Fig. 2

LasB induces intraepithelial lymphocytes (IELs) and microbiota shifts. a Visual expression of lasB in the small intestine (left panel) and large intestine (right panel) of clean specific pathogen free (SPF) mice 2 weeks following colonization with a luminescent producing P. aeruginosa mutant linked to the lasB promoter (n = 3). One representative image is shown. b Protocol for gluten sensitization and challenge (gluten treatment) in clean SPF C57BL/6 mice colonized with P. aeruginosa PA14 WT (wild-type (WT) gluten) or the lasB mutant (lasB gluten). Sham controls consisted of non-sensitized and non-gluten challenged clean SPF C57BL/6 mice colonized with P. aeruginosa PA14 WT (WT control) or the lasB mutant (lasB control). c P. aeruginosa bacterial load in the small intestine of clean SPF C57BL/6 colonized with P. aeruginosa PA14 WT or lasB mutant with gluten treatment (gray bars; n = 4 WT, n = 5 lasB) or without gluten treatment (white bars; n = 5 WT, n = 4 lasB). d Elastase activity measured in the small intestine of clean SPF C57BL/6 mice colonized with P. aeruginosa PA14 WT or the lasB mutant with gluten treatment (gray bars; n = 4 WT, n = 5 lasB) or without gluten treatment (white bars; n = 5 WT, n = 4 lasB). e β-Diversity Bray–Curtis dissimilarity principal coordinates analysis (PCoA) plot of microbiota profiles from clean SPF C57BL/6 mice colonized with P. aeruginosa PA14 WT (n = 10) or the lasB mutant (n = 9). Each dot represents an individual mouse. Differences between bacterial communities were tested by permutational multivariate analysis of variance (PERMANOVA) using Qiime. f Quantitative measurement of IELs/100 enterocytes in small intestinal villi tips of clean SPF C57BL/6 mice colonized with P. aeruginosa PA14 WT or the lasB mutant, with gluten treatment (gray bars; n = 4 WT, n = 5 lasB) or without gluten treatment (white bars; n = 5 WT, n = 4 lasB). g Small intestinal villus-to-crypt ratios of clean SPF C57BL/6 mice colonized with P. aeruginosa PA14 WT or the lasB mutant, with gluten treatment (gray bars; n = 4 WT, n = 5 lasB) or without gluten treatment (white bars; n = 5 WT, n = 4 lasB). Data for c, d, f, g are presented as mean ± s.e.m. where each dot represents an individual mouse. Displayed P values were calculated by a one-way analysis of variance (ANOVA) with Tukey's post-hoc test