Intranuclear HSV-1 DNA ejection induces major mechanical transformations suggesting mechanoprotection of nucleus integrity

Abstract

Significance We discovered major mechanical transformations in both chromatin and nuclear lamina at the initial stage of herpesvirus replication. We found that chromatin stiffness is dramatically increased, while nuclear laminar rigidity is decreased, immediately after viruses eject their genomes into a host cell nucleus. A stiffness increase in chromatin mechanics suggests a viral DNA–induced chromatin compaction, helping to maintain nuclear morphology. The observed softening of the nuclear lamina, on the other hand, provides mechanoprotection of the nuclear envelope since lamina act as an internal shock absorber for mechanical deformations. These transitions lead to a robust mechanical response aimed at maintaining nuclear integrity; this mechanism could facilitate viral genome replication. This is an observation of mechanoadaptation in cells utilized by herpesviruses.