IL-36γ has proinflammatory effects on human endothelial cells

Interleukin-36 cytokines are predominantly expressed by epithelial cells. Significant upregulation of epidermal IL-36 is now a recognised characteristic of psoriatic skin inflammation. IL-36 is known to induce inflammatory responses in dendritic cells, fibroblasts and epithelial cells. Although vascular alterations are a hallmark of psoriatic lesions and dermal endothelial cells are well known to play a critical role in skin inflammation, the effects of IL-36 on endothelial cells are unexplored. We here show that endothelial cells including dermal microvascular cells express a functionally active IL-36 receptor. Adhesion molecules VCAM-1 and ICAM-1 are upregulated by IL-36γ stimulation and this is reversed by the presence of the endogenous IL-36 receptor antagonist. IL-36γ stimulated endothelial cells secrete the proinflammatory chemokines IL-8, CCL2 and CCL20. Chemotaxis assays showed increased migration of T cells following IL-36γ stimulation of endothelial cells. These results suggest a role for IL-36γ in the dermal vascular compartment and it is likely to enhance psoriatic skin inflammation by activating endothelial cells and promoting leukocyte recruitment. This article is protected by copyright. All rights reserved.