title: Type II tumour necrosis factor-alpha receptor (TNFR2) activates c-Jun N-terminal kinase (JNK) but not mitogen-activated protein kinase (MAPK) or p38 MAPK pathways.
abstract: The pleitropic actions of tumour necrosis factor-alpha (TNF) are transmitted by the type I 55 kDa TNF receptor (TNFR1) and type II 75 kDa TNF receptor (TNFR2), but the signalling mechanisms elicited by these two receptors are not fully understood. In the present study, we report for the first time subtype-specific differential kinase activation in cell models that respond to TNF by undergoing apoptotic cell death. KYM-1 human rhabdomyosarcoma cells and HeLa human cervical epithelial cells, engineered to overexpress TNFR2, displayed c-Jun N-terminal kinase (JNK) activation by wild-type TNF, a TNFR1-specific TNF mutant and a TNFR2-specific mutant TNF in combination with an agonistic TNFR2-specific monoclonal antiserum. A combination of the TNFR2-specific mutant and agonistic antiserum elicited maximal endogenous or exogenous TNFR2 responsiveness. Moreover, alternative expression of a TNFR2 deletion mutant lacking its cytoplasmic domain rendered the cells unable to activate JNK activity through this receptor subtype. The profile of JNK activation by TNFR1 was more transient than that of TNFR2, with TNFR2-induced JNK activity also being more sensitive to the caspase inhibitor, benzyloxycarbonyl-Val-Ala-DL-Asp-fluoromethylketone. Conversely, only activation of the TNFR1 could stimulate mitogen-activated protein kinase (MAPK) or p38 MAPK activities in a time-dependent manner. The role of TNFR2 activation in enhanced apoptotic cell death was confirmed with agonistic monoclonal antisera in cells expressing high levels of TNFR2. Activation of TNFR2 alone elicited cell death, but full TNF-induced death required stimulation of both receptor types. These findings indicate that efficient activation of TNFR2 by soluble TNFs is achievable with co-stimulation by antisera, and that both receptors differentially modulate extracellular signal-regulated kinases contributing to the cytokine's cytotoxic response.
authors.affiliation: Department of Biomedical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom.
authors.forename: O J
authors.initials: OJ
authors.lastname: Jupp
authors.forename: S M
authors.initials: SM
authors.lastname: McFarlane
authors.forename: H M
authors.initials: HM
authors.lastname: Anderson
authors.forename: A F
authors.initials: AF
authors.lastname: Littlejohn
authors.forename: A A
authors.initials: AA
authors.lastname: Mohamed
authors.forename: R H
authors.initials: RH
authors.lastname: MacKay
authors.forename: P
authors.initials: P
authors.lastname: Vandenabeele
authors.forename: D J
authors.initials: DJ
authors.lastname: MacEwan
mesh_terms: D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis / Q000502:physiology; D002469:Cell Separation; D004789:Enzyme Activation; D005434:Flow Cytometry; D006801:Humans; D007527:Isoenzymes; D048031:JNK Mitogen-Activated Protein Kinases; D020935:MAP Kinase Signaling System / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism*; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D011994:Recombinant Proteins / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D015703:Antigens, CD; D007527:Isoenzymes; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases