Expression of a 4-(hydroxy-3-nitro-phenyl) acetyl (NP) specific equi-murine IgE antibody that mediates histamine release in vitro and a type I skin reaction in vivo.
Authors: Wagner B, Siebenkotten G, Leibold W, Radbruch A
Journal: Equine veterinary journal
Summary
# Editorial Summary Equine allergic diseases are clinically recognised as IgE-mediated conditions, yet their investigation has been severely limited by the lack of purified equine IgE and specific detection tools. Wagner and colleagues addressed this gap by developing a recombinant equi-murine IgE antibody (approximately 230 kDa) with specificity for the hapten 4-(hydroxy-3-nitro-phenyl) acetyl, establishing a stable cell line capable of consistent production. Using equine blood leucocytes in vitro, the researchers demonstrated functional IgE-mediated histamine release upon antigen crosslinking, and subsequently confirmed biological activity in vivo through intradermal injection that provoked a classical type I hypersensitivity skin reaction in horses. These findings validate that the recombinant IgE maintains an intact Fc(epsilon)RI binding site and can activate both basophils and cutaneous mast cells as expected in natural allergic responses. For equine practitioners, this work provides a critical research tool that should facilitate better characterisation of IgE-mediated allergic mechanisms—potentially leading to improved diagnostic approaches and targeted interventions for conditions such as sweet itch, food sensitivities and environmental allergies that significantly affect performance and welfare.
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Practical Takeaways
- •This tool enables better investigation of IgE-mediated allergic mechanisms in horses, potentially improving understanding and diagnosis of equine allergic diseases
- •The ability to specifically activate mast cells and basophils using NP-specific IgE provides a research model for studying type I hypersensitivity reactions in equines
- •Development of IgE-specific antibodies from this work could improve diagnostic capabilities for identifying IgE involvement in equine allergic conditions
Key Findings
- •Recombinant equi-murine IgE antibody (NP-IgE) was successfully constructed and expressed as a highly glycosylated monomer of approximately 230,000 Da
- •NP-IgE mediated histamine release from equine blood leucocytes in vitro following antigen crosslinking
- •Intradermal application of NP-IgE with antigen challenge induced a type I hypersensitivity skin reaction in vivo in horses
- •The recombinant antibody contains a functional FcεRI binding site and mediates effector functions in equine basophils and mast cells