Influence of Epinastine Hydrochloride, an -Receptor Antagonist, on the Function of Mite Allergen-Pulsed Murine Bone Marrow-Derived Dendritic Cells In Vitro and In Vivo

There is established concept that dendritic cells (DCs) play essential roles in the development of allergic immune responses. However, the influence of H 1 receptor antagonists on DC functions is not well defined. The aim of the present study was to examine the effect of epinastine hydrochloride (EP), the most notable histamine H 1 receptor antagonists in Japan, on Dermatophagoides farinae (Der f) -pulsed mouse bone marrow-derived DCs in vitro and in vivo. EP at more than 25 ng/mL could significantly inhibit the production of IL-6, TNF- α and IL-10 from Der f -pulsed DCs, which was increased by Der f challenge in vitro. On the other hand, EP increased the ability of Der f -pulsed DCs to produce IL-12. Intranasal instillation of Der f -pulsed DCs resulted in nasal eosinophilia associated with a significant increase in IL-5 levels in nasal lavage fluids. Der f -pulsed and EP-treated DCs significantly inhibited nasal eosinophila and reduced IL-5. These results indicate that EP inhibits the development of Th2 immune responses through the modulation of DC functions and results in favorable modification of clinical status of allergic diseases.