基于颗粒酶B启动子的磁共振报告基因成像监测CAR-T细胞激活状态  

Magnetic resonance imaging based on a granzyme B promoter-driven reporter gene expression monitors CAR-T cell activation

作　　者：倪晓英 秦勇[1] 贺小娅 黄杰 张湘敏 祝慧如 胡倩 蔡金华[1] NI Xiaoying;QIN Yong;HE Xiaoya;HUANG Jie;ZHANG Xiangmin;ZHU Huiru;HU Qian;CAI Jinhua(Department of Radiology,National Clinical Research Center for Child Health and Disorders,Key Laboratory of Child Development and Disorders of Ministry of Education,Children’s Hospital of Chongqing Medical University,Chongqing,400014,China;Chongqing Key Laboratory of Child Neurodevelopment and Cognitive Disorders,National Clinical Research Center for Child Health and Disorders,Key Laboratory of Child Development and Disorders of Ministry of Education,Children’s Hospital of Chongqing Medical University,Chongqing,400014,China)

机构地区：[1]重庆医科大学附属儿童医院,国家儿童健康与疾病临床医学研究中心,儿童发育疾病研究教育部重点实验室放射科,重庆400014 [2]重庆医科大学附属儿童医院,国家儿童健康与疾病临床医学研究中心,儿童发育疾病研究教育部重点实验室儿童神经发育与认知障碍重庆市重点实验室,重庆400014

出　　处：《陆军军医大学学报》2024年第17期1959-1968,共10页Journal of Army Medical University

基　　金：中国博士后科学基金第74批面上资助(2023M740456);重庆市自然科学基金面上项目(cstc2020jcyj-msxmX0235)。

摘　　要：目的利用颗粒酶B(granzyme B,GB)启动子控制铁蛋白(ferritin heavy chain,FTH1)报告基因表达,探讨通过磁共振成像(magnetic resonance imaging,MRI)监测嵌合抗原受体T细胞(chimeric antigen receptor T cells,CAR-T细胞)激活状态的可行性。方法通过Ficoll密度梯度离心法以及流式分选得到细胞毒性T淋巴细胞(cytotoxic T lymphocytes,CTLs)。将GB启动子和FTH1基因连接,连同二唾液酸神经节苷脂(disialoganglioside 2,GD2)嵌合抗原受体(chimeric antigen receptor,CAR)以慢病毒为载体转入CTLs,构建GD2-CAR-T/pGB-FTH1细胞,以GD2-CAR-T/pCMV-FTH1、GD2-CAR-T和T细胞为对照。CytoTox96@非放射性细胞毒性检测各组细胞与人神经母细胞瘤细胞(SK-N-SH)共培养后的杀伤效果,ELISA检测共孵育因子以及GB分泌量,Western blot、普鲁士蓝染色、细胞MRI检测共培养后FTH1基因的表达。结果成功获得CTLs并构建GD2-CAR-T/pGB-FTH1、GD2-CAR-T/pCMV-FTH1、GD2-CAR-T细胞,3组细胞对肿瘤细胞杀伤效果、共孵育因子以及GB分泌量均显著高于T细胞组,GB表达水平在与SK-N-SH细胞共培养后1 d最高,3 d和7 d依次降低。GD2-CAR-T/pGB-FTH1组FTH1相对表达量以及铁含量变化趋势与GB表达一致,MRI信号呈逐渐升高趋势。GD2-CAR-T/pCMV-FTH1组FTH1相对表达量、铁含量及MRI信号在各时间点均无显著差异。GD2-CAR-T和T细胞组无明显FTH1表达及聚铁效应。结论基于GB启动子的MRI报告基因成像可实时反映CAR-T细胞的GB表达水平和肿瘤杀伤作用,为CAR-T治疗提供了一种监测细胞激活状态的可视化手段。Objective To investigate the feasibility of granzyme B(GB)promoter-controlled ferritin heavy chain(FTH1)reporter gene expression for monitoring the activation status of chimeric antigen receptor T cells(CAR-T)by magnetic resonance imaging(MRI).Methods Cytotoxic T lymphocytes(CTLs)were screened by Ficoll density gradient centrifugation and flow sorting.The GB promoter and FTH1 gene were ligated together with disialoganglioside 2(GD2)CAR,and lentiviral vectors were transfected into CTLs to construct GD2-CAR-T/pGB-FTH1 cells.GD2-CAR-T/pCMV-FTH1,GD2-CAR-T,and T cells served as control cells.CytoTox96@non-radioactive cytotoxicity was used to detect the killing effect of each group of cells after co-culture with human neuroblastoma cells(SK-N-SH).ELISA was employed to detect the coincubation factor as well as the amount of GB secretion.Western blotting,Prussian blue staining and cellular MRI were applied to detect the expression of the FTH1 gene after co-culture.Results CTLs were successfully obtained,and then GD2-CAR-T/pGB-FTH1,GD2-CAR-T/pCMV-FTH1 and GD2-CAR-T cells were constructed.The killing effect,co-incubation factor and GB secretion of the above 3 groups of cells were significantly higher than those of the T cells,and the level of GB expression was highest at day 1,and then decreased in order at day 3 and day 7 after co-culturing with SK-N-SH cells.The relative expression of FTH1 and iron content of the GD2-CAR-T/pGB-FTH1 cells showed the same trend as GB expression,and the MRI signals were gradually increased.There were no significant differences in the relative expression of FTH1,iron content and MRI signals in the GD2-CAR-T/pCMV-FTH1 cells at all time points.No FTH1 expression or iron aggregation was observed in the GD2-CAR-T and T cells groups.Conclusion MRI based on the FTH1 reporter gene driven by the granzyme B promoter can reflect the GB expression level and tumor killing effect of CAR-T cells,which provides a potential real-time visual means to monitor the cell activation status for CAR-T therapy.

关 键 词：颗粒酶B 铁蛋白 报告基因 磁共振成像 嵌合抗原受体T细胞 二唾液酸神经节苷脂 

分 类 号：R392.12[医药卫生—免疫学] R445.2[医药卫生—基础医学] R73-362