Helios is not associated with Treg lineage commitment in mice.

<p>(A) Murine CD4+ CD25- Teffs stimulated with CD3/CD28 mAbs, IL-2 and TGF-beta to become iTregs upregulated Helios in both Foxp3+ and Foxp3- subsets (middle). Withdrawal of TCR stimulation and TGF-beta led to loss of Helios expression (right). (B) Murine Tregs after isolation (left) and after 4 d with IL-2 but without stimulation (right). In resting conditions Helios expression decreased, and Foxp3 expression by Tregs decreased mainly in the Helios+ subset. (C) Induction of Foxp3 in mouse CD8+ cells in the same conditions as in (A). Foxp3+ converted CD8 cells co-expressed Helios and Ki-67.