免疫治疗是发展最快的肿瘤治疗策略之一。免疫检查点抑制剂（immune checkpoint inhibitors，ICIs）通过抑制肿瘤细胞对T细胞的抑制作用，增强抗肿瘤的免疫反应。目前，针对细胞毒性T淋巴细胞相关蛋白4（cytotoxic T-lymphocyte-associated protein 4，CTLA-4）、程序性死亡蛋白-1（programmed death-1，PD-1）和程序性死亡蛋白配体-1（programmed death ligand-1，PD-L1）的抗体已被批准应用于临床治疗，但仅在少部分患者中显示有效。这可能与骨髓来源的抑制性细胞（myeloid-derived suppressor cells，MDSCs）、调节性T细胞（regulatory cells，Tregs）等免疫抑制细胞介导的更深层次的免疫抑制有关。肺的微环境以其独特的生理功能影响肿瘤免疫，可快速抵御病原体以维持肺内免疫平衡，但也可促进肿瘤进展。该文针对免疫抑制细胞在ICIs治疗中的作用及其在肺内免疫环境中所扮演的角色进行分析，探讨改善肺癌患者免疫治疗效果的策略。

Immunotherapy is one of the most rapidly developed tumor treatment strategies. Immune checkpoint inhibitors (ICIs) enhance the anti-tumor immune response by inhibiting the inhibitory effect of tumor cells on T cells. At present, antibodies against cytotoxic T-lymphocyte associated protein 4 (CTLA-4), programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) have been approved for clinical therapies. However, those treatments are only effective in the minority of patients. This may be related to the deeper immunosuppression mediated by myeloid-derived suppressor cells (MDSCs) and regulatory cells (Tregs). The microenvironment of the lung affects tumor immunity with its unique physiological function, which can quickly resist pathogens to maintain immune balance in the lung, but also can promote tumor progression. In this paper, the effects of immunosuppressive cells in the treatment of ICIs and the role of them in the lung immune environment are analyzed to explore the strategies to improve the effect of immunotherapy in patients with lung cancer.