Constitutive p40 promoter activation and IL-23 production in the terminal ileum mediated by dendritic cells
J. Clin. Invest. Christoph Becker, et al. 112:693 doi:10.1172/JCI17464 [Go to this article.]

Figure 4
Nonreducing Western blot analysis of gut samples from the small intestine (D1–D4) and colon (C). Samples were analyzed for p40, p40/p19 (IL-23), p40/p35 (IL-12), and p40 homodimer (p40)₂ levels. β-Actin staining served as loading control. (a) Western blot for monomeric p40 protein using extracts from different mouse strains. Extracts from IL-12 p40 S129/B6 KO mice served as negative control (far right panel). (b) Analysis of higher molecular weight p40 complexes in FVB and BALB/c mice (left panels) and S129/B6 mice (middle panel, same blot as in a). A marked increase of IL-23 p40/p19, but not IL-12 p40/p19 levels was noted in the distal small bowel as compared with the proximal segments of the small intestine. Right panel: These data were confirmed by Western blot analysis using an IL-23–specific AB (four mice per group, two shown). (c) Densitometry of above p40 Western blots. Data are reported as percentage of expression as compared with D4 (100%). Data represent average values ± SD of six to eight mice per group. Statistically significant differences (*P < 0.05, **P < 0.01, ***P < 0.001) are indicated. (d) RT-PCR analysis of RNA isolated from the small (D1–D4) and large (C) intestine of healthy FVB mice. A marked upregulation in D4 as compared to the proximal small intestine and colon was seen for the mRNAs of p19 and p40, but, importantly, also for the mRNA of IL-17, a recently identified target gene of IL-23 in memory T cells (56).