Abstract
Background
Long acting beta2 adrenergic agonist (LABA) is commonly used combination with inhaled corticosteroid (ICS) in asthmatic patients. Previous reports suggested that LABA have anti-inflammatory effect to airway inflammation. However, little is known that mechanisms of anti-inflammatory effect of LABA. The aim of this study was to clarify whether LABA can inhibit allergic airway inflammation in vivo, and mechanisms of LABA effect in vitro.
Methods
Balb/c mice were sensitized and challenged to house dust mite (HDM). The effect of formoterol (FORM) treatment in HDM-induced murine airway inflammation was assessed using these models by inflammatory cells, cytokines, and histological findings. Bone marrow derived dendritic cells (BMDCs) were stimulated with HDM in vitro to evaluate cytokine production.
Results
FORM decreased the number of eosinophils (HDM 2.8 ± 1.6 v.s. HDM+FORM 0.5 ± 0.6 × 104 / ml, p<0.01) and neutrophils (5.4 ± 2.9 v.s. 1.4 ± 1.0 × 104 / ml, p<0.01) in BAL, IL-4 (19.8 ± 2.9 v.s. 9.1 ± 3.3 pg / ml, p<0.01) and IL-17 (143.6 ± 63.1 v.s. 47.4 ± 33.5 pg / ml, p<0.01) in lung tissue, and IL-4, IL-13, IL-17 production in supernatant of lymphocytes culture from bronchial lymphnodes in HDM-induced airway inflammation. We found that FORM inhibited IL-6 (61.9 ± 7.1 v.s. 30.9 ± 6.5 ng / ml, p<0.01) and IL-23 (381.1 ± 36.4 v.s. 195.2 ± 38.6 pg / ml, p<0.01) production in BMDCs after stimulation with HDM in vitro.
Conclusion
These data indicate that LABA inhibit Th2 and Th17 cytokines production and neutrophils and eosinophils in airways. Inhibitory effects of LABA in DCs suggested that DCs might be attenuated HDM-induced airway inflammation.
- © 2014 ERS