Fig. 5

Markers of cytotoxicity and spatial orientation of T-cells in human latently HSV-1-infected trigeminal ganglia. Triple immunofluorescence staining for various markers (as indicated) in TG tissue sections (8 µm). Nuclei were stained with DAPI (blue color). Images of representative stainings are shown. a CD3 (red), CD4 (white) and CD8 (green) T-cells surround neurons (indicated with dotted white circles). Panel ‘a’ is zoom-in of region shown in Additional file 4: Fig. S4b. Majority of T-cells (CD3⁺ cells) express CD8. b CD107a (green) and TIA-1 (white) staining of T-cells (red) cells. Majority of T-cells cells express TIA-1, but not the degranulation marker CD107a. c TUNEL (green) and Ki-67 (white) staining of T-cells (red) cells. T-cells do not express TUNEL (late apoptosis marker), but occasionally T-cells express Ki-67 (cell proliferation marker). d CD137 (white) and CD40L (green) staining of T-cells (white) cells. T-cells express the activation markers CD137 and CD40L. e Majority of T-cells (CD3, white) express CD69 (green) of which a subset expressed CD103 (red). f PD1 (red) and p16INK4a (green) staining of T-cells (white) cells. Majority of T-cells express the exhaustion marker PD1, but do not express the senescence marker p16INK4a. Selected number of neuronal somata, with or without lipofuscin (L), are marked with a dotted circle. Representative images of one donor out of five are shown