Artemisia sieversiana pollen allergy and immunotherapy in mice

This study developed a murine model of asthma using Artemisia sieversiana pollen extract (ASE) and subcutaneous immunotherapy (SCIT) without an adjuvant. BALB/c mice were sensitized subcutaneously with 25 μg of ASE and challenged with 0.1% ASE aerosol. To investigate the efficacy of SCIT, mice were subcutaneously injected with 0.3 mg ASE without adjuvant once a week for 8 weeks, followed by challenge for 3 additional days. Airway hyperresponsiveness (AHR) to methacholine, pulmonary inflammatory cell infiltration, cytokine levels of bronchoalveolar lavage fluid, histopathology of the lung, and serum allergen-specific serum IgE and IgG2a levels were assessed following the final challenge. Mice sensitized with ASE developed AHR and had significantly higher interleukin (IL)-4, IL-5, and IL-13 levels as well as lower IL-12 level than those of control mice. Moreover, mice sensitized with ASE showed increased plasma levels of allergen-specific IgE, and histologic analyses showed peribranchial infiltration of inflammatory cells and mucosal hyperplasia. After SCIT, allergic symptoms and immunological parameters were effectively improved, and the plasma level of allergen-specific IgG2a was significantly increased cmpared to that in the vehicle group. These findings described successful development of an A. sieversiana pollen-induced asthma model in BALB/c mice, with in vivo findings revealing that SCIT without adjuvant significantly improved the symptoms and pathophysiology of asthmatic mice.