IL-16 Variability and Modulation by Antiallergic Drugs in a Murine Experimental Allergic Rhinitis Model

Background: Interleukin-16 (IL-16) is a cytokine that induces selective migration of CD4+ cells and participates in inflammatory diseases including allergic rhinitis. Histamine and prostaglandin D 2 are important chemical mediators of allergic inflammation, and antiallergic drugs are commonly used for the treatment of allergic rhinitis. It remains unknown whether treatment with the drugs affects IL-16. Objective: We evaluated the variability of IL-16 and the effects of the antiallergic drugs fexofenadine (40 mg/kg/day) and ramatroban (30 mg/kg/day) on IL-16 in an OVA-sensitized BALB/c murine experimental allergic rhinitis model. Methods: We measured the expression level of IL-16 protein in the mouse nasal septal mucosa by immunohistochemistry, and the serum level of IL-16 by ELISA. Several other parameters associated with allergic rhinitis (nasal symptoms, OVA-specific IgE, eosinophil and T cell infiltration) were also measured. Results: Local and systemic expressions of IL-16 were significantly increased in OVA-sensitized mice when compared to the non-sensitized group. Fexofenadine and ramatroban significantly inhibited the following OVA-induced allergic features when compared to the nontreated sensitized group: sneezing, nasal rubbing, eosinophil infiltration, IL-16 expressions in nasal tissue, and serum IL-16 level. Serum OVA-specific IgE and local T cell infiltration were reduced, but they did not reach significant values. Conclusions: These results suggest that IL-16 was both systemically and locally upregulated in the murine allergic rhinitis model and that IL-16 changed in parallel to allergic state by treatment with the drugs. Copyright (C) 2009 S. Karger AG, Basel