Extended Data Fig. 8: Role of IFNγ secretion by FOXP3^int unstable T_reg cells selectively in tumour tissue.

a–c, Frequencies of total YFP⁺ T_reg cells and of YFP⁺ eT_reg cells among CD4⁺ T cells (a), absolute YFP⁺ T_reg and eT_reg cell numbers (b), and normalized FOXP3 expression in YFP⁺ T_reg and eT_reg (c) in tdLN and tumour tissue of 18-day-old D4M.3A tumours in female heterozygous F^cre/+ × C1^+/+, C1 ^f/+ or C1 ^f/f mice. d, tdLN and tumour cellularities. e, Growth of MC38 tumours in female heterozygous F^cre/+ × C1^+/+ or C1 ^f/+ mice. f, g, Tumour-bearing mice were treated with brefeldin A for 5 h, injected intravenously with 3 μg of anti-THY1.2 monoclonal antibodies, and 3 min later collected for direct ex vivo analysis of IFNγ expression in extravascular YFP⁺ T_reg cells in the lung (f) and skin (g). Gates for IFNγ⁺ cells drawn based on fluorescence-minus-one (FMO) controls. h, Normalized FOXP3 expression in IFNγ⁺ and IFNγ^– T_reg cells from tumour tissue. n.d., not detectable. i, Tumour growth in indicated mice implanted with D4M.3A melanoma and19 treated with or without neutralizing anti-IFNγ antibody. j, Frequency of adoptively transferred, YFP⁺ T_reg cells of indicated genotypes in tdLNs of Ifng^−/− hosts at day 18 of tumour growth. k–m, Frequency (k, l) and effector cytokine expression (m) of adoptively transferred, YFP⁺ T_reg cells in tumours in Ifng^−/− hosts. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 (one-way ANOVA with Tukey post hoc test in a–d, f, g; two-tailed Student’s t-test in e, h, j, l, m; two-way ANOVA with Bonferroni post hoc test in i).