Fig. 4

Human brain CD69⁺CD103⁺ CD8⁺ T cells are enriched for tissue-homing chemokine receptors. a–h Quantification of CD8⁺ T-cell expression levels of CX₃CR1, CXCR3, CCR5, and CXCR6 (GMFI, geometric mean fluorescence intensity). Bars show median values. p-values show Mann–Whitney U test for unpaired data (a, c, e, g) and Friedman test for paired data with Wilcoxon signed ranks as post hoc test (b, d, f, h) (*p < 0.05, **p < 0.01); no brackets indicate no significant difference. i, j Immunofluorescent staining for CD3 and CD103 of paraffin tissue shows a parenchymal (i) and perivascular (j) localization of CD3 (green) and CD103 (red) immunoreactive cells. Borders of the perivascular space were designated based on histological hallmarks (i.e., lymphocytes in close relationship with the extraluminal side of a blood vessel) and are marked with a dotted white line (scale bar = 10 µm)