Fig. 1.

Detection and characterization of Treg. (A) The phenotype of Treg from melanoma patients (A, left), Memory/naïve phenotype of the Treg (A, middle and right). Dot plots showed one representative profile from 14 patients. (B) CD27-, CTLA-4-, GITR-, PD-1- and PD-L1-specific staining on gated CD4⁺CD25^Hi Treg (solid black lines), CD4⁺CD25^Low T cells (gray dashed lines) and CD4⁺CD25^Negative T cells (gray dotted lines) overlaid with isotype-matched control antibodies (shaded gray histograms). (C) Intracellular FoxP3, PD-1 and CTLA-4 staining on gated CD4⁺CD25^Hi Treg (solid black lines), CD4⁺CD25^Low T cells (gray dashed line) and CD4⁺CD25^Negative T cells (gray dotted line) overlaid with isotype-matched control antibodies (shaded gray histograms). (D) PD-1 and PD-L1 expression on melanoma antigen-specific CD8⁺ cells, shown in the upper right quadrant was the percentage of PD-1/PD-L1-positive tetramer + CD8⁺ cells.