Fig. 2. CD4⁺ YFP⁺ Foxp3⁻ cells have a non-T_reg surface phenotype.

(A) Lymph node and spleen CD4⁺ GFP⁺ T cells were FACS purified from Foxp3-GFP-Cre mice and CD4⁺ YFP⁺ T cells sort-purified from Foxp3-GFP-Crex R26-YFPmice. Purified populations were analyzed for CD127, CD25, and GITR and Foxp3 by intracellular staining. (B) As in (A), analysis of FR4, CTLA-4 and CD103 expression and Foxp3 by intracellular staining. Histograms show YFP⁻ T_conv (thick line), YFP⁺ Foxp3⁺ T_reg (thin line), and YFP⁺ Foxp3⁻ (filled histogram). Representative plots from 6–9 week old mice of 3 experiments.