Survival Factor A (SvfA) Contributes to Aspergillus nidulans Pathogenicity

Area of Science:

• Mycology
• Molecular Biology
• Pathogenesis

Background:

• Survival factor A (SvfA) in Aspergillus nidulans is implicated in growth and development.
• SvfA homologs in other fungi are vital for stress survival.
• SvfA is a potential VeA-dependent protein involved in sexual development.

Purpose of the Study:

• To investigate the role of SvfA in the virulence of Aspergillus nidulans.
• To evaluate the impact of svfA deletion on fungal cell wall components, biofilm formation, and protease activity.
• To assess the in vitro and in vivo pathogenicity of an Aspergillus nidulans svfA-deletion strain.

Main Methods:

• Gene deletion and overexpression of svfA in Aspergillus nidulans.
• Analysis of cell wall components (β-1,3-glucan, chitin synthase, β-1,3-glucan synthase gene expression).
• Biofilm formation and protease activity assays.
• In vitro phagocytosis assays with mouse alveolar macrophages.
• In vivo survival studies in zebrafish and chronic granulomatous disease mouse models.

Main Results:

• The svfA-deletion strain exhibited reduced β-1,3-glucan production, decreased chitin synthase and β-1,3-glucan synthase gene expression.
• Biofilm formation and protease production were diminished in the svfA-deletion strain.
• Phagocytosis by macrophages was reduced, but killing rate increased with ERK activation; host mortality was lower in animal models infected with the svfA-deletion strain.

Conclusions:

• SvfA significantly contributes to the pathogenicity of Aspergillus nidulans.
• The absence of SvfA impairs fungal cell wall integrity, biofilm formation, and protease secretion.
• SvfA deletion attenuates Aspergillus nidulans virulence, offering potential targets for antifungal strategies.