Figure 3.

Crtam^−/− CD4⁺ T cells have dysfunctional gut homing and retention properties but normal cytokine production. (A) Purified splenic T cells from WT (CD45.1) and Crtam^−/− (CD45.2) mice were mixed at 1:1 ratio and transferred i.v. into Rag1^−/− mice. Plots and bar graphs show the frequencies of CD45.2 versus CD45.1 within the CD4⁺ and CD4⁺CD8⁺ T cells (gated on CD45⁺CD3⁺ cells) in the siIEL and siLPL 8 wk after transfer. (B) Intracellular content of IL-17 and IFN-γ in the siIEL and siLPL recovered from the competitive adoptive transfer in A. (C) T cell adherence was analyzed in the siIEL of WT and Crtam^−/− mice by a sequential gentle then stringent isolation. Percentages of CD4⁺ and CD4⁺CD8⁺ T cells in the loose fraction (gentle isolation) of the small intestine are shown. (D) Frequency of CD4⁺ T cells expressing CD103, CD69, and CCR9 in the siIEL and siLPL of WT and Crtam^−/− mice. Data represent two (A and B) and at least three (C and D) independent experiments. Statistical analysis was performed using Student’s t test (*, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001). Error bars are SEM.