Muramic Acid, Endotoxin, 3-Hydroxy Fatty Acids, and Ergosterol Content Explain Monocyte and Epithelial Cell Inflammatory Responses to Agricultural Dusts
- 23 March 2010
- journal article
- research article
- Published by Taylor & Francis Ltd in Journal of Toxicology and Environmental Health, Part A
- Vol. 73 (10), 684-700
- https://doi.org/10.1080/15287390903578539
Abstract
In agricultural and other environments, inhalation of airborne microorganisms is linked to respiratory disease development. Bacterial endotoxins, peptidoglycans, and fungi are potential causative agents, but relative microbial characterization and inflammatory comparisons amongst agricultural dusts are not well described. The aim of this study was to determine the distribution of microbial endotoxin, 3-hydroxy fatty acids (3-OHFA), muramic acid, and ergosterol and evaluate inflammatory responses in human monocytes and bronchial epithelial cells with various dust samples. Settled surface dust was obtained from five environments: swine facility, dairy barn, grain elevator, domestic home (no pets), and domestic home with dog. Endotoxin concentration was determined by recombinant factor C (rFC). 3-OHFA, muramic acid, and ergosterol were measured using gas chromatography–mass spectrometry. Dust-induced inflammatory cytokine secretion in human monocytes and bronchial epithelial cells was evaluated. Endotoxin-independent dust-induced inflammatory responses were evaluated. Endotoxin and 3-OHFA levels were highest in agricultural dusts. Muramic acid, endotoxin, 3-OHFA, and ergosterol were detected in dusts samples. Muramic acid was highest in animal farming dusts. Ergosterol was most significant in grain elevator dust. Agricultural dusts induced monocyte tumor necrosis factor (TNF) α, interleukin (IL)-6, IL-8, and epithelial cell IL-6 and IL-8 secretion. Monocyte and epithelial IL-6 and IL-8 secretion was not dependent on endotoxin. House dust(s) induced monocyte TNFα, IL-6, and IL-8 secretion. Swine facility dust generally produced elevated responses compared to other dusts. Agricultural dusts are complex with significant microbial component contribution. Large animal farming dust(s)-induced inflammation is not entirely dependent on endotoxin. Addition of muramic acid to endotoxin in large animal farming environment monitoring is warranted.Keywords
This publication has 46 references indexed in Scilit:
- Endotoxin Exposure and Inflammation Markers Among Agricultural Workers in Colorado and NebraskaJournal of Toxicology and Environmental Health, Part A, 2009
- Organic dust exposure alters monocyte-derived dendritic cell differentiation and maturationAmerican Journal of Physiology-Lung Cellular and Molecular Physiology, 2009
- Intranasal organic dust exposure-induced airway adaptation response marked by persistent lung inflammation and pathology in miceAmerican Journal of Physiology-Lung Cellular and Molecular Physiology, 2009
- Repetitive organic dust exposure in vitro impairs macrophage differentiation and functionJournal of Allergy and Clinical Immunology, 2008
- Toll-like receptor 2 is upregulated by hog confinement dust in an IL-6-dependent manner in the airway epitheliumAmerican Journal of Physiology-Lung Cellular and Molecular Physiology, 2008
- Characterization of the Microbial Community in Indoor Environments: a Chemical-Analytical ApproachApplied and Environmental Microbiology, 2003
- Characterization and Variability of Endotoxin and 3-Hydroxy Fatty Acids in an Office Building During a Particle Intervention StudyIndoor Air, 2000
- PATHOBIOLOGY OF LIPOPOLYSACCHARIDEJournal of Toxicology and Environmental Health, 1997
- Respiratory dysfunction in swine production facility workers: Dose‐response relationships of environmental exposures and pulmonary functionAmerican Journal of Industrial Medicine, 1995
- Endotoxin levels in farming: absence of symptoms despite high exposure levels.Occupational and Environmental Medicine, 1989