Inhalation of organic dusts in agricultural environments causes airway inflammatory diseases. Despite advances in understanding the airway response to dust-induced inflammation, less is known about the transition from lung injury to repair and recovery. The objective of this study was to define the post-inflammation homeostasis events following organic dust-induced lung injury. Using an established protocol, mice were intranasally treated with swine confinement facility organic dust extract (ODE) daily for 3 weeks (repetitive exposure) or treated daily with ODE for 3 weeks followed by no treatment for 1–4 weeks (recovery period) whereupon lavage fluid, lung tissue, and sera were processed. During recovery period, a significant decrease was observed in ODE-induced neutrophil levels after 1 week, lymphocytes at 2 weeks, and macrophages at 4 weeks in the lavage fluid. ODE-induced lung cellular aggregates and bronchiolar compartment inflammation were diminished, but persisted for 4 weeks post-injury. Alveolar inflammation resolved at 3 weeks. ODE-induced lung neutrophils were cleared by 3 weeks, B-cells by 2 weeks, and CD3+CD4+ and CD3+CD8+ T cells by 4 week recovery period. Amphiregulin levels increased post-ODE exposure to the 4 week recovery period. Ex vivo amphiregulin production was demonstrated in lung type 2 innate lymphoid cells and macrophages isolated from the 4 week recovery (post-ODE exposure) animals. Collectively, these results identify important processes during recovery period following agricultural dust-induced inflammation, and present possible strategies for improving lung repair and resolution.
- Innate lymphoid cells
- Swine barn
ASJC Scopus subject areas
- Safety, Risk, Reliability and Quality
- Public Health, Environmental and Occupational Health
- Safety Research