Fig. 1.

CD4⁺CD25⁺TGF-β⁺ Treg cells congregate only in the islets of mice that showed delayed kinetics to diabetes. (A) Tet-TNF-α/CD80 mice were induced to express TNF-α from 0 to 28 or from 0 to 25 days of age. On day 32, cell suspensions were prepared from the tissues shown and incubated with anti-CD4 (GK1.5), anti-CD25 (PC61), anti-hTGF-β1 (A75–3.1), or rat IgG2aκ isotype control [for anti-(human)hTGF-β] Abs. The proportion of CD4⁺CD25⁺ cells or CD4⁺CD25^– cells expressing TGF-β (black) versus isotype control (gray) Ab is shown. The data represent three mice examined in three independent experiments. (B) Tet-TNF-α/CD80 mice were induced to express TNF-α from 0 to 28 (filled bars) or from 0 to 25 (hatched bars) days of age. The cells were isolated on day 32 from the tissues indicated and incubated with anti-CD4, anti-CD25, and anti-hTGF-β1 Abs, and the percentage of CD4⁺CD25⁺ versus CD4⁺CD25^– cells expressing TGF-β1 was determined by FACS. The data are presented as mean ± SD of three individual mice examined for each group after three independent experiments. (C) Cells were prepared as before, and the total percentage of CD4⁺ T cells that expressed both CD25 and TGF-β was calculated. The data are presented as mean ± SD of three individual mice examined for each group after three independent experiments.