CCL21 and allergic rhinitis: In the murine allergic rhinitis model, the CCR7-CCL19/CCL21 signal is involved in the migration of CD4+CD25+ Tregs into CLN and nasal administration of plasmids encoding CCL19/CCL21 DNA leads to an increase of Tregs with an alteration of the DC profile in CLN, a decrease of serum antigen-specific IgE, and the suppression of allergic nasal symptoms.