557 IL-13 production and accumulation in lesional, non-lesional and ex vivo activated skin of atopic dermatitis patients

Abstract

IL-13 is a key cytokine mediating pathogenesis in atopic dermatitis patient skin. The cellular source and accumulation sites of this cytokine remain elusive in human skin, largely due to methodological limitations. Here we introduce three validated methodologies for the detection of IL-13 in skin biopsies and skin-derived T cells of patients with atopic dermatitis. Using confocal microscopy and flow cytometry, we show that IL-13 protein is highly sensitive to fixation with PFA, which masks key epitopes for the optimal detection by specific antibodies; this limitation requires the use of PFA-free protocols or heat-mediated protein retrieval for accurate quantification and study of this cytokine in the skin of patients.