Human transbodies to VP40 inhibit cellular egress of Ebola virus-like particles

• Published in: Biochemical and biophysical research communications 2016-10, Vol.479 (2), p.245-252
• Main Authors: Teimoori, Salma, Seesuay, Watee, Jittavisutthikul, Surasak, Chaisri, Urai, Sookrung, Nitat, Densumite, Jaslan, Saelim, Nawannaporn, Chulanetra, Monrat, Maneewatch, Santi, Chaicumpa, Wanpen
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; Carcinoma, Hepatocellular - pathology; Carcinoma, Hepatocellular - ultrastructure; Carcinoma, Hepatocellular - virology; Cell Line, Tumor; Cell penetrating antibody (transbody); CLINICAL TRIALS; COMPUTERIZED SIMULATION; Ebola virus; Ebolavirus; Ebolavirus - drug effects; Ebolavirus - physiology; Ebolavirus - ultrastructure; GENES; GLOBAL POSITIONING SYSTEM; Host-Pathogen Interactions; Human scFv; Humans; INHIBITION; LIFE CYCLE; LIVER CELLS; Liver Neoplasms - pathology; Liver Neoplasms - ultrastructure; Liver Neoplasms - virology; MATRICES; Microscopy, Electron, Scanning; Models, Molecular; PARTICLES; Peptide Library; Protein Binding; Protein Domains; Scanning electron microscopy; Single-Chain Antibodies - chemistry; Single-Chain Antibodies - immunology; Single-Chain Antibodies - pharmacology; Viral Matrix Proteins - chemistry; Viral Matrix Proteins - genetics; Viral Matrix Proteins - immunology; Virion - drug effects; Virion - physiology; Virion - ultrastructure; Virus Release - drug effects; Virus Release - physiology; Virus-like particles; VP40
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2016.09.052

A direct acting anti-Ebola agent is needed. VP40, a conserved protein across Ebolavirus (EBOV) species has several pivotal roles in the virus life cycle. Inhibition of VP40 functions would lessen the virion integrity and interfere with the viral assembly, budding, and spread. In this study, cell penetrable human scFvs (HuscFvs) that bound to EBOV VP40 were produced by phage display technology. Gene sequences coding for VP40-bound-HuscFvs were subcloned from phagemids into protein expression plasmids downstream to a gene of cell penetrating peptide, i.e., nonaarginine (R9). By electron microscopy, transbodies from three clones effectively inhibited egress of the Ebola virus-like particles from human hepatic cells transduced with pseudo-typed-Lentivirus particles carrying EBOV VP40 and GP genes. Computerized simulation indicated that the effective HuscFvs bound to multiple basic residues in the cationic patch of VP40 C-terminal domain which are important in membrane-binding for viral matrix assembly and virus budding. The transbodies bound also to VP40 N-terminal domain and L domain peptide encompassed the PTAPPEY (WW binding) motif, suggesting that they might confer VP40 function inhibition through additional mechanism(s). The generated transbodies are worthwhile tested with authentic EBOV before developing to direct acting anti-Ebola agent for preclinical and clinical trials. •Cell penetrable human scFvs (transbodies) to Ebolavirus (EBOV) VP40 were produced.•The transbodies inhibited egress of EBOV-like particles (VLPs) from human hepatocytes.•They interacted with VP40 CTD basic residues important for plasma membrane binding.•And hence interfere with viral matrix assembly and viral progeny budding.•This is the first report on human antibodies that target intracellular EBOV VP40.