Eosinophils are bone marrow-derived granulocytes that are traditionally associated with type 2 immune responses, such as those that occur during parasite infections and allergy. Emerging evidence demonstrates the remarkable functional plasticity of this elusive cell type and its pleiotropic functions in diverse settings. Eosinophils broadly contribute to tissue homeostasis, host defence and immune regulation, predominantly at mucosal sites. The scope of their activities primarily reflects the breadth of their portfolio of secreted mediators, which range from cytotoxic cationic proteins and reactive oxygen species to multiple cytokines, chemokines and lipid mediators. Here, we comprehensively review basic eosinophil biology that is directly related to their activities in homeostasis, protective immunity, regeneration and cancer. We examine how dysregulation of these functions contributes to the physiopathology of a broad range of inflammatory diseases. Furthermore, we discuss recent findings regarding the tissue compartmentalization and adaptation of eosinophils, shedding light on the factors that likely drive their functional diversification within tissues.

嗜酸性粒细胞是骨髓来源的粒细胞，传统上与​​ 2 型免疫反应相关，例如寄生虫感染和过敏期间发生的免疫反应。新的证据表明这种难以捉摸的细胞类型具有显着的功能可塑性及其在不同环境中的多效性功能。嗜酸性粒细胞广泛促进组织稳态、宿主防御和免疫调节，主要是在粘膜部位。它们的活动范围主要反映了其分泌介质组合的广度，范围从细胞毒性阳离子蛋白和活性氧物质到多种细胞因子、趋化因子和脂质介质。在这里，我们全面回顾了与嗜酸性粒细胞稳态、保护性免疫、再生和癌症活性直接相关的基本嗜酸性粒细胞生物学。我们研究这些功能的失调如何导致多种炎症性疾病的病理生理学。此外，我们讨论了有关嗜酸性粒细胞的组织区室化和适应的最新发现，揭示了可能驱动其在组织内功能多样化的因素。