Keeping a lid on eosinophil activation

Spred-1 moderates eosinophil activation normally mediated by IL-5, according to a study by Inoue et al. on page 73. Mice lacking Spred-1 have overly exuberant eosinophils and develop exaggerated allergic responses to inhaled antigens.

Allergies and asthma are characterized by invasion of the airways by T cells and eosinophils. A subset of CD4⁺ T cells, known as Th2 cells, produce an array of cytokines, including IL-5 and IL-13, which recruit eosinophils to the lung where they release their stores of histamine and other inflammatory proteins. The importance of Th2 cells and their associated cytokines in allergic responses is well established, but less is known about the regulation of eosinophil recruitment and activation.The Spred (Sprouty-related EVH1 domain–containing protein) family of membrane-bound proteins was identified recently by this group and shown to encode...