042 Epidermal leucotriene B4 receptor expression as a marker of regulatory T-cell–driven responses in resolved psoriasis

Pathogenic memory T cells are implicated in the local of chronic skin diseases. The factors underlying their persistence and function human resolved epidermis not understood. Lipid composition transcriptional programs lipid metabolism known to be altered active non-lesional psoriasis, faculty resident uptake fatty acids is essential survival. Here, we wished correlate functionality epidermal psoriasis patients using transcriptomic data. Skin biopsies from with were collected both on non-involved (non-lesional) areas, as well healthy controls. Flow cytometry was performed cell suspension controls, assessment surface markers cytokine production. activated explants pan T-cell agonist OKT-3 compared an IgG2a control. RNA purified compartment analyzed by a custom panel Nanostring focused inflammatory metabolism. In epidermis, proportion expressing checkpoint inhibitor PD1+ among negatively correlated expression transcripts LTB4R PTGES2 suggesting involvement immune regulation. receptor pro-inflammatory leukotriene LTB4 its decreased skin. Furthermore, ex vivo activation but induced IL10 IDO1 level this upregulation positively baseline LTB4R. Altogether, our data suggest link between regulation present epidermis.