Fig. 4

Card9 regulates Lactobacillus strains capacity to produce AhR ligands. A Schematic representation of the gavage of GF WT or Card9^−/− mice five different bacterial strains and analyses performed. B Concentration of bacterial strains in feces reported as CFU/g of feces of GF WT and GF Card9^−/− mice after gavage with three Lactobacillus strains known to produce AhR ligands, L. murinus CNCM I-5020, L. reuteri CNCM I-5022, and L. taiwanensis CNCM I-5019 (left panel), Bacteroides thetaiotaomicron VPI-5482 (middle panel), or Escherichia coli MG1655 (right panel). C qRT-PCR detection of each of the three gavaged Lactobacillus strains (L. murinus CNCM I-5020, L. reuteri CNCM I-5022, and L. taiwanensis CNCM I-5019) in colon of GF WT and GF Card9^−/− mice. D Induction of AhR activity (shown as “fold change”) induced by Lactobacillus strains colonization in GF WT and GF Card9^−/− mice at days 11 and 23 after gavage. E Percentage of IL-22⁺ cells among CD4⁺ αβ T cells (left) and NKp46⁺ ILCs in the colon lamina propria of GF WT and GF Card9^−/− mice, at days 0 and 24 after gavage with the three Lactobacillus strains. Data points represent individual mice. Data are mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, as determined by Mann–Whitney test