title: Enhanced expression of the Erns protein of classical swine fever virus in yeast and its application in an indirect enzyme-linked immunosorbent assay for antibody differentiation of infected from vaccinated animals.
abstract: Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is a devastating disease of swine worldwide. Although a mandatory vaccination with the modified live vaccine C-strain has been implemented in China for decades, CSF remains a serious threat to the swine industry. To facilitate the control and eradication of CSF in China, the E2-based marker vaccine rAdV-SFV-E2, an adenovirus-delivered, alphavirus replicon-vectored vaccine, has been developed. Accordingly, an accompanying discriminatory test that allows differentiating infected from vaccinated animals (DIVA) is required. Here, the enhanced expression of E(rns) protein of CSFV was achieved in the methyltropic yeast Pichia pastoris by codon-optimization of the E(rns) gene, and an indirect enzyme-linked immunosorbent assay (iELISA) based on the yeast-expressed E(rns) (yE(rns)) was developed and evaluated. The optimized iELISA was able to detect CSFV-specific antibodies in the serum samples from the CSFV-infected pigs as early as 6 days post-infection, and discriminate the CSFV-infected pigs from those vaccinated with rAdV-SFV-E2. The iELISA was evaluated using a panel of swine sera, and showed comparable sensitivity (94.6%) and specificity (97.1%), and the consistence rates with the virus neutralization test were 96.8% for CSFV-infected swine sera, 83.3% for C-strain-vaccinated swine sera, and 95.0% for field swine sera. In addition, the iELISA showed higher sensitivity (90.4%) compared with PrioCHECK CSFV E(rns) (59.6%). Taken together, the yE(rns)-based iELISA is specific and sensitive, representing a promising DIVA test for E2-based marker vaccines against CSF.
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Yuzi
authors.initials: Y
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: EU and OIE Reference Laboratory for Classical Swine Fever, Institute of Virology, University of Veterinary Medicine Hannover, Buenteweg 17, D-30559 Hannover, Germany.
authors.forename: Sophia
authors.initials: S
authors.lastname: Austermann-Busch
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Lina
authors.initials: L
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Jianlin
authors.initials: J
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Wen-Rui
authors.initials: WR
authors.lastname: He
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Bibo
authors.initials: B
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Su
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Virology, Immunobiology and Parasitology, National Veterinary Institute (SVA), 75189 Uppsala, Sweden; Joint Laboratory on Veterinary Microbiology between HVRI and SVA.
authors.forename: Lihong
authors.initials: L
authors.lastname: Liu
authors.affiliation: EU and OIE Reference Laboratory for Classical Swine Fever, Institute of Virology, University of Veterinary Medicine Hannover, Buenteweg 17, D-30559 Hannover, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Becher
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA. Electronic address: sunyuan@hvri.ac.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute (HVRI), Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, China; Joint Laboratory on Veterinary Microbiology between HVRI and SVA. Electronic address: huajiqiu@hvri.ac.cn.
authors.forename: Hua-Ji
authors.initials: HJ
authors.lastname: Qiu
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D002681:China; D006691:Classical Swine Fever / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control*; D006692:Classical Swine Fever Virus / Q000235:genetics / Q000276:immunology*; D003937:Diagnosis, Differential; D003955:Diagnostic Tests, Routine / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D015870:Gene Expression; D010843:Pichia / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012680:Sensitivity and Specificity; D013552:Swine; D022581:Vaccines, Marker / Q000008:administration & dosage / Q000276:immunology; D015678:Viral Structural Proteins / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D011994:Recombinant Proteins; D022581:Vaccines, Marker; D015678:Viral Structural Proteins; D014765:Viral Vaccines
keywords: Classical swine fever virus; Differentiation of infected from vaccinated animals (DIVA); E(rns) protein; Indirect enzyme-linked immunosorbent assay; Yeast expression