Fig. 4

Enhanced anti-Salmonella SIgA by apyrase. a ATP concentrations in culture medium (bars) and bacterial growth (OD₆₀₀) over time for S.Tm^pBAD28 and S.Tm^pApyr. b Quantification of Tfh and GC B cells and c representative contour plots with statistical analysis of plasma cells specific for S.Tm LPS in PPs 48 h after orogastric infection with S.Tm^WT in non-immunized mice (CTRL) and mice immunized with S.Tm^pBAD28 or S.Tm^pApyr. d Intestinal anti-S.Tm IgA titer in non-immunized mice (CTRL) and mice immunized with S.Tm^pBAD28 or S.Tm^pApyr. e Representative 2D (upper panels, scale bar: 5 µm) and 3D (lower panels, scale bar: 5 µm) images, and statistical analysis of bacterial clumping in live cecal content from mice vaccinated with S.Tm^pBAD28 or S.Tm^pApyr, 8 h after orogastric administration of a 1:1-mix of mCherry- and GFP-tagged S.Tm^att (10⁷ CFU). CTRL, non-vaccinated mice. f Images from two-photon confocal microscopy of caeca and 3D rendering of crypts from E-cadherin-mCFP mice 18 h after infection with 10⁷ CFU of GFP-tagged S.Tm^att. Infected mice were either non-vaccinated (CTRL) or vaccinated with the indicated S.Tm transformant. Graph shows the statistics of total fluorescence inside the crypts per unit of internal area. The boxplots show median and upper and lower quartiles. The extreme lines show the highest and lowest value . The boxplot is overlaid with the visualization of single observations. Kruskal–Wallis with Dunn’s post-test. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. One representative experiment out of at least three is shown