Fig. 1

Card9 contributes to colitis recovery and controls intestinal immune response independently of the gut microbiota. A Weight (left) and Disease Activity Index (DAI, right) score of DSS-exposed GF WT and GF Card9^−/− mice. B Representative H&E-stained images of colon cross sections from DSS-exposed GF WT (upper panel) and GF Card9^−/− (lower panel) mice at day 7 (left) and day 12 (right). Scale bars, 200 μm. C Histological score of colon sections at days 7 and 12. One representative experiment out of two. D Gene Ontology analysis of microarray data showing downregulation of the expression of genes involved in host defense (GO:0006952), immune response (GO:0006955), and inflammatory response (GO:0006954) (top signature, DAVID annotation) in the colon of GF Card9^−/− versus GF WT mice at day 7 of colitis. E Il-22, Reg3β, and Reg3γ and F Il-1β and TNF-α expression by qRT-PCR in total colon tissue of DSS-exposed GF WT and GF Card9.^−/− mice at days 0, 7, and 12, normalized to Gapdh. Data points represent individual mice. Data are mean ± SEM of two independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001, as determined by as determined by two-way analysis of variance (ANOVA) with Sidak’s posttest (A, C) and Mann–Whitney test (E, F)