Inhibitory effects of aprotinin on influenza A and B viruses in vitro and in vivo

Abstract

Influenza viruses cause significant morbidity and mortality worldwide. Long-term or frequent use of approved anti-influenza agents has resulted in drug-resistant strains, thereby necessitating the discovery of new drugs. In this study, we found aprotinin, a serine protease inhibitor, as an anti-influenza candidate through screening of compound libraries. Aprotinin has been previously reported to show inhibitory effects on a few influenza A virus (IAV) subtypes (e.g., seasonal H1N1 and H3N2). However, because there were no reports of its inhibitory effects on the other types of influenza viruses, we investigated the inhibitory effects of aprotinin in vitro on a wide range of influenza viruses, including avian and oseltamivir-resistant influenza virus strains. Our cell-based assay showed that aprotinin had inhibitory effects on seasonal human IAVs (H1N1 and H3N2 subtypes), avian IAVs (H5N2, H6N5, and H9N2 subtypes), an oseltamivir-resistant IAV, and a currently circulating influenza B virus. We have also confirmed its activity in mice infected with a lethal dose of influenza virus, showing a significant increase in survival rate. Our findings suggest that aprotinin has the capacity to inhibit a wide range of influenza virus subtypes and should be considered for development as a therapeutic agent against influenza.

Design of Three Residues Peptides against SARS-CoV-2 Infection

“…Many peptides currently analyzed for their anti-SARS-CoV-2 effect are repurposing peptides. For example, aprotinin is a very long peptide (58 amino acid residues) already well-known as a transmembrane serine protease 2 (TMPRSS2) inhibitor influencing negatively influenza A and B viruses [ 51 , 52 ] replication. Several antimicrobial peptides (AMPs) have also been tested for their anti-SARS-CoV-2 activity.…”

Host directed therapies: COVID-19 and beyond

“… Drug Host Factor Mechanism Viruses Ref. Fludase (DAS181) SA Cleaves SA on the cell surface of host to prevent viral entry IV, PIV Zenilman et al (2015) Maraviroc (MVC) CCR5 A CCR5-antagonist, binds to CCR5 and blocks viral entry HIV-1 Woollard and Kanmogne (2015) Myrcludex B NTCP Binds to NTCP to block the viral entry into liver cells HBV, HDV Bogomolov et al (2016) Ezetimibe NPC1L1 Blocks viral entry by binding to NPC1L1 HCV ( Feld et al, 2020 ; Monrroy et al, 2017 ) Aprotinin Endosomes A serine protease inhibitor, inhibition of viral protease activity during viral entry and endosome fusion IAV, IBV, SARS-CoV-2 ( Bojkova et al, 2020a ; Song et al, 2021b ) Niclosamide Endsomes A category B anthelmintic drug approved by FDA, targets acidic vacuoles, endosomes and interferes with membrane fusions. Also inhibits viral RNA replication and viral maturation SARS-CoV-2 DENV ( Backer et al, 2021 ; Jung et al, 2019 ) Emetine Lysosomes FDA approved drug for amebiasis, accumulates into the lysosomes, alters the pH to impair the intracellular traffic and inhibits autophagy to hinder the autophagy mediated viral infection, accumulation of emetine in lysosomes also limits free cholesterol availability for viral assembly ZIKV, EBV Yang et al (2018) Selective Inhibitor of Nuclear Export (SINE) Compound Verdinexor (KPT-185) Nuclear export A slow-reversible inhibitor of Exportin 1(CRM1/XPO1), inhibits interaction between NEP and exportin-1 (XPO1) to prevent nuclear export in vRNP.…”

“…In addition to cell surface receptors, viruses also depend on host proteases for their surface protein splicing which aid them in host entry ( Böttcher-Friebertshäuser et al, 2013 ; Izaguirre, 2019 ). Aprotinin, a serine protease inhibitor which is in clinical use in Russia prevents influenza virus membrane fusion ( Song et al, 2021a ; Zhirnov et al, 2011 ). The effectiveness of aprotinin against SARS-CoV-2 has also been demonstrated at therapeutically achievable concentrations ( Bojkova et al, 2020a ).…”

The Efficacy of Aprotinin Combinations with Selected Antiviral Drugs in Mouse Models of Influenza Pneumonia and Coronavirus Infection Caused by SARS-CoV-2

“…APR inhibits transmembrane serine protease 2 (TMPRSS2), which is actively involved in the viral entry process [ 12 , 24 , 25 , 26 , 27 , 28 , 29 ], and also the cleavage of hemagglutinin (HA), which is required for influenza virus fusion with a host cell and which can also be facilitated by TMPRSS2 during viral egress and by the membrane-bound human airway-trypsin like protease (HAT) prior to attachment to host cells [ 19 , 30 , 31 , 32 , 33 , 34 , 35 ].…”

“…Previous studies have shown that APR inhibits a broad spectrum of influenza A viruses (IAV) and influenza B viruses (IBV). Anti-influenza viral activity includes seasonal human IAVs (H1N1 and H3N2 subtypes): A/CA/04/09 (H1N1) [ 34 ], A/PR/8/34 (H1N1) [ 18 , 35 , 36 ], A/WSN/34 (H1N1) [ 37 ], A/CA/04/09 (pH1N1), A/Hamburg/05/2009 (pH1N1) [ 36 ], A/Aichi/2/68 (H3N2) [ 18 , 35 , 37 ], and A/PH/2/82 (H3N2) [ 35 ]; avian IAVs A/AB/Kor/CN2/09 (H5N2), A/AB/Kor/CN05/09 (H6N5) and A/Ck/Kor/01310/01 (H9N2) [ 35 ]; an oseltamivir-resistant IAV: A/Bris/10/07 H3N2 [ 37 ]; IBV B/Seoul/32/2011 [ 35 ], B/Hong Kong/73 [ 30 ], and B/Lee/40 [ 30 ]. It should be noted that the aprotinin-based aerosol patented in 2010 for the treatment of viral respiratory infections [ 38 ] has been approved in Russia for the treatment of influenza [ 19 ].…”