目的：探讨小分子化学诱导药AP1903能否在体内外终止过表达iCasp9自杀基因的CD19靶向嵌合抗原受体修饰T（CD19CAR-T）细胞毒性功能。方法：构建过表达iCasp9的CD19CAR-T（iCasp9-CD19CAR-T）细胞并和AP1903共孵育，采用流式细胞术检测细胞表型及凋亡的方法，分别在K562和T细胞上验证iCasp9/CID自杀基因系统，在体内（观察荷Raji细胞移植瘤NCG小鼠的生存率）和体外（流式细胞术检测细胞的杀伤功能）检测AP1903给药情况下iCasp9-CD19CAR-T细胞的杀伤功能。结果：和 CD19CAR-T 细胞相比，iCasp9-CD19CAR-T 细胞的增殖能力、表型及体内外杀伤功能均无显著差异（均 P>0.05）。AP1903给药2 h后双表达iCasp9和CD19CAR的K562和T细胞分别有（33.8±0.9）%和（27.95±0.35）%的细胞出现凋亡，AP1903给药 24 h 后双表达 iCasp9 和 CD19CAR 的 K562 和 T 细胞均已经全部死亡。检测 AP1903 给药和未给药两种条件下的 iCasp9-CD19CAR-T细胞体外杀伤效率，前者明显低于后者（P<0.01）；iCasp9-CD19CAR-T细胞治疗荷Raji细胞移植瘤NCG小鼠，其60 d 生存率同样是AP1903给药的明显低于未给药的（P<0.01）。结论：小分子化学诱导药物AP1903能在体内外有效终止iCasp9-CD19CAR-T细胞毒性功能。

Objective: To investigate whether AP1903, a small-molecule chemical inducer, can terminate the cytotoxicity of CD19CAR-T cells over-expressing iCasp9 suicide gene in vivo and in vitro. Methods: CD19CAR-T cells over-expressing iCasp9 (iCasp9-CD19CAR-T) were constructed and co-incubated with AP1903. Then, the cell phenotype and apoptosis were detected by Flow cytometry, and the iCasp9/CID suicide gene system was verified on K562 and T cells, respectively. The cytotoxicity of iCasp9-CD19CAR-T cells was detected in vivo (survival rate of NCG mice bearing Raji cell transplanted xenograft) and in vitro (cell killing function was detected by Flow cytometry) under the administration of AP1903. Results: Compared with CD19CAR-T cells, iCasp9-CD19CAR-T cells showed in significant difference in proliferation, phenotype and cytotoxicity both in vitro and in vivo (all P>0.05). At 2 h after AP1903 administration, the apoptosis rates of K562 and T cells co-expressing iCasp9 and CD19CAR were (33.8±0.9)% and (27.95±0.35)%, respectively; and at 24 h after AP1903 administration, the apoptosis rates reached 100% in both cell lines. The in vitro cytotoxicity of iCasp9-CD19CAR-T cells induced by AP1903 was significantly lower than that without AP1903 treatment (P<0.01); the 60-day survival rate of mice bearing Raji cell transplanted tumor treated with AP1903-induced iCasp9-CD19CAR-T cells was also significantly lower than those treated with iCasp9-CD19CAR-T cells alone (P<0.01). Conclusion: AP1903 can effectively terminate the cytotoxicity of CD19CAR-T cells over-expressing iCasp9 suicide gene in vitro and in vivo.

山东省重点研发计划资助项目（No. 2016ZDJS07B05）