Supplementary Material for: An Antagonist for CCR4 Alleviates Murine Allergic Rhinitis by Intranasal Administration

Background: CCR4 is highly expressed on Th2 cells. These cells play an important role in acute inflammatory responses, including those involved in allergic rhinitis. We determined whether disrupting the CCR4 ligand interaction with CCR4 antagonist could alleviate allergic rhinitis in a mouse model. Methods: BALB/c mice were sensitized with ovalbumin and alum by intraperitoneal injection and challenged with intranasally administered ovalbumin. Compound 22, which has been reported as a novel small-molecule antagonist of CCR4, was also administered intranasally. In addition, budesonide, an efficient glucocorticoid, was used as a positive control. The effects of compound 22 were quantified by multiple parameters of allergic responses in both nasal and pulmonary tissues. Results: Compound 22 significantly improved symptoms of allergic rhinitis and suppressed levels of total IgE of serum. It dramatically reduced the levels of IL-4 in bronchoalveolar lavage fluid and also decreased the number of inflammatory cells in the fluid. The infiltration of inflammatory cells, especially eosinophils, was markedly reduced in the nasal and pulmonary tissues. The number of IL-4+ cells was also significantly reduced in these tissues. Moreover, the numbers of Foxp3+ cells and IL-17+ cells were reduced, though not to a statistically significant degree. Conclusions: In our research, CCR4 antagonists such as compound 22 were proven for the first time to alleviate murine allergic rhinitis when administered nasally. CCR4 antagonists may have therapeutic potential for the treatment of allergic rhinitis.