Abstract

Interferon-alpha (IFN-alpha) is a type I interferon that is secreted during the early stages of the innate immune response and is often induced upon infection with viral pathogens. IFN-alpha production affects multiple downstream events influencing both innate and adaptive immune responses. Here, we describe the expression of an equine rIFN-alpha/IgG4 fusion protein in mammalian cells. The anti-viral activity of rIFN-alpha/IgG4 was found to be 70-fold higher than that of a previously described rFN--gamma/IgG1 as tested by bioassay. The purified rIFN-alpha was subsequently used for the generation of six monoclonal antibodies (mAbs) to equine IFN-a. Four of these mAbs inhibited the protective anti-viral effect of equine leukocyte IFN in bioassays. One mAb (clone 240-2) showed a high-neutralizing capacity. An ELISA was established using two anti-equine IFN-a. mAbs (clones 29B and 240-2) and its analytical sensitivity for was found to be around 800 pg/ml and 3 U/ml for rIFN-a and equine leukocyte IFN, respectively. When analyzing samples with a likely dominance of IFN-alpha among type I IFNs, such as supernatants from equine peripheral blood mononuclear cells stimulated with CpG-oligodeoxyribonucleotides, the results obtained by ELISA and IFN bioassay showed a high agreement (r(sp)(2) = 0.98). When analyzing samples likely containing a mixture of type I IFNs, such as serum and nasal secretions from virally infected horses, the ELISA only detected some of the IFN-activity recorded in the bioassay. Overall, the data showed that the new anti-equine IFN-alpha mAbs are valuable tools to detect native IFN-alpha for further characterization of the early innate immune response and anti-viral immunity in horses. (c) 2008 Elsevier B.V. All rights reserved.

Keywords

Interferon-alpha; Monoclonal antibodies; Neutralization; Bioassay; ELISA; Plasmacytoid dendritic cells

Published in

Veterinary Immunology and Immunopathology
2008, Volume: 125, number: 3-4, pages: 315-325
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Wattrang, Eva

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    
  • National Veterinary Institute (SVA)

UKÄ Subject classification

Medical Bioscience


Publication identifier

DOI: https://doi.org/10.1016/j.vetimm.2008.05.016

Permanent link to this page (URI)

https://res.slu.se/id/publ/78144