Activation of an interleukin 1 converting enzyme-dependent apoptosis pathway by granzyme B.
Cytotoxic T lymphocytes (CTL) can induce apoptosis through a granzyme B-based killing mechanism. Here we show that in cells undergoing apoptosis by granzyme B, both p45 pro-interleukin 1 beta converting enzyme (ICE) and pro-CPP32 are processed. Using ICE deficient (ICE -/-) mice, embryonic fibroblasts exhibit high levels of resistance to apoptosis by granzyme B or granzyme 3, while B lymphoblasts are granzyme B-resistant, thus identifying an ICE-dependent apoptotic pathway that is activated by CTL granzymes. In contrast, an alternative ICE-independent pathway must also be activated as ICE -/- thymocytes remain susceptible to apoptosis by both granzymes. In ICE -/- B cells or HeLa cells transfected with mutant inactive ICE or Ich-1S that exhibit resistance to granzyme B, CPP32 is processed to p17 and poly(ADP-ribose) polymerase is cleaved indicating that this protease although activated was not associated with an apoptotic nuclear phenotype. Using the peptide inhibitor Ac-DEVD-CHO, apoptosis as well as p45 ICE hydrolysis are suppressed in HeLa cells, suggesting that a CPP32-like protease is upstream of ICE. In contrast, p34cdc2 kinase, which is required for granzyme B-induced apoptosis, remains inactive in ICE -/- B cells indicating it is downstream of ICE. We conclude that granzyme B activates an ICE-dependent cell death pathway in some cell types and requires a CPP32-like Ac-DEVD-CHO inhibitable protease acting upstream to initiate apoptosis.
Shi
L
L
Manitoba Institute of Cell Biology, Manitoba Cancer Treatment and Research Foundation, University of Manitoba, Winnipeg, Canada.
Chen
G
G
MacDonald
G
G
Bergeron
L
L
Li
H
H
Miura
M
M
Rotello
R J
RJ
Miller
D K
DK
Li
P
P
Seshadri
T
T
Yuan
J
J
Greenberg
A H
AH
D000818:Animals; D017209:Apoptosis; D016203:CDC2 Protein Kinase / Q000378:metabolism; D020170:Caspase 1; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004789:Enzyme Activation; D005347:Fibroblasts / Q000378:metabolism; D053804:Granzymes; D006367:HeLa Cells; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D051379:Mice; D009842:Oligopeptides / Q000494:pharmacology; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D051381:Rats; D012697:Serine Endopeptidases / Q000378:metabolism / Q000502:physiology*
D007375:Interleukin-1; D009842:Oligopeptides; C099158:acetyl-aspartyl-glutamyl-valyl-aspartal; D011065:Poly(ADP-ribose) Polymerases; D016203:CDC2 Protein Kinase; C509213:GZMB protein, human; C088546:GZMK protein, human; D053804:Granzymes; C509214:Gzmb protein, mouse; C509215:Gzmb protein, rat; D012697:Serine Endopeptidases; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases; D020170:Caspase 1