Fig. 4

Immune cell composition in POLE-mutated compared to POLE WT primary glioblastomas and spinal metastases as determined by multiplexed fluorescence immunohistochemistry. (a, b) Representative images showing immune cells expressing CD3 (white), CD4 (cyan), CD8 (yellow), CD68 (green), PD-1 (red) in sections of POLE-mutated and POLE WT glioblastomas (a) and spinal metastases (b) showing an increased immune cell infiltrate in the POLE-mutated glioblastoma and spinal metastasis. Nuclei were stained with 4′,6-diamidino-2-phenylindole (DAPI, blue) and used for cell detection. Scale bar, 50 μm. (c, d) Number of CD3+, CD4+, CD8+ T lymphocytes and CD68+ macrophages per mm² in POLE-mutated glioblastomas relative to the mean in five POLE WT glioblastomas (c), and in POLE-mutated spinal metastases relative to a POLE WT spinal metastasis (d). In all but one POLE-mutated glioblastoma or spinal metastasis, the density of total CD3+ T lymphocytes and/or CD4+ or CD8+ subsets was increased compared to controls with WT POLE. (e, f) Number of PD-1-positive CD3+, CD4+, and CD8+ T lymphocytes per mm² in POLE-mutated glioblastomas relative to the mean in five POLE WT glioblastomas (e), and in POLE-mutated spinal metastases relative to a POLE WT spinal metastasis (f). The density of PD-1-positive CD3+ T lymphocytes and/or CD4+ or CD8+ subsets was increased in one or two POLE-mutated glioblastomas and spinal metastases compared to controls with WT POLE. W/o, without; WT, wildtype