Objective: This study aimed to create a type of CAR-T cells that targets LMP1 antigen and study its immunotherapeutic effect on LMP1-positive hematological malignancies. Methods: To generate LMP1 CAR-T cells, a plasmid expressing LMP1 CAR was created using molecular cloning technology, and T cells were infected with LMP1 CAR lentivirus. The effects of LMP1 CAR-T cells on specific cytotoxicity against LMP1-positive tumor cell lines infected with the EB virus had been confirmed. Results: ① LMP1 protein expressing on EB virus-positive lymphoma cells surface was verified. ② The LMP1 CAR-expressing plasmid was created, and LMP1 CAR-T cells were obtained by infecting T cells with a lentivirus packaging system, with an infection efficiency of more than 80% . ③LMP1 CAR-T cells have a 4∶1 effect-to-target ratio in killing LMP1-positive lymphoma cells. The killing effect of LMP1 CAR-T cells on Raji cells was enhanced after 48 h of coculture, but there was no significant killing effect on Ramos, which are LMP1-negative lymphoma cells. ④After coculture with LMP1-positive lymphoma cells at a ratio of 1∶1 for 5 h, the degranulation effect was enhanced. The proportion of CD107a(+) T cells in the LMP1 CAR-T cell treatment group was significantly higher than that in the vector-T cell group [ (13.25±2.94) % vs (1.55±0.05) % , t=3.972, P=0.017]. ⑤After coculture with LMP1-positive lymphoma cells, the proportion of CD69(+) and CD25(+) T cells in the LMP1 CAR-T cell group was significantly higher than that in vector-T cell group [ (7.40±0.41) % vs (3.48±0.47) % , t=6.268, P=0.003; (73.00±4.73) % vs (57.67±2.60) % , t=2.842, P=0.047]. ⑥After coculture with LMP1-positive lymphoma cells, cytokine secretion in the LMP1 CAR-T cell group was higher than that in the vector-T cell group [interferon-gamma: (703±73) ng/L vs (422±87) ng/L, t=2.478, P=0.068; tumor necrosis factor-alpha: (215±35) ng/L vs (125±2) ng/L, t=2.536, P=0.064]. Conclusion: In this study, we found that the LMP1 protein is only found on the surface of the EBV-positive tumor cell. Simultaneously, we created an LMP1 CAR-expressing plasmid and obtained LMP1 CAR-T cells by infecting T cells with a lentivirus packaging system. Furthermore, we demonstrated that LMP1 CAR-T cells could specifically kill LMP1-positive tumor cells in vitro. The degranulation and activation effects of LMP1 CAR-T cells were enhanced after coculture with LMP1-positive tumor cells, indicating a potential clinical application.
目的： 制备一种靶向LMP1抗原的嵌合抗原受体T细胞（CAR-T细胞），研究其对EB病毒（EBV）阳性淋巴瘤的免疫治疗作用。 方法： 应用分子克隆技术构建二代LMP1 CAR表达质粒，通过慢病毒包装体系包装病毒后感染人T细胞，获得LMP1 CAR-T细胞，体外实验验证LMP1 CAR-T细胞对感染EBV后的LMP1阳性淋巴瘤细胞的特异性细胞毒性作用。 结果： ①LMP1蛋白表达于EBV阳性的淋巴瘤细胞表面；②成功构建了二代LMP1 CAR慢病毒载体，感染人T细胞，获取LMP1 CAR-T细胞，感染效率大于80%；③LMP1 CAR-T细胞可特异性杀伤LMP1阳性淋巴瘤细胞，当效靶比按4∶1共培养48 h后，LMP1 CAR-T细胞对Raji细胞的杀伤作用增强，对Ramos细胞无明显杀伤作用；④与LMP1阳性淋巴瘤细胞按1∶1共培养5 h后，LMP1 CAR-T细胞处理组CD107a(+) T细胞比例显著高于Vector-T细胞组[（13.25±2.94）%对（1.55±0.05）%，t＝3.972，P＝0.017]，脱颗粒效果增强；⑤与LMP1阳性淋巴瘤细胞共培养后，LMP1 CAR-T细胞组CD69(+)、CD25(+) T细胞比例显高于Vector-T细胞组[（7.40±0.41）%对（3.48±0.47）%，t＝6.268，P＝0.003；（73.00±4.73）%对（57.67±2.60）%，t＝2.842，P＝0.047]，活化效应增强。⑥与LMP1阳性淋巴瘤细胞共培养后，LMP1 CAR-T细胞组细胞因子分泌增强，高于Vector-T细胞组[IFN-γ：（703±73）ng/L对（422±87）ng/L，t＝2.478，P＝0.068；TNF-α：（215±35）ng/L对（125±2）ng/L，t＝2.536，P＝0.064]。 结论： 该研究证实EBV阳性淋巴瘤细胞表面可特异表达LMP1蛋白，成功构建了LMP1 CAR慢病毒载体并感染人T细胞，成功获得LMP1 CAR-T细胞。体外实验证实：与LMP1阳性淋巴瘤细胞共培养后，LMP1 CAR-T细胞脱颗粒效果增强，活化效应增强，高效分泌细胞因子，可特异杀伤LMP1阳性淋巴瘤细胞，具有潜在的临床应用前景。.
Keywords: Chimeric antigen receptor T cell; Epstein-Barr virus; LMP1 antigen.