Neutrophil granulocytes are the most abundant leukocytes in the blood and constitute a critical arm of innate immunity. They are generated in the bone marrow, and under homeostatic conditions enter the bloodstream to patrol tissues and scout for potential pathogens that they quickly destroy through phagocytosis, intracellular degradation, release of granules and formation of extracellular traps. Thus, neutrophils are important effector cells involved in antibacterial defense. However, neutrophils can also be pathogenic. Emerging data suggest they have critical functions related to tissue repair and fibrosis. Moreover, similarly to other innate immune cells, neutrophil cell states are affected by their microenvironment. Notably, this includes tumors that co-opt neutrophils. Neutrophils can undergo transcriptional and epigenetic reprogramming, thus causing or modulating inflammation and injury. It is also possible that distinct neutrophil subsets are generated with designated functions in the bone marrow. Understanding neutrophil plasticity and alternative cell states will help resolve their contradictive roles. This Review summarizes the most recent key findings surrounding protective versus pathogenic functions of neutrophils; elaborating on phenotype-specific subsets of neutrophils and their involvement in homeostasis and disease.

中性粒细胞粒细胞是血液中最丰富的白细胞，构成了先天免疫的关键臂。它们在骨髓中产生，在稳态条件下进入血液以巡逻组织并寻找潜在的病原体，它们通过吞噬作用、细胞内降解、颗粒释放和细胞外陷阱的形成迅速破坏这些病原体。因此，中性粒细胞是参与抗菌防御的重要效应细胞。然而，中性粒细胞也可能是致病性的。新出现的数据表明，它们具有与组织修复和纤维化相关的关键功能。此外，与其他先天免疫细胞类似，中性粒细胞状态受其微环境的影响。值得注意的是，这包括选择中性粒细胞的肿瘤。中性粒细胞可以经历转录和表观遗传重编程，从而引起或调节炎症和损伤。也有可能在骨髓中产生具有指定功能的不同中性粒细胞亚群。了解中性粒细胞的可塑性和替代细胞状态将有助于解决它们的矛盾作用。本综述总结了围绕中性粒细胞保护功能与致病功能的最新主要发现;详细说明中性粒细胞的表型特异性亚群及其在体内平衡和疾病中的参与。