Fig. 5

γ-secretase inhibitor DAPT reduces the expression and secretion of IL-17A. Both IL-17A mRNA expression level (a) and serum concentration (b) in IMQ-treated mice were significantly elevated in comparison with control mice (^#P < 0.01), while the IL-17A expression levels were reduced in IMQ + DAPT-treated mice (^#P < 0.01). After DAPT treatment and Th17-cell polarization in vitro, IL-17A mRNA expression in splenic CD4⁺ T cells (c) and its concentration in cell-free supernatant (d) of IMQ-treated mice were decreased in DAPT treated groups compared to control group in a dose-dependent way (^#P < 0.01)