Herpes simplex virus type 1 reshapes host chromatin architecture via transcription machinery hijacking.

Herpes simplex virus type 1 (HSV-1) remodels the host chromatin structure and induces a host-to-virus transcriptional switch during lytic infection. We combine super-resolution imaging and chromosome-capture technologies to identify the mechanism of remodeling. We show that the host chromatin undergoes massive condensation caused by the hijacking of RNA polymerase II (RNAP II) and topoisomerase I (TOP1). In addition, HSV-1 infection results in the rearrangement of topologically associating domains and loops, although the A/B compartments are maintained in the host. The position of viral genomes and their association with RNAP II and cohesin is determined nanometrically. We reveal specific host-HSV-1 genome interactions and enrichment of upregulated human genes in the most contacting regions. Finally, TOP1 inhibition fully blocks HSV-1 infection, suggesting possible antiviral strategies. This viral mechanism of host chromatin rewiring sheds light on the role of transcription in chromatin architecture.