Fig. 5

Influenza A virus infection causes small intestinal mucosal tissue damage and activates Paneth cells. a Representative H&E stained longitudinal sections of SI are shown (from six independent samples). b Representative Alcian Blue staining of longitudinal sections of SI tissue from mock-treated or IAV-infected mice. Tissue damage and mucus layer destruction are indicated by white or black arrows heads, respectively. Quantification of tissue damage and mucus layer integrity (lower panels) by single-blinded scorings of sections from six individual mice (7 dpi or mock treatment, from two independent experiments) performed by two independent researchers are depicted. c 18S normalized specific qPCR results (n-fold over mock) for DUOX2 are depicted for individual mice (mock (n = 3), IAV (n = 4)). d Representative pictures of phloxine-tartrazine stained SI sections or mock-treated or IAV-infected mice. Lower panel: quantification of two independent blinded scorings of samples for six mice per experimental group from two independent experiments. e Bacterial titers of intracellular S. typhimurium in SI tissue. Numbers indicate percentage of invaded samples per experimental group. Individual mice from two independent experiments and median are depicted, SI samples (left side), fecal samples (right side) (mock intestine (n = 12) and feces (n = 12), iav intestine (n = 11), feces (n = 12)). f Bacterial titers of intracellular S. typhimurium in SI tissue. Numbers indicate percentage of invaded samples per experimental group. Individual mice from two independent experiments and median are depicted, SI samples (left side), fecal samples (right side) (n = 10 per group except Mock Strep + (n = 16 intestine, n = 17 feces)