IL-1 beta converting enzyme (ICE) is not required for apoptosis induced by lymphokine deprivation in an IL-2-dependent T cell line.
Clonal T cells undergo programmed cell death (PCD) or apoptosis when cultured without the appropriate cytokines. The cysteine protease, IL-1 beta converting enzyme (ICE), is implicated in apoptosis based on its structural similarity to the PCD gene, ced-3, in Caenorhabditis elegans and the induction of PCD in fibroblasts transfected with recombinant ICE. We show that the murine IL-2-dependent CTLL T cell line expresses ICE but not IL-1 beta. Interestingly, ICE mRNA and protein levels increase during apoptosis. Yet inhibition of ICE enzymatic activity (> 90%) with either of two cell-permeable ICE inhibitors does not abrogate or delay apoptosis following IL-2 deprivation, as measured by DNA fragmentation and viability. Our results suggest that ICE is not required for apoptosis in lymphokine-deprived T cells.
Vasilakos
J P
JP
Neuroscience Therapeutics, Parke-Davis Pharmaceutical Research Company, Ann Arbor, MI 48105, USA.
Ghayur
T
T
Carroll
R T
RT
Giegel
D A
DA
Saunders
J M
JM
Quintal
L
L
Keane
K M
KM
Shivers
B D
BD
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D020170:Caspase 1; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000032:analysis; D007375:Interleukin-1 / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000502:physiology*
D007375:Interleukin-1; D007376:Interleukin-2; D004247:DNA; D003546:Cysteine Endopeptidases; D020170:Caspase 1