Cell penetrable human scFv specific to middle domain of matrix protein-1 protects mice from lethal influenza.

Fonthip Dong-Din-On,Kanyarat Thueng-In,Jeeraphong Thanongsaksrikul,Tippawan Pissawong,Preeda Lertwatcharasarakul,Wanpen Chaicumpa,Potjanee Srimanote,Thaweesak Songserm,Pattra Moonjit,Watee Seesuay

doi:10.3390/v7010154

Fonthip Dong-Din-On, Kanyarat Thueng-In + Show 8 more

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https://doi.org/10.3390/v7010154

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Abstract

A new anti-influenza remedy that can tolerate the virus antigenic variation is needed. Influenza virus matrix protein-1 (M1) is highly conserved and pivotal for the virus replication cycle: virus uncoating, assembly and budding. An agent that blocks the M1 functions should be an effective anti-influenza agent. In this study, human scFv that bound to recombinant M1 middle domain (MD) and native M1 of A/H5N1 was produced. Phage mimotope search and computerized molecular docking revealed that the scFv bound to the MD conformational epitope formed by juxtaposed helices 7 and 9 of the M1. The scFv was linked molecularly to a cell penetrable peptide, penetratin (PEN). The PEN-scFv (transbody), when used to treat the cells pre-infected with the heterologous clade/subclade A/H5N1 reduced the viral mRNA intracellularly and in the cell culture fluids. The transbody mitigated symptom severity and lung histopathology of the H5N1 infected mice and caused reduction of virus antigen in the tissues as well as extricated the animals from the lethal challenge in a dose dependent manner. The transbody specific to the M1 MD, either alone or in combination with the cognate human scFvs specific to other influenza virus proteins, should be an effective, safe and mutation tolerable anti-influenza agent.

Highlights

Type A influenza viruses are etiologic agents of highly contagious acute respiratory disease, i.e., influenza, of humans, other mammals and avian species [1]
DNA sequence coding for recombinant middle domain of matrix protein-1 of
The SDS-PAGE-separated pattern of the Recombinant MD (rMD) expressed by the transformed E. coli stained with

Summary

Introduction

Type A influenza viruses are etiologic agents of highly contagious acute respiratory disease, i.e., influenza, of humans, other mammals and avian species [1]. The world has experienced several catastrophic influenza pandemics/panzootics which have resulted in exceptionally high fatality rates among infected humans and animals, especially poultry, which has led to severe economic loss [2,3,4]. Vaccination is the most effective measure for influenza intervention, both prevention of the infection and mitigation of the symptom severity. There are limitations in the production and efficacy of the current influenza vaccines which the vaccine viruses have to be propagated in embryonated eggs [5,6]. New generation vaccines that are egg-independent, rapidly and timely produced at the time of high demand, more tolerable to virus antigenic variations and cross-protect against viruses of different strains and subtypes, such as those based on the highly conserved influenza virus proteins, have been sought [7,8]. Only two families of anti-viral drugs have been approved for clinical use, namely, inhibitors of the M2 ion channel activity and the neuraminidase inhibitors

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