IL-7 availability affected IL-2 binding capacity by Treg.

Abstract

<p>(A) Splenocytes from FOXP3/GFP mice were incubated for 30 min with biotinylated IL-2. Bound biotinylated IL-2 was revealed with fluorochrome-conjugated streptavidine. Shown are representative profiles of IL-2 fluorescence on CD4+GFP- cells (open thick line) or CD4+GFP+ cells (gray shaded profiles). Cells not exposed to biotinylated IL-2 and directly stained with fluorochrome-conjugated streptavidine are shown as negative controls (open thin lines) (B) Total CD4+ cells isolated from FOXP3/GFP mice were cultured in the absence (NT) or in the presence of IL-7 at 10 ng/ml (IL-7). After 24 hours cells were harvested and stained with biotinylated IL-2 as described above. Shown are representative profiles of IL-2 fluorescence on CD4+GFP+ cells cultured with (gray shaded profiles) or without (open thick line) IL-7. Cells not exposed to biotinylated IL-2 and directly stained with fluorochrome-conjugated streptavidine are shown as negative controls (open thin lines). MFI of triplicates ± SD are shown. Data are representative of three independent experiments performed in triplicate. (C) Splenocytes from WT, IL-7Rα-/-, IL-7-/- and IL-7Tg mice were analyzed directly <i>ex vivo</i> for IL-2 binding capacity as in (A). Shown are IL-2 MFI on CD4+TCRβ+FOXP3+ cells. Results are representative of two independent experiments with four to six mice per group.</p