Figure 4

Immunohistochemical staining showing the expression of FOXP3, B7-H1 and PD-1 molecules by different subsets of TIL. Representative micrographs at × 530 magnification of (A) double staining of B7-H1 (brown color, membranous/cytoplasmic) and FOXP3 (red color, nuclear) in an area rich in TIL of tumor section. (B) Double staining of PD-1 (brown color, membranous) and FOXP3 (red color, nuclear) in sections from the same tumor as in A. (C) double staining of FOXP3 (brown color, nuclear) and CD8 (red color, membranous). (D) double staining of PD-1 (brown color, membranous) and CD8 (red color, membranous). Solid arrows indicate CD8⁺/PD-1⁺ T lymphocytes and dashed arrow indicates a CD8^-/PD-1⁺ T lymphocyte. (E) Double staining of B7-H1 (brown color, membranous/cytoplasmic) and CD8 (red color, membranous). Solid arrow indicates a CD8⁺/B7-H1⁺ T lymphocyte and dashed arrow indicates a CD8^-/B7-H1⁺ T lymphocyte.