靶向PD-L1的嵌合抗原受体修饰的NK-92细胞具有抗A549肺癌细胞增殖活性

NK-92 cells modified with chimeric antigen receptor targeting PD-L1 inhibits the proliferation of A549 lung cancer cells

目的 探究靶向程序性死亡蛋白1配体1(PD-L1)的嵌合抗原受体修饰的NK-92细胞在肺癌中的抗肿瘤活性。方法利用慢病毒感染获得嵌合抗原受体修饰的NK-92细胞(pCAR-92);使用γ干扰素(IFN-γ)诱导肿瘤细胞过表达PD-L1,通过检测乳酸脱氢酶(LDH)的释放水平表征pCAR-92细胞对靶细胞A549细胞的细胞毒性,流式细胞术检测pCAR-92细胞中CD107a以及IFN-γ的水平来反映激活状态,通过IFN-γ诱导后的A549细胞NCG小鼠皮下移植建立异种移植瘤模型以验证pCAR-92细胞的体内抗肿瘤活性。结果 流式细胞术检测pCAR-92细胞的感染阳性率为70%~80%,与对照组相比,LDH结果显示pCAR-92细胞可以显著裂解经过IFN-γ诱导的A549细胞,此外,CD107a表达显著上调;pCAR-92细胞与IFN-γ诱导的A549细胞共孵育后;与对照组相比,pCAR-92细胞具有更强的抗移植瘤生长能力,且经pCAR-92细胞治疗后肿瘤部位PD-L1的表达降低,肿瘤浸润自然杀伤(NK)细胞的数量增加。结论 靶向PD-L1的嵌合抗原受体修饰的NK-92细胞具有明显抗肿瘤效果。

Objective To investigate the anti-tumor activity of PD-L1-redirected chimeric antigen receptor modified NK-92 cells in lung cancer. Methods NK-92 cells modified by chimeric antigen receptor(pCAR-92) was obtained by lentivirus transfection. Tumor cells overexpressing PD-L1 were induced by IFN-γ. Lactic dehydrogenase(LDH) level was used cells to identify the cytotoxicity of pCAR-92 cells to target cells. The activation markers of CD107a and IFN-γ in pCAR-92 cells were detected by flow cytometry, and the anti-tumor activity of pCAR-92 cells in vivo was verified by xenograft model. ResultsFlow cytometry showed that the positive ratio of pCAR-92 cells ranged from 70% to 80%. The LDH detection showed that pCAR-92 cells could significantly lyse tumor cells induced by IFN-γ compared to control group. Flow cytometry for the expression of CD107a and IFN-γ showed that pCAR-92 cells could be significantly activated after co-incubation with tumor cells induced by IFN-γ. The tumor inhibitory effect of pCAR-92 cells was stronger than that of control group. In addition, after pCAR-92 cells treatment, the expression of PD-L1 in tumor decreased and the number of tumor infiltrating NK cells increased. ConclusionNK-92 cells modified with chimeric antigen receptors targeting PD-L1 have evident anti-tumor effects.