SARS-CoV-2 entry is blocked by a serine protease inhibitor
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a positive-sense, single-stranded RNA virus that causes the potentially lethal COVID-19 respiratory tract infection. This new virus belongs to the genus Betacoronavirus, which also includes SARS-CoV and MERS-CoV.
With SARS-CoV-2 now reaching pandemic status, researchers and clinicians have been working furiously to learn more about the virus’s biology and pathogenesis as well as how to treat the more clinically aggressive COVID-19 cases. As with any viral pathogen, understanding how SARS-CoV-2 enters host cells is of great significance.
In a study published recently in Cell, Hoffmann et al. confirm findings reported by Zhou et al. that angiotensin-converting enzyme 2 (ACE2) is the cellular receptor for SARS-CoV-2, as it is for SARS-CoV (2, 3). In addition, they identify the serine protease TMPRSS2 as a critical factor in the priming of the SARS-CoV-2 spike (S) protein, an essential step for viral entry into host cells through fusion of the viral and cellular membranes. The authors also demonstrate that the serine protease inhibitor camostat mesylate, an agent that has already seen clinical application as a treatment for chronic pancreatitis in Japan, is able to interfere with SARS-CoV-2 infection of lung cells. Finally, the study presents data that antibodies generated to SARS-CoV S protein may have some protective activity against SARS-CoV-2. Together, this work expands our knowledge of key factors involved in SARS-CoV-2’s entry into cells and reveals some promising avenues for SARS-CoV-2-directed therapies.