Division of Pulmonary and Critical Care, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
J Leukoc Biol. 2018 Jul;104(1):95-108. doi: 10.1002/JLB.1MR1117-442RR. Epub 2018 Apr 14.
Eosinophils play homeostatic roles in different tissues and are found in several organs at a homeostatic baseline, though their tissue numbers increase significantly in development and disease. The morphological, phenotypical, and functional plasticity of recruited eosinophils are influenced by the dynamic tissue microenvironment changes between homeostatic, morphogenetic, and disease states. Activity of the epithelial-mesenchymal interface, extracellular matrix, hormonal inputs, metabolic state of the environment, as well as epithelial and mesenchymal-derived innate cytokines and growth factors all have the potential to regulate the attraction, retention, in situ hematopoiesis, phenotype, and function of eosinophils. This review examines the reciprocal relationship between eosinophils and such tissue factors, specifically addressing: (1) tissue microenvironments associated with the presence and activity of eosinophils; (2) non-immune tissue ligands regulatory for eosinophil accumulation, hematopoiesis, phenotype, and function (with an emphasis on the extracellular matrix and epithelial-mesenchymal interface); (3) the contribution of eosinophils to regulating tissue biology; (4) eosinophil phenotypic heterogeneity in different tissue microenvironments, classifying eosinophils as progenitors, steady state eosinophils, and Type 1 and 2 activated phenotypes. An appreciation of eosinophil regulation by non-immune tissue factors is necessary for completing the picture of eosinophil immune activation and understanding the functional contribution of these cells to development, homeostasis, and disease.
嗜酸性粒细胞在不同组织中发挥着维持内环境稳定的作用，在基础生理状态下存在于多个器官中，但其在组织中的数量在发育和疾病过程中会显著增加。募集而来的嗜酸性粒细胞的形态、表型和功能可塑性受到组织微环境在稳态、形态发生和疾病状态之间动态变化的影响。上皮-间充质界面的活性、细胞外基质、激素输入、环境的代谢状态以及上皮和间充质衍生的固有细胞因子和生长因子都有可能调节嗜酸性粒细胞的趋化、滞留、原位造血、表型和功能。本文综述了嗜酸性粒细胞与这些组织因子之间的相互关系，特别关注：（1）与嗜酸性粒细胞存在和活性相关的组织微环境；（2）非免疫组织配体对嗜酸性粒细胞募集、造血、表型和功能的调节（重点关注细胞外基质和上皮-间充质界面）；（3）嗜酸性粒细胞对调节组织生物学的贡献；（4）不同组织微环境中嗜酸性粒细胞的表型异质性，将嗜酸性粒细胞分为祖细胞、稳态嗜酸性粒细胞以及 1 型和 2 型激活表型。了解非免疫组织因子对嗜酸性粒细胞的调节作用，对于完整了解嗜酸性粒细胞免疫激活的情况以及理解这些细胞对发育、稳态和疾病的功能贡献是必要的。
