Antigen capture competitive enzyme-linked immunosorbent assays using baculovirus-expressed antigens for diagnosis of bluetongue virus and epizootic hemorrhagic disease virus

J Clin Microbiol. 2004 Feb;42(2):518-23. doi: 10.1128/JCM.42.2.518-523.2004.

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.

MeSH terms

  • Animals
  • Antibodies, Viral / blood
  • Antigens, Viral / analysis
  • Antigens, Viral / genetics*
  • Blotting, Western
  • Bluetongue / diagnosis*
  • Bluetongue virus / isolation & purification
  • Cattle
  • Cloning, Molecular
  • Deer
  • Enzyme-Linked Immunosorbent Assay / methods
  • Hemorrhagic Disease Virus, Epizootic / isolation & purification*
  • Recombinant Proteins / analysis
  • Reoviridae Infections / diagnosis*
  • Sheep
  • Spodoptera
  • Time Factors

Substances

  • Antibodies, Viral
  • Antigens, Viral
  • Recombinant Proteins