Figure 2.

HMGB1-stimulated BMDCs induce IL-17A production and Th17 differentiation via IL-23 in vitro. (a) HMGB1-induced IL-23 expression in BMDCs. BMDCs were stimulated with graded concentrations of HMGB1 or culture medium for 2 d or stimulated with 500 ng/mL HMGB1 for the indicated times. The IL-23 levels in the cell culture supernatants were measured using ELISA. The values represent the means ± standard deviations (n = 5). **P < 0.01 compared with the medium control. (b and c) HMGB1-stimulated BMDCs modulate Th17 polarization. Activated, autologous CD4⁺ T cells (1 × 10⁵) were cultured alone or cocultured with BMDCs (2.5 × 10⁴) that were treated with or without 500 ng/mL HMGB1 in the presence or absence of IL-23p19 Ab or control IgG for 5 d, the culture supernatants were analyzed for IL-17A using ELISA (b), and the expression of intracellular IL-17 by CD4⁺ T cells was analyzed using FACS (c). The values represent the means ± standard deviations (n = 5). **P < 0.01 compared with the HMGB1-DC group.