title: Development of an in vitro model system for studying the interaction of Equus caballus IgE with its high-affinity receptor FcɛRI.
abstract: The binding of immunoglobulin E (IgE) to its high-affinity receptor (FcɛRI) is the central protein interaction in IgE-mediated allergic reactions. The cross-linking of the IgE/FcɛRI complex, through cognate allergens, on the surface of mast cells and basophil cells results in mediator release, and thus leads to the symptoms of type I hypersensitivity responses in mammals. To develop a baseline value for subsequent equine anti-allergy drug and vaccine research, the interaction of equine IgE with its high-affinity FcɛRI receptor was investigated following the cloning and expression of equine IgE with specificity for NIP-HSA (4-hydroxy-5-iodo-3-nitrophenylacetic acid conjugated to human serum albumin). Receptor recognition and effector functions were assessed in Rat Basophil Leukemia (RBL-2H3.1) cells transfected with the α chain of equine and canine FcɛRI. Results obtained showed that the equine FcɛRI receptor recognizes both equine and canine IgE and supports similar β-hexosaminidase release levels from RBL cells transfected with equine FcɛRI, peaking at 36.68% at 100ngml(-1) antigen and 32.00% at 100ngml(-1) antigen respectively. Furthermore, the binding kinetics of the equine IgE to the equine FcɛRI receptor and the canine IgE to the same receptor was measured to be KA=6.33×10(9)M(-1) and KA=1.84×10(9)M(-1) respectively. This research established basic reagents and vitro assay systems to underpin the development of rational therapeutic intervention strategies to combat equine allergic manifestations.
authors.affiliation: The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield S10 2TN, UK. sari.sabban@gmail.com
authors.forename: Sari
authors.initials: S
authors.lastname: Sabban
authors.forename: Hongtu
authors.initials: H
authors.lastname: Ye
authors.forename: Birgit
authors.initials: B
authors.lastname: Helm
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D004285:Dogs; D006736:Horses / Q000276:immunology*; D007073:Immunoglobulin E / Q000378:metabolism*; D051381:Rats; D017455:Receptors, IgE / Q000378:metabolism*; D020349:Surface Plasmon Resonance; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism
chemical_list: D017455:Receptors, IgE; D007073:Immunoglobulin E; D001619:beta-N-Acetylhexosaminidases