Methods: Six-week-old female BALB/c mice divided into 4 groups: control group, allergic rhinitis (AR) group, immunotherapy (IT) group, and IT with anti-IL-9 antibody (anti-IL-9 Ab) group. All mice except control group were sensitized with ovalbumin (OVA) and aluminum hydroxide 3times for two weeks consecutively. After two weeks, mice except control group and AR group underwent immunotherapy by feeding of OVA. During the immunotherapy, mice in anti-IL-9 Ab group were injected with purified anti-mouse IL-9 Antibody. All sensitized mice were challenged intranasally with OVA. Allergic symptoms and eosinophils in nasal mucosa, interferone-γ, interleukin (IL)-4, IL-9, IL-17, TGF-ß, IL-10, T-bet, GATA-3, ROR- γ t and Foxp3 mRNA expression in nasal mucosa and serum OVA-specific IgE were measured.
Results: Serum OVA-specific IgE and Eosinophil counts were significantly decreased in anti-IL-9 Ab group compared with IT group (p<0.05). The levels of mRNA expression of IL-4 were significantly decreased in anti-IL-9 Ab group compared with IT group (p<0.05). The levels of mRNA expression of IL-10 and Foxp3 were significantly increased in in anti-IL-9 Ab group compared with IT group (p<0.05). The levels of mRNA expression of IL-10 and Foxp3 were significantly increased in in anti-IL-9 Ab group compared with IT group (p<0.05).
Conclusion: Administration of anti-IL-9 antibody increased the induction of tolerance in a mouse model of allergic rhinitis. These results suggest that anti-IL-9 antibody have immunomodulatory effect on immune tolerance. We claim that the application of this property can enhance the efficiency of allergen-specific immunotherapy.