Nucleus softens during herpesvirus infection
Nuclear mechanics is remodeled not only by extracellular forces but also by internal modifications, such as those induced by viral infections. During herpes simplex virus type 1 infection, the nuclear structures undergo drastic reorganization, but little is known about how nuclear mechanobiology changes as a result. We show that the nucleus softens dramatically during the infection. To understand the phenomenon, we used advanced microscopy and computational modeling. We discovered that the enlarged viral replication compartment had a low biomolecular density, partially explaining the observed nuclear softening. The mobility of the nuclear lamina decreased, which suggests increased rigidity and an inability to induce softening. However, computational modeling supported by experimental data showed that reduced outward forces, such as cytoskeletal pull and intranuclear osmotic pressure acting both on and within the nucleus, can explain the decreased nuclear stiffness. Our findings reveal that during infection, the nucleus is subject to changes in multiple mechanical forces, leading to decreased nuclear stiffness.
Authors
- Teemu O. Ihalainen (ORCID: https://orcid.org/0000-0003-4351-8697)
- Katie V. Tieu (ORCID: https://orcid.org/0000-0001-6166-6648)
- Henri Niskanen (ORCID: https://orcid.org/0000-0002-8361-5531)
- Minna Unelma Kaikkonen (ORCID: https://orcid.org/0000-0001-6294-0979)
- Salla Mattola (ORCID: https://orcid.org/0000-0002-0305-2549)
- Daniel E. Conway (ORCID: https://orcid.org/0000-0001-6624-177X)
- Sébastien Lyonnais (ORCID: https://orcid.org/0000-0002-3154-8568)
- Vesa Aho (ORCID: https://orcid.org/0000-0003-3142-2452)
- Maija Vihinen‐Ranta (ORCID: https://orcid.org/0000-0003-0959-1153)
- Delphine M. Muriaux (ORCID: https://orcid.org/0000-0001-8517-9342)
- Aapo Tervonen (ORCID: https://orcid.org/0000-0002-2770-0563)
- Carolyn A. Larabell (ORCID: https://orcid.org/0000-0002-6262-4789)
- Alka Gupta (ORCID: https://orcid.org/0000-0002-2498-592X)
- Jian-Hua Chen (ORCID: https://orcid.org/0000-0002-7998-0878)
- Visa Ruokolainen
- Simon Leclerc
Institutions
- Centre National de la Recherche Scientifique (FR)
- Lawrence Berkeley National Laboratory (US)
- Tampere University (FI)
- University of Eastern Finland (FI)
- Université de Montpellier (FR)
- Institut de Recherche en Infectiologie de Montpellier (FR)
- The Ohio State University (US)
- University of Jyväskylä (FI)
Publication Details
- Journal
- PLoS Pathogens
- Published
- 2026-01-20
- DOI
- https://doi.org/10.1371/journal.ppat.1013873
- Primary Topic
- Herpesvirus Infections and Treatments
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Helsingin Yliopisto
- European Commission
- Jane ja Aatos Erkon Säätiö
- Lawrence Berkeley National Laboratory