Neuropathogenicity of Two Saffold Virus Type 3 Isolates in Mouse Models

Area of Science:

• Virology
• Neuroscience
• Immunology

Background:

• Saffold virus (SAFV), a picornavirus, is linked to neurological conditions in children.
• The neuropathogenic potential of SAFV remains unclear.

Purpose of the Study:

• To evaluate the neuropathogenicity of two Saffold virus type 3 (SAFV-3) clinical isolates.
• To compare the virulence and cell tropism of aseptic meningitis (AM) and upper respiratory (UR) strains of SAFV-3.

Main Methods:

• Analysis of two SAFV-3 clinical isolates (AM and UR strains) in neonatal and young mice.
• Utilized virological, pathological, and immunological methods to assess virulence.
• Examined infectivity, neurotropism, neurovirulence, cell tropism, inflammation, demyelination, and seroconversion.

Main Results:

• Both SAFV-3 strains exhibited neurotropism and mild neurovirulence in neonatal mice.
• Strains differed in cell tropism: infecting neural progenitor and glial cells, with UR strain also infecting epithelial cells.
• UR strain caused prolonged brain/spinal cord inflammation and demyelination; AM strain showed higher cerebellar infectivity. UR strain induced seroconversion in young mice.

Conclusions:

• Both SAFV-3 isolates demonstrate neurotropism and mild neurovirulence with distinct cell tropisms.
• The mouse model effectively recapitulates potential neuropathogenicity of SAFV-3.
• Further research is warranted to understand SAFV's role in human neurological diseases.