A broad-spectrum virus- and host-targeting antiviral peptide against SARS-CoV-2 and other respiratory viruses

The 2019 novel respiratory virus (SARS-CoV-2) causes COVID-19 with rapid global socioeconomic disruptions and disease burden to healthcare. The current COVID-19 and previous emerging virus outbreaks highlight the urgent need for broad-spectrum antivirals. Here, we showed that a defensin-like peptide P9R exhibited potent antiviral activity against pH-dependent viruses that require endosomal acidification for virus-host membrane fusion, including the enveloped coronaviruses (SARS-CoV-2, SARS-CoV and MERS-CoV), the pandemic A(H1N1)pdm09 virus, avian influenza A(H7N9) virus, and the non-enveloped rhinovirus. P9R could significantly protect mice from lethal challenge by A(H1N1)pdm09 virus and showed low possibility to cause drug-resistance virus. Mechanistic studies indicated that the antiviral activity of P9R depended on the direct binding to viruses and the inhibition of virus-host endosomal acidification, which provides a new concept that virus-binding alkaline peptides could broadly inhibit pH-dependent viruses. These results suggest that the dual-functional virus- and host-targeting P9R could be a promising candidate for combating pH-dependent respiratory viruses.Authors Hanjun Zhao, Kelvin K. W. To, and Kong-Hung Sze contributed equally to this work.