When cultured in medium containing low concentrations (1 ng/ml) of IL-2, a significantly large proportion of TCR-δ^-/- T cells, as compared to wt-B6 T cells, expressed Foxp3.

<p>A&B). Groups (n = 6) of B6 and TCR-δ^-/- mice were immunized with IRBP_1-20/CFA. Thirteen days after immunization, CD3⁺ cells were separated from spleen and draining lymph nodes cells using a MACS column. They were stained with anti-mouse CD4 and anti-Foxp3 antibodies, either immediately (A) or after a 5-day culture in medium containing 1ng/ml IL-2 (B). Data are from one single experiment, which are representative of multiple (>5) independent experiments. C). Low dose of IL-2 favors Foxp3 T cell response. CD3⁺ cells separated from TCR-δ^-/- mice were cultured in medium containing indicated amounts of IL-2. Five days later, the proportion of Foxp3⁺ T cells was evaluated by FACS analysis, after staining with anti-Foxp3 antibodies.