le Clorennec, C.* ; Ouk, TS.* ; Youlyouz-Marfak, I.* ; Panteix, S.* ; Martin, C.C.* ; Rastelli, J.* ; Adriaenssens, E.* ; Zimber-Strobl, U. ; Coll, J.* ; Feuillard, J.* ; Jayat-Vignoles, C.*
Molecular basis of cytotoxicity of Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) in EBV latency III B cells: LMP1 induces type II ligand-independent autoactivation of CD95/Fas with caspase 8-mediated apoptosis.
J. Virol. 82, 6721-6733 (2008)
The Epstein-Barr virus (EBV) oncoprotein latent membrane protein 1 (LMP1) is thought to act as the major transforming protein in various cell types, by rerouting the tumor necrosis factor receptor family signaling pathway. Despite this implication in EBV-associated transformation of cells, LMP1 toxicity is a well-known but poorly studied feature, perhaps because it contradicts its role in transformation. We show that LMP1 physiological levels are very heterogeneous and that the highest levels of LMP1 correlate with Fas overexpression and spontaneous apoptosis in lymphoblastoid cell lines (LCLs). To understand the cytotoxic effect of LMP1 in LCLs, we cloned wild-type LMP1 into a doxycycline double-inducible episomal vector pRT-1, with a truncated version of NGFR as a surrogate marker of inducibility. We found that LMP1 overexpression induced apoptosis in LCL B cells, as shown by annexin V labeling, sub-G(1) peak, and poly(ADP ribose) polymerase cleavage. Knocking down Fas expression by small interfering RNA abolished LMP1-induced apoptosis. The absence of detectable levels of Fas ligand mRNA suggested a ligand-independent activation of Fas. LMP1 induced Fas overexpression with its relocalization in lipid raft microdomains of the membrane. Fas immunoprecipitation detected FADD (Fas-associated death domain protein) and caspase 8, suggesting a Fas-dependent formation of the death-inducing signaling complex. Caspases 8, 9, 3, and 7 were activated by LMP1. Caspase 8 activation was associated with BID cleavage and truncated-BID mitochondrial relocalization, consistent with type II apoptosis. Therefore, our results are in agreement with a model where LMP1-dependent NF-kappaB activation induces Fas overexpression and autoactivation that could overwhelm the antiapoptotic effect of NF-kappaB, revealing an ambivalent function of LMP1 in cell survival and programmed cell death.
Impact Factor
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Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Typ der Hochschulschrift
Herausgeber
Schlagwörter
EBV; Epstein-Barr Virus; Latent Membrane Protein 1 (LMP1);
Keywords plus
Sprache
englisch
Veröffentlichungsjahr
2008
Prepublished im Jahr
HGF-Berichtsjahr
0
ISSN (print) / ISBN
0022-538X
e-ISSN
1098-5514
ISBN
Bandtitel
Konferenztitel
Konferzenzdatum
Konferenzort
Konferenzband
Quellenangaben
Band: 82,
Heft: 13,
Seiten: 6721-6733
Artikelnummer: ,
Supplement: ,
Reihe
Verlag
American Society for Microbiology (ASM)
Verlagsort
Tag d. mündl. Prüfung
0000-00-00
Betreuer
Gutachter
Prüfer
Topic
Hochschule
Hochschulort
Fakultät
Veröffentlichungsdatum
0000-00-00
Anmeldedatum
0000-00-00
Anmelder/Inhaber
weitere Inhaber
Anmeldeland
Priorität
Begutachtungsstatus
Peer reviewed
POF Topic(s)
30203 - Molecular Targets and Therapies
Forschungsfeld(er)
Immune Response and Infection
PSP-Element(e)
G-501500-003
Förderungen
Copyright
Erfassungsdatum
2008-08-29