Fig. 5

HSV-1 and HSV-2 infection induces cell death in human fetal organotypic brain slice cultures. A Immunofluorescence staining for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL; green color) counterstained with Hoechst (nuclear stain; blue color) on transverse sections cut from brain slices that were infected with GFP-expressing HSV-1 and HSV-2 (10⁶ plaque-forming units/mL) or sham-infected (mock), and subsequently cultured for 72 h post-infection (hpi). Upper 2 rows show stainings on the whole brain slice, with specific regions (boxed) enlarged and shown in the lower row. Scale bar: 20 µm. B Quantification of the percentages of TUNEL-positive cells in mock-, HSV-1- and HSV-2-infected brain slices shown in panel A. Data are mean percentage TUNEL-positive cells ± SD of three independent subjects. C Data of lactate dehydrogenase (LDH) assay on conditioned medium of mock, HSV-1, or HSV-2 infected brain slices shown in A and B. Data shown as the mean absorbance ± SD of 5 independent subjects. Two-tailed Student’s t test for B and C: p > 0.05 (ns); *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001. D Brain slices treated as in panel A were subjected to double immunofluorescence staining for TUNEL (green color) and GFAP (astrocytes; magenta color) or MAP2 (neurons; magenta color). Hoechst, (nuclear stain; blue) and scale bar = 20 µm. Images are representative of three independent subjects