Importance of IgE-Induced Unique Plasma Leakage in the Skin for Urticaria-Like Symptoms in an Anaphylaxis-Dependent Spotted Distribution of Immune Complex in Skin (ASDIS) Mouse Model

Abstract

Plain Language SummaryUrticaria, a skin allergy causing itchy bumps, is often treated with antihistamines. However, these treatments may not always be effective. To address this, researchers aim to develop new anti-allergic drugs. While several methods to induce urticaria-like symptoms in experimental animals have been explored, few are currently available. In a previous study, we successfully induced anaphylaxis-dependent spotted distribution of immune complex in skin (ASDIS) in hairless mice, resembling human urticaria. In this study, we investigated and clarified several key aspects using this method. First, we found that ASDIS in mice is mediated by an increase in vascular permeability, similar to human urticaria. This discovery supports the idea of considering mouse ASDIS as a model for human urticaria. Second, we demonstrated that ASDIS could be induced by IgE but not by histamine, a key mediator of vascular permeability increase. The unique plasma leakage induced by IgE was identified as a contributing factor to the urticaria-like symptoms in ASDIS. Third, a comparison of ASDIS and histamine-induced anaphylaxis in haired and hairless mice revealed that hairless mice were more sensitive. This suggests that hairless mice possess a unique mechanism induced by IgE, partially associated with histamine function. Finally, the inhibition of ASDIS by applying an adrenaline α1 receptor agonist to the skin strongly suggested the potential of this drug as an anti-allergic ointment. In summary, our mouse ASDIS model can be utilized as an urticaria model. Further detailed clarification of the underlying mechanisms of ASDIS induction will expedite the development of new anti-allergic drugs.