title: Tumor necrosis factor alpha exerts powerful anti-influenza virus effects in lung epithelial cells.
abstract: Previous studies have associated influenza virus-induced expression of inflammatory cytokines, including tumor necrosis factor alpha (TNF-alpha), with influenza pathogenesis in the human respiratory tract and have suggested that alpha and beta interferons are the first cytokines recruited to counteract such infection. However, we report here that TNF-alpha has powerful anti-influenza virus activity. When infected with influenza virus, cultured porcine lung epithelial cells expressed TNF-alpha in a dose-dependent manner. Expression of TNF-alpha was induced only by replicating virus. TNF-alpha showed strong antiviral activity against avian, swine, and human influenza viruses, and the antiviral effect of TNF-alpha was greater than that of gamma or alpha interferon. These findings suggest that TNF-alpha serves as the first line of defense against influenza virus infection in the natural host.
authors.affiliation: Department of Virology and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-2794, USA.
authors.forename: Sang Heui
authors.initials: SH
authors.lastname: Seo
authors.forename: Robert G
authors.initials: RG
authors.lastname: Webster
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000276:immunology* / Q000494:pharmacology; D002460:Cell Line; D002642:Chick Embryo; D015870:Gene Expression; D006801:Humans; D009980:Influenza A virus / Q000187:drug effects / Q000276:immunology* / Q000502:physiology; D009981:Influenza B virus / Q000187:drug effects / Q000276:immunology* / Q000502:physiology; D016898:Interferon-alpha / Q000276:immunology / Q000494:pharmacology; D016899:Interferon-beta / Q000276:immunology / Q000494:pharmacology; D007371:Interferon-gamma / Q000276:immunology / Q000494:pharmacology; D013552:Swine; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D016898:Interferon-alpha; D014409:Tumor Necrosis Factor-alpha; D016899:Interferon-beta; D007371:Interferon-gamma