Abstract
Introduction: Exposure to soybean allergens and diesel exhaust particles (DEPs) have been linked to the onset of asthma and asthma exacerbations.
Aim: Study how the combination of soybean allergens and DEPs can affect the induction or exacerbation of asthma in a murine model.
Methods: Female BALB/c mice received intranasal instillations of saline, 3 or 5 mg protein/ml soybean hull extract (SHE), 5 consecutive days (3 weeks). Three days per week the solutions were administered in combination with 150 µg of DEPs. Airway hyperresponsiveness (AHR) was assessed using a methacholine provocation test. Bronchoalveolar lavage (BAL) was used to evaluate pulmonary inflammation and to measure levels of different Th1, Th2, Th17 cytokines.
Results: The 3 mg protein/ml SHE solution did not induce asthma. The co exposure with DEPs resulted in a enhanced AHR (p=0.0019), eosinophilic inflammation (p=0.0079), decreased levels of IFN-γ and IL-31 and increased levels of IL-5, IL-17F and CCL20. The 5 mg protein/ml SHE is capable of enhance significantly the AHR (p=0,0002), eliciting an increase in eosinophils (p=0,0003), decreased levels of IFN-γ and increased levels of IL-4, IL-5, IL-10, IL-13, IL-17A, IL-17F and CCL20. The combination of 5 mg protein/ml SHE with DEP produce an increase in AHR and eosinophilic inflammation but a slightly different cytokine profile with lower levels of Th2 cytokines, a decrease in IL-31 besides higher levels of Th17 related cytokines.
Conclusions: The combination of soybean allergens and DEPs is capable of triggering an asthmatic response even when soybean allergen concentration is too low to promote a response by itself.
Funding: CP12/03101 (Instituto de Salud Carlos III) and FEDER.
- Copyright ©the authors 2016