PD-L1+巨噬细胞在肿瘤发生发展中的研究进展

巨噬细胞为肿瘤微环境中最重要的免疫细胞，不同起源和表型的巨噬细胞在肿瘤的发生发展过程中发挥不同的作用。程序性死亡受体-1（programmed death receptor-1，PD-1）/程序性死亡受体-1配体（programmed death receptor-1 ligand，PD-L1）轴可通过多种途径进行免疫调节，介导肿瘤细胞免疫逃逸，肿瘤相关巨噬细胞（tumor associated macrophages，TAMs）可通过趋化因子、自噬和缺氧诱导因子等途径调控自身PD-L1的高表达，但PD-L1+巨噬细胞在肿瘤进展过程中的作用尚未明确，临床意义尚存争议，免疫组织化学染色判读标准尚未统一。本文就近年来PD-L1+巨噬细胞的研究现状和进展进行概述。 

The role of PD-L1+ macrophages in the development and progression of tumors

Macrophages are the most important immune cells in tumor microenvironments. Macrophages of different origins and phenotypes play a variety of roles in tumor development. The PD-1/PD-L1 axis can be immunomodulated in a variety of ways to enable the tumor cells in evading the host immune system. TAMs regulate the (high) expression of PD-L1 via the activity of chemokines, autophagy, hypoxia-inducible factors, etc. However, the role and clinical significance of PD-L1+ macrophages in tumor progression remain controversial and, ultimately, unclear. The immunohistochemical staining techniques and scoring standards used are not uniform. This article summarizes the current status and progress of PD-L1+ macrophage research over the years.