T-cell subsets in contact with HRS cells. (A) Representative image (40× resolution; case N12) showing CD4⁺ T cells (left panel, green) with coexpression of PD-1 (right panel, yellow) touching a CD30⁺ HRS cell (left and right panels, orange). (B) Membrane map depicting CD4⁺ T cells (PD-1⁺ dark green; PD-1⁻ light green), and PD-L1⁺ HRS cells (orange). Cells are generally only outlined, with the exceptions of PD-1⁺ CD4⁺ T cells and PD-L1⁺ HRS cells that are in contact, which are filled to highlight the interaction. (C) Representative image (40× resolution; case P6) showing CD8⁺ T cells (left panel, red) with coexpression of PD-1 (right panel, yellow) touching CD30⁺ HRS cells (left and right panels, orange). (D) Membrane map depicting CD8⁺ T cells (PD-1⁺ dark red; PD-1⁻ light red), and PD-L1⁺ HRS cells (orange). Cells are generally only outlined, with the exceptions of PD-1⁺ CD8⁺ T cells and PD-L1⁺ HRS cells that are in contact, which are filled. (E) Mean and standard error of the proportion of cells that are CD4⁺ T cells, CD8⁺ T cells, or undefined and that are in contact with HRS cells (red bars), within 75 µm of HRS cells (blue bars), or more than 75 µm from the HRS cells (green bars), respectively. P values calculated by the Wilcoxon test. (F) Mean and standard error of the proportion of cells that are PD-1⁺ CD4⁺ T cells, PD-1⁻ CD4⁺ T cells, PD-1⁺ CD8⁺ T cells, or PD-1⁻ CD8⁺ T cells in contact with PD-L1⁺ HRS cells (red bars), within 75 µm of PD-L1⁺ HRS cells (blue bars), or more than 75 µm from PD-L1⁺ HRS cells (green bars), respectively. P values calculated by the Wilcoxon test.