Allergen specific immunotherapy regulates macrophage property in the airways

Background Allergen specific immunotherapy (AIT) has been widely used in allergy clinics. The therapeutic effects of it are to be improved. Macrophages occupy the largest proportion of airway immune cells. The aim of this study is to measure the effects of nasal instillation AIT (nAIT) on airway allergy by regulating macrophage functions. Methods An airway allergy mouse model was established with the ovalbumin-alum protocol. nAIT was conducted for mice with airway allergy through nasal instillation. The effects of nAIT were compared with subcutaneous injection AIT (SCIT) and sublingual AIT (SLIT). Results Mice with airway allergy showed the airway allergic response, including lung inflammation, airway hyper responsiveness, serum specific IgE, increase in the amounts of eosinophil peroxidase, mouse mast cell protease-1, and Th2 cytokines in bronchoalveolar lavage fluid. nAIT had a much better therapeutic effect on the airway allergic response than SCIT and SLIT. Mechanistically, we observed better absorption of allergen in macrophages, better production of IL-10 by macrophages, and better immune suppressive functions in macrophages in mice received nAIT than SCIT and SLIT. Conclusions The nAIT has a much better therapeutic effect on suppressing the airway allergic response, in which macrophages play a critical role.