Th10 - Effect of Cigarette Smoke on Immune Response to Pollen Allergen in the Lung

Introduction:  Cigarette smoke (CS) is a major risk factor for pulmonary diseases. Alveolar macrophages (AM) are known to play an important role in the lung immune system. Cryptomeria Japonica pollen (CJp) is known as pollen allergen. However, it is not fully understood the relationship of CS and CJp. Therefore, we investigated the effects of CS and CJp on immune cells response in the lung. MATERIALS &

Methods:  Mice were exposed to CS  during 10 days. The next day, mice were inhaled 600μg of CJp. After CJp inhalation, bronchoalveolar lavage (BAL) cells were obtained. Expression of cytokines mRNA were measured by RT-PCR. Chemotactic active ity were measured by EZ-TAXIScan. Surface antigens measured by FACS. Histopathological findings was analyzed by H&E stain. 

Results:  The number of neutrophils was significantly increased in mice treated with CJp. The number of CJp-induced neutrophils was decreased by CS. Although IL-1β and CXCL2 mRNA expressions of AM were increased by CJp, the expressions were decreased by CS. Chemotactic activity of neutrophils for CJp were decreased by CS. Percentage of CD11b in AM was increased by CJp, Increased CD11b positive cells by CJp were decreased by CS. Neutrophils were accumulated and kept in the lung interstitial tissue by CS. 

Conclusions:  CJp induced neutrophil and lung inflammation. CS inhibited neutrophils influx to alveolar space and increased accumulation of neutrophils in the lung interstitial tissue by the suppressions of IL-1β and CXCL2 mRNA expressions in AM. These results suggest that CS may exacerbate immunological allergic response against pollen allergen.