The Role of Interleukin-9 in Asthma

Interleukin(IL)-9 is a pleiotropic Th2 type cytokine which has been shown to play an important role in the pathogenesis of bronchial asthma. This review will concentrate on the structure, the source, and the effects of IL-9 as well as its induction and inhibition. The signaling of IL-9 through its receptor will be outlined. Moreover the role of IL-9 in airway hyperresponsiveness, mucus overproduction and airway remodeling in bronchial asthma will be discussed. Possible treatment options by blocking IL-9 will be outlined.