Michel J, Pauly S, Langstein J, Krammer P H, Schwarz H
Department of Pathology, University of Regensburg, Regensburg, Germany.
Immunology. 1999 Sep;98(1):42-6. doi: 10.1046/j.1365-2567.1999.00851.x.
CD95 (APO-1/Fas) and CD137 (ILA/4-1BB) are members of the tumour necrosis factor receptor family, and both are involved in induction of apoptosis in lymphocytes. Contrary to the case of CD95, apoptosis by CD137 is caused by cross-linking of the respective ligand rather than the receptor. Nothing is known so far about the mechanism of CD137-induced cell death. Here, we show that immobilized CD137 protein induces expression of CD95 in resting primary T and B lymphocytes. However, induction of apoptosis by CD137 is independent of CD95, because: (1) antagonistic anti-CD95 antibody fragments do not block CD137-induced apoptosis; and (2) CD137, but not anti-CD95, can induce apoptosis in resting lymphocytes.
CD95(APO-1/Fas)和CD137(ILA/4-1BB)是肿瘤坏死因子受体家族的成员,二者均参与淋巴细胞凋亡的诱导过程。与CD95的情况相反,CD137诱导的凋亡是由相应配体而非受体的交联所引起的。迄今为止,关于CD137诱导细胞死亡的机制尚不清楚。在此,我们表明固定化的CD137蛋白可诱导静息原代T淋巴细胞和B淋巴细胞中CD95的表达。然而,CD137诱导的凋亡不依赖于CD95,原因如下:(1)拮抗型抗CD95抗体片段不能阻断CD137诱导的凋亡;(2)CD137而非抗CD95能够诱导静息淋巴细胞凋亡。