ABSTRACT
Interleukin-4 (IL-4) mediates important proinflammatory functions in asthma including Th2 lymphocyte differentiation, induction of IgE production, upregulation of IgE receptors, expression of VCAM-1, promotion of eosinophil transmigration into the lungs, inhibition of T-lymphocyte apoptosis, and mucus secretion. The role of IL-4 in the pathogenesis of asthma is further supported by identification of polymorphisms linked to asthma in the IL-4 gene promoter and proteins involved in IL-4 signaling.
