Thymic stromal lymphopoietin–activated invariant natural killer T cells trigger an innate allergic immune response in atopic dermatitis

Background Although invariant natural killer T (iNKT) cells have been shown to play a critical role in the pathogenesis of asthma, the role of iNKT cells in atopic dermatitis (AD) has not been well evaluated. Objective We investigated whether iNKT cells in patients with AD increased and whether iNKT cells were activated by thymic stromal lymphopoietin (TSLP), which is highly expressed in keratinocytes of AD. Methods We assessed the population of iNKT cells in PBMCs of patients with AD and healthy controls (HCs) using flow cytometry. Immunohistochemistry was used to evaluate iNKT cells and TSLP expression in AD and HC skin. We also evaluated whether iNKT cells expressed the TSLP receptor, the effects of TSLP on iNKT cells, and iNKT cell–dendritic cell interactions in a TSLP-rich environment. Results There were more iNKT cells among PBMCs of patients with moderate to severe AD than mild AD ( P < .05) and HC ( P