Targeting eosinophils by active vaccination against interleukin-5 reduces basophil counts in horses with insect bite hypersensitivity in the 2nd year of vaccination. (October 2022)

• Record Type: Journal Article
• Authors: Rhiner, Tanya; Fettelschoss, Victoria; Schoster, Angelika; Birkmann, Katharina; Fettelschoss-Gabriel, Antonia
• Is Part Of: Veterinary journal. Volume 288(2022)
• Publication Date: 2022-10
• Subjects: Allergy -- Basophils -- Eosinophils -- Equine -- Interleukin-5; Veterinary medicine -- Periodicals; 636
• DOI: 10.1016/j.tvjl.2022.105896
• Languages: English
• ISSNs: 1090-0233

Abstract

Abstract: Previously, virus-like particle (VLP)-based self-vaccinations targeting interleukin (IL)-5 or IL-31 have been suggested to treat equine insect bite hypersensitivity (IBH), a seasonal recurrent allergic dermatitis in horses. The IL-5-targeting equine vaccine significantly reduced blood eosinophil counts in horses, similar to human monoclonal antibodies targeting IL-5 or the IL-5 receptor alpha (IL-5Rα). Previous studies in humans have also reported an additional effect on reduction of basophil counts. The aim of the present study was to evaluate whether an equine anti-IL-5 vaccine affected blood basophil counts. Horses with IBH were followed in a 3-year trial consisting of a placebo administered in the 1st year, followed by vaccination using an equine (e)IL-5-VLP vaccine in the 2nd and 3rd years. There was a strong reduction in circulating eosinophil counts after vaccination against IL-5. Additionally, there were reduced basophil counts, but only in the 3rd year of the study, suggesting a bystander effect of the anti-IL-5 vaccine on basophil counts. Highlights: Anti interleukin-5 (IL-5) vaccination significantly eosinophil counts in blood. Anti-IL-5 vaccination also reduced basophil counts in blood. Basophil counts were only reduced following the booster in the second year. Targeting IL-5 thus affected two key cell types in allergy. Eosinophils and monocytes followed a parallel cell course in allergic horses.