Figure 4.

T reg cells develop more rapidly from activated than from naive DO11 cells. Purified CD4⁺ DO11 Rag^−/− cells were stimulated on mitomycin C–treated splenocytes in the presence of 1 μg/ml OVA peptide for 4 d. 10⁶ in vitro–activated DO11 Rag^−/− or naive DO11 Rag^−/− cells were transferred into sOVA Tg Rag^−/− on day 0. (A) FoxP3 expression of naive and in vitro–activated DO11 Rag^−/− cells before transfer. (B) Splenocytes were harvested 4, 10, and 30 d after transfer. FoxP3 expression of gated KJ1-26⁺CD4⁺ cells was measured by flow cytometric analysis. Splenocytes were restimulated with OVA peptide and APCs and stained for IFN-γ on days 4, 10, and 30 after transfer. All plots are gated on KJ1-26⁺CD4⁺ cells. Representative plots are shown from three experiments with two mice per group.