In vitro migration of human alveolar macrophages: effects of cigarette smoking

The responsiveness of alveolar macrophages lavaged from healthy volunteers to migration inhibitory factor (MIF) was tested by using the capillary-tube assay method. In every instance, macrophages from nonsmokers responded to MIF as demonstrated by a depression in migration of at least 30%, whereas MIF did not inhibit migration of macrophages from smokers. Cells from smokers migrated at a rate three times faster than cells from nonsmokers. Migration of macrophages from nonsmokers with delayed hypersensitivity skin reactions to Candida albicans antigen was inhibited when antigen was present in the tissue culture medium. Antigen did not inhibit macrophages from subjects who lacked delayed hypersensitivity to the antigen, or from subjects who were cigarette smokers. Since alveolar macrophages can respond to MIF in vitro, they may play a role in cell-mediated immune reactions in the lung. Cigarette smoking may interfere with this participation.