TGF-β regulatesin vivoexpansion of Foxp3-expressing CD4⁺CD25⁺regulatory T cells responsible for protection against diabetes

CD4 + CD25 + regulatory T cells are essential in the protection from organ-specific autoimmune diseases. In the pancreas, they inhibit actions of autoreactive T cells and thereby prevent diabetes progression. The signals that control the generation, the maintenance, or the expansion of regulatory T cell pool in vivo remain poorly understood. Here we show that a transient pulse of transforming growth factor β (TGF-β) in the islets during the...