title: Upregulation of IL-17A/F from human lung tissue explants with cigarette smoke exposure: implications for COPD.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is an inflammatory disorder marked by relative resistance to steroids. The IL-17 superfamily, which mediates cross-talk between the adaptive and innate immune systems, has been associated with diminished responses to steroids. Increasing evidence supports elevated IL-17 expression in the lung of COPD subjects. However, whether cells of the immune system (systemic) and/or local lung cells are contributing to the elevated IL-17 remains unclear. To address this issue, we utilized a human parenchymal lung tissue explant culture system with cigarette smoke exposure to investigate the expression of IL-17 and the mechanisms involved.
  
  
  METHODS
  Parenchymal lung tissue removed from 10 non-COPD and 8 COPD patients was sectioned and cultured with different concentrations of cigarette smoke extract (CSE) for 3 or 6 hours. Tissue viability was evaluated by LDH (lactate dehydrogenase) in culture supernatants. Western blot and real-time PCR were performed to evaluate IL-17A/F expression. To investigate the mechanisms, pharmacological inhibitors for MAPK p38, ERK1/2, NF-κB and PI3K pathways were added into the culture media.
  
  
  RESULTS
  No tissue damage was observed after the cigarette smoke exposure for 3 h or 6 h compared with the control media. At the protein level, the expression of both IL-17A (2.4 ± 0.6 fold) and IL-17 F (3.7 ± 0.7 fold) in the tissue from non-COPD subjects was significantly increased by 5% of CSE at 3 h. For COPD subjects, IL-17A/F expression were significantly increased only at 6 h with 10% of CSE (IL-17A: 4.2 ± 0.8 fold; IL-17 F: 3.3 ± 0.8 fold). The increased expression of IL-17A/F is also regulated at the mRNA level. The inhibitors for NF-κB and PI3K pathways significantly inhibited CSE-induced IL-17A/F expression from lung tissue of non-COPD subjects.
  
  
  CONCLUSIONS
  We found the evidence that the expression of both IL-17A and IL-17 F is increased by the cigarette smoke exposure in explants from both non-COPD and COPD subjects, supporting that local lung cells contribute IL-17 production. The elevated IL-17A/F expression is dependent on NF-κB and PI3K pathways. These observations add to the growing evidence which suggests that Th17 cytokines play a significant role in COPD.
authors.affiliation: Meakins-Christie Laboratories and Respiratory Division, McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, Canada. changyingcn@hotmail.com.|Center for Translational Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China. changyingcn@hotmail.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Meakins-Christie Laboratories and Respiratory Division, McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, Canada. laila.al-alwan@mail.mcgill.ca.
authors.forename: Laila
authors.initials: L
authors.lastname: Al-Alwan
authors.affiliation: Meakins-Christie Laboratories and Respiratory Division, McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, Canada. sama.alshakfa@gmail.com.
authors.forename: Sama
authors.initials: S
authors.lastname: Alshakfa
authors.affiliation: Meakins-Christie Laboratories and Respiratory Division, McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, Canada. severine.audusseau@mcgill.ca.
authors.forename: Severine
authors.initials: S
authors.lastname: Audusseau
authors.affiliation: Meakins-Christie Laboratories and Respiratory Division, McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, Canada. andrea.mogas@mail.mcgill.ca.
authors.forename: Andrea Karen
authors.initials: AK
authors.lastname: Mogas
authors.affiliation: Meakins-Christie Laboratories and Respiratory Division, McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, Canada. fazila.chouiali@mcgill.ca.
authors.forename: Fazila
authors.initials: F
authors.lastname: Chouiali
authors.affiliation: Firestone Institute for Respiratory Health, St. Joseph's Healthcare and Department of Medicine, McMaster University, Hamilton, Ontario, Canada. parames@mcmaster.ca.
authors.forename: Parameswaran
authors.initials: P
authors.lastname: Nair
authors.affiliation: Meakins-Christie Laboratories and Respiratory Division, McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, Canada. carolyn.baglole@mcgill.ca.
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Baglole
authors.affiliation: Meakins-Christie Laboratories and Respiratory Division, McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, Canada. qutayba.hamid@mcgill.ca.
authors.forename: Qutayba
authors.initials: Q
authors.lastname: Hamid
authors.affiliation: Meakins-Christie Laboratories and Respiratory Division, McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, Canada. david.eidelman@mcgill.ca.
authors.forename: David H
authors.initials: DH
authors.lastname: Eidelman
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D020381:Interleukin-17 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008168:Lung / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D012906:Smoke / Q000009:adverse effects*; D012907:Smoking / Q000009:adverse effects*; D013997:Time Factors; D046509:Tissue Culture Techniques; D015854:Up-Regulation
chemical_list: C508717:IL17A protein, human; C440021:IL17F protein, human; D020381:Interleukin-17; D016328:NF-kappa B; D012333:RNA, Messenger; D012906:Smoke; D058539:Phosphatidylinositol 3-Kinase