IL-10 Deficiency as a Factor in Airway Cellular Responses to Inhaled Sulfur Dioxide

Sulfur dioxide (SO2) is a problem air pollutant in areas of widespread industrialization, not only in the United States, but also in countries undergoing rapid industrialization, such as China. Thus, air pollution and its effects on the asthmatic condition have become a major focus in environmental research. Asthmatics are known to have: 1) exaggerated bronchospasmic responses in response to SO2, 2) enhanced airway hyperresponsiveness to reactive oxygen species, and 3) deficient airway IL-10 production. This combination of factors may explain why asthmatics react with greater sensitivity to SO2 than non-asthmatics. A literature review was undertaken to evaluate the evidence in support of this postulate. While there is indirect support for the postulate, there were few studies which directly tested this possibility and none investigating the role of IL-10 in SO2-exacerbated asthma. Thus, this study was designed to test the hypothesis that IL-10 deficiency may potentially predispose toward airway SO2 sensitivity that could manifest itself as increased airway inflammation.