Thymic stromal lymphopoietin: A potential therapeutic target for allergy and asthma

Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)-7-like cytokine that has recently been implicated as central to the microenvironment and is permissive for the immunologic cascade that initiates and propagates allergic immune responses. In humans, TSLP is produced predominantly by epithelial cells and activated mast cells, and stimulates myeloid dendritic cells (mDC), which uniquely express the heterodimeric TSLP receptor. TSLP-activated mDC can promote naïve CD4⁺ T cells to differentiate into a Th2 phenotype and can promote the expansion of CD4⁺ Th2 memory cells. Recent evidence implicates TSLP as playing a pivotal role in the pathobiology of allergic asthma and atopic dermatitis. The potential for TSLP to provide a new therapeutic target for the treatment of allergic disorders is compelling, and elucidating the mechanisms that regulate TSLP expression and the effects of TSLP on orchestrating the immune response toward a Th2 phenotype should facilitate this quest.