DC-induced Foxp3⁺ T cells suppress OVA specific immunity in vivo. (A) BALB/c mice were sublethally irradiated (4.5 Gy). After 6 hours, they were injected intradermally on back with OVA-expressing A20 tumor (4 × 10⁶). (B) As in panel A, but irradiated recipients were injected intradermally with OVA-expressing A20 tumor and were also injected intravenously with freshly isolated CD25⁻CD4⁺ T cells (2 × 10⁶) from DO11.10 RAG^−/− mice. (C) As in panel B, but irradiated recipients were injected intradermally with OVA-expressing A20 tumor and were also injected intravenously with freshly isolated CD25⁻CD4⁺ T cells from DO11.10 RAG^−/− mice along with the TGF-β cultured Foxp3⁺ T regs (2 × 10⁶). The TGF-β cultured Foxp3⁺ T regs were induced by DCs and TGF-β from RAG^−/− DO11.10 mice and purified as in Figure 6A and supplemental Figure 9. (D) As in panel C, but instead of the TGF-cultured Foxp3⁺ T regs, TGF-cultured Foxp3⁻ T cells (2 × 10⁶) were injected. The TGF-cultured Foxp3⁻ T cells were from the same culture with panel C and purified as in Figure 7A-C. (E-H) The same experiment with panels A-D was repeated.