Fas ligand induces cell-autonomous NF-kappaB activation and interleukin-8 production by a mechanism distinct from that of tumor necrosis factor-alpha.
Fas ligand (FasL) has been well characterized as a death factor. However, recent studies revealed that FasL possesses inflammatory activity. Here we found that FasL induces production of the inflammatory chemokine IL-8 without inducing apoptosis in HEK293 cells. Reporter gene assays involving wild-type and mutated IL-8 promoters and NF-kappaB- and AP-1 reporter constructs indicated that an FasL-induced NF-kappaB and AP-1 activity are required for maximal promoter activity. FasL induced NF-kappaB activation with slower kinetics than did TNF-alpha, yet this response was cell autonomous and not mediated by secondary paracrine factors. The death domain of Fas, FADD, and caspase-8 were required for NF-kappaB activation by FasL. A dominant-negative mutant of IKKgamma inhibited the FasL-induced NF-kappaB activation. However, TRADD and RIP, which are essential for the TNF-alpha-induced NF-kappaB activation, were not involved in the FasL-induced NF-kappaB activation. Moreover, CLARP/FLIP inhibited the FasL- but not the TNF-alpha-induced NF-kappaB activation. These results show that FasL induces NF-kappaB activation and IL-8 production by a novel mechanism, distinct from that of TNF-alpha. In addition, we found that mouse FADD had a dominant-negative effect on the FasL-induced NF-kappaB activation in HEK293 cells, which may indicate a species difference between human and mouse in the FasL-induced NF-kappaB activation.
Imamura
Ryu
R
Center for the Development of Molecular Target Drugs, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa 920-0934, Japan.
Konaka
Kenji
K
Matsumoto
Norihiko
N
Hasegawa
Mizuho
M
Fukui
Masayuki
M
Mukaida
Naofumi
N
Kinoshita
Takeshi
T
Suda
Takashi
T
D000818:Animals; D017209:Apoptosis; D029681:Arabidopsis Proteins / Q000378:metabolism; D015153:Blotting, Western; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival; D053222:Fas Ligand Protein; D044943:Fatty Acid Desaturases / Q000378:metabolism; D005799:Genes, Dominant; D017930:Genes, Reporter; D006801:Humans; D051550:I-kappa B Kinase; D007249:Inflammation; D016209:Interleukin-8 / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000494:pharmacology; D019169:Jurkat Cells; D008156:Luciferases / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000502:physiology; D051379:Mice; D009154:Mutation; D016328:NF-kappa B / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014176:Protein Biosynthesis; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D029681:Arabidopsis Proteins; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C506386:CFLAR protein, human; C506387:Cflar protein, mouse; C505661:FASLG protein, human; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D016209:Interleukin-8; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D018808:Transcription Factor AP-1; D014409:Tumor Necrosis Factor-alpha; D008156:Luciferases; D044943:Fatty Acid Desaturases; C084083:Fad7 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; C496564:Chuk protein, mouse; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; C496562:Ikbkb protein, mouse; C496566:Ikbke protein, mouse; C505530:CASP8 protein, human; C505526:Casp8 protein, mouse; D053181:Caspase 8; D020169:Caspases