Fig. 8: TOP1 is essential for viral infection and propagation.

a-d, l and m Representative conventional images of white top hat-filtered hDNA (magenta), conventional ICP4 (cyan) and cropped STORM images of TOP1 (green), in mock and HSV-1 infected cells untreated (a) or treated with β-lap before (c) or during infection (l). Representative conventional images of hDNA (magenta), ICP4 (cyan) and cropped STORM images of RNAP II phSer5 (green), in mock and HSV-1 infected cells untreated (b) or treated with β-lap before (d) or during infection (m). Yellow dotted lines delimit the location of VRCs. Scale bar: 2 µm. e, f Percentage of TOP1 (e) and RNAP II phSer5 (f) clusters co-localizing with hDNA regions over the whole nucleus in mock or HSV-1 infected A549 cells treated or untreated with β-lap. For TOP1: mock (n = 11), mock β-lap treated (n = 9), 3 hpi (n = 7), 3 hpi–β-lap_pre (n = 12), 8 hpi (n = 10), 8 hpi–β-lap_pre (n = 16), 8 hpi–β-lap_post (n = 14). For RNAP II: mock (n = 7), mock β-lap treated (n = 7), 3 hpi (n = 7), 3 hpi–β-lap_pre (n = 13), 8 hpi (n = 11), 8 hpi–β-lap_pre (n = 16), 8 hpi–β-lap_post (n = 16). Mean and SD represented; Statistical significance compared to mock untreated is p < 0.0001 for all conditions (not included in the plots). Statistical significance compared to mock β-lap treated is shown in the graph (green): ns, p > 0.05; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001, calculated by ordinary one-way ANOVA test followed by Dunnett’s multiple comparison test. g Percentage of hDNA-free areas per nucleus quantified from SR images of mock and HSV-1 infected cells, untreated or treated with β-lap. Mock (n = 4), mock β-lap treated (n = 18), 3 hpi (n = 11), 3 hpi–β-lap_pre (n = 15), 8 hpi (n = 8), 8 hpi–β-lap_pre (n = 17), 8 hpi–β-lap_post (n = 7). Mean and SD are shown; statistical significance compared to mock untreated is p < 0.0001 for all conditions (not included in the plots). Statistical significance compared to mock β-lap treated is shown in the graph (green): ns, p > 0.05; **p < 0.01; ****p < 0.0001, calculated by ordinary one-way ANOVA test followed by Dunnett’s multiple comparison test. h–k Representative STORM density rendering images of hDNA in mock (h) or HSV-1 infected (i–k) A549 cells treated or not with β-lap. Top: whole nucleus. Scale bar: 2 µm. Bottom: Zoomed images of the regions inside the yellow boxes. Scale bar: 200 nm. DNA density follows the color scale bar; top: 0.00001 nm⁻² (dark blue) to 0.01640 nm⁻² (white); bottom: 0.00001 nm⁻² (dark blue) to 0.01978 nm⁻² (white)). Source data are provided as a Source Data file. p-values are indicated in Supplementary Data 1.