Ex vivo innate responses to particulate matter from livestock farms in asthma patients and healthy individuals

Abstract

Background Asthma patients suffer from periodic acute worsening of symptoms (i.e. loss of asthma control or exacerbations), triggered by a variety of exogenous stimuli. With the growing awareness that air pollutants impact respiratory diseases, we investigated whether particulate matter (PM) derived from various livestock farms (BioPM) differentially affected innate and oxidative stress responses in asthma and health. Methods Peripheral blood mononuclear cells (PBMCs), collected from patients sequentially before and during loss of asthma control and from healthy individuals, were exposed to BioPM collected from chicken, goat and pig farms (1 and 5 μg/ml), with or without pre-treatment with antioxidants. Cytokine release and oxidative stress were assessed. Results PBMCs produced IFNγ, IL-1β, IL-10 and TNFα upon stimulation with BioPM, with that from pig farms inducing the highest cytokine levels. Overall, cytokine production was irrespective of the presence or state of disease. However, PBMCs from stable asthma patients upon exposure to the three BioPM showed more extreme TNFα responses than those from healthy subjects. Furthermore, PBMCs obtained during loss of asthma control that were exposed to BioPM from pig farms showed enhanced IFNγ release as well as decreased oxidative stress levels upon pre-treatment with N-acetylcysteine (NAC) compared to stable disease. NAC, but not superoxide dismutase and catalase, also counteracted BioPM-induced cytokine release, indicating the importance of intracellular reactive oxygen species in the production of cytokines. Conclusions BioPM triggered enhanced pro-inflammatory responses by PBMCs from both healthy subjects and asthma patients, with those from patients during loss of asthma control showing increased susceptibility to BioPM from pig farms in particular.

Characteristics of PM2.5 and Its Correlation with Feed, Manure and NH3 in a Pig-Fattening House

“…If the body is exposed to high concentrations of PM 2.5 for a long time, chronic cough, chronic bronchitis, asthma, and other respiratory diseases may occur [ 4 ]. In addition, due to a series of innate immune reactions, the body’s resistance to other diseases and self-healing power are significantly decreased [ 5 , 6 , 7 ]. In addition, removal of PM 2.5 from pig houses with ventilation can pollute the surrounding environment of pig farms and increase the chances of contracting respiratory diseases and health burden of nearby residents, potentially producing asthma and allergic rhinitis in children and adults [ 8 ].…”

Evaluation of the microbiome composition in particulate matter inside and outside of pig houses

“…PM from pig houses comprises feces, feedstuff, hair, bedding particles, and animal skin, where feces and feeds occur as smaller particles than biological structures such as animal skin and hair [ 4 ], and feedstuff accounts for a considerable proportion in PM [ 5 ]. Airborne PM can lead to increased prevalence of respiratory diseases such as asthma [ 6 ] and chronic obstructive pulmonary disease [ 7 ] in humans. Moreover, airborne PM negatively affects respiratory health of pigs [ 8 ], and nursery pigs are more susceptible to respiratory disease than finishing pigs [ 9 ].…”