Cross-linking peptide and repurposed drugs inhibit both entry pathways of SARS-CoV-2

Abstract

So far, effective antivirals have not been widely available for treating COVID-19. In this study, we identify a dual-functional cross-linking peptide 8P9R which can inhibit the two entry pathways (endocytic pathway and TMPRSS2-mediated surface pathway) of SARS-CoV-2 in cells. The endosomal acidification inhibitors (8P9R and chloroquine) can synergistically enhance the activity of arbidol, a spike-ACE2 fusion inhibitor, against SARS-CoV-2 and SARS-CoV in cells. In vivo studies indicate that 8P9R or the combination of repurposed drugs (arbidol, chloroquine and camostat which is a TMPRSS2 inhibitor), simultaneously interfering with the two entry pathways of coronavirus, can significantly suppress SARS-CoV-2 replication in hamsters and SARS-CoV in mice. Here, we use drug combination (arbidol, chloroquine, and camostat) and a dual-functional 8P9R to demonstrate that blocking the two entry pathways of coronavirus can be a promising and achievable approach for inhibiting SARS-CoV-2 replication in vivo. Cocktail therapy of these drug combinations should be considered in treatment trials for COVID-19.

Peptide and peptide-based inhibitors of SARS-CoV-2 entry

“…Although targeting acidification might have several side effects in a physiological setting, A(H1N1)pdm09 infected mice showed better outcomes upon intranasal treatment with P9R [ 116 ]. A follow up study, currently available as preprint, suggests that virus-binding P9R-derived oligomers may cross-link viral particles [ 117 ]. The analyzed eight-branched 8P9R is more potent than P9R in blocking SARS-CoV-2 entry and also inhibits infection of TMPRSS2 positive Calu-3 cells by aggregating viral particles, confirming its dual-antiviral mechanism.…”

“…The antiviral effect was confirmed in vivo in mice and hamsters where its application decreased viral loads. In contrast, the TMPRSS2 inhibitor camostat mesylate was inactive, further illustrating that blocking only one entry pathway might be insufficient [ 117 ].…”

Construction of a potent pan-vaccine based on the evolutionary tendency of SARS-CoV-2 spike protein

“…SARS-CoV-2 mainly depended on two pathways (TMPRSS2 mediated membrane fusion pathway and cathepsin B/L mediated endocytic pathway) to enter cells (36). Previous studies showed that SARS-CoV-2 entry into the Vero E6 cells mainly through the endocytic pathway due to the low expression of TMPRSS2 in this cell.…”

Endosomal acidification inhibitors broadly inhibit influenza virus and coronavirus in vivo

“…No drugresistant virus was found after 20 viral passages in the presence of P16. Interestingly and importantly, chloroquine, despite not showing effective antiviral activity in vivo (23,24,29,30) when administrated through systemic routes in many studies, could target host endosomes to block pH-dependent viral infection and signi cantly inhibit in uenza virus and coronavirus replication in mice and hamsters when administrated by intranasal routes. The host-targeting antiviral activity of chloroquine indicates that chloroquine is less likely to induce drug-resistant problem.…”

“…These in vivo data provided the information that the endosomal acidi cation inhibitor chloroquine, which could not inhibit coronavirus or in uenza virus replication in vivo when administrated by oral inoculation ( Supplementary Fig. 14) or intraperitoneal injection (24,25,29,30), might effectively inhibit coronavirus and in uenza virus replication in humans if chloroquine could be administrated to lungs by intranasal routes to provide effective chance of keeping lung cells in the bath of chloroquine environment. Thinking about the TMPRSS2-mediated entry pathway of SARS-CoV-2 in humans, we further demonstrated that chloroquine could signi cantly inhibit SARS-CoV-2 replication in ex vivo human lung tissues which were kept in the bath of chloroquine (Fig.…”