Miossec C, Dutilleul V, Fassy F, Diu-Hercend A
Roussel Uclaf, 102 route de Noisy, 93235 Romainville Cedex, France.
J Biol Chem. 1997 May 23;272(21):13459-62. doi: 10.1074/jbc.272.21.13459.
Cysteine proteases of the interleukin-1beta-converting enzyme family have been implicated in the effector process of apoptosis in several systems. Among these, CPP32 has been shown to be processed to active enzyme at the onset of apoptosis. Here, we show that CPP32 precursor is cleaved into its active form during phytohaemaglutinin A activation of T lymphocytes. Maximal processing is observed between day 3 and day 4 following addition of mitogen and is a transient process. Precursor cleavage is associated with the appearance of a CPP32-like enzymatic activity in cell lysates. At this time in the culture, almost no apoptotic cell and no dead cell can be detected, and T lymphocytes are actively proliferating. CPP32 processing also occurs when lymphocytes are stimulated through an allogeneic primary mixed lymphocyte reaction. Our results suggest that proteolytic activation of CPP32 could be a physiological step during T lymphocyte activation. In addition, these data indicate that CPP32 activation can occur independently of programmed cell death in T lymphocytes.
白细胞介素-1β转化酶家族的半胱氨酸蛋白酶在多个系统的细胞凋亡效应过程中发挥作用。其中，CPP32已被证明在细胞凋亡开始时被加工成活性酶。在此，我们表明CPP32前体在T淋巴细胞被植物血凝素A激活的过程中被切割成其活性形式。在添加有丝分裂原后的第3天至第4天观察到最大程度的加工，且这是一个短暂的过程。前体切割与细胞裂解物中出现类似CPP32的酶活性相关。在培养的这个阶段，几乎检测不到凋亡细胞和死亡细胞，并且T淋巴细胞在积极增殖。当淋巴细胞通过同种异体原发性混合淋巴细胞反应受到刺激时，CPP32加工也会发生。我们的结果表明，CPP32的蛋白水解激活可能是T淋巴细胞激活过程中的一个生理步骤。此外，这些数据表明CPP32的激活可以独立于T淋巴细胞中的程序性细胞死亡而发生。
