Identification of a linear epitope within domain I of Duck Tembusu virus envelope protein using a novel neutralizing monoclonal antibody

• Published in: Developmental and comparative immunology Vol. 115; p. 103906
• Main Authors: Gong, Huimin, Fan, Yufang, Zhou, Peng, Li, Yaqian, Hu, Xueying, Jin, Hui, Luo, Rui
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.02.2021
• Subjects: Animals; Antibodies, Monoclonal - metabolism; Antibodies, Neutralizing - metabolism; Antibodies, Viral - metabolism; Cells, Cultured; China; Conserved Sequence; Disease Resistance; Duck Tembusu virus; Ducks - immunology; Ducks - virology; Envelope protein; Epitope Mapping - methods; Epitopes, B-Lymphocyte - genetics; Epitopes, B-Lymphocyte - immunology; Fibroblasts - physiology; Fibroblasts - virology; Flavivirus - physiology; Flavivirus Infections - immunology; Neutralizing epitope; Poultry Diseases - immunology; Single-Chain Antibodies - genetics; Single-Chain Antibodies - immunology; Single-chain variable antibody fragment; Viral Envelope Proteins - genetics; Viral Envelope Proteins - immunology; Viral Vaccines - immunology; China; Neutralizing epitope; Envelope protein; Duck Tembusu virus; Single-chain variable antibody fragment
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2020.103906

Duck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that caused severe egg drop syndrome in laying ducks in China since 2010, leading to massive economic losses to the duck industry. Although the DTMUV E protein is considered to be critical in inducing the protective immune response, the functional epitopes within this protein remain largely unknown. In the present study, we isolated a DTMUV neutralizing monoclonal antibody (mAb) 3B8 from DTMUV E-immunized mice. Epitope mapping showed that mAb 3B8 recognized a novel linear epitope FSCLGMQNR located on the extreme N-terminal of the domain I (EDI) of E protein. Sequence alignment and Western blot analyses showed that the epitope is greatly conserved with high DTMUV-specificity. Moreover, upon cloning the heavy and light chain variable region sequences of mAb 3B8, we prepared the single-chain variable antibody fragment (scFv) 3B8 by connecting the two chains via a flexible peptide linker. The recombinant scFv 3B8 exhibited antiviral activity against DTMUV infection in vitro and in vivo. Our results provide valuable implications for the development of DTMUV vaccines and therapeutics. •We identified a novel neutralizing epitope 1FSCLGMQNR9 located on the DTMUV EDI.•The identified epitope is highly conserved and DTMUV-specific.•We generated an anti-DTMUV scFv exhibiting an effective neutralization against DTMUV.