Inhibition of tumor necrosis factor-induced phenotypes by short intracellular versions of latent membrane protein-1.
Tumor necrosis factor (TNF) is a potent multi-functional cytokine with a homeostatic role in host defence. In case of deregulation, TNF is implicated in numerous pathologies. The latent membrane protein-1 (LMP1) is expressed by Epstein-Barr virus during viral latency and displaying properties of a constitutively activated member of the TNF receptor family. Both TNFR1 and LMP1 share a similar set of proximal adapters and signalling pathways although they display different biological responses. We previously demonstrated that the intracellular part of LMP1, LMP1-CT, a dominant-negative form of LMP1, inhibits LMP1 signalling. Here, we developed shorter versions derived from C-terminal part of LMP1 to investigate their roles on LMP1 and TNF signalling. We constructed several mutants of LMP1 containing a part of cytoplasmic signalling region fused to the green fluorescent protein. These mutants selectively impair signalling by LMP1 and TNF but not by IL-1beta which uses other adapters. Dominant-negative effect was due to binding and sequestration of LMP1 adapters RIP, TRAF2 and TRADD as assessed by coimmunoprecipitation experiments and confocal analysis. Expression of these mutants impairs the recruitment of these adapters by TNFR1 and TNF-associated phenotypes. These mutants did not display cytostatic properties but were able to modulate TNF-induced phenotypes, apoptosis or cell survival, depending on the cell context. Interestingly, these mutants are able to inhibit a pro-inflammatory response in endothelial cells. These data demonstrate that LMP1 derived molecules can be used to design compounds with potential therapeutic roles in diseases due to TNF overactivation.
CNRS UMR, Institut de Biologie de Lille, IFR, Université Lille-Nord de France, France.
Papa Alioune
PA
Ndour
Tan-Sothéa
TS
Ouk
Guillaume
G
Brocqueville
Alexandra
A
Mougel
Elsa
E
Vanhecke
Jean
J
Feuillard
Jean
J
Coll
Eric
E
Adriaenssens
D017209:Apoptosis; D002460:Cell Line; D004854:Herpesvirus 4, Human; D006801:Humans; D010641:Phenotype; D011485:Protein Binding; D034741:RNA, Small Interfering / Q000378:metabolism; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D053199:TNF Receptor-Associated Death Domain Protein / Q000378:metabolism; D047992:TNF Receptor-Associated Factor 2 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014763:Viral Matrix Proteins / Q000378:metabolism*
C037662:EBV-associated membrane antigen, Epstein-Barr virus; D034741:RNA, Small Interfering; D047888:Receptors, Tumor Necrosis Factor, Type I; D011993:Recombinant Fusion Proteins; D053199:TNF Receptor-Associated Death Domain Protein; D047992:TNF Receptor-Associated Factor 2; D014409:Tumor Necrosis Factor-alpha; D014763:Viral Matrix Proteins; D053422:Receptor-Interacting Protein Serine-Threonine Kinases