Gamma interferon controls mouse polyomavirus infection in vivo

Area of Science:

• Immunology
• Virology
• Oncology

Background:

• Human polyomaviruses cause significant illness in immunocompromised individuals.
• Effective antiviral treatments for polyomaviruses are lacking.
• Host factors predicting susceptibility remain unidentified.

Purpose of the Study:

• To investigate the role of gamma interferon (IFN-γ) in host defense against mouse polyomavirus (MPyV) infection and tumorigenesis.
• To determine if IFN-γ is an antiviral effector molecule against MPyV.

Main Methods:

• Utilized the mouse polyomavirus (MPyV) infection model.
• Assessed viral loads and tumor development in wild-type and IFN-γ receptor-deficient (IFN-γR(-/-)) mice.
• Examined MPyV protein expression and replication in vitro.
• Studied an acute MPyV kidney transplant model.
• Administered IFN-γ to persistently infected mice.

Main Results:

• IFN-γ inhibits MPyV protein expression and viral replication in cells.
• IFN-γR(-/-) mice exhibit higher viral loads and increased susceptibility to MPyV-induced tumors.
• IFN-γ deficiency does not impair MPyV-specific CD8(+) T cell responses.
• IFN-γR(-/-) donor kidneys show higher MPyV levels.
• IFN-γ treatment reduces MPyV levels in persistently infected mice.

Conclusions:

• IFN-γ is a critical host defense mechanism against MPyV infection and MPyV-associated tumorigenesis.
• IFN-γ acts as an antiviral effector molecule, reducing viral loads in multiple organs, including the kidney.
• These findings highlight IFN-γ's potential as a therapeutic strategy for polyomavirus infections.