Sublingual Immunotherapy Attenuates Nasal Symptoms Upon Allergen Exposure in Murine Allergic Rhinitis Model via an Induction of IL-10 producing T cells in Submandibular Lymph Node.

Abstract

Sublingual immunotherapy has been considered to be a painless and effective therapeutic treatment of patients with allergic rhinitis. Its mechanism of action has been elucidated, but there are still controversies among many reports between clinical efficacy and laboratory data. Therefore, its mechanism of action needs to be investigated further by using promising animal models such as rodents and monkeys. Bearing this in mind, in our present study, we successfully constructed an effective murine model for sublingual immunotherapy (SLIT) in allergic rhinitis in which mice were sublingually administered ovalbumin (OVA), followed by intraperitoneal (ip) sensitization and intranasal (i.n.) challenge of OVA. To summarize our experimental data, nasal symptoms such as sneezing and nasal rubbing of sublingually treated mice were significantly attenuated in accordance with lower specific IgE antibodies in sera. Histological analysis of eosinophil recruitment in nasal mucosae reveals less allergic inflammation in sublingually treated mice. Interleukin-10 (IL-10) production and IL-10-specific mRNA gene expression of cultured submandibular lymph node (SMLN) cells with OVA, obtained from sublingually treated mice, were significantly higher than those of mice without sublingual treatment. These results demonstrate that sublingually introduced antigens can actually attenuate nasal symptoms in a murine allergic rhinitis model upon allergen exposures. Furthermore, our immunological data might indicate an important role of IL-10 producing T cells in SMLN to control nasal allergic reaction.