Neuropeptide-induced chemotaxis of eosinophils in pulmonary diseases

Eosinophilic lung diseases include various disease entities, and the incide nce of pulmonary infiltration with eosinophilia is on the rise. Because eos inophils, well known as inflammatory cells, respond to peripheral neuropept ides in vitro and in vivo, and these peptides are also present in human air way nerves, their interactions are thought to play a major role in the init iation and perpetuation of inflammatory lung diseases. This article reviews the current literature on eosinophil biology and interactions of these cel ls with the neuroendocrine system. Also, implications of tachykinins and ot her neuropeptides in eosinophilic pulmonary diseases is discussed based on recently investigated mechanisms. Eosinophils and sensory nerves most likel y influence each other in a two-directional way in the pathogenesis of pulm onary diseases. Although release of sensory neuropeptides is involved in mo st conditions of airway hyper-responsiveness, increased bronchial resistanc e, and lung eosinophilia, the role of these nervous system-derived mediator s in pulmonary diseases may be underestimated.