063 The role of OX40/OX40L axis in atopic dermatitis

Background: OX40 (CD134) is a costimulatory molecule induced by its ligand (OX40L). expresses predominantly on activated/memory CD4+ T cells and regulatory (Treg) cells. Atopic dermatitis (AD) common inflammatory skin disease, currently considered as biphasic disease with TH2 predominating in the acute phase switching to TH1 skewing chronic phase. A recent clinical trial suggests monoclonal antibody for blocking OX40-OX40L binding significant improvements patients AD. However, molecular link between signaling AD unknown. Objective: We sought decipher role of Methods: lesional was stained several key immune biomarkers including OX40L comparison healthy subjects psoriasis patients. Flow cytometric analyses were performed characterize expressions circulating Tregs from treated or without analyzed explore immunoinflammatory responses. Results: increased skin. In vitro results exhibited that expression keratinocytes presence IL-13 IFN-γ. Consistent this, associated severity. Moreover, IL-10 production significantly suppressed Conclusions: Our indicate OX40L/OX40 axis may act an enhancing loop through impairing Tregs.