Supplementary Figure 7: IRF4 expression in T_reg cells is restricted to CD44^hi cells, is TCR dependent and can be inducibly ablated in Irf4^FL/FLFoxp3^Cre-ERT2 mice.

(a) Histograms showing IRF4 protein levels in TCR⁺ Foxp3⁺ cells in Tcra^WT/WTFoxp3^Cre-ERT2 (WT/WT; CD44^loCD62L^hi in green and CD44^hiCD62L^lo in black) and in Tcra^FL/FLFoxp3^Cre-ERT2 (FL/FL; CD44^loCD62L^hi in orange and CD44^hiCD62L^lo in blue) mice (above), and in TCR^- Foxp3⁺ cells in Tcra^FL/FLFoxp3^Cre-ERT2 (FL/FL; CD44^loCD62L^hi in green and CD44^hiCD62L^lo in red) mice (below). (b) Histograms demonstrating an increase in eGFP median fluorescence intensity (MFI) in eGFP⁺ cells following tamoxifen administration to Irf4^FL/FLFoxp3^Cre-ERT2 (red line) vs. Irf4^WT/WTFoxp3^Cre-ERT2 (black line) mice (left); quantitation of eGFP median fluorescence intensity of eGFP⁺ cells in Irf4^WT/WTFoxp3^Cre-ERT2 (white squares) and Irf4^FL/FLFoxp3^Cre-ERT2 (black squares) mice (right). Mice were administered tamoxifen on days 0, 3, 7 and 10 and were analyzed on day 13. Data is representative of two experiments with three or more (a) or four or more (b) mice per group each. P-value in (b) was calculated using a two-tailed unpaired t-test.