小鼠H22肝癌移植瘤模型在PD-1单抗治疗肝癌中的应用

Application of mouse model of transplanted H22 hepatocellular carcinoma in treatment of liver cancer with PD-1 monoclonal antibody

目的探讨小鼠H22肝癌移植瘤模型在PD-1单抗治疗肝癌中的应用。方法制备小鼠H22肝癌移植瘤模型,用淋巴细胞分离液分离肿瘤浸润淋巴细胞(tumor-infiltrating lymphocytes,TILs),然后采用流式细胞术分析TILs中T细胞、CD8^(+)T细胞、CD4^(+)T细胞和调节性T细胞比例,以及肿瘤组织和脾脏组织中T细胞表达PD-1的分子水平。经H22肝癌移植瘤模型小鼠腹腔注射PD-1单抗[200μg/(只·次),共3次],观察肿瘤生长情况。结果小鼠肿瘤组织中T细胞、CD8^(+)T细胞及调节性T细胞比例分别为(33.7±1.5)%、(22.4±0.9)%和(24.0±2.3)%。在肿瘤组织浸润的CD8^(+)T细胞[(28.6±8.7)%]和CD4^(+)T细胞[(26.0±4.6)%]表达PD-1分子水平显著高于在脾脏组织中的表达水平[(4.3±0.7)%和(17.2±3.8)%],差异有统计学意义(P<0.01)。PD-1单抗治疗组小鼠肿瘤体积[(663.09±385.99)mm3]显著低于模型组小鼠[(1435.25±683.96)mm^(3)],差异有统计学意义(P<0.05)。结论H22肝癌移植瘤模型小鼠肿瘤组织有T细胞浸润,且表达高水平PD-1分子,对PD-1单抗治疗有响应,提示该模型用于PD-1单抗治疗肝癌研究具有可行性。

Objective To investigate the application of mouse model of transplanted H22 hepatocellular carcinoma in treatment of liver cancer with PD-1 monoclonal antibody(McAb).Methods A mouse model of transplanted H22 hepatocellular carcinoma was prepared.The tumor-infiltrating lymphocytes(TILs)were isolated by using lymphocyte separation medium,in which the proportions of T cells,CD8^(+)T cells and regulatory T cells(Tregs),as well as the expression levels of PD-1 of T cells in tumor and spleen tissues were analyzed by flow cytometry.The tumor-bearing mice were injected i.p.with PD-1 McAb at a dosage of 200μg for 3 times and observed for tumor growth.Results The proportions of T cells,CD8+T cells,CD4^(+)T cells and Tregs in mouse tumor tissue were(33.7±1.5)%,(22.4±0.9)%and(24.0±2.3)%respectively.The expression levels of PD-1 in CD8^(+)[(28.6±8.7)%]and CD4^(+)[(26.0±4.6)%]T cells in tumor tissue were significantly higher than those in spleen tissue[(4.3±0.7)%and(17.2±3.8)%respectively](P<0.01).The tumor volume of mice treated with PD-1 McAb[(663.09±385.99)mm3]was significantly smaller than that of model mice treated with physiological saline as control[(1435.25±683.96)mm^(3)](P<0.05).Conclusion T cell infiltration was found in the tumor tissue of model mice with transplanted H22 hepatocellular carcinoma,and PD-1 molecules were highly expressed.The transplanted tumor was responsive to the treatment with PD-1 McAb,suggesting the feasibility of this model for the study on therapy of liver cancer.