Combined loss of the BH3-only proteins Bim and Bmf restores B-cell development and function in TACI-Ig transgenic mice.

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Version: Final published version
Serval ID
serval:BIB_B82633CE58C5
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Combined loss of the BH3-only proteins Bim and Bmf restores B-cell development and function in TACI-Ig transgenic mice.
Journal
Cell Death and Differentiation
Author(s)
Woess C., Tuzlak S., Labi V., Drach M., Bertele D., Schneider P., Villunger A.
ISSN
1476-5403 (Electronic)
ISSN-L
1350-9047
Publication state
Published
Issued date
2015
Volume
22
Number
9
Pages
1477-1488
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
Terminal differentiation of B cells depends on two interconnected survival pathways, elicited by the B-cell receptor (BCR) and the BAFF receptor (BAFF-R), respectively. Loss of either signaling pathway arrests B-cell development. Although BCR-dependent survival depends mainly on the activation of the v-AKT murine thymoma viral oncogene homolog 1 (AKT)/PI3-kinase network, BAFF/BAFF-R-mediated survival engages non-canonical NF-κB signaling as well as MAPK/extracellular-signal regulated kinase and AKT/PI3-kinase modules to allow proper B-cell development. Plasma cell survival, however, is independent of BAFF-R and regulated by APRIL that signals NF-κB activation via alternative receptors, that is, transmembrane activator and CAML interactor (TACI) or B-cell maturation (BCMA). All these complex signaling events are believed to secure survival by increased expression of anti-apoptotic B-cell lymphoma 2 (Bcl2) family proteins in developing and mature B cells. Curiously, how lack of BAFF- or APRIL-mediated signaling triggers B-cell apoptosis remains largely unexplored. Here, we show that two pro-apoptotic members of the 'Bcl2 homology domain 3-only' subgroup of the Bcl2 family, Bcl2 interacting mediator of cell death (Bim) and Bcl2 modifying factor (Bmf), mediate apoptosis in the context of TACI-Ig overexpression that effectively neutralizes BAFF as well as APRIL. Surprisingly, although Bcl2 overexpression triggers B-cell hyperplasia exceeding the one observed in Bim(-/-)Bmf(-/-) mice, Bcl2 transgenic B cells remain susceptible to the effects of TACI-Ig expression in vivo, leading to ameliorated pathology in Vav-Bcl2 transgenic mice. Together, our findings shed new light on the molecular machinery restricting B-cell survival during development, normal homeostasis and under pathological conditions. Our data further suggest that Bcl2 antagonists might improve the potency of BAFF/APRIL-depletion strategies in B-cell-driven pathologies.
Keywords
Adaptor Proteins, Signal Transducing/metabolism, Animals, Apoptosis/physiology, Apoptosis Regulatory Proteins/metabolism, B-Lymphocytes/cytology, B-Lymphocytes/metabolism, Membrane Proteins/metabolism, Mice, Mice, Inbred C57BL, Mice, Transgenic, Peptide Fragments/metabolism, Proto-Oncogene Proteins/metabolism, Recombinant Fusion Proteins/genetics, Recombinant Fusion Proteins/metabolism, Signal Transduction
Pubmed
Web of science
Open Access
Yes
Create date
31/08/2015 10:11
Last modification date
20/08/2019 16:26
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