title: Human monoclonal single-chain antibodies specific to dengue virus envelope protein.
abstract: Dengue virus (DENV) infection is an arthropod-borne disease with increasing prevalence worldwide. Attempts have been made to develop therapeutic molecules for treatment for DENV infection. However, most of potentially therapeutic DENV monoclonal antibody was originated from mouse, which could cause undesirable effects in human recipients. Thus, fully human antibody is preferable for therapeutic development. Human single-chain variable fragments (HuScFv) with inhibitory effect to DENV infection were generated in this study. HuScFv molecules were screened and selected from the human antibody phage display library by using purified recombinant DENV full-length envelope (FL-E) and its domain III (EDIII) proteins as target antigens for biopanning. HuScFv molecules were then tested for their bindings to DENV particles by indirect ELISA and immunofluorescent microscopy. EDIII-specific HuScFv exhibited neutralizing effect to DENV infection in Vero cells in a dose-dependent manner as determined by plaque formation and cell ELISA. Epitope mapping and molecular docking results concordantly revealed interaction of HuScFv to functional loop structure in EDIII of the DENV E protein. The neutralizing HuScFv molecule warrants further development as a therapeutic biomolecule for DENV infection.
  
  
  CONCLUSIONS
  No approved vaccine and specific drug for dengue virus (DENV) infection are available; thus, their developments are urgently required. The human single-chain variable antibody fragments (HuScFv) specific to DENV envelope (E) protein are potential to be developed as therapeutic biomolecules. HuScFv that bound specifically to recombinant full-length DENV E (FL-E) and its domain III (EDIII) were generated and testified for its inhibitory effect in DENV infection. EDIII-specific HuScFv inhibited DENV infection in a dose-dependent manner and has potential to be further developed as a therapeutic biomolecule for DENV infection.
authors.affiliation: Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand; Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: N
authors.initials: N
authors.lastname: Saokaew
authors.forename: O
authors.initials: O
authors.lastname: Poungpair
authors.forename: A
authors.initials: A
authors.lastname: Panya
authors.forename: M
authors.initials: M
authors.lastname: Tarasuk
authors.forename: N
authors.initials: N
authors.lastname: Sawasdee
authors.forename: T
authors.initials: T
authors.lastname: Limjindaporn
authors.forename: W
authors.initials: W
authors.lastname: Chaicumpa
authors.forename: P
authors.initials: P
authors.lastname: Yenchitsomanus
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000008:administration & dosage / Q000276:immunology*; D002522:Chlorocebus aethiops; D003715:Dengue / Q000276:immunology / Q000517:prevention & control / Q000821:virology; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology*; D018604:Epitope Mapping; D006801:Humans; D007116:Immunization, Passive; D051379:Mice; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D057127:Single-Chain Antibodies / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D057127:Single-Chain Antibodies; D014759:Viral Envelope Proteins
keywords: dengue virus; envelope protein; human single-chain variable fragments; monoclonal antibody; phage display; virus entry