Figure 2.

Foxp3⁺CD25⁻ Treg cell precursors differentiate largely independent of NF-κB into mature Treg cells. (A) Foxp3⁺CD25⁻ CD122⁺ Treg cell precursors were sorted from wildtype, c-Rel-deficient (Rel^−/−) and IκB_NS-deficient (Nfkbid^−/−) DEREG mice. Wildtype cells were left untreated or were stimulated with 100 ng/ml IL-15, and IκB_NS-deficient (Nfkbid^−/−) as well as c-Rel-deficient (Rel^−/−) cells were stimulated with 100 ng/ml IL-15. Representative dot plots are shown. (B) Statistical summary to (A). Frequencies of induced Foxp3⁺CD25⁺ cells are shown; open bars indicate c-Rel-deficient (Rel^−/−; upper panel; n = 4 both) or IκB_NS-deficient (Nfkbid^−/−; lower panel; n = 3 for wt, n = 4 for Nfkbid^−/−) cells, filled bars wildtype. Statistical analyses were performed via two tailed Mann–Whitney tests (C) Scheme of contributions of c-Rel and IκB_NS for the classical and alternative developmental routes of Treg cells.