Figure 5. Thymic involution does not impair the production nor function of nTregs.

Two – three weeks after inducing FoxN1^fx/fx deletion with TM in F-cKO or FF-Ctr mice (3 – 4 months old) thymoyctes were freshly isolated for cell surface staining of CD4, CD8, CD25 and intracellular staining of FoxP3 (A, B, and C), or freshly isolated erythrocyte-depleted spleen cells were sorted for Treg-containing (CD4⁺CD25⁺) cells and T effector cells (CD4⁺CD25⁻ Teffs) and then co-cultured to determine the suppressive function of Tregs on Teffs (D and E). (A) Representative dot plots show nTregs (CD4⁺CD25⁺FoxP3⁺) in the thymi of F-cKO and FF-Ctr control mice. Summarized results show the percentage (B), and absolute number (C) of thymic nTregs. (D) Representative dot plots before and after sorting of Treg and Teff cells from the spleen of F-cKO and FF-Ctr control mice. (E) Summarized results show suppressive function of Treg cells from F-cKO (dark bar) and FF-Ctr control mice (light bar), and proliferation of Teff cells from F-cKO (dark striped bar) and FF-Ctr control mice (light striped bar). A Student t-test was used to determine statistical significance between groups. All data are expressed as mean ± SEM. Data are pooled from three independent experiments with 6 animals/group (A, B, C) and 3 animals/group (D and E).