Role of Th2 cytokines on the onset of asthma induced by meta‐xylene in mice

Abstract meta ‐Xylene ( m ‐xylene) is one of three isomers of xylene, which is widely used as a solvent and detergent in various industries and medical technology. Exposure to volatile organic compounds, such as m ‐xylene, causes pulmonary inflammation and airway inflammation, thereby contributing to the onset of asthma . Exposure to m ‐xylene increases acute wheezing and intensity of asthma symptom. However, the mechanism of the onset of asthma by m ‐xylene has not been studied yet. C57BL/6 mice were sensitized and challenged by m ‐xylene at 100 or 300 mg/kg. The mice were then sacrificed after the last challenge. Exposure to m ‐xylene increased the total number of inflammatory cells and the production of interleukin (IL)‐4, IL‐5, IL‐13, and immunoglobulin E related to the Th2 immune response. In contrast, the production of interferon‐γ related to the Th1 immune response was decreased. In addition, the airway resistance increased according to the airway hyper‐responsiveness measurements. Finally, a histological analysis revealed infiltration of inflammatory cells, mucus production, and lung fibrosis. These results suggest that m ‐xylene is a potential risk factor for asthma and the onset of asthma is caused by TH2 cytokines.