髓源抑制性细胞(myeloidderived suppressor cells, MDSCs)是一群异质性细胞，来源于骨髓祖细胞和未成熟髓细胞(immature myeloid cells, IMCs)，是树突状细胞（dendritic cells, DCs）、巨噬细胞和（或）粒细胞的前体。在荷瘤小鼠的血液、脾脏和肿瘤组织及肿瘤患者的外周血和肿瘤组织存在大量MDSCs的扩增。MDSCs可以通过多种途径抑制机体的获得性和天然抗肿瘤免疫，使肿瘤细胞逃避机体的免疫监视和攻击，促进肿瘤发展。MDSCs首先从骨髓募集到外周，并在外周被激活后才能发挥抗肿瘤免疫抑制功能，肿瘤来源的慢性炎症相关的一系列因子在介导MDSCs的募集和活化中起关键作用。当前靶向MDSCs的抗肿瘤治疗取得了一定的进展，但MDSCs从发现到现在仅仅经历了10年左右的时间，该领域中许多的未知尚需要大量的基础和临床研究来阐明。本文主要介绍MDSCs的特征及其亚群、MDSCs的募集和活化、MDSCs介导免疫逃逸的机制及当前靶向MDSCs的抗肿瘤治疗策略，以期为从事该领域的研究工作者提供参考。

Myeloidderived suppressor cells (MDSCs) are heterogeneous cells derived from myeloid progenitor cells and immature myeloid cells (IMCs) in bone marrow; they are the progenitors of dendritic cells (DCs), macrophages and granulocytes. MDSCs proliferate in the blood, spleen, and tumor tissues in tumorbearing mice and in the peripheral blood and tumor tissues in patients with cancer. MDSCs prevent tumors from attacks by body immunosurveillance and promote tumors progression through inhibiting both innate and adaptive antitumor immunity by a variety of pathways; they are recruited to the peripheral tissues from bone marrow and exert their inhibitory effects on antitumor immunity after activation in peripheral tissues. Chronic inflammationrelated cytokines produced by tumors play crucial roles in the recruitment and activation of MDSCs. Progress has been made in antitumor therapies targeting MDSCs. But it has only been 10 years since the discovery of MDSCs, and many questions remain to be answered through experimental and clinical investigations. This review focuses on progress in MDSCs and its subsets, the recruitment and activation of MDSCs, the mechanisms of MDSCsmediated immunosurveillance and antitumor treatment targeting MDSCs.

国家自然科学基金资助项目(No.30771984)