Monocytes are innate immune cells that develop in the bone marrow and are continually released into circulation, where they are poised to enter tissues in response to homeostatic or inflammatory cues. Monocytes are highly plastic cells that can differentiate in tissues into a variety of monocyte-derived cells to replace resident tissue macrophages, promote inflammatory responses, or resolution of inflammation. As such, monocytes can support tissue homeostasis as well as productive and pathogenic immune responses. Recent work shows previously unappreciated heterogeneity in monocyte development and differentiation in the steady state and during infectious, autoimmune, and inflammatory diseases. Monocyte-derived cells can differentiate via signals from cytokines, pattern recognition receptors or other factors, which can influence development in the bone marrow or in tissues. An improved understanding of these monocyte-derived cells and the signals that drive their differentiation in distinct inflammatory settings could allow for targeting these pathways in pathological inflammation.

单核细胞是先天免疫细胞，在骨髓中发育并不断释放到循环中，在那里它们准备好进入组织以响应稳态或炎症信号。单核细胞是高度可塑的细胞，可以在组织中分化成各种单核细胞衍生细胞，以取代常驻组织巨噬细胞，促进炎症反应或消退炎症。因此，单核细胞可以支持组织稳态以及生产性和致病性免疫反应。最近的研究表明，在稳态以及感染、自身免疫和炎症性疾病期间，单核细胞发育和分化存在以前未被重视的异质性。单核细胞来源的细胞可以通过来自细胞因子、模式识别受体或其他因子的信号进行分化，这会影响骨髓或组织的发育。更好地了解这些单核细胞衍生细胞和驱动它们在不同炎症环境中分化的信号，可以允许在病理性炎症中靶向这些通路。