title: Modulation of the immune response to respiratory viruses by vitamin D.
abstract: BACKGROUND
  Vitamin D deficiency has been shown to be independently associated with increased risk of viral acute respiratory infection (ARI) in a number of observational studies, and meta-analysis of clinical trials of vitamin D supplementation for prevention of ARI has demonstrated protective effects. Several cellular studies have investigated the effects of vitamin D metabolites on immune responses to respiratory viruses, but syntheses of these reports are lacking.
  
  
  METHODS
  In this article, we review the literature reporting results of in vitro experiments investigating immunomodulatory actions of vitamin D metabolites in human respiratory epithelial cells infected with respiratory viruses.
  
  
  RESULTS
  Vitamin D metabolites do not consistently influence replication or clearance of rhinovirus, respiratory syncytial virus (RSV) or influenza A virus in human respiratory epithelial cell culture, although they do modulate expression and secretion of type 1 interferon, chemokines including CXCL8 and CXCL10 and pro-inflammatory cytokines, such as TNF and IL-6.
  
  
  CONCLUSIONS
  More studies are needed to clarify the effects of vitamin D metabolites on respiratory virus-induced expression of cell surface markers mediating viral entry and bacterial adhesion to respiratory epithelial cells.
authors.affiliation: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AB, UK. c.l.greiller@qmul.ac.uk.
authors.forename: Claire L
authors.initials: CL
authors.lastname: Greiller
authors.affiliation: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AB, UK. a.martineau@qmul.ac.uk.
authors.forename: Adrian R
authors.initials: AR
authors.lastname: Martineau
mesh_terms: D054357:Chemokine CXCL10 / Q000378:metabolism; D019587:Dietary Supplements; D004847:Epithelial Cells / Q000187:drug effects / Q000821:virology; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects*; D056747:Immunomodulation; D009980:Influenza A virus / Q000187:drug effects; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D012136:Respiratory Syncytial Viruses / Q000187:drug effects; D012141:Respiratory Tract Infections / Q000188:drug therapy / Q000276:immunology* / Q000821:virology; D012229:Rhinovirus / Q000187:drug effects; D048069:Tumor Necrosis Factors / Q000378:metabolism; D014777:Virus Diseases / Q000188:drug therapy / Q000276:immunology*; D014807:Vitamin D / Q000008:administration & dosage*; D014808:Vitamin D Deficiency / Q000150:complications / Q000188:drug therapy
chemical_list: C114753:CXCL10 protein, human; C508606:CXCL8 protein, human; D054357:Chemokine CXCL10; D015850:Interleukin-6; D016209:Interleukin-8; D048069:Tumor Necrosis Factors; D014807:Vitamin D
keywords: antiviral immunity; respiratory viruses; vitamin D