Basic Science

Characterization Of Spike Glycoprotein Of Sars-Cov-2 On Virus Entry And Its Immune Cross-Reactivity With Sars-Cov

Since 2002, beta coronaviruses (CoV) have caused three disease oubreaks : SARS, MERS, and now COVID-19. However, little is currently known about the biology of SARS-CoV-2. The authors X Ou et al. developed a SARS-CoV-2 pseudovirus system to study, in BSL2 settings, the biology of this virus, mainly focusing on the role of S protein for cell entry.Moreover, the paper presents the results from cross-neutralization tests using recovered SARS and COVID-19 patients’ sera, suggesting that recovery from SARS might not protect against COVID-19 and vice versa.

Coronavirus Protease Inhibitors

The main protease of SARS-CoV-2 is Mpro and its activity is essential for viral replication. Since no human proteases with a similar cleavage specificity are known, inhibitors are unlikely to be toxic. Zhang et al. optimized an inhibitor developed previously for other coronaviruses, in order to enhance the half-life of the compound in plasma. The pharmacokinetic characterization of the optimized inhibitor reveals a pronounced lung tropism and suitability for administration by the inhalation route.

Inhibition of SARS-CoV-2 (previously 2019-nCoV) infection by a highly potent pan-coronavirus fusion inhibitor targeting its spike protein that harbors a high capacity to mediate membrane fusion

In this study the authors describe the role of the membrane fusion mechanism by spike proteins, at the basis of SARS-CoV2 infection. They demonstrate, in vitro and in vivo, the efficacy of the inhibition of HR1 domain of SARS-CoV2 spike proteins using lipopeptides (in particular EK1C4) which, by blocking the fusion mechanism, protect against viral SARS-CoV2 infection.