Basophils are important effector cells in allergic disorders and anti-parasitic immune response. A number of activators including interleukin 3 (IL-3) and IgE have been identified in the regulation of human basophils expressing mediators such as histamine and leukotriene C4 (LTC4) and cytokines, including IL-4 and IL-13. Human basophils express high levels of IL-2 receptors. However, the function of the IL-2 pathway in basophils remains unknown. Here, we identified that IL-2 induced the activation of human basophils in vitro to express a variety of inflammatory cytokines and chemokines including IL-5, IL-13, GM-CSF and CCL-17. This effect by IL-2 is confirmed by an upstream regulator analysis using Ingenuity pathway analysis. Of note, one of the top regulated cytokines, IL-5, was for the first time identified to be induced by IL-2 in human basophils rather than IL-3 or anti-IgE. Immunofluorescence analysis of skin specimens from bullous pemphigoid and eczema revealed that infiltrating basophils in skin lesions widely expressed IL-5 and GM-CSF. Together, our findings reveal IL-2 as a novel regulator of human basophils. This adds a new layer to support the importance of basophils in allergic disorders.

中文翻译：

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白细胞介素2调节人嗜碱性粒细胞的活化

嗜碱性粒细胞是过敏性疾病和抗寄生虫免疫反应中的重要效应细胞。包括白细胞介素 3 (IL-3) 和 IgE 在内的许多激活剂已被鉴定用于调节人类嗜碱性粒细胞表达介质，如组胺和白三烯 C4 (LTC4) 以及细胞因子，包括 IL-4 和 IL-13。人类嗜碱性粒细胞表达高水平的 IL-2 受体。然而，IL-2 通路在嗜碱性粒细胞中的功能仍然未知。在这里，我们发现 IL-2 在体外诱导人嗜碱性粒细胞的活化，以表达多种炎性细胞因子和趋化因子，包括 IL-5、IL-13、GM-CSF 和 CCL-17。使用 Ingenuity 通路分析的上游调节器分析证实了 IL-2 的这种作用。值得注意的是，最受调控的细胞因子之一，IL-5，首次确定是由人嗜碱性粒细胞中的 IL-2 而不是 IL-3 或抗 IgE 诱导的。来自大疱性类天疱疮和湿疹的皮肤标本的免疫荧光分析显示，皮肤病变中浸润的嗜碱性粒细胞广泛表达 IL-5 和 GM-CSF。总之，我们的研究结果揭示了 IL-2 作为人类嗜碱性粒细胞的新型调节剂。这增加了一个新层来支持嗜碱性粒细胞在过敏性疾病中的重要性。