Fig. 3.

Loss of intestinal core 1-derived O-glycans impairs mucus barrier function and leads to spontaneous colitis. (A) Fluorescence in situ hybridization (FISH, bacterial 16S rDNA probe) revealed that WT colon epithelium was covered by an intact inner layer of mucus (FITC-labeled glycosylation-independent polyclonal antibody to Muc2) that was devoid of bacteria. In contrast, IEC C1galt1^–/– epithelium had no mucus layer and directly contacted commensal bacteria. Dashed lines mark epithelial surfaces. Scale bar, 20 mm. (B) H&E staining showing distal colon sections from 16-week-old WT and IEC C1galt1^−/− mice. Severe inflammatory disease that resembles human UC occurs in IEC C1galt1^−/− mice, as shown by numerous infiltrating inflammatory cells (arrowheads), and a crypt abscess (arrow).