CpG ODN–induced IL-12 production depends on Tyk2 and is required for IFN-γ production in DCs. (A-B) Isolated CD11c⁺ DCs from WT or Tyk2^−/− splenocytes were cultured with CpG ODN or LPS for 24 hours. The amounts of (A) IL-12 and (B) IL-23 in the supernatants were measured by ELISA. Data are means (± SD) from 5 independent experiments. ND indicates not detectable. *Significantly different from the corresponding mean values of WT DCs, *P < .01. (C) Isolated CD11c⁺ DCs from WT splenocytes were cultured with CpG ODN in the presence of anti–type I IFN receptor antibody, anti–IL-12 p70 antibody, or anti–IL-12 p40 antibody for 3 days. The amounts of IFN-γ in the supernatants were measured by ELISA. Data are means (± SD) from 5 independent experiments. *Significantly different from the mean value of the control response (CpG ODN alone), P < .01.