Department of Radiation Oncology, Shandong University Cancer Center, Jinan, Shandong, China; Department of Radiation Oncology and Shandong Provincial Key Laboratory of Radiation Oncology, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China.
Department of Radiation Oncology and Shandong Provincial Key Laboratory of Radiation Oncology, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China.
Int J Radiat Oncol Biol Phys. 2023 Aug 1;116(5):1175-1189. doi: 10.1016/j.ijrobp.2023.02.005. Epub 2023 Feb 13.
Although the combination of immunotherapy and radiation therapy to treat various malignancies is rapidly expanding, concerns regarding increased pulmonary toxicities remain. The mechanisms of immunotherapy- and irradiation-induced lung injury involve a complex interplay of cell types and signaling pathways, much of which remains to be elucidated.
C57/BL6 mice were treated with a single fraction (20 Gy) of radiation therapy to the right lung or 200 μg anti-Programmed cell death protein 1 antibody twice a week. At 7, 30, and 60 days after treatment, the lung tissues were obtained for unbiased single-cell RNA sequencing or histologic staining. The Seurat analysis pipeline, Cellchat, Monocol, and Single-Cell rEgulatory Network Inference and Clustering were used to define cell types, mechanisms, and mediators driving pathologic remodeling in response to this lung injury. Reverse transcription polymerase chain reaction, immunofluorescent staining, and multiplex immunohistochemistry were applied to validate the key results.
Thirty distinct cell subsets encompassing 75,396 cells were identified. A comprehensive investigation of cell-cell crosstalk revealed that monokine signals derived from senescent fibroblasts were substantially elevated after lung injury. Independent analytical strategies revealed that senescence-like subtypes of fibroblasts, alveolar epithelial cells, B cells, and myeloid immune cells were functionally pathologic, with high expression of senescence-signature proteins, especially Apolipoprotein E, during injury response. Senescence markers were also elevated in irradiated human cell lines, mouse cell lines (B3T3 and L929), and the publicly available human pulmonary fibrosis data set.
These findings demonstrate that the accumulation of senescence-like fibroblasts, macrophages, and alveolar epithelial cells is the primary common pathologic mechanism of immunotherapy- and irradiation-induced lung injury. These high-resolution transcriptomic data provide novel insights into therapeutic opportunities to predict or prevent therapy-induced lung injury.
虽然免疫疗法和放射疗法联合治疗各种恶性肿瘤的应用正在迅速扩大，但人们仍对增加的肺部毒性表示担忧。免疫疗法和放疗引起的肺损伤的机制涉及细胞类型和信号通路的复杂相互作用，其中许多仍有待阐明。
C57/BL6 小鼠的右肺接受单次 20 Gy 的放射治疗或每周两次接受 200 μg 的抗程序性细胞死亡蛋白 1 抗体治疗。在治疗后 7、30 和 60 天，获取肺组织进行无偏单细胞 RNA 测序或组织学染色。使用 Seurat 分析管道、Cellchat、Monocol 和 Single-Cell rEgulatory Network Inference and Clustering 来定义细胞类型、机制和介导物，以驱动对这种肺损伤的病理重塑。应用逆转录聚合酶链反应、免疫荧光染色和多重免疫组化来验证关键结果。
鉴定出 30 个不同的细胞亚群，共包含 75396 个细胞。对细胞间串扰的全面研究表明，肺损伤后源自衰老成纤维细胞的单因子信号显著增加。独立的分析策略表明，衰老样成纤维细胞、肺泡上皮细胞、B 细胞和髓样免疫细胞的亚型在功能上是病理性的，在损伤反应中高表达衰老特征蛋白，特别是载脂蛋白 E。辐射处理的人细胞系、小鼠细胞系（B3T3 和 L929）和公开的人类肺纤维化数据集也观察到衰老标志物的升高。
这些发现表明，衰老样成纤维细胞、巨噬细胞和肺泡上皮细胞的积累是免疫疗法和放疗引起的肺损伤的主要共同病理机制。这些高分辨率转录组数据为预测或预防治疗引起的肺损伤提供了新的治疗机会。
