目的研究抗Fas锤头状核酶对T细胞Fas表达及其凋亡的影响,探讨增强供者淋巴细胞输注时移植物抗白血病(graft versus leukemia,GVL)效应的新策略。方法构建可有效切割Fas mRNA的锤头状核酶真核质粒,电穿孔法将其导入小鼠细胞毒T淋巴细胞(cytotoxic T lymphocyte,CTL)细胞株CTLL-2中,借助RT-PCR和Western blot检测细胞Fas的表达,同时检测转染前后细胞Caspase-3活性的改变和细胞凋亡(AnnexinⅤ-FITC法)。MTT法检测空白对照组、转染空载体组及转染pU6-RZ596组CTLL-2细胞的增殖情况和体外杀伤粒-单核白血病细胞(WEHI-3)的活性。结果构建的U6嵌合型锤头状核酶RZ596在细胞内能有效切割Fas,RT-PCR电泳检测其与β-actin条带的灰度比值:CTLL-2细胞空白对照组为(1.06±0.12),转染空载体组为(0.98±0.15),转染pU6-RZ596组为(0.43±0.11)(n=3);Fas蛋白的Western blot检测显示:以空白对照组灰度值为1,转染空载体组和转染pU6-RZ596组电泳条带的灰度比值分别为(0.98±0.13)和(0.45±0.08)(n=3),提示抗Fas锤头状核酶可明显降低小鼠活化CTLL-2的Fas水平。与高表达Fas配体(FasL)的WEHI-3细胞共孵育,CTLL-2细胞的存活率和体外杀伤活性明显增加,空白对照组、转染空载体组和转染pU6-RZ596组的细胞凋亡率分别为88%、84%和37%,对WEHI-3细胞杀伤活性分别为32%、31%和67%。结论抗Fas锤头状核酶能显著降低小鼠活化CTLL-2细胞的Fas表达,使其免于Fas途径的凋亡。
Objective： To investigate the expression of Fas, Fas ligand （FasL） and CD80 on the cell surface of mouse acute myelomonocytic leukemia cell line WEHI-3 and the function of FasL. Methods： The expression of Fas, FasL and CD80 was detected on WEHI-3 cell surface by flow cytometry. Simultaneously the function of FasL was determined by Thymidine （^3H-TdR） Incorporation. Results： The expression of CD80 and Fas on WEHI-3 cell surface was 5.06%±0.41% and 6.75%±2.31% （n=5） respectively, and the expression of FasL was up to 63.73%±5.23% （n=5）. The apoptotic rate of YAC-1 cells was 26%±4.5%, 35%±3.2% and 43%±2.7% （n=5） respectively when WEHI-3 （effector cell, E） and Fas^＋ YAC-1 cells （target cell, T） were cultured in the ratio of 3：1, 10：1 and 30：1. Conclusion： WEHI-3 cells express high FasL, low Fas and CD80, and can induce apoptosis of Fas^＋ YAC-1 cells.
