MYCOLab Ai Logo - gold and army green

Aspergillus fumigatus dsRNA virus promotes fungal fitness and pathogenicity in the mammalian host

Summary

A virus that infects the fungus Aspergillus fumigatus makes the fungus more dangerous by helping it survive stress and resist immune cell attack. When researchers removed the virus from the fungus, it became weaker and less harmful to infected mice. Treating infected mice with an antiviral drug called ribavirin reduced the virus, lowering fungal burden and improving survival, suggesting that targeting fungal viruses could be a new way to treat serious fungal infections.

Background

Aspergillus fumigatus causes approximately 65% of invasive fungal infections in humans with mortality rates approaching 50%. Mycoviruses are viruses that infect fungi, and their impact on fungal pathogenesis in mammals has remained largely unexplored. Previous studies in plant pathogens suggest mycoviruses can modulate fungal virulence, but their role in human fungal pathogens is underappreciated.

Objective

To investigate how naturally occurring mycoviral infection affects Aspergillus fumigatus fitness, stress tolerance, and virulence in mammalian hosts. The study aimed to determine whether the double-stranded RNA virus AfuPmV-1M enhances or diminishes fungal pathogenicity in mice.

Results

AfuPmV-1M enhanced conidiation, melanin production, and stress tolerance to oxidative, heat, pH, and osmotic stresses. Virus-infected strains showed increased survival in neutrophils and enhanced virulence in both immunocompetent and immunocompromised mice. Antiviral ribavirin treatment reduced mycoviral load and improved mouse survival, reducing mortality to levels comparable to virus-cured strains.

Conclusion

AfuPmV-1M acts as a molecular driver of fungal fitness and pathogenicity through upregulation of stress-response proteins, stress granule formation, and antioxidant pathways. The mycovirus represents a viable therapeutic target, suggesting that antiviral treatments could serve as antipathogenicity therapies for fungal infections caused by virus-bearing pathogenic fungi.
  • Published in:Nature Microbiology,
  • Study Type:Experimental Study,
  • Source: PMID: 40813922, DOI: 10.1038/s41564-025-02096-3
Scroll to Top