Truncated Bovine Integrin Alpha-v/Beta-6 as a Universal Capture Ligand for FMD Diagnosis

PLoS One. 2016 Aug 5;11(8):e0160696. doi: 10.1371/journal.pone.0160696. eCollection 2016.

Abstract

Foot-and-mouth disease (FMD) is endemic in many regions of the world and is one of the most prevalent epizootic animal diseases. FMD affects livestock, such as cattle, sheep, goats and pigs, and causes enormous economic losses due to reduced productivity and trade restrictions. Preparedness and early diagnosis are essential for effective control of FMD. Many diagnostic assays are dependent on raising high-affinity, anti-FMD virus (FMDV) serotype-specific antibodies in small animals (rabbits and guinea pigs) that give broad virus coverage. Here we show that soluble, truncated forms of bovine αvβ6 bind FMDV in an authentic RGD and divalent cation dependent interaction and can be used as the trapping reagent in a FMDV sandwich ELISA. In addition, inclusion of FLAG or His tags facilitates simple purification without the loss of virus binding. We also provide evidence that when combined with a guinea pig polyclonal serum, or serotype-specific monoclonal antibodies, the integrin can be used to detect viruses representative of all FMDV serotypes. We also show that recombinant FMDV empty capsids, with stabilising disulphide bonds, can serve as an antigen in the ELISA and can therefore replace inactivated virus antigen as a positive control for the assay. Our results demonstrate the potential use of bovine αvβ6 and FMDV empty capsids in FMD diagnostic assays.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology*
  • Antibodies, Viral / immunology*
  • Antigens, Neoplasm / immunology*
  • Capsid / immunology*
  • Cattle
  • Foot-and-Mouth Disease / diagnosis*
  • Foot-and-Mouth Disease / virology
  • Foot-and-Mouth Disease Virus / immunology
  • Foot-and-Mouth Disease Virus / isolation & purification*
  • Integrins / immunology*
  • Rabbits

Substances

  • Antibodies, Monoclonal
  • Antibodies, Viral
  • Antigens, Neoplasm
  • Integrins
  • integrin alphavbeta6

Grants and funding

This work was supported by the Biotechnology and Biological Sciences Research Council, project BBS/E/I/00001716 to TJ, http://www.bbsrc.ac.uk/, and the United Kingdom Department for Environment, Food and Rural Affairs, projects SE1127 and SE1128 to DPK, https://www.gov.uk/government/organisations/department-for-environment-food-rural-affairs. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.