Fig 1: Generation of IL-23 signaling deficient mice. (A) Schematic illustration of IL-23 receptor chains IL-23R and IL-12Rβ1 in complex with IL-23. Indicated are the canonical tyrosine residues and the non-canonical region for binding/activation of AKT, MAPK and STAT signaling. In IL-23R-Y416F mice tyrosine 416 is mutated into phenylalanine and in IL-23R-Y416FΔICD signaling deficient mice Y416F is combined with a deletion of the IL-23R from amino acid residue 432. (B) Targeting strategy for the generation of floxed IL-23-Y416F and IL-23R-Y416FΔICD signaling deficient mice. The arrows indicate the locations of primers used for genomic PCR and RT-PCR. (C) Partial amino acid sequence of IL-23R, IL-23R-Y416F and IL-23R-Y416FΔICD mice. (D) PCR to characterize genomic organization of IL-23R, IL-23R-Y416F and IL-23R-Y416FΔICD in mice. Primer combinations are indicated. (E) RT-PCR on RNA from spleen tissue of IL-23R, IL-23R-Y416F and IL-23R-Y416FΔICD mice. GAPDH served as control. (F) IL-23R cell surface expression of spleen cells from IL-23R (light gray), IL-23R-Y416F (black) and IL-23R-Y416FΔICD (dark gray) mice 5 days after stimulation with anti-CD3, anti-CD28, TGF-β1, IL-6 and IL-1 by flow cytometry. (G) Splenocytes were incubated for 5 days with anti-CD3 and anti-CD28, in the absence (white bars) or presence of TGF-β1, IL-6 and mouse IL-1β (black dotted bars). Supernatants were collected and analyzed by ELISA for IL-17. Results are mean ± S.D. of three replicates. Significance of difference (two-tailed Student t test): *p < 0.05, **p < 0.01, ****p < 0.0001.