Intranasal Treatment With 1, 25-Dihydroxyvitamin D3 Alleviates Allergic Rhinitis Symptoms in a Mouse Model.

Purpose: Vitamin D is a potent immunomodulator. However, its role in the pathogenesis of allergic rhinitis is unclear.

Methods: The aim of this study was to evaluate the antiallergic effect of intranasally applied vitamin D in an allergic rhinitis mouse model. BALB/c mice were intraperitoneally sensitized with ovalbumin (OVA) and alum before they were intranasally challenged with OVA. Then, they were intranasally administered 1, 25-dihydroxyvitamin D3 (0.02 μg) or solvent. Allergic symptom scores, eosinophil infiltration, cytokine mRNA levels (interleukin [IL]-4, IL-5, IL-10, IL-13 and interferon-γ) in the nasal tissue, and serum total immunoglobulin E (IgE) and OVA-specific IgE, IgG1, and IgG2a were analyzed and compared with negative and positive control groups. Cervical lymph nodes (LNs) were harvested for flow cytometry analysis and cell proliferation assay.

Results: In the treatment group, allergic symptom scores, eosinophil infiltration, and mRNA levels of IL-4 and IL-13 were significantly lower in the nasal tissue than in the positive control group. The IL-5 level, serum total IgE, and OVA-specific IgE and IgG1 levels decreased in the treatment group; however, the difference was not significant. In the cervical LNs, CD86 expression had been down-regulated in CD11c⁺major histocompatibility complex II-high (MHCII) in the treatment group. Additionally, IL-4 secretion in the lymphocyte culture from cervical LNs significantly decreased.

Conclusions: The results confirm the antiallergic effect of intranasal 1,25-dihydroxyvitamin D3. It decreases CD 86 expression among CD11c⁺MHCII cells and T-helper type 2-mediated inflammation in the cervical LNs. Therefore, topically applied 1,25-dihydroxyvitamin D3 can be a future therapeutic agent for allergic rhinitis.