Fig. 1. HVEM is important for maintaining IET.

(A) Total IEL numbers by flow cytometry in proximal SI (Pro-SI), middle SI (Mid-SI), distal SI (Dis-SI), cecum and colon from Hvem^+/+ (n=9) and Hvem^−/− (n=9) mice. (B) Representative immunofluorescence staining of CD45⁺ cells from the SI in Hvem^+/+ and Hvem^−/− mice. White arrowheads indicate CD45⁺ intraepithelial cells (IEL) in the epithelium. Dashed white lines indicate the interface between the epithelium and lamina propria. Scale bars, 25μm. (C) Quantification of CD45⁺ IEL in villi from Hvem^+/+ (n=4) and Hvem^−/− (n=4) mice. (D) Representative plots of TCRαβ⁺CD8αα⁺ and TCRαβ⁺CD8αβ⁺ IET in TCRαβ⁺ IET from proximal SI in Hvem^+/+ and Hvem^−/− mice. (E) Absolute numbers of the indicated subsets in total IEL from proximal SI in Hvem^+/+ (n=5) and Hvem^−/− (n=5) mice. Statistical analysis was performed using an unpaired t-test (A, C, E). Statistical significance is indicated by *, p < 0.05; **, p < 0.01; ***, p < 0.001. Data in A, C, and E show means ± SEM. In A and E, each symbol represents a measurement from a single mouse. In C, each symbol represents cell numbers of CD45⁺ IEL per a boundary approximating a villus. Data represent pooled results from at least two independent experiments with at least four mice per group in each experiment (A), compiled from four independent experiments (B, C) or representative results from one of at least two independent experiments with at least four mice in each experimental group (E). Groups of co-housed mice were analyzed.