de Duve Institute, Université catholique de Louvain, Brussels, Belgium.
Institut de Neurosciences, Université catholique de Louvain, Brussels, Belgium.
Sci Rep. 2019 Feb 12;9(1):1852. doi: 10.1038/s41598-018-38156-4.
Para-Phenylenediamine (PPD) is an aromatic amine used in hair dyes and in temporary black henna tattoos, which is a frequent cause of allergic contact dermatitis (ACD). ACD is a skin inflammatory reaction characterized by modifications such as spongiosis, exocytosis and acanthosis. The aim of this study is to characterize the expression and the role of IL-20-related cytokines, including IL-19, IL-20, IL-22 and IL-24, in ACD. The expression of IL19, IL20, IL22 and IL24 is increased in affected skin from PPD allergic patients compared with uninvolved skin. In addition, the expression of these cytokines positively correlates with clinical symptoms. To assess their role in ACD, we set up a mouse model of PPD-induced allergic contact dermatitis and we showed that, in contrast to Il22-deficient mice, Il22ra1-, Il20rb- and Il24-deficient mice are partially protected against development of PPD-induced contact hypersensitivity. These mice have decreased ear thickening and less acanthosis compared with WT mice after PPD treatment. In addition, the absence of IL-22R, IL-20R2 or IL-24 affects the recruitment of neutrophils into the skin but not the total IgE production. Taken together, these results demonstrate the implication of IL-24 via the IL-20R type II receptor in the inflammatory process of ACD.
对苯二胺（PPD）是一种用于染发剂和临时黑色指甲花纹身的芳香胺，是过敏性接触性皮炎（ACD）的常见原因。ACD 是一种皮肤炎症反应，其特征在于海绵形成、胞吐和棘皮症等改变。本研究旨在描述 IL-20 相关细胞因子（包括 IL-19、IL-20、IL-22 和 IL-24）在 ACD 中的表达和作用。与未受累皮肤相比，PPD 过敏患者受累皮肤中 IL19、IL20、IL22 和 IL24 的表达增加。此外，这些细胞因子的表达与临床症状呈正相关。为了评估它们在 ACD 中的作用，我们建立了 PPD 诱导的过敏性接触性皮炎小鼠模型，结果表明，与 Il22 缺陷小鼠相比，Il22ra1、Il20rb 和 Il24 缺陷小鼠对 PPD 诱导的接触超敏反应有部分保护作用。与 WT 小鼠相比，这些小鼠在 PPD 处理后耳部增厚和棘皮症减少。此外，缺乏 IL-22R、IL-20R2 或 IL-24 会影响中性粒细胞向皮肤的募集，但不会影响总 IgE 的产生。总之，这些结果表明，IL-24 通过 IL-20R 型 II 受体参与 ACD 的炎症过程。
