Fig. 9: Contribution of individual cellular sources of TNF to epithelial cell proliferation and IL-22BP expression in the colon.

Representative images of tissue sections stained with Haematoxylin/Eosin A (Scale bar is equal to 100 µm), colitis inflammation score B, mTNF levels in colonic explants C and expression of IL-22BP mRNA in colon D of Rag1^−/− mice reconstituted with naive T cells from WT or T-TNF^−/− mice. Representative images of tissue sections stained with Haematoxylin/Eosin E (Scale bar is equal to 100 µm), colitis inflammation score F, number of CD3 positive cells per 10 hpf in the colon G and frequency of proliferating epithelial cells in the colon H of Rag1^−/− mice reconstituted with naive T cells from WT or tmTNF KI mice. Representative images of colon sections stained for expression of CD3 (red) and Ki67 (brown) I, mean numbers of proliferating epithelial cells (Ki67 staining) J, mTNF levels in colonic explants K, IL-22BP mRNA levels in colonic tissue (L) of Rag1^−/−, TNF^−/−×Rag1^−/− and TNF^f/f×Vil-Cre×Rag1^−/− mice reconstituted with naive T cells from WT donors. TACE mRNA expression levels in various cell subsets (IECs: CD45^- cells isolated from intraepithelial layer; T cells –CD45⁺TCRβ⁺CD4⁺ sorted from LP; CD11c⁺MHCII⁺ cells were sorted from LP) from Rag1^−/− reconstituted with WT naive T cells. All data are representative of two independent experiments. Data represent mean values ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, as calculated by Student’s t-test; ns, not significant.