Intranasal CpG DNA therapy during allergen exposure in allergic rhinitis.

OBJECTIVE 1) To estimate the effectiveness of intranasal administration of CpG DNA alone on allergic rhinitis compared with intradermal administration; and 2) to find out how CpG DNA therapy is useful in treatment of allergic rhinitis. STUDY DESIGN Mice were intraperitoneally sensitized and intranasally challenged with Japanese cedar. Therapy with CpG DNA alone was also performed during challenge, either intranasally or intradermally. Immunologic variables and nasal symptom were studied. RESULTS Intranasal administration of CpG DNA alone significantly reduced the levels of IgE, IL-5 productions from nasal lymphocytes and splenocytes, nasal eosinophilia, and nasal symptoms, although intradermal administration of CpG DNA alone showed no significant reduction. CONCLUSION This study demonstrated that CpG DNA has effects not only on splenocytes but also on nasal lymphocytes to attenuate allergic rhinitis, and that intranasal administration, but not intradermal administration, of CpG DNA alone during allergen exposure is useful for control of allergic rhinitis.