Figure 5.

α4 Is important for T-cell localization to mesenteric lymph nodes (MLNs) and colon in colitic mice. Wild-type (WT; CD45.1) and α4^−/− (CD45.2) CD4⁺CD45RB^high T cells were coinjected (1:1 ratio, 0.5 × 10⁶ each cell type per mouse) into recombination activating gene-1-deficient (RAG-1^−/−) mice. After colitis developed (6–7 weeks), mice were killed and their MLN and colon lamina propria (LP) were dissected for T-cell analysis using flow cytometry. (a) T cells were initially gated on CD4 ⁺T-cell receptor (TCR)αβ⁺ cells. Representative contour plots from colon LP and MLN showing percent of WT and α4^−/− T cells. (b) Absolute numbers of CD4⁺ T cells. For all bar graphs in this figure, combined data from five individually analyzed mice are expressed as mean±s.e.m. (c) After isolation, cells from colon LP and MLN were restimulated with phorbol 12-myristate 13-acetate (PMA)/ionomycin in the presence of GolgiStop for 4 h followed by intracellular staining to detect interferon-γ (IFN-γ) and interleukin-17 (IL-17). (c) Representative plots gated on WT or α4^−/− TCRαβ⁺CD4⁺ T cells and (d) combined data are shown. (e) Representative contour plots and (f) pooled data show foxp3⁺ induced regulatory T cells (Tregs) among colon LP cells. Significance is indicated as*P<0.05 and ***P<0.001.