Dual role of NOX2 in respiratory syncytial virus- and sendai virus-induced activation of NF-kappaB in airway epithelial cells.
Human respiratory syncytial virus (RSV), a member of the Paramyxoviridae family, is the most important viral agent of pediatric respiratory tract disease worldwide. Human airway epithelial cells (AEC) are the primary targets of RSV. AEC are responsible for the secretion of a wide spectrum of cytokines and chemokines that are important mediators of the exacerbated airway inflammation triggered by the host in response to RSV infection. NF-kappaB is a key transcription factor responsible for the regulation of cytokine and chemokine gene expression and thus represents a potential therapeutic target. In the present study, we sought to delineate the role of RSV-induced reactive oxygen species in the regulation of the signaling pathways leading to NF-kappaB activation. First, we demonstrate that besides the well-characterized IkappaBalpha-dependent pathway, phosphorylation of p65 at Ser(536) is an essential event regulating NF-kappaB activation in response to RSV in A549. Using antioxidant and RNA-interference strategies, we show that a NADPH oxidase 2 (NOX2)-containing NADPH oxidase is an essential regulator of RSV-induced NF-kappaB activation. Molecular analyses revealed that NOX2 acts upstream of both the phosphorylation of IkappaBalpha at Ser(32) and of p65 at Ser(536) in A549 and normal human bronchial epithelial cells. Similar results were obtained in the context of infection by Sendai virus, thus demonstrating that the newly identified NOX2-dependent NF-kappaB activation pathway is not restricted to RSV among the Paramyxoviridae. These results illustrate a previously unrecognized dual role of NOX2 in the regulation of NF-kappaB in response to RSV and Sendai virus in human AEC.
Fink
Karin
K
Centre Hospitalier de l'Université de Montréal Research Center- St-Luc Hospital and Institut National de la Santé et de la Recherche Médicale Unité 743, Montreal, Quebec, Canada.
Duval
Annick
A
Martel
Alexis
A
Soucy-Faulkner
Anton
A
Grandvaux
Nathalie
N
D000975:Antioxidants / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects / Q000276:immunology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D006801:Humans; D015151:Immunoblotting; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000276:immunology / Q000378:metabolism*; D016328:NF-kappa B / Q000276:immunology / Q000378:metabolism*; D010766:Phosphorylation; D034622:RNA Interference; D012333:RNA, Messenger / Q000032:analysis; D020545:Respiratory Mucosa / Q000276:immunology / Q000378:metabolism / Q000821:virology; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology* / Q000378:metabolism; D012136:Respiratory Syncytial Viruses / Q000276:immunology; D010253:Respirovirus Infections / Q000276:immunology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D029082:Sendai virus / Q000276:immunology; D051996:Transcription Factor RelA / Q000378:metabolism; D014162:Transfection
D000975:Antioxidants; D004791:Enzyme Inhibitors; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D012333:RNA, Messenger; D051996:Transcription Factor RelA; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases