Interleukin-33-activated dendritic cells induce the production of thymus and activation-regulated chemokine and macrophage-derived chemokine

Abstract

Background: Interleukin (IL)-33, a new member of the IL-1 cytokine family, is involved in T helper (Th)2-type responses in a wide range of diseases and is mediated by expression of the ST2 receptor in many immune cells. As the effects of IL-33 on dendritic cells (DCs) remain controversial, we investigated the ability of IL-33 to modulate the functions of these cells. Methods: DCs were derived from mouse bone marrow, and the expression of the IL-33 receptor ST2 was examined by fluorescence-activated cell sorting and RT-PCR. The responses of the DCs to IL-33 were examined by RT-PCR and ELISA, and activation of mitogen-activated protein kinases (MAPKs) was determined by Western blotting. Results: ST2 ligand mRNA and protein were detectable in DCs. IL-33 induced the production of thymus and activation-regulated chemokine/CCL17 and macrophage-derived chemokine/CCL22 and the activation of extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase and p38 MAPK. Conclusions: DCs respond directly to IL-33 through ST2. The interaction between IL-33 and DCs may represent a new pathway to initiate Th2-type immune responses. IL-33 and ST2 may play important roles in allergic inflammation.