Biology of common β receptor–signaling cytokines IL-3, IL-5, and GM-CSF

IL-3, IL-5, and GM-CSF are related hematopoietic cytoines that are important for allergic inflammation. The receptors for human IL-5, IL-3, and GM-CSF are members of the hematopoietin receptor superfamily and are comprised of a cytokine-specific α chain and the common β chain that is shared among these cytokines for signaling. Each of these cytokines contributes to the differentiation and function of leukocyte subpopulations and have clinical importance in protective immunity and in the pathophysiology of a spectrum of immunologic diseases that are as diverse as allergy and asthma, pulmonary alveolar proteinosis, neurodegenerative diseases, and malignancies. Delineating the biology of these cytokines is enabling the development of new strategies for diagnosing and treating these diseases and modulating immune responses.