Fig. 3: PD-1 deficiency enhances T_reg cell function through CD30 within the TME.

a,b, Suppressive function of T_reg cells from Foxp3^RFP and Pd1^−/−Foxp3^RFP mice (n = 8 per group) as demonstrated by a representative CellTrace Violet flow plot (a) and percentages of T_eff cell proliferation (b). c,d, For Rag1^−/− mice with B16F10 melanoma cells and reconstituted with CD45.1⁺ T cells and CD45.2⁺ T_reg cells from either WT or Pd1^−/− mice, tumor volumes (n = 8 for WT and n = 6 for Pd1^−/− groups) (c) and frequencies of CD30 expression on CD45.1⁺ T_eff and CD45.2⁺ Pd1^−/− T_reg cells in TILs (n = 5) (d) are shown. e,f, For tamoxifen-treated Pd1^fl/fl and Pd1^fl/flFoxp3^ERT2Cre mice with tumors, tumor volumes (n = 10 for Pd1^fl/fl and n = 9 for Pd1^fl/flFoxp3^ERT2Cre) (e) and absolute counts of CD30⁺ T_reg cells (n = 12 for Pd1^fl/fl and n = 11 for Pd1^fl/flFoxp3^ERT2Cre) (f) are shown. g, Tumor-bearing Rag1^−/− mice were reconstituted with different T cell populations (n = 3 for T_eff plus WT T_reg cell group and n = 7 for T_eff plus Pd1^−/− Treg cell groups); in the Teff plus Pd1^−/− Treg cohorts, mice were treated with either 0.1 mg anti-IgG2a (n = 5) or anti-CD153 (CD30L, n = 4), and tumors were measured. h, Tumor-bearing Rag1^−/− mice were reconstituted with T_eff plus WT T_reg (treated with either 0.1 mg anti-IgG2a (n = 5) or anti-CD153 (n = 5)), and tumors were measured. Ab, antibody. i–m, Tamoxifen-treated and tumor-bearing Pd1^fl/fl (n = 10) and Pd1^fl/flFoxp3^ERT2Cre (n = 8 or 9) mice were immunophenotyped on day 19: frequencies of FoxP3 (i); ST2, TIGIT and GzmB in Pd1^fl/fl mice (j); IFNγR (CD119), GzmB, Tbet, TIGIT and IL-10 in Pd1^fl/flFoxp3^ERT2Cre mice (k); NK cells (l); and DCs (m) are shown. Data are presented as the mean ± s.e.m. Each data point represents an in vitro biological replicate in b or an individual animal in f, i, l and m. Data points in each group were matched to the same individual mouse in d, j and k. One-way analysis of variance (ANOVA) with Sidak’s multiple comparison was used in b; two-way ANOVA with Sidak’s multiple comparison in c, e, g and h, two-tailed paired Student’s t-test in d; two-tailed unpaired Student’s t-test in f, i, l and m; and matched one-way ANOVA with Sidak’s multiple comparison in j and k. Cumulative data from n = 3 independent experiments are shown. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.