By Neha MathurJul 21 2023Reviewed by Lily Ramsey, LLM In a recent study published in Scientific Reports, researchers investigated whether trypsin, a protease, increased severe acute respiratory syndrome coronavirus 2 infectivity.
Tryptase Clara cleaves the hemagglutinin of the influenza virus near airway epithelial cells, a step crucial for influenza infection. Likewise, SARS-CoV-2 infects by endocytosis using the angiotensin-converting enzyme 2 , a protease. Related StoriesFurther, the team generated pseudotyped vesicular stomatitis viruses bearing spike protein of SARS-CoV-2 for the trypsinization experiments. Specifically, they examined the effect of trypsin on SARS-CoV-2pv or VSVpv by exposing them to various concentrations of trypsin in Dulbecco’s modified Eagle’s medium for five minutes at 37 °C.
Treatment with trypsin also increased the infectivity of SARS-CoV-2 present in clinical samples derived from the nasal/oral cavities of COVID-19 patients. The authors noted an increase of up to 36,000-fold in infectivity of the Delta variant after trypsin treatment, whereas it increased to a meager few dozen-fold for Omicron.