Fig. 2.

Flow cytometric analysis of small intestine intra-epithelial lymphocytes (IELs) reveals enrichment of αβ⁺ T cell subsets in older pIgR^−/− mice. IELs were collected from age- and sex-matched B6 (closed circle, 12-week n = 7, 34-week n = 14) and B6.pIgR^−/− (open circle, 12-week n = 8, 34-week n = 11) mice. a The total number of small intestine IELs (SI-IELs, CD45⁺), αβ⁺ T cells (TCRβ⁺) and γδ⁺ T cells (TCRγδ⁺) was increased in pIgR^−/− mice compared to B6 mice. Representative FACS profiles of SI-IEL αβ⁺ T cell are shown for b MAIT cells by MR1 tetramer staining with SI-IELs from Vα19i MAIT cell transgenic mice as positive control for gating (Kawachi et al. 2006), and c NKT cells by CD1d tetramer staining with splenocytes as positive control for gating. The number of d SI-IEL CD8α⁺αβ⁺ T cells (TCRβ⁺CD8α⁺CD4⁻) and SI-IEL CD4⁺αβ⁺ T cells (TCRβ⁺CD4⁺) was significantly increased in pIgR^−/− mice especially with age, and e representative FACS profiles for these subsets are shown. f Serum was collected from B6 and pIgR^−/− mice at indicated age and small intestine was homogenised in 2 ml RPMI. The concentration of IFN-γ was determined using mouse Th1/Th2/Th17 cytometric bead array (CBA). Dotted line indicates detection limit (DL). Data points indicate individual mice that were pooled from 3 to 4 independent experiments, mean ± SEM is shown. Unpaired t-test was used for statistical analyses and p-values are shown where < 0.05 is considered significant