Figure 6.

Tob1^–/–CD45RB^highCD4⁺T cells induce exaggerated intestinal mucosal inflammation in Rag1^–/–mice. Naïve CD25^–CD45RB^highCD4⁺ T cells were sorted from spleen of WT littermates and Tob1^–/– mice (n = 5) and injected intraperitoneally into 8-week-old Rag1^–/– mice (5 × 10⁵ cells/mouse and n = 10, respectively). (A) Changes of body weight in Rag1^–/– mice reconstituted intraperitoneally with WT and Tob1^–/–CD45RB^highCD4⁺ T cells, respectively, or injected intraperitoneally with phosphate-buffered saline as negative control, were monitored weekly after T cell transfer. (B) The scores of disease activity index (DAI) were calculated daily after T cell adoptive transfer. (C and D) Mice were sacrificed on week 7 after T cell transfer, and gross morphology of colons is shown. (E and F) Pathological scores of the colon tissues were calculated and are shown as indicated, and representative colon sections were stained with hematoxylin and eosin. Scale bars = 100 μm. (G) LPMCs were isolated from the colons of Rag1^–/– mice transferred with WT and Tob1^–/–CD45RB^highCD4⁺ T cells, respectively, and intracellular expression of IFN-γ and IL-17A in LP-CD4⁺ T cells was analyzed by flow cytometry. (H) Percentages of IFN-γ⁺CD4⁺ and IL-17A⁺CD4⁺ T cells are shown in the bar chart. (I–K) Representative images for the detection of CD4⁺ T cells and F4/80⁺ macrophages in colon tissues 7 weeks after T cell transfer in Rag1^–/– mice by immunohistochemistry. Scale bar = 100 μm. (L–Q) Colon tissues were collected from these recipient mice 7 weeks after T cell transfer, and the expression of Ifn-γ, T-bet, Il-17a, Rorγt, Tnf-α, and Il-10 mRNA was examined by qRT-PCR. Statistical analysis was performed with unpaired 2-sided Student’s t tests. ∗P < .05 and ∗∗P < .01 vs Rag1^–/– mice transferred with WT CD45RB^highCD4⁺ T cells.