Figure 1. Tregs exhibit a high ratio of TIGIT/CD226 expression in the periphery and at tumor sites of melanoma patients.

(A and B) Dot plots from 3 representative donors (A) and summary data (B) showing ex vivo percentages and mean fluorescence intensity (MFI) of TIGIT expression by CD25^hiFoxp3⁺CD4⁺ Tregs (gated among total CD4⁺ T cells, as shown in A, with frequencies on the left), CD25^– and CD25⁺Foxp3^–CD4⁺ T effector cells (Teffs), and total CD4⁺ T cells in PBMCs of healthy donors (HDs) and melanoma patients (MPs) and in metastatic melanoma (MM) tumor-infiltrating lymphocytes (TILs). n = 20. (C and D) Dot plots from 3 representative donors (C) and summary data (D) showing ex vivo percentages and MFI of CD226 expression by CD25^– or CD25⁺Foxp3^–CD4⁺ Teffs, CD25^hiFoxp3⁺ Tregs, and total CD4⁺ T cells in PBMCs of HDs and MPs and in MM TILs. n = 20. (E) Summary data showing the ratio of TIGIT to CD226 ex vivo expression (percentage and MFI) by CD25^– or CD25⁺Foxp3^–CD4⁺ Teffs and CD25^hiFoxp3⁺ Tregs in PBMCs of HDs and MPs and in MM TILs. n = 20. Results represent the mean of independent experiments. P values were obtained by 1-way ANOVA and repeated-measures ANOVA followed by Tukey’s test (B and D) or by Kruskal-Wallis test and Friedman’s test followed by Dunn’s test (E). Horizontal bars depict mean values. Error bars indicate SEM. *P < 0.05; **P < 0.01; ***P < 0.001.