Lm interacts preferentially with GCs at sites where hEcad is luminally accessible and transits toward the lamina propria. (A) The intestinal loop of iFABP-hEcad transgenic mice was infected with 3 × 109 Lm for 40 min. The intestinal tissue was fixed and stained with WGA and for hEcad and nuclei. Optical sections of intestinal mucosa show Lm interacting in and entering an IEC away from (left), next to (middle), and in (right) GCs at sites where hEcad is luminally accessible (top). (middle) Lm in an IEC. (bottom) Lm exits IECs at their basolateral side. Dashed lines indicate basal membrane separating the intestinal epithelium from the lamina propria. Pictures are representative of three mice. Bar, 10 µm. (B) Quantification of cell subtypes per villus. n = 30 villi from three mice. (C) Relative infection per cell type: number of Lm WT (left) and ΔinlA (right) associated with the different cell subtypes expressing or not luminally accessible (acc) hEcad 30 min after infection has been calculated and AGC Lm WT set to 1. n = 12 villi from two mice.
