Phenotype and function of IgE-binding monocytes in equine Culicoides hypersensitivity

PLoS One. 2020 May 22;15(5):e0233537. doi: 10.1371/journal.pone.0233537. eCollection 2020.

Abstract

Human IgE-binding monocytes are identified as allergic disease mediators, but it is unknown whether IgE-binding monocytes promote or prevent an allergic response. We identified IgE-binding monocytes in equine peripheral blood as IgE+/MHCIIhigh/CD14low cells that bind IgE through an FcεRI αɣ variant. IgE-binding monocytes were analyzed monthly in Culicoides hypersensitive horses and nonallergic horses living together with natural exposure to Culicoides midges. The phenotype and frequency of IgE-binding monocytes remained consistent in all horses regardless of Culicoides exposure. All horses upregulated IgE-binding monocyte CD16 expression following initial Culicoides exposure. Serum total IgE concentration and monocyte surface IgE densities were positively correlated in all horses. We also demonstrated that IgE-binding monocytes produce IL-10, but not IL-4, IL-17A, or IFN-γ, following IgE crosslinking. In conclusion, we have characterized horse IgE-binding monocytes for the first time and further studies of these cells may provide important connections between regulation and cellular mechanisms of IgE-mediated diseases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Allergens / immunology
  • Animals
  • Antigens, Surface / immunology
  • Ceratopogonidae / immunology*
  • Cytokines / metabolism
  • Horse Diseases / immunology*
  • Horses
  • Hypersensitivity, Immediate / veterinary*
  • Immunoglobulin E / blood
  • Immunoglobulin E / immunology*
  • Insect Bites and Stings* / immunology
  • Insect Bites and Stings* / veterinary
  • Leukocytes, Mononuclear* / cytology
  • Leukocytes, Mononuclear* / immunology
  • Receptors, IgE / immunology

Substances

  • Allergens
  • Antigens, Surface
  • Cytokines
  • Receptors, IgE
  • Immunoglobulin E