FceRI-mediated thymic stromal lymphopoietin production by interleukin-4- primed human mast cells

A significant increase of mRNA expression of thymic stromal lymphopoietin (TSLP) has been reported in the bronchial mast cells (MCs) of asthmatic subjects; however, the mechanism underlying the upregulation of TSLP mRNA and protein remains unknown. FcϵRI-mediated activation of human MCs upregulated TSLP mRNA expression by 5.2±2.9-fold, while activation of the MCs using lipopolysaccharide and polyriboinosinic:polyribocytidylic acid failed to upregulate TSLP. Stimulation of MCs with interleukin (IL)-4 alone did not affect the TSLP mRNA expression, while pre-incubation of MCs with IL-4 for 48 h significantly enhanced the FcϵRI-mediated TSLP mRNA expression (by 53.7±15.9-fold; p −1 to 121.5±3.7 pg·mL −1 (p Thus, MCs are able to store TSLP intracellularly and to produce TSLP following aggregation of FcϵRI in the presence of IL-4.