Single‐cell transcriptomics reveals prominent expression of IL‐14, IL‐18, and IL‐32 in psoriasis

Abstract

AbstractRationalePsoriasis is a chronic inflammatory skin disease involving different cytokines and chemokines.ObjectivesHere we use single‐cell transcriptomic analyses to identify relevant immune cell and nonimmune cell populations for an in‐depth characterization of cell types and inflammatory mediators in this disease.MethodsPsoriasis skin lesions of eight patients are analyzed using single‐cell technology. Data are further validated by in situ hybridization (ISH) of human tissues, serum analyses of human samples and tissues of a murine model of psoriasis, and by in vitro cell culture experiments.ResultsSeveral different immune‐activated cell types with particular cytokine patterns are identified such as keratinocytes, T‐helper cells, dendritic cells, macrophages, and fibroblasts. Apart from well‐known factors, IL‐14 (TXLNA), IL‐18, and IL‐32 are identified with prominent expression in individual cell types in psoriasis. The percentage of inflammatory cellular subtypes expressing IL‐14, IL‐18, and IL‐32 was significantly higher in psoriatic skin compared with healthy control skin. These findings were confirmed by ISH of human skin samples, in a murine model of psoriasis, in human serum samples, and in in vitro experiments.ConclusionsTaken together, we provide a differentiated view of psoriasis immune‐cell phenotypes that support the role of IL‐14, IL‐18, and IL‐32 in psoriasis pathogenesis.