髓源抑制性细胞（myeloid-derived suppressor cell，MDSC）是在骨髓中产生的一群具有高度异质性的免疫抑制细胞， 在 肿瘤等病理状态下大量聚集，是促进肿瘤进展、降低患者对传统治疗反应性的关键因素。近年来，免疫检查点阻断剂和基因工程 T细胞过继回输治疗延长了许多晚期恶性肿瘤患者的生存期，但上述免疫疗法在肺癌、结直肠癌等实体瘤中有效率仅为 15%~40%，这与实体瘤免疫抑制微环境密切相关。MDSC在肿瘤微环境中聚集，通过抑制T细胞或NK细胞增殖及功能减弱宿主 抗肿瘤免疫反应，是患者对免疫治疗耐受的关键机制。因此，明确MDSC聚集及功能特征是探索提高免疫治疗效果的重要研究 方向。本文将系统阐述MDSC的产生、聚集及其免疫抑制功能的调控机制，概述目前靶向MDSC治疗的最新研究进展。

Myeloid-derived suppressor cells (MDSCs) are a group of highly heterogeneous immunosuppressive cells produced in the bone marrow, which accumulate in large amounts under pathological conditions such as malignant tumors. MDSCs are the significant cell subsets that reduce patients' response to traditional treatment and promote tumor progression. In recent years, immune checkpoint blockade and adoptive transfusion of engineered T cells have significantly prolonged the survival of many patients with advanced malignant tumors, but the effective rate from 15% to 40% in some solid tumors including lung cancer, colorectal cancer etc., which is closely related to the immunosuppressive microenvironment in solid cancers. With the accumulation in tumor microenvironment, MDSCs reduce the anti-tumor immune response of patients by inhibiting T cell or NK cell proliferation and function, which is the key mechanism for patients tolerating to immunotherapy. Therefore, clarifying the accumulation and functional characteristics of MDSCs is an important research direction to explore the improvement of restoring immunotherapy. This article will systematically elaborate the regulatory mechanism of MDSC production, aggregation and immunosuppressive function, and outline the latest research progress of targeted MDSC therapy.

国家自然科学基金资助项目（No.U1804281）