Th2-dependent airway eosinophilia is regulated by preproenkephalin

We have used preproenkephalin (PPNK)-deficient mice to study the role of PP NK in the development of airway inflammation. Airway eosinophilia was estab lished by either sensitization followed by airway challenge with OVA or by infection with Nippostrongylus brasiliensis. Both models induce a strong Th 2 immune response, characterized by an IL-5-dependent airway eosinophilia. We observed that although the accumulation of lymphocytes in the airways of PPNK-deficient mice was similar to that induced in control mice, IL-5 prod uction and eosinophil infiltration were reduced. We conclude from this work that PPNK has a role in enhancing Th2 cell function and that this molecule may be an important target in asthma immunotherapy. (C) 2000 Elsevier Scie nce B.V. All rights reserved.