Broad spectrum antiviral activity for paramyxoviruses is modulated by biophysical properties of fusion inhibitory peptides

Abstract

Human paramyxoviruses include global causes of lower respiratory disease like the parainfluenza viruses, as well as agents of lethal encephalitis like Nipah virus. Infection is initiated by viral glycoprotein-mediated fusion between viral and host cell membranes. Paramyxovirus viral fusion proteins (F) insert into the target cell membrane, and form a transient intermediate that pulls the viral and cell membranes together as two heptad-repeat regions refold to form a six-helix bundle structure that can be specifically targeted by fusion-inhibitory peptides. Antiviral potency can be improved by sequence modification and lipid conjugation, and by adding linkers between the protein and lipid components. We exploit the uniquely broad spectrum antiviral activity of a parainfluenza F-derived peptide sequence that inhibits both parainfluenza and Nipah viruses, to investigate the influence of peptide orientation and intervening linker length on the peptides’ interaction with transitional states of F, solubility, membrane insertion kinetics, and protease sensitivity. We assessed the impact of these features on biodistribution and antiviral efficacy in vitro and in vivo. The engineering approach based on biophysical parameters resulted in a peptide that is a highly effective inhibitor of both paramyxoviruses and a set of criteria to be used for engineering broad spectrum antivirals for emerging paramyxoviruses.

Fusion Inhibitory Lipopeptides Engineered for Prophylaxis of Nipah Virus in Primates

“…Sera from African green monkeys (AGMs) were tested in an interferon type I (IFN-I) bioassay based on the protection from vesicular stomatitis virus infection, as described previously [25] Golden Hamster Infection Eight-week-old female Syrian golden hamsters (Mesocricetus auratus; Janvier, Le Genest-Saint-Isle, France) were infected intranasally (i.n.) with 10 4 to 10 6 plaque-forming units (pfu) of NiV in 40 µL or 100 µL DMEM [11]. Groups of 6-12 animals were treated daily with peptide i.n.…”

“…Weight and temperature were measured after each anesthesia. Blood sampling was on days −1, 2, 4, 6,8,11,13,15,18,20,22,25, and 28 p.i. Hematology was analyzed using MS9-5 (Melet Schloesing) within 4 hours after collection in EDTA-containing tubes.…”

“…Nipah virus F-mediated entry into target cells can be specifically targeted by fusion-inhibitory peptides that interfere with this initial step of viral entry by blocking formation of the 6-helix bundle. We have shown that fusion inhibitory peptide entry inhibitors, if conjugated to lipid moieties linked to the amino acid sequence by a flexible linker, can be highly effective inhibitors of NiV central nervous system (CNS) infection [10][11][12][13]. Exploiting the criteria that emerged from our previous biophysical studies, we designed a set of new lipopeptides with an amino acid sequence that confers greater stability to protease degradation and improved efficacy in vitro and in vivo.…”

NMR structure and localization of a large fragment of the SARS-CoV fusion protein: Implications in viral cell fusion

“…Fusion peptide inserts into the outer leaflet of the plasma membrane of the host cell initiating membrane fusion process [5][6][7][8][9]. Understating fusion mechanism not only garners knowledge of virus pathology but also can be exploited for the development of antiviral drugs [10][11][12][13][14]. Consequently, atomic-resolution structures of fusion proteins have provided important molecular insights for the membrane fusion process [2,4,[15][16][17][18][19].…”

The Heptad Repeat C Domain of the Respiratory Syncytial Virus Fusion Protein Plays a Key Role in Membrane Fusion

“…To date, the majority of research into the fusion function of RSV F has been focused on regions within the F 1 subunit, in particular, the HRA and HRB coiled coil (23)(24)(25). While these studies have provided deeper insight into formation and antiviral targeting of the terminal 6HB fusion core (26), the roles of residues and domains within the F 2 subunit remain relatively unexplored. Here, we performed a comprehensive mutational analysis of the HRC ␣-helix (Lys-75 to Met-97) and demonstrated that the region has an important role in RSV F-mediated membrane (21).…”