Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023

Specific antibody response is induced by feeding transgenic barley mixture to horses, a possible oral immunotherapy for insect bite hypersensitivity

Höfundar / Authors: Fenja von der Höden (1) , Sigurbjörg Þorsteinsdóttir (1), Vilhjálmur Svansson (1), Jón Már Björnsson (2), Sigríður Jónsdóttir (1)

Starfsvettvangur / Affiliations: 1. Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavik, Iceland. 2. ORF Genetics, Kópavogur Iceland.

Kynnir / Presenter: Fenja von der Höden

Introduction: Insect Bite Hypersensitivity (IBH) is an IgE mediated allergy in horses caused by salivary gland proteins of biting midges (Culicoides spp.). IBH poses a significant challenge to Icelandic horses exported to the mainland. We developed a method to treat horses with transgenic barley expressing Culicoides allergen using special designed spiral bits. The treatment induced an allergen-specific IgG response but was rather impractical and time consuming. The aim is to develop a more practical approach by replacing the spiral bits with a simplified method for horse owners by feeding the barley using stable buckets. Material & Methods: Twelve Icelandic horses were treated with Culo2p recombinant barley (6 horses) or control barley (6 horses). The horses were treated 34 times over 8 weeks (initiation phase) with the barley mixture, total of 7.5 g of recombinant Culo2p/horse. Blood serum was collected every other week for 12 weeks and saliva at week 10. Culo2p-specific total IgG and its subclasses were analysed by ELISA. Results: Four out of six Culo2p barley treated horses showed an IgG-mediated immune response, particularly IgG1 and IgG4/7. Both IgG1 and IgG4/7 peaked at week 4 of the treatment and declined after week 8, when the initiation phase ended. Conclusion: The simplified feeding method using transgenic barley is suitable to induce an allergen-specific IgG immune response and can easily be carried out by the horse owners.