AM	alveolar macrophages
BAL	bronchoalveolar lavage
BCA	bicinchoninic acid
COPD	chronic obstructive pulmonary disease
CS	cigarette smoke
IL	interleucin
KC	keratinocyte chemoattractant
MMP	matrix metalloproteinase
MPO	myeloperoxidase
NO	nitric oxide
ROS	reactive oxygen species
TGF-β	transforming growth factor-β
TNF-α	tumor necrosis factor-α