Induction of IL-8 release in lung cells via activator protein-1 by recombinant baculovirus displaying severe acute respiratory syndrome-coronavirus spike proteins: identification of two functional regions.
The inflammatory response and the intracellular signaling pathway induced by severe acute respiratory syndrome (SARS)-coronavirus (CoV) were studied in lung epithelial cells and fibroblasts. SARS-CoV spike (S) protein-encoding plasmid induced activations of IL-8 promoter and AP-1, but not NF-kappaB in these cells. Mutation of the AP-1, not the kappaB site, abolished the SARS-CoV S protein-induced IL-8 promoter activity. IL-8 release was effectively induced by vAtEpGS688, a baculovirus exhibiting the aa 17-688 fragment of S protein, and this induction was attenuated by the angiotensin-converting enzyme 2 Ab. Recombinant baculovirus expressing different deletion and insertion fragments identified the functional region of S protein from aa 324-688 (particularly the N-terminal aa 324-488 and the C-terminal aa 609-688), which is responsible for IL-8 production. Activations of AP-1 DNA-protein binding and MAPKs after vAtEpGS688 transduction were demonstrated, and SARS-CoV S protein-induced IL-8 promoter activity was inhibited by the specific inhibitors of MAPK cascades. These results suggested that the S protein of SARS-CoV could induce release of IL-8 in the lung cells via activations of MAPKs and AP-1. The identification of the functional domain for IL-8 release will provide for the drug design on targeting specific sequence domains of S protein responsible for initiating the inflammatory response.
Chang
Ya-Jen
YJ
Department of Pharmacology, College of Medicine, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan.
Liu
Catherine Y-Y
CY
Chiang
Bor-Luen
BL
Chao
Yu-Chan
YC
Chen
Ching-Chow
CC
D016367:Baculoviridae / Q000235:genetics* / Q000276:immunology; D002460:Cell Line; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D010450:Endopeptidases / Q000502:physiology; D004789:Enzyme Activation / Q000235:genetics / Q000276:immunology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D008168:Lung / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D016328:NF-kappa B / Q000378:metabolism; D010957:Plasmids; D011401:Promoter Regions, Genetic / Q000276:immunology; D017434:Protein Structure, Tertiary / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics* / Q000276:immunology*; D064370:Spike Glycoprotein, Coronavirus; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D014760:Viral Fusion Proteins / Q000096:biosynthesis / Q000235:genetics
D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D016209:Interleukin-8; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D011993:Recombinant Fusion Proteins; D064370:Spike Glycoprotein, Coronavirus; D018808:Transcription Factor AP-1; D014759:Viral Envelope Proteins; D014760:Viral Fusion Proteins; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus; D048049:Extracellular Signal-Regulated MAP Kinases; D010450:Endopeptidases; C047491:angiotensin-producing serum enzyme II