Antiviral activity of Staphylococcus aureus V8 protease against bovine alphaherpesvirus-1 in vitro

Human and other mammals harbor diverse commensal bacteria that may protect their hosts from invading pathogens. Here, we demonstrated that Staphylococcus aureus V8 protease significantly suppressed bovine alphaherpesvirus-1 (BHV-1) infectivity in vitro. V8 protease exhibited concentration-dependent antiviral activity by degrading BHV-1 glycoprotein D (gD), essential for viral entry. Treatment with V8 protease inhibited both viral attachment and the infectivity of released virions, suppressing incoming viruses and limiting spread during established infections. These findings reveal that proteases from commensal bacteria can directly target major viral proteins. However, to deepen our understanding of the antiviral activity of commensal bacterial enzymes on the body surface, establishing methods to measure the quantity of specific enzymes is urgently needed.