Deltaviruses spread through a viral Trojan Horse
Joe McKellar1, Aurélien Fouillen2, Sébastien Lyonnais3
1Institut de Génétique Moléculaire de Montpellier (IGMM), Univ Montpellier, CNRS, Montpellier, France.
Cell
|March 7, 2026
Summary
Deltaviruses, or Hepatitis D-like satellite viruses, use helper viruses as "Trojan Horses" to infect cells. This hitchhiking mechanism allows deltaviruses to spread more effectively across different hosts and tissues.
Area of Science:
- Virology
- Molecular Biology
- Microscopy
Background:
- Deltaviruses are satellite viruses requiring helper viruses for replication and spread.
- Previous understanding suggested deltaviruses acquire helper virus glycoproteins to form infectious particles.
Purpose of the Study:
- To challenge the existing paradigm of deltavirus packaging and demonstrate a novel mechanism of viral entry and spread.
- To investigate the role of helper virus particles in deltavirus dissemination.
Main Methods:
- Orthogonal electron microscopy
- Super-resolution optical microscopy
- Visualization of deltaviruses within helper virus particles (rhabdoviruses, herpesviruses, arenaviruses)
Main Results:
- Deltaviruses are packaged within helper virus particles, not expropriating glycoproteins.
- This "hitchhiking" mechanism facilitates cell entry and ensures co-dissemination of deltavirus and helper virus.
- Demonstrated deltavirus packaging within diverse viral families, indicating a conserved transmission strategy.
Conclusions:
- Deltaviruses utilize helper virus particles as a "Trojan Horse" for cell entry and spread.
- This newly identified transmission mode broadens deltavirus host range and tropism.
- Provides a framework for investigating deltavirus infections beyond the human liver.
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