title: Antigen capture competitive enzyme-linked immunosorbent assays using baculovirus-expressed antigens for diagnosis of bluetongue virus and epizootic hemorrhagic disease virus.
abstract: Bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) are orbiviruses that infect both livestock and wild ruminants. Antigenic cross-reactivity between BTV and EHDV often results in serologic misdiagnosis. Competitive enzyme-linked immunosorbent assays (c-ELISAs) show increased sensitivity and specificity for the identification of these viral diseases; however, the preparation of cell culture-derived viral antigen for these tests is laborious and variable from batch to batch, and the resulting antigen may be infectious. To overcome these problems, the genes coding for a structural protein, VP7, of BTV and EHDV were cloned into baculovirus and the recombinant proteins were expressed in Sf9 cultured insect cells. Recombinant viral proteins released into the baculovirus-infected Sf9 cell culture supernatant were used in antigen capture c-ELISAs (Ag Cap c-ELISA) tests that specifically detected antibody in the serum of cattle experimentally infected with BTV and EHDV. The diagnostic utility of the Ag Cap c-ELISA was demonstrated by comparison with a commercial c-ELISA. The Ag Cap c-ELISA offers the advantages of using an easily produced, easily standardized, noninfectious antigen that does not require further purification or concentration.
authors.affiliation: Arthropod-Borne Animal Diseases Research Laboratory, Agricultural Research Service, US Department of Agriculture, Laramie, Wyoming 82071, USA. jmecham@uwyo.edu
authors.forename: J O
authors.initials: JO
authors.lastname: Mecham
authors.forename: W C
authors.initials: WC
authors.lastname: Wilson
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000032:analysis / Q000235:genetics*; D015153:Blotting, Western; D001819:Bluetongue / Q000175:diagnosis*; D001820:Bluetongue virus / Q000302:isolation & purification; D002417:Cattle; D003001:Cloning, Molecular; D003670:Deer; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D018164:Hemorrhagic Disease Virus, Epizootic / Q000302:isolation & purification*; D011994:Recombinant Proteins / Q000032:analysis; D012088:Reoviridae Infections / Q000175:diagnosis*; D012756:Sheep; D018411:Spodoptera; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D011994:Recombinant Proteins