Figure 2. The presence of Prkch^–/– Tregs reduces tumor growth and increases intratumoral Teff cell accumulation.

Rag1^−/− mice received CD25-depleted C57BL/6 spleen cells as a source of Teff cells either alone (no Tregs, gray) or together with CD4⁺GFP⁺ Tregs from WT (black) or Prkch^−/− (white) FIG mice. B16-F10 melanoma cells (0.5 × 10⁶) were inoculated i.d. 1 day later. (A) Tumor sizes were measured 3 times a week to calculate tumor area (mm²), and cumulative data of 3–4 experiments are shown (mean ± SEM). no Tregs, n = 16; + WT Tregs, n = 14; + Prkch^−/− Tregs, n = 16. (B–E) Numbers of tumor-infiltrating CD8⁺ Teff (B), CD4⁺ Teff (C), and GFP⁺ Tregs (D) per mg of tumor and CD8/Treg ratios (E) were analyzed in B16-F10 tumors on day 14. Cumulative data of 3 experiments are shown (mean ± SEM). no Tregs, n = 7; + WT Tregs, n = 10; + Prkch^−/− Tregs, n = 9. Statistical significance of differences between groups was determined by repeated-measures 2-way ANOVA (A) or 1-way ANOVA (B–E) followed by Tukey’s multiple comparisons test. ns, P > 0.05; *P ≤ 0.05; **P ≤ 0.01; ****P ≤ 0.0001. Statistical significance levels in A are shown against the no Tregs group.