EESS seminar talk on "The Proteolytic Inactivation of Viruses in Lakewater"

Many human viruses are transmitted via the environment and thereby come into contact with indigenous microorganisms. Microbes are known to decrease the stability of viruses in the lakewater through the action of their secreted proteases, enzymes that cleave proteins and can hence compromise the integrity of the viral capsid. Interestingly, the antiviral activity of microbial proteases appears to be virus type specific. Yet, the molecular basis for this remains unexplored. In this work, we integrate lakewater decay experiments, proteolytic-cleavage profiling, and capsid structural data to identify the viral features that control the stability of an enterovirus, echovirus 11, in Lake Genva. Using a reverse-genetics system, we identify a single capsid residue, VP2.Y97, as a major determinant of the susceptibility of echovirus 11 to environmental proteases. Notably, this residue is absent in several enterovirus types that exhibit greater environmental stability, indicating that substitution at a single position can shift enterovirus persistence in natural waters. These findings improve mechanistic understanding of pathogen fate in surface waters relevant to water quality and public-health protection.

I completed both my bachelor’s and master’s degrees in chemistry at EPFL, Switzerland. Currently, I am a last-year PhD student in the Laboratory of Environmental Virology (LEV) at EPFL, supervised by Prof. Tamar Kohn. My work focuses on the fate of human viruses in lakewater and understanding the role that microbial proteases play in virus inactivation.