Identification of a Common Conformational Epitope on the Glycoprotein E2 of Classical Swine Fever Virus and Border Disease Virus
Yu-Liang Huang,
Denise Meyer,
Alexander Postel,
Kuo-Jung Tsai,
Hsin-Meng Liu,
Chia-Huei Yang,
Yu-Chun Huang,
Nicholas Berkley,
Ming-Chung Deng,
Fun-In Wang,
Paul Becher,
Helen Crooke,
Chia-Yi Chang
Affiliations
Yu-Liang Huang
OIE Reference Laboratory for Classical Swine Fever, Animal Health Research Institute, Council of Agriculture, Executive Yuan, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan
Denise Meyer
EU and OIE Reference Laboratory for Classical Swine Fever, Institute of Virology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
Alexander Postel
EU and OIE Reference Laboratory for Classical Swine Fever, Institute of Virology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
Kuo-Jung Tsai
OIE Reference Laboratory for Classical Swine Fever, Animal Health Research Institute, Council of Agriculture, Executive Yuan, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan
Hsin-Meng Liu
OIE Reference Laboratory for Classical Swine Fever, Animal Health Research Institute, Council of Agriculture, Executive Yuan, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan
Chia-Huei Yang
OIE Reference Laboratory for Classical Swine Fever, Animal Health Research Institute, Council of Agriculture, Executive Yuan, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan
Yu-Chun Huang
OIE Reference Laboratory for Classical Swine Fever, Animal Health Research Institute, Council of Agriculture, Executive Yuan, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan
Nicholas Berkley
OIE Reference Laboratory for Classical Swine Fever, Animal and Plant Health Agency, New Haw KT15 3NB, Surrey, UK
Ming-Chung Deng
OIE Reference Laboratory for Classical Swine Fever, Animal Health Research Institute, Council of Agriculture, Executive Yuan, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan
Fun-In Wang
School of Veterinary Medicine, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
Paul Becher
EU and OIE Reference Laboratory for Classical Swine Fever, Institute of Virology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
Helen Crooke
OIE Reference Laboratory for Classical Swine Fever, Animal and Plant Health Agency, New Haw KT15 3NB, Surrey, UK
Chia-Yi Chang
OIE Reference Laboratory for Classical Swine Fever, Animal Health Research Institute, Council of Agriculture, Executive Yuan, 376 Chung-Cheng Road, Tansui, New Taipei City 25158, Taiwan
Classical swine fever virus (CSFV) shares high structural and antigenic homology with bovine viral diarrhea virus (BVDV) and border disease virus (BDV). Because all three viruses can infect swine and elicit cross-reactive antibodies, it is necessary to differentiate among them with regard to serological diagnosis of classical swine fever. To understand the mechanism of cross-reactivity, it is important to define common or specific epitopes of these viruses. For this purpose, epitope mapping of six monoclonal antibodies (mAbs) was performed using recombinant expressed antigenic domains of CSFV and BDV E2 proteins. One CSFV-specific conformational epitope and one CSFV and BDV common epitope within domain B/C of E2 were identified. Site-directed mutagenesis confirmed that residues G725 and V738/I738 of the CSFV-specific epitope and P709/L709 and E713 of the second epitope are important for mAbs binding. Infection of CSFV in porcine cells was significantly reduced after pre-incubation of the cells with the domain B/C of E2 or after pre-incubation of CSFV with the mAbs detecting domain B/C. 3D structural modeling suggested that both epitopes are exposed on the surface of E2. Based on this, the identified epitopes represent a potential target for virus neutralization and might be involved in the early steps of CSFV infection.
