Chiba T, Takahashi S, Sato N, Ishii S, Kikuchi K
Department of Pathology 1, Sapporo Medical University School of Medicine, Japan.
Eur J Immunol. 1996 May;26(5):1164-9. doi: 10.1002/eji.1830260530.
Fas antigen is a member of the tumor necrosis factor receptor family that transduces a lethal signal to the Fas-sensitive cells. We previously established the Fas-resistant variant cell lines LAC2D1R and JKT2D1R from the parental Fas-sensitive cell lines, SUPT13 and Jurkat, respectively. Recently, we isolated the Fas-resistant variant CEM2D1R from CCRF-CEM. All of the variants were Fas+ but resistant to Fas-mediated apoptosis. Further biochemical analysis revealed that the intracellular glutathione (GSH) content of the Fas-resistant variants was higher than in the original cells. When the Fas-resistant variants were incubated with buthionine sulfoximine (BSO) or in GSH-free/cysteine-free medium to deplete GSH, Fas resistance was reversed. Incubation of the cells with cycloheximide also decreased intracellular GSH and reversed the Fas resistance. Furthermore, incubation of activated peripheral blood lymphocytes with BSO enhanced Fas-mediated apoptosis. When the Fas-sensitive cells were incubated with N-acetylcysteine (NAC), intracellular GSH was increased and Fas-mediated apoptosis was blocked. In contrast, Fas-resistant variants, as well as Fas-sensitive cells pre-treated with NAC remained susceptible to allogeneic lymphokine-activated killer cells, most likely due to perforin-dependent killing. The results suggest that Fas-mediated apoptosis, but not perforin-dependent killing, is modulated by intracellular GSH in human T lymphocytes.
Fas抗原是肿瘤坏死因子受体家族的成员，可将致死信号传导至对Fas敏感的细胞。我们之前分别从亲代Fas敏感细胞系SUPT13和Jurkat建立了Fas抗性变异细胞系LAC2D1R和JKT2D1R。最近，我们从CCRF-CEM中分离出了Fas抗性变异体CEM2D1R。所有变异体均为Fas阳性，但对Fas介导的凋亡具有抗性。进一步的生化分析表明，Fas抗性变异体的细胞内谷胱甘肽（GSH）含量高于原始细胞。当Fas抗性变异体与丁硫氨酸亚砜胺（BSO）一起孵育或在无GSH/无半胱氨酸的培养基中孵育以耗尽GSH时，Fas抗性被逆转。用放线菌酮孵育细胞也会降低细胞内GSH并逆转Fas抗性。此外，用BSO孵育活化的外周血淋巴细胞可增强Fas介导的凋亡。当Fas敏感细胞与N-乙酰半胱氨酸（NAC）一起孵育时，细胞内GSH增加，Fas介导的凋亡被阻断。相反，Fas抗性变异体以及用NAC预处理的Fas敏感细胞对同种异体淋巴因子激活的杀伤细胞仍然敏感，这很可能是由于穿孔素依赖性杀伤。结果表明，在人T淋巴细胞中，Fas介导的凋亡而非穿孔素依赖性杀伤受细胞内GSH的调节。
