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

Several different immune-activated cell types with particular cytokine patterns are identified such as keratinocytes, T helper cells, cytotoxic T cells, dendritic cells, macrophages, fibroblasts, and endothelial cells. The expression of well-known pathogenic factors such as TNF-α, IL-8 (CXCL8), L-23 and IL-17 is confirmed in different inflammatory cells. Furthermore, IL-14 (TXLNA; alpha-taxilin), IL-18 and IL-32 are identified as less well-known, and putative new pathogenic factors. Prominent expression of IL-18 is found in keratinocytes, macrophages and Langerhans cells, prominent IL-32 is found in T helper and regulatory T cells, IL-14 is mainly expressed by keratinocytes, fibroblasts and macrophages. Validation of gene expression is performed by ISH of human skin samples. In a murine model of psoriasis, IL-14 and IL-18 are significantly higher expressed in psoriasis-like skin lesions than in normal skin. In an analysis of serum samples from psoriasis patients, IL-18 shows higher expression in psoriasis patients compared to controls, and serum levels in psoriasis responded to treatment with IL-17 inhibitors. Overall design: Human skin biopsies of lesional skin from patients suffering from plaque-type psoriasis were isolated using the Whole Skin Dissociation Kit (Miltenyi, Gladbach, Germany) and analyzed using 10x Genomics RNAseq.