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Updated: Jul 14, 2026

Development of an in vitro model system for studying the interaction of Equus caballus IgE with its high-affinity receptor FcεRI
Published on: November 1, 2014
Molecular identification of an IgE-dependent histamine-releasing factor
S M MacDonald1, T Rafnar, J Langdon
1Department of Medicine, Johns Hopkins University School of Medicine, Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
Abstract:
An immunoglobulin E (IgE)-dependent histamine-releasing factor (HRF) produced by lymphocytes of atopic children and present in biological fluids of allergic patients has been identified and purified. Amino-terminal sequencing revealed extensive homology to a mouse protein, p21, and its human homolog, p23. Both recombinant proteins caused histamine release from the human basophils of a subpopulation of donors, and this release was dependent on IgE. Polyclonal antibodies recognized and removed the biological activity of recombinant and native HRF. HRF identifies a heterogeneity of IgE and is believed to play a prominent role in chronic allergic disease processes.
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