus 48 hours after exposure to 20 ng/mL of IL-4 (inset shows 1 experiment representative of 3 performed, shown as means ± SD). (D) Expression levels of the c-MYC transcript in monocytes (Mono), resting macrophages (M0), and macrophages stimulated for 24 hours with 20 ng/mL of IFN-γ plus 10 ng/mL of LPS (M1), 20 ng/mL of IL-4, 20 ng/mL of IL-13, 20 ng/mL of IL-10, 20 ng/mL of TGF-β, 20 ng/mL of dexamethasone (GC). Results are shown as means ± SD of n = 6 independent experiments. (E) c-MYC induction after exposure to 20 ng/mL of IL-4 is reverted when cells are shifted to M1-polarizing conditions (20 ng/mL of IFN-γ plus 10 ng/mL of LPS) for an additional 24 hours.