Figure 1.

Passive Transfer of a Young Microbiota Enhances M Cell Development in Aged Mice

(A) Cartoon describing the experimental setup. Aged mice (~20 months old) were housed for 6 weeks in cages of used bedding that had previously housed young mice. Bedding was replaced twice weekly. Control aged mice were housed in clean cages.

(B) Whole-mount immunostaining of GP2+ M cells (green) in Peyer's patches from young, aged, and aged mice given young bedding. Counterstain, F-actin (blue). Scale bar, 100 μm. Broken line, the boundary of the FAE.

(C) Quantitation of the number of GP2+ M cells in Peyer's patches from mice from each group. Each point represents an individual FAE. Horizontal line, median. n = 12–16/group from 3 to 4 mice. Statistical differences determined by one-way ANOVA.

(D) Immunohistochemistry (IHC) detection of Spi-B+ cells (green) in the FAE of Peyer's patches from mice in each group. Nuclei detected using DAPI (blue). Scale bar, 20 μm. Broken line, the apical surface of the FAE.

(E) Quantitation of the number of Spi-B+ cells in the FAE of Peyer's patches from mice from each group. Each point represents an individual section. Horizontal line, median. n = 17–31/group from 3 to 4 mice. Statistical differences determined by one-way ANOVA.

(F) IHC detection of CCL20 (red) in the FAE of Peyer's patches from mice from each group. Nuclei detected using DAPI (blue). Scale bar, 20 μm. Broken line, the apical surface of the FAE.

(G) Quantitation of the % area CCL20+ immunostaining in the FAE of Peyer's patches from mice from each group. Each point represents an individual FAE section. Horizontal line, median. n = 11–17/group from 3 to 4 mice. Statistical differences determined by one-way ANOVA.