Cigarette smoke promotes dendritic cell accumulation in COPD; a Lung Tissue Research Consortium study

Respir Res. 2010 Apr 26;11(1):45. doi: 10.1186/1465-9921-11-45.


Background: Abnormal immune responses are believed to be highly relevant in the pathogenesis of chronic obstructive pulmonary disease (COPD). Dendritic cells provide a critical checkpoint for immunity by their capacity to both induce and suppress immunity. Although evident that cigarette smoke, the primary cause of COPD, significantly influences dendritic cell functions, little is known about the roles of dendritic cells in the pathogenesis of COPD.

Methods: The extent of dendritic cell infiltration in COPD tissue specimens was determined using immunohistochemical localization of CD83+ cells (marker of matured myeloid dendritic cells), and CD1a+ cells (Langerhans cells). The extent of tissue infiltration with Langerhans cells was also determined by the relative expression of the CD207 gene in COPD versus control tissues. To determine mechanisms by which dendritic cells accumulate in COPD, complimentary studies were conducted using monocyte-derived human dendritic cells exposed to cigarette smoke extract (CSE), and dendritic cells extracted from mice chronically exposed to cigarette smoke.

Results: In human COPD lung tissue, we detected a significant increase in the total number of CD83+ cells, and significantly higher amounts of CD207 mRNA when compared with control tissue. Human monocyte-derived dendritic cells exposed to CSE (0.1-2%) exhibited enhanced survival in vitro when compared with control dendritic cells. Murine dendritic cells extracted from mice exposed to cigarette smoke for 4 weeks, also demonstrated enhanced survival compared to dendritic cells extracted from control mice. Acute exposure of human dendritic cells to CSE induced the cellular pro-survival proteins heme-oxygenase-1 (HO-1), and B cell lymphoma leukemia-x(L) (Bcl-xL), predominantly through oxidative stress. Although activated human dendritic cells conditioned with CSE expressed diminished migratory CCR7 expression, their migration towards the CCR7 ligand CCL21 was not impaired.

Conclusions: These data indicate that COPD is associated with increased numbers of cells bearing markers associated with Langerhans cells and mature dendritic cells, and that cigarette smoke promotes survival signals and augments survival of dendritic cells. Although CSE suppressed dendritic cell CCR7 expression, migration towards a CCR7 ligand was not diminished, suggesting that reduced CCR7-dependent migration is unlikely to be an important mechanism for dendritic cell retention in the lungs of smokers with COPD.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Animals
  • Antigens, CD / analysis
  • Antigens, CD / genetics
  • Antigens, CD1 / analysis
  • Case-Control Studies
  • Cell Survival
  • Cells, Cultured
  • Chemokine CCL21 / metabolism
  • Chemotaxis
  • Dendritic Cells / drug effects
  • Dendritic Cells / immunology*
  • Dose-Response Relationship, Drug
  • Female
  • Heme Oxygenase-1 / metabolism
  • Humans
  • Immunoglobulins / analysis
  • Langerhans Cells / immunology
  • Lectins, C-Type / genetics
  • Lung / immunology*
  • Male
  • Mannose-Binding Lectins / genetics
  • Membrane Glycoproteins / analysis
  • Mice
  • Middle Aged
  • Nicotine / pharmacology
  • Nicotinic Agonists / pharmacology
  • Pulmonary Disease, Chronic Obstructive / genetics
  • Pulmonary Disease, Chronic Obstructive / immunology*
  • RNA, Messenger / analysis
  • Receptors, CCR7 / metabolism
  • Smoke / adverse effects
  • Smoking / adverse effects*
  • Smoking / genetics
  • Smoking / immunology
  • Time Factors
  • bcl-X Protein / metabolism


  • Antigens, CD
  • Antigens, CD1
  • BCL2L1 protein, human
  • CCR7 protein, human
  • CD1a antigen
  • CD207 protein, human
  • CD83 antigen
  • Chemokine CCL21
  • Immunoglobulins
  • Lectins, C-Type
  • Mannose-Binding Lectins
  • Membrane Glycoproteins
  • Nicotinic Agonists
  • RNA, Messenger
  • Receptors, CCR7
  • Smoke
  • bcl-X Protein
  • Nicotine
  • HMOX1 protein, human
  • Heme Oxygenase-1