Absence of Nasal Blockage in a Japanese Cedar Pollen-Induced Allergic Rhinitis Model Mouse

Background: Japanese cedar pollen-induced allergic rhinitis in a guinea pig model clearly induced not only sneezing but also biphasic nasal blockage. To date, there have only been a few reports on models of murine allergic rhinitis which clearly show nasal blockage. Therefore, in order to try and develop such a model, we administered multiple dosages of intranasal pollen or purified antigen protein Cry j 1. Methods: B10.S mice were sensitized by intranasal instillations of either pollen extract or Cry j 1 twice a day for 7 days, which was adsorbed on Al(OH)3. Subsequently, once a week, the mice were given multiple intranasal instillation challenges of either the pollen suspension or Cry j 1 and the frequency of sneezing was observed after respective challenges were made. Specific airway resistance (sRaw) was measured as an indicator for nasal blockage. Cry j 1-specific IgE levels were measured using an enzyme-linked immunosorbent assay. Results: The serum Cry j 1-specific IgE level showed clear elevation only in the group sensitized by Cry j 1 + Al(OH)3 and then challenged by Cry j 1. No elevations were seen in the groups sensitized by pollen extract + Al (OH)3 followed by a pollen suspension challenge. There was an immediate increase in sneezing after challenges in all of the sensitized-challenged groups. Nevertheless, no increases in sRaw in any of the groups were detected at any of the time points during the 8 hours following the challenges. Conclusions: Cry j 1 may be more effective than crude antigens for efficient sensitization/challenge in mice. No increase in sRaw occurred, even in mice that possessed high amounts of Cry j 1-specific IgE and that exhibited sneezing.