[摘要] 目的: 通过CRISPR-Cas9 基因编辑技术及质粒电转染技术制备T 细胞免疫球蛋白黏液素3（TIM3）基因敲除的人外周血T淋巴细胞，探讨敲除TIM3 基因后能否增强T细胞免疫功能及其抗肿瘤作用。方法: 通过电转染法将hTIM3 sgRNA/Cas9 双质粒共转染EBV阳性胃癌患者外周血T淋巴细胞，电转24 h 后流式细胞术检测转染效率并利用荧光显微镜观察；体外培养过程中观察基因敲除后T细胞增殖活性，流式细胞术验证TIM3 基因敲除效率以及细胞表型的变化。用肿瘤抗原肽活化T细胞检测TIM3 基因敲除后T 细胞分泌细胞因子水平及体外杀伤胃癌AGS-EBV 细胞的能力。结果:电转染法能够有效地将hTIM3 sgRNA/Cas9 双质粒敲除体系转入人外周血T淋巴细胞，其转染效率平均达（41.5±3.6）%，基因敲除效率波动在40.0%～50.0%（均P<0.01）；经抗原活化后的基因敲除组T细胞的增殖活性和免疫表型未见明显变化，表面活化分子中仅见HLA-DR较对照组明显提高（P<0.05）；TIM3 基因敲除T细胞分泌TNF-α、IFN-γ 的水平显著增高（P<0.01 或P<0.05），体外杀伤胃癌AGS-EBV 细胞的能力也明显增强（均P<0.05）。结论: 用CRISPR-Cas9 基因编辑及质粒电转染技术制备人外周血TIM3 基因敲除T淋巴细胞的方法简易可行，在体外的扩增活化中保持TIM3 基因水平下调并具有更高的免疫应答水平以及更强的抗肿瘤作用。这一新技术的研发为基因工程化细胞免疫治疗提供了新的思路。

[Abstract] Objective: To prepare human peripheral blood T lymphocytes with TIM3 (T cell immunologlobulin and mucin-3) gene knockout by using CRISPR-Cas9 gene editing technique and plasmid electrotransfection system, and to discuss whether the knockout of TIM3 gene could enhance the immune response and anti-tumor efficacy of T cells. Methods: Double plasmids hTIM3 sgRNA/Cas9 were transfected into human peripheral blood T lymphocytes of EBV positive gastric cancer patients by using electrotransfection system.The transfection efficiency was examined 24 h later by flow cytometry and fluorescence microscope. The proliferation activity of the T cells after gene knockout was observed during in vitro culture, and the knockout efficiency and phenotypes of the modified T cells were evaluated by flow cytometry. Furthermore, tumor antigen peptide was used to activate T cells, and the level of modified T cells secreting cytokines and its cytotoxicity against gastric cancer AGS-EBV cells were evaluated. Results: Electrotransfection system could successfully transfect hTIM3 sgRNA/Cas9 double plasmids into human peripheral blood T lymphocytes with an average transfection efficiency of (41.5±3.6)%, and the gene knockout efficiency fluctuated between 40.0% and 50.0% (all P<0.01). The proliferation of the modified T cells was not significantly changed in the TIM3 gene knockout group even after the prolonged co-culturing with tumor antigenicpeptide; and for the activated molecules, only HLA-DR exhibited significant elevation as compared with control group (P<0.05).Remarkably, T cells with TIM3 gene knockout showed significantly elevated secretion of TNF-α and IFN-γ (P<0.01 or P<0.05), as well as obviously enhanced in vitro cytotoxicity against gastric cancer AGS-EBV cells (P<0.05). Conclusion: It’s simple and feasible of CRISPR-Cas9 gene editing technique and plasmid electrotransfection system to prepare T lymphocytes with engineered TIM3 gene knockout. The expression level of TIM3 was down-regulated in in vitro culture. More importantly, the modified T cells performed superior immune response and cytotoxicity, which may provide a new idea for gene engineering cell immunotherapy.

国家重点研发计划专项经费资助项目（No.2017YFC1308900）；国家自然科学基金资助项目（No.81702811, No.81803093）；江苏省自然科学基金资助项目（No. SBK2018040809）