Figure 9. CD103 is important for proper T cell localization in the small intestine.

(A) The number of total CD4⁺ T cells and CD4⁺ Foxp3⁺ Tregs in the IEL compartment of small and large intestine was determined by flow cytometry. Age-matched 12-24 week-old mice were assessed for each genotype. The number of mice/group is indicated by individual symbols in scatter graphs. (B) Representative confocal images show E-cadherin⁺ epithelial cells, CD4⁺ T cells, Foxp3⁺ Tregs and DAPI stained nucleated cells in the small intestine from age-matched 8-10 week-old mice. Foxp3⁺ Tregs are marked with yellow arrow head and co-localized CD4⁺ and E-cadherin⁺ cells are indicated with yellow arrow. (C) Co-localization of CD4⁺ T and E-cadherin⁺ cells was determined by two approaches. Left, total CD4⁺ T cells and CD4⁺ T cells that co-localized or closely associated with E-cadherin were counted. The percent of cells that were co-localized or closely associated with E-cadherin⁺ cells was determined after counting 674 total CD4⁺ T cells from 26 fields for Y3 and 576 total CD4⁺ T cells from 27 fields for Y3/CD103^−/− mice (PPs were excluded). Right, co-localization was measured by relative mean pixel intensity (Relative Mean) and show graphically. Each symbol represents one relative mean pixel intensity from one field (n ≥ 6 sections per tissue obtained from 3 individual mice for each group).