The IL-8 production by Streptococcal pyrogenic exotoxin B.
We have previously identified alpha(v)beta(3) and Fas as receptors for the streptococcal pyrogenic exotoxin B (SPE B), and G308S, a mutant of SPE B with RSD motif, which interacts with Fas only. This study aims to evaluate how SPE B interacts with cells to induce the production of IL-8. Our results showed that following exposure to SPE B or G308S, the levels of IL-8 protein and mRNA were increased and the increase was inhibited by the addition of anti-Fas antibody, suggesting that the increased production of IL-8 by SPE B is mediated through Fas receptor. In the presence of G308S, the association of FADD and procaspase 8, and activation of NF-kappaB were also detected. The application of siRNA of FADD and of procaspase 8 could inhibit the NF-kappaB activity. The proteolytic activity of caspase 8 was required for the NF-kappaB activity. Further studies showed that G308S could increase the phosphorylation of ERK and the translocation of NF-kappaB into the nucleus, and the inhibition of ERK phosphorylation decreased the IL-8 production, mRNA expression and activation of NF-kappaB. In addition, siRNA of procaspase 8 could inhibit the G308S-induced cleavage of MEKK1, binding of MEKK1 to caspase 8, activation of ERK and the NF-kappaB activity. Taken together, the production of IL-8 by SPE B in A549 cells is mediated by Fas, and followed by the activation of FADD, caspase 8, MEKK1, ERK and NF-kappaB.
Chang
Chia-Wen
CW
Institute of Basic Medical Sciences, Department of Biochemistry, National Cheng Kung University Medical College, Tainan 70101, Taiwan.
Wu
Siang-Yu
SY
Chuang
Woei-Jer
WJ
Lin
Yee-Shin
YS
Wu
Jiunn-Jong
JJ
Liu
Ching-Chuan
CC
Tsai
Pei-Jane
PJ
Lin
Ming-T
MT
D019943:Amino Acid Substitution / Q000187:drug effects; D001426:Bacterial Proteins / Q000494:pharmacology; D055162:Biocatalysis / Q000187:drug effects; D053181:Caspase 8 / Q000378:metabolism; D061945:Caspase Inhibitors; D045744:Cell Line, Tumor; D004789:Enzyme Activation / Q000187:drug effects; D005098:Exotoxins / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D053200:Fas-Associated Death Domain Protein / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D048728:MAP Kinase Kinase Kinase 1 / Q000378:metabolism; D008954:Models, Biological; D050505:Mutant Proteins / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D019014:fas Receptor / Q000378:metabolism
D001426:Bacterial Proteins; D061945:Caspase Inhibitors; D005098:Exotoxins; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein; D016209:Interleukin-8; D050505:Mutant Proteins; D016328:NF-kappa B; D012333:RNA, Messenger; C027951:erythrogenic toxin; D019014:fas Receptor; D048049:Extracellular Signal-Regulated MAP Kinases; D048728:MAP Kinase Kinase Kinase 1; C482576:MAP3K1 protein, human; D053181:Caspase 8