天然免疫细胞在移植免疫反应中发挥着重要作用。巨噬细胞是重要的天然免疫细胞；在发生排斥反应的同种异基因移植器官中，巨噬细胞也是浸润的众多免疫细胞之一。巨噬细胞的浸润与器官移植的短期和长期效果呈负相关。在功能方面，巨噬细胞具有异质性和可塑性。在器官移植排斥反应中，巨噬细胞可以为适应性免疫提呈同种异基因抗原以及提供共刺激信号和细胞因子，也可以直接损伤移植器官。此外，一些具有免疫调节功能的巨噬细胞亚群，可以通过抑制排斥反应和促进免疫耐受来保护移植器官。尽管目前研究人员已认识到巨噬细胞在移植器官损伤过程中的潜在作用，但他们对巨噬细胞在移植排斥反应中的不同作用关注不够。为此，本文就巨噬细胞在急性移植免疫反应中的独特作用以及免疫抑制剂对巨噬细胞的影响进行了综述和讨论。通过分析发现，对于巨噬细胞在移植免疫中的作用的相关研究中，应更多地关注其复杂性和关键功能，并应更多地致力于开发针对巨噬细胞的免疫抑制药物，并使之有利于提高移植器官的长期存活率和移植免疫耐受的建立。

Innate immune cells are critical for transplant response. As an important cellular component of innate immune cells, macrophages are the predominate infiltrated cells in allografts, and macrophage accumulation in allografts is negatively associated with the short- and long-term outcomes of organ transplantation. Macrophages are functionally heterogeneous and plastic. They participate in organ graft rejection through multiple pathways, including antigen presentation, the expression of costimulatory molecules and cytokines, and direct cytotoxicity and injury ability to allografts. However, some macrophage subpopulations, such as regulatory macrophages, can protect allografts from immune rejection and promote transplant immune tolerance with their immune regulatory properties. Although researchers recognize the potential roles macrophages play in allograft injury, they pay insufficient attention to the diverse roles of macrophages in allograft rejection. We herein briefly summarize the distinctive roles of macrophages in acute transplant immune response and the effect of immunosuppressive drugs on macrophages. Greater attention should be paid to the complex and critical function of macrophages in allograft rejection, and more effort should be put into developing immunosuppressive drugs that specifically target macrophages, which would ultimately improve the long-term survival of organ grafts in patients.