Existence of antigen-specific immunoglobulin E is not sufficient for allergic nasal eosinophil infiltration in mice.

ABSTRACT

BACKGROUND: Immunoglobulin E (IgE) is important for the development of allergic rhinitis (AR), though the contribution of IgE to the infiltration of eosinophils in the nasal mucosa has not been fully elucidated. In this study, antigen-induced sneezing and nasal eosinophil accumulation were comparatively investigated in anti-ovalbumin (OVA)-IgE transgenic (Tg) and wild-type (WT) mice. METHODS: Tg and OVA-immunized WT mice were intranasally challenged with OVA. Antigen-specific serum IgE level, sneezing and infiltration of eosinophil into the nasal cavity were then examined. RESULTS: The level of serum OVA-specific IgE in Tg mice was significantly higher than that in antigen-immunized WT mice. Compared to saline challenge, intranasal challenge with OVA significantly induced sneezing in both Tg and immunized WT mice. However, antigen-induced nasal eosinophil infiltration was observed in immunized WT mice but not in Tg mice. CONCLUSIONS: IgE-mediated responses might not play a crucial role in antigen-induced eosinophil infiltration in AR.