title: Virus-induced expression of retinoic acid inducible gene-I and melanoma differentiation-associated gene 5 in the cochlear sensory epithelium.
abstract: The inner ear has been regarded as an immunoprivileged site because of isolation by the blood-labyrinthine barrier. Several reports have indicated the existence of immune cells in the inner ear, but there are no reports showing immunocompetence of the cochlear tissue. In this report, we examined the potential involvement of retinoic acid inducible gene-I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5), which are critical for initiating antiviral innate immune responses. We found that RIG-I and MDA5 are expressed in the mouse cochlear sensory epithelium, including Hensen's and Claudius' cells. Ex vivo viral infection using Theiler's murine encephalomyelitis virus revealed that the virus replicates in these cells and that protein levels of RIG-I and MDA5 are up-regulated. Furthermore, the critical antiviral transcription factor, interferon (IFN) regulatory factor-3, is activated in the infected cells as judged by its nuclear translocation and the accumulation of type I IFN transcripts. These results strongly suggest that RIG-I and MDA5 participate in innate antiviral responses in cochlear tissue.
authors: Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan.
authors: Yushi
authors: Y
authors: Hayashi
authors: Koji
authors: K
authors: Onomoto
authors: Ryo
authors: R
authors: Narita
authors: Mitsutoshi
authors: M
authors: Yoneyama
authors: Hiroki
authors: H
authors: Kato
authors: Takayuki
authors: T
authors: Nakagawa
authors: Juichi
authors: J
authors: Ito
authors: Akiko
authors: A
authors: Taura
authors: Takashi
authors: T
authors: Fujita
mesh_terms: D000818:Animals; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000096:biosynthesis*; D004848:Epithelium / Q000276:immunology* / Q000821:virology*; D020869:Gene Expression Profiling; D007113:Immunity, Innate; D066298:In Vitro Techniques; D050838:Interferon Regulatory Factor-3 / Q000096:biosynthesis; D007370:Interferon Type I / Q000096:biosynthesis; D000072640:Interferon-Induced Helicase, IFIH1; D051379:Mice; D008813:Mice, Inbred ICR; D017945:Theilovirus / Q000276:immunology*; D015854:Up-Regulation; D014779:Virus Replication
chemical_list: D050838:Interferon Regulatory Factor-3; D007370:Interferon Type I; C503356:Ddx58 protein, mouse; C510592:Ifih1 protein, mouse; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases; D000072640:Interferon-Induced Helicase, IFIH1
keywords: Cochlear sensory epithelium; Hensen's and Claudius' cells; Innate immunity; Interferon; Retinoic acid inducible gene-I family; Supporting cells