|
|
||||||||
Institut National de la Santé et de la Recherche Médicale, Unité 131 and Unité 542, and Claude Bernard Research Center, Clamart, France; and Hôpital Paul Brousse, Villejuif, France
We have previously reported that B cell receptors, depending on the degree to which they are cross-linked, can promote apoptosis in various human B cell types. In this study, we show that B cell receptors can trigger two apoptotic pathways according to cross-linking and that these pathways control mitochondrial activation in human Burkitts lymphoma cells. Whereas soluble anti-µ Ab triggers caspase-independent mitochondrial activation, cross-linked anti-µ Ab induces an apoptotic response associated with a caspase-dependent loss of mitochondrial transmembrane potential. This B cell receptor-mediated caspase-dependent mitochondrial activation is associated with caspase-8 activation. We show here that caspase-8 inhibitors strongly decrease cross-linking-dependent B cell receptor-mediated apoptosis in Burkitts lymphoma BL41 cells. These inhibitors act upstream from the mitochondria as they prevented the loss of mitochondrial membrane potential observed in B cell receptor-treated BL41 cells. Caspase-8 activation in these cells was also evident from the detection of cleaved fragments of caspase-8 and the cleavage of specific substrates, including Bid. Our data show that cross-linked B cell receptors induced an apoptotic pathway involving sequential caspase-8 activation, loss of mitochondrial membrane potential, and the activation of caspase-9 and caspase-3. Cells expressing a dominant negative mutant of Fas-associated death domain protein were sensitive to cross-linked B cell receptor-induced caspase-8 activation and apoptosis; therefore, this caspase-8 activation was independent of the death effector domain of Fas-associated death domain protein.
This article has been cited by other articles:
![]() |
D. Sohn, K. Schulze-Osthoff, and R. U. Janicke Caspase-8 Can Be Activated by Interchain Proteolysis without Receptor-triggered Dimerization during Drug-induced Apoptosis J. Biol. Chem., February 18, 2005; 280(7): 5267 - 5273. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Mouhamad, L. Besnault, M. T. Auffredou, C. Leprince, M. F. Bourgeade, G. Leca, and A. Vazquez B Cell Receptor-Mediated Apoptosis of Human Lymphocytes Is Associated with a New Regulatory Pathway of Bim Isoform Expression J. Immunol., February 15, 2004; 172(4): 2084 - 2091. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. T. C. Chan, D. Hughes, R. R. French, A. L. Tutt, C. A. Walshe, J. L. Teeling, M. J. Glennie, and M. S. Cragg CD20-induced Lymphoma Cell Death Is Independent of Both Caspases and Its Redistribution into Triton X-100 Insoluble Membrane Rafts Cancer Res., September 1, 2003; 63(17): 5480 - 5489. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. H. Dho and K.-S. Kwon The Ret Finger Protein Induces Apoptosis via Its RING Finger-B Box-Coiled-coil Motif J. Biol. Chem., August 22, 2003; 278(34): 31902 - 31908. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. E. Muscarella and S. E. Bloom Cross-linking of Surface IgM in the Burkitt's Lymphoma Cell Line ST486 Provides Protection against Arsenite- and Stress-induced Apoptosis That Is Mediated by ERK and Phosphoinositide 3-Kinase Signaling Pathways J. Biol. Chem., January 31, 2003; 278(6): 4358 - 4367. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Varghese, H. Sade, P. Vandenabeele, and A. Sarin Head Involution Defective (Hid)-triggered Apoptosis Requires Caspase-8 but Not FADD (Fas-associated Death Domain) and Is Regulated by Erk in Mammalian Cells J. Biol. Chem., September 13, 2002; 277(38): 35097 - 35104. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Pifer, D. Robison, and P. E. Funk The Avian Chb6 Alloantigen Triggers Apoptosis in a Mammalian Cell Line J. Immunol., August 1, 2002; 169(3): 1372 - 1378. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |