The purpose of the present study was to investigate the effect of nucleotide-binding oligomerization domain I (NODI), an innate immune sensor, on allergic inflammation and induction of regulatory T cells in a mouse model of allergic rhinitis. We also aimed to explore whether there were differences in the effect of NOD I ligand according to the timing of administration.Study Design.
An in vivo study using an animal model.Setting.
Catholic Research Institutes of Medical Science.Subjects and Methods.
Forty BALB/c mice were divided into 4 groups: control, OVA, pre-NODI, and post-NODI. Ovalbumin (OVA) was used for sensitization and challenge. The pre-NODI group received NODI ligand intranasally before sensitization, whereas the post-NODI group received it after sensitization. The effects of allergic inflammation and regulatory T cells were compared among the groups.Results.
In the post-NODI group, serum OVA-specific IgE, eosinophil counts, interleukin (IL)-13 levels, and GATA-3 mRNA expression were significantly increased and Foxp3+ mRNA expression and CD4+ Foxp3+ T cells were decreased compared with the OVA group. In the pre-NODI group, Foxp3 mRNA expression and CD4+ Foxp3+ T cells were significantly decreased compared with the OVA group. Although not significant, the pre-NODI group showed increases in serum OVA-specific IgE, eosinophil counts, IL-13 levels, and GATA-3 mRNA expression compared with the OVA group.Conclusion.
The innate immune response through NODI enhances allergen-specific Th2 response and suppresses induction of regulatory T cells in a mouse model of allergic rhinitis, and the effects are different depending on the timing of exposure to NODI ligand.