title: The airway epithelium: soldier in the fight against respiratory viruses.
abstract: The airway epithelium acts as a frontline defense against respiratory viruses, not only as a physical barrier and through the mucociliary apparatus but also through its immunological functions. It initiates multiple innate and adaptive immune mechanisms which are crucial for efficient antiviral responses. The interaction between respiratory viruses and airway epithelial cells results in production of antiviral substances, including type I and III interferons, lactoferrin, β-defensins, and nitric oxide, and also in production of cytokines and chemokines, which recruit inflammatory cells and influence adaptive immunity. These defense mechanisms usually result in rapid virus clearance. However, respiratory viruses elaborate strategies to evade antiviral mechanisms and immune responses. They may disrupt epithelial integrity through cytotoxic effects, increasing paracellular permeability and damaging epithelial repair mechanisms. In addition, they can interfere with immune responses by blocking interferon pathways and by subverting protective inflammatory responses toward detrimental ones. Finally, by inducing overt mucus secretion and mucostasis and by paving the way for bacterial infections, they favor lung damage and further impair host antiviral mechanisms.
authors.affiliation: Division of Respiratory Medicine, Department of Pediatrics, University Children's Hospital of Bern, Inselpital, 3010 Bern, Switzerland.
authors.forename: Marjolaine
authors.initials: M
authors.lastname: Vareille
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kieninger
authors.forename: Michael R
authors.initials: MR
authors.lastname: Edwards
authors.forename: Nicolas
authors.initials: N
authors.lastname: Regamey
mesh_terms: D056704:Adaptive Immunity; D006801:Humans; D007113:Immunity, Innate; D020545:Respiratory Mucosa / Q000276:immunology*; D012141:Respiratory Tract Infections / Q000276:immunology* / Q000821:virology*; D014780:Viruses / Q000276:immunology* / Q000472:pathogenicity*