Autoimmune regulator affects macrophage polarization in murine RAW 264.7 cells

The role of autoimmune regulator (AIRE) in the peripheral tolerance is poorly understood. We hypothesize that AIRE may affect peripheral immune tolerance, to a certain extent, which causes the susceptibility to Candida infection in APS I patients. The GFP/RAW cells and GFP-AIRE/RAW cells were cultured. After M1 ELISA induction. NO in the cell supernatant was detected. The intracellular Arg1 activity was assessed. Our results showed AIRE could promote classically activated macrophages (M1) polarization, up-regulate inflammatory cytokines such as IL-1 alpha, and nitric oxide (NO) mRNA and protein expression. Meanwhile, AIRE inhibited alternatively activated macrophages (M2) polarization, down-regulated anti-inflammatory cytokines such as Arg1, IL-10, and GAS6 mRNA and protein expression. In addition, AIRE mRNA expression was closely related to the macrophages polarization, and it was up-regulated when RAW 264.7 cells were induced to M1 phenotype and down-regulated when they were in M2 phenotype. Thus, our findings suggest that AIRE may promote macrophage differentiation into M1 phenotype, and enhance the killing of pathogenic microorganisms of macrophages, playing an important role in the peripheral immune tolerance.