Thymic stromal lymphopoietin: master switch for allergic inflammation

Thymic stromal lymphopoietin ( TSLP) is an interleukin (IL) 7-like cytokine that triggers dendritic cell-mediated T helper (Th) 2 inflammatory responses. TSLP is highly expressed by keratinocytes in skin lesions of patients with atopic dermatitis and is associated with dendritic cell activation in situ, suggesting that TSLP might be a master switch for allergic inflammation at the epithelial cell-dendritic cell interface. New reports now establish a direct link between TSLP expression and the pathogenesis of atopic dermatitis and asthma in vivo, and begin to reveal the molecular mechanisms underlying TSLP-induced allergic inflammation.