title: Different interleukin-1 beta converting enzyme (ICE) family protease requirements for the apoptotic death of T lymphocytes triggered by diverse stimuli.
abstract: Two cell permeable peptide fluoromethyl ketone inhibitors of Interleukin-1 beta converting enzyme (ICE) family proteases were tested as inhibitors of apoptotic cell death of T lymphocytes at various stages of differentiation. The CPP-32-like protease activity in apoptotic cell lysates was blocked by both the ICE inhibitor Cbz-Val-Ala-Asp(OMe)-fluoromethyl ketone (ZVAD-FMK) as well as its truncated analog Boc-Asp(OMe)-fluoromethyl ketone (BD-FMK), which failed to block ICE. In vitro apoptotic death in murine thymocytes triggered by the independent agents dexamethasone, etoposide, radiation, anti-Fas, and anti-CD3 was blocked equally well by BD-FMK and ZVAD-FMK, but not by the control reagent Cbz-Phe-Ala-fluoromethyl ketone. In activated T cell blasts, while anti-CD3/ Fas-induced death was almost completely inhibited by both ZVAD-FMK, and BD-FMK, death induced by dexamethasone, etoposide, or irradiation was more sensitive to inhibition by BD-FMK. In the murine T cell line CTLL-2, apoptotic death induced by IL-2 withdrawal, etoposide, or dexamethasone was inhibited by BD-FMK, while ZVAD-FMK was without effect. These data indicate that ICE-family proteases comprise a common functional step in distinct T cell apoptotic death pathways, but suggest that different family members are likely to be critical in various differentiated T cell types, even when triggered by the same stimulus.
authors.affiliation: Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-1360, USA.
authors.forename: A
authors.initials: A
authors.lastname: Sarin
authors.forename: M L
authors.initials: ML
authors.lastname: Wu
authors.forename: P A
authors.initials: PA
authors.lastname: Henkart
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D017252:CD3 Complex / Q000276:immunology / Q000502:physiology; D020170:Caspase 1; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D003907:Dexamethasone / Q000494:pharmacology; D005047:Etoposide / Q000494:pharmacology; D007700:Kinetics; D051379:Mice; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D013997:Time Factors; D019014:fas Receptor / Q000276:immunology / Q000502:physiology
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D000906:Antibodies; D017252:CD3 Complex; D015853:Cysteine Proteinase Inhibitors; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C103192:butyloxycarbonyl-O-methyl-aspartyl-fluoromethyl ketone; D019014:fas Receptor; D005047:Etoposide; D003907:Dexamethasone; D003546:Cysteine Endopeptidases; D020170:Caspase 1