Cryptomeria japonica-induced allergic conjunctivitis in mice

Japanese cedar pollen (Cryptomeria japonica, Cry j) is the most common allergen causing pollinosis in Japan. However, short ragweed pollen is used commonly as the antigen for experimentally-induced allergic conjunctivitis (EC) and Cry j-induced EC in mice has not been published. We actively immunized BALB/c mice with Cry j, and then performed a challenge with eye drops containing Cry j. We evaluated the early phase and late phase reactions in the conjunctiva, using Evans blue dye leakage and eosinophil infiltration, respectively. Significant inhibition of the early phase reaction was observed following pre-challenge with eye drops that block histamine H1 receptor in the conjunctiva. Thus, Cry j-induced EC appears to represent a suitable model for the study of pollinosis in Japan.