Functional characterization of Jurkat T cells rescued from CD95/Fas-induced apoptosis through the inhibition of caspases

The caspases are known to play a pivotal role in the triggering and executi on of apoptosis in virtually all cell types. Because inappropriate apoptosi s is a prominent feature of many human diseases, the caspases are attractiv e targets for therapeutic intervention, In the present study we investigate d whether Jurkat T lymphocytes rescued from Fas-induced cell death through the inhibition of caspases are functional. Here we show that the pan-caspas e, tripeptide inhibitor, benzyloxycarbonyl-Val-Ala-Asp (Ome) fluoromethylke tone (z-VAD-FMK), inhibited the activation of caspase-2, -3, -7, and -8, an d subsequently apoptosis in Jurkat T lymphocytes induced by agonistic anti- Fas, The apoptotic signals induced by the cross-linking of the Fas antigen have a relatively long half-life, as z-VAD-FMK had to be continuously prese nt in the culture medium for 72 h after Fas stimulation in order to maintai n cell survival. After 72 h, the z-VAD-FMK-rescued cells proliferate normal ly and responded to activation induced cell, death after phytohaemaglutinin treatment, and readily undergo apoptosis when restimulated with agonistic Fas antibodies. Taken together, our results demonstrate that Jurkat T cells rescued from Fas-mediated cell death through the inhibition of caspases ar e functional, (C) 2000 Academic Press.