title: Baculovirus expression and antigenic characterization of classical swine fever virus E2 proteins.
abstract: Genes encoding a major structural glycoprotein, E2, of classical swine fever viruses (CSFV) Brescia (subgroup 1.2), Paderborn (subgroup 2.1) and Kanagawa (subgroup 3.4) were constructed by removing the transmembrane domain and adding a C-terminal 6 histidine (His) tag. All the E2 constructs were efficiently expressed in a baculovirus system as 53-kDa glycosylated proteins that were identified in Western blots by their reaction with anti-His and CSFV-specific antibodies. These proteins were used as ELISA antigens to confirm the existence of an antigenic relationship between the viruses using group-specific polyclonal antisera. Antigenic differences were identified by Western blot and ELISA reactivity of the E2 proteins with a panel of monoclonal antibodies. Specifically, one monoclonal antibody (WH303) reacted with all three proteins, two monoclonal antibodies (M1660 and M1665) reacted with only the Brescia E2 protein, and three monoclonal antibodies (M1654, M1664 and M1669) reacted equally well with only Brescia and Kanagawa E2 proteins. Therefore, antibody reactivity profiles, established using recombinant E2 proteins, could be used to quickly identify novel CSFV strains as illustrated in this report with only a limited number of monoclonal antibodies. These proteins could also have added utility in the production of monoclonal antibodies and as critical reagents in diagnostic assays.
authors.affiliation: National Centre for Foreign Animal Disease, Winnipeg, MB, Canada. lizhong.luo@inspection.gc.ca
authors.forename: L
authors.initials: L
authors.lastname: Luo
authors.forename: K
authors.initials: K
authors.lastname: Nishi
authors.forename: E
authors.initials: E
authors.lastname: Macleod
authors.forename: M I
authors.initials: MI
authors.lastname: Sabara
authors.forename: M
authors.initials: M
authors.lastname: Lin
authors.forename: K
authors.initials: K
authors.lastname: Handel
authors.forename: J
authors.initials: J
authors.lastname: Pasick
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000940:Antigenic Variation / Q000235:genetics / Q000276:immunology*; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology*; D016367:Baculoviridae / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D006691:Classical Swine Fever / Q000276:immunology / Q000821:virology; D006692:Classical Swine Fever Virus / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D014644:Genetic Variation; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment; D013552:Swine; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; C087086:glycoprotein E2, classical swine fever virus