Signal transduction around thymic stromal lymphopoietin (TSLP) in atopic asthma

Thymic stromal lymphopoietin (TSLP), a novel interleukin-7-like cytokine, triggers dendritic cell-mediated inflammatory responses ultimately executed by T helper cells of the Th2 subtype. TSLP emerged as a central player in the development of allergic symptoms, especially in the airways, and is a prime regulatory cytokine at the interface of virus- or antigen-exposed epithelial cells and dendritic cells (DCs). DCs activated by epithelium-derived TSLP can promote naïve CD4+ T cells to adopt a Th2 phenotype, which in turn recruite eosinophilic and basophilic granulocytes as well as mast cells into the airway mucosa. These different cells secrete inflammatory cytokines and chemokines operative in inducing an allergic inflammation and atopic asthma. TSLP is, thus, involved in the control of both an innate and an adaptive immune response. Since TSLP links contact of allergen with the airway epithelium to the onset and maintainance of the asthmatic syndrome, defining the signal transduction underlying TSLP expression and function is of profound interest for a better understandimg of the disease and for the development of new therapeutics.