Benzo(a)pyrene suppresses tracheal antimicrobial peptide gene expression in bovine tracheal epithelial cells

Publication date: Available online 16 August 2018Source: Veterinary Immunology and ImmunopathologyAuthor(s): Laura A. Bourque, Stephen Raverty, Carmon Co, Brandon N. Lillie, Pierre-Yves Daoust, Mary Ellen Clark, Jeff L. CaswellAbstractRespiratory disease is an important cause of morbidity and mortality in cetaceans, which are also threatened by environmental degradation caused by crude oil spills. Following oil spills, cetaceans at the water surface may inhale droplets of oil containing toxic polycyclic aromatic hydrocarbons (PAHs), which could potentially alter respiratory immunity via activation of the aryl hydrocarbon receptor (AHR) and its subsequent interaction with nuclear factor kappa B (NF-κB). β-defensins are antimicrobial peptides secreted by airway epithelial cells and their expression is known to be dependent on NF-κB. We hypothesized that PAHs may suppress the expression of β-defensins, and thereby contribute to the pathogenesis of pneumonia. This hypothesis was modeled by measuring the in vitro effects of benzo(a)pyrene (BAP), phenanthrene, and naphthalene on tracheal antimicrobial peptide (TAP) gene expression in bovine tracheal epithelial cells. Stimulation with lipopolysaccharide (LPS) induced 20 ± 17-fold (mean ± SD) increased TAP gene expression. Exposure of tracheal epithelial cells to 5 μM BAP for 4 or 8 hours, followed by incubation with a combination of LPS and 5 μM BAP for another 16 hours, significantly (P = 0.002) suppress...
Source: Veterinary Immunology and Immunopathology - Category: Veterinary Research Source Type: research