title: Bronchial platelet-activating factor receptor in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Bacteria expressing phosphorylcholine (ChoP) co-opt host-expressed platelet-activating factor receptor (PAFR) to adhere to lower airway cells. Cigarette smoke and rhinovirus (RV) infection upregulate PAFR-dependent bacterial adhesion to airway cells in vitro, and in healthy adults smoking increases the proportion of PAFR positive bronchial epithelial cells. To date the effect of chronic obstructive pulmonary disease (COPD) on smoke-induced PAFR is unknown. We therefore sought to test the hypothesis that bronchial PAFR mRNA expression is increased in smokers with chronic obstructive pulmonary disease (COPD), and further increases after RV infection.
  
  
  METHODS
  Endobronchial biopsies were obtained by fibreoptic bronchoscopy from healthy non-smokers, smokers without airway obstruction, and smokers with COPD, before and after infection with rhinovirus (RV) serotype 16. Endobronchial PAFR mRNA expression was assessed by quantitative PCR and expressed as a ratio of glyceraldehyde-3-phosphate dehydrogenase. The distribution of PAFR was assessed by immunohistochemistry.
  
  
  RESULTS
  Baseline PAFR mRNA expression was increased (p < 0.05) in smokers (n = 16), and smokers with COPD (n = 14) compared with non-smokers (n = 18). In RV16 infected subjects there was no increase in PAFR mRNA expression in either non-smokers (n = 9), smokers (n = 8), or smokers with COPD (n = 7). PAFR immunoreactivity in all 3 groups was predominately restricted to the bronchial epithelium and submucosal glands.
  
  
  CONCLUSIONS
  Endobronchial PAFR mRNA is increased in both smokers without airway obstruction and smokers with COPD. We found preliminary evidence that RV16 infection does not increase PAFR mRNA expression in either smokers or smokers with COPD.
authors.affiliation: Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK.
authors.forename: Reetika
authors.initials: R
authors.lastname: Suri
authors.affiliation: Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, London W2 1PG, UK.
authors.forename: Patrick
authors.initials: P
authors.lastname: Mallia
authors.affiliation: Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK.
authors.forename: Joanne E
authors.initials: JE
authors.lastname: Martin
authors.affiliation: Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, London W2 1PG, UK.
authors.forename: Joseph
authors.initials: J
authors.lastname: Footitt
authors.affiliation: Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, London W2 1PG, UK.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, London W2 1PG, UK.
authors.forename: Maria-Belen
authors.initials: MB
authors.lastname: Trujillo-Torralbo
authors.affiliation: Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, London W2 1PG, UK.
authors.forename: Sebastian L
authors.initials: SL
authors.lastname: Johnston
authors.affiliation: Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK. Electronic address: j.grigg@qmul.ac.uk.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Grigg
mesh_terms: D001980:Bronchi / Q000378:metabolism; D004847:Epithelial Cells; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010850:Picornaviridae Infections / Q000378:metabolism; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism*; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D012907:Smoking / Q000378:metabolism*
chemical_list: D010980:Platelet Membrane Glycoproteins; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor
keywords: COPD; Platelet-activating factor receptor; Rhinovirus 16; Smoking