title: Inflammatory signals increase Fas ligand expression by inner ear cells.
abstract: There is considerable evidence that hearing and vestibular function can be influenced by immune processes. The inner ear has evolved mechanisms, such as the blood-labyrinthine barrier that limit immune responses and autoimmune processes to reduce the potential for damage to cochlear cells. Recently, expression of Fas ligand (FasL) in some non-lymphoid tissue, as in the anterior chamber of the eye, has been hypothesized to play a role in protection of sensitive organs from activated T-cells. We show that under resting conditions, cochlear cells express little or no FasL. However, after exposure to interferon-gamma in vitro, FasL is induced in many neonatal cochlear cells. In addition, we show that FasL is upregulated in adult cochlear cells after induction of a sterile labyrinthitis in vivo. The induction of FasL by inflammation may serve to limit cochlear immune responses, and to protect sensorineural tissue from immune and autoimmune damage.
authors.affiliation: Department of Surgery, Division of Otolaryngology, UCSD School of Medicine and VA Medical Center, La Jolla, CA 92093, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bodmer
authors.forename: Dominik
authors.initials: D
authors.lastname: Brors
authors.forename: Kwang
authors.initials: K
authors.lastname: Pak
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Keithley
authors.forename: Lina
authors.initials: L
authors.lastname: Mullen
authors.forename: Allen F
authors.initials: AF
authors.lastname: Ryan
authors.forename: Bertrand
authors.initials: B
authors.lastname: Gloddek
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D053222:Fas Ligand Protein; D006198:Hair Cells, Auditory / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000276:immunology / Q000494:pharmacology; D007762:Labyrinthitis / Q000276:immunology* / Q000378:metabolism / Q000503:physiopathology; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008808:Mice, Inbred CBA; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology*; D019014:fas Receptor / Q000276:immunology*
chemical_list: D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D019014:fas Receptor; D007371:Interferon-gamma