Fig. 3.
RARβ controls an epithelial immune gene expression program and promotes host resistance to bacterial infection. (A–C) Epithelial RARβ controls SAA expression. (A) Immunofluorescence detection of SAA in the small intestines of Rarbfl/fl and RarbΔIEC mice. (Scale bars, 50 μm.) (B) qPCR analysis of Saa expression in small intestinal epithelial cells acquired by laser capture microdissection and (C) Western blot of small intestinal SAA from Rarbfl/fl and RarbΔIEC mice, with actin as a control. (D) Gene ontology biological process enrichment analysis of genes identified by RNA sequencing analysis as being differentially regulated in small intestines of Rarbfl/fl and RarbΔIEC mice. Immunological gene categories are highlighted in red. (E) Heat map displaying expression levels of the 52 genes that were identified as having immune functions by the gene ontology analysis shown in D, and which had a −log10(P value) > 5. (F) Bacterial burdens (colony-forming units) in the small intestine (ileum), spleen, and liver of Rarbfl/fl and RarbΔIEC littermates 48 h after oral infection with 1010 colony-forming units of Salmonella Typhimurium. n = 5 mice/group; data represent three independent experiments. Means ± SEM are plotted. *P < 0.05; **P < 0.01; ***P < 0.001 as determined by Student’s t test.