Effect of elevated carbon dioxide on bronchial epithelial innate immune receptor response to organic dust from swine confinement barns.
Hypercapnia is known to have immunoregulatory effects within the lung. Cell culture systems demonstrate this in both macrophages and alveolar cell lines, suggesting that the alveoli are affected by changes in CO2 levels. We hypothesized that hypercapnia would also modulate human bronchial epithelial cell immune responses. Innate immune responses to Pam3CSK4 (TLR2 ligand), LPS (TLR4 ligand) and a complex innate immune stimulus, an extract from the organic dust of swine confinement barns (barn dust extract or BDE), were tested in a human bronchial epithelial cell line, BEAS-2B. Both TLR ligands showed a decrease in IL-6 and IL-8 production, and an increase in MCP-1 in response to elevated CO2 indicating an enhancement in cytokine production to hypercapnia. This change was not reflected in expression levels of TLR receptor RNA which remained unchanged in response to elevated CO2. Interestingly, barn dust showed an increase in IL-6, IL-8 and MCP-1 response at 9% CO2, suggesting that elevated CO2 exerts different effects on different stimuli. Our results show that airway epithelial cell immune responses to barn dust respond differently to hypercapnic conditions than individual TLR ligands.
Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, 985910 The Nebraska Medical Center, Omaha, NE 68198-5910, United States.
D
D
Schneberger
Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, 985910 The Nebraska Medical Center, Omaha, NE 68198-5910, United States.
D
D
Cloonan
Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, 985910 The Nebraska Medical Center, Omaha, NE 68198-5910, United States.
J M
JM
DeVasure
Research Service, Veterans Administration Nebraska Western Iowa Health Care System, Omaha, NE 68105, United States; Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, 985910 The Nebraska Medical Center, Omaha, NE 68198-5910, United States.
K L
KL
Bailey
Research Service, Veterans Administration Nebraska Western Iowa Health Care System, Omaha, NE 68105, United States; Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, 985910 The Nebraska Medical Center, Omaha, NE 68198-5910, United States.
D J
DJ
Romberger
Research Service, Veterans Administration Nebraska Western Iowa Health Care System, Omaha, NE 68105, United States; Pulmonary, Critical Care, Sleep & Allergy Division, Department of Internal Medicine, University of Nebraska Medical Center, 985910 The Nebraska Medical Center, Omaha, NE 68198-5910, United States; Department of Environmental, Agricultural and Occupational Health, College of Public Health, University of Nebraska Medical Center, 985910 The Nebraska Medical Center, Omaha, NE 68198-5910, United States. Electronic address: twyatt@unmc.edu.
T A
TA
Wyatt
D016902:Air Pollution, Indoor / Q000009:adverse effects; D000818:Animals; D001980:Bronchi / Q000473:pathology*; D002245:Carbon Dioxide / Q000097:blood*; D002460:Cell Line; D018932:Chemokine CCL2 / Q000378:metabolism; D004391:Dust / Q000276:immunology; D006935:Hypercapnia / Q000276:immunology*; D007113:Immunity, Innate; D018836:Inflammation Mediators / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D055666:Lipopeptides / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D013552:Swine; D051195:Toll-Like Receptor 2 / Q000819:agonists; D051197:Toll-Like Receptor 4 / Q000819:agonists
D018932:Chemokine CCL2; D004391:Dust; D018836:Inflammation Mediators; D016209:Interleukin-8; D055666:Lipopeptides; D008070:Lipopolysaccharides; C508075:Pam(3)CSK(4) peptide; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D002245:Carbon Dioxide
Barn dust; Bronchial epithelium; Carbon dioxide; Hypercapnia; LPS; Lung; TLR