Mouse lung immune response after acute exposure to flour dust

To approach the physiopathology of the mucosal immune response in flour-mill and bakery workers, the authors developed a mouse model, which allowed them to study immune responses induced in the deep lung by acute inhalation of flour dust. In situ quantification of T lymphocytes (Thy1-2) and T-cell subsets (CD4 and CD8), macrophages, B lymphocytes, and immunoglobulin A plasma cells in the lungs of all animals revealed significant modifications of these cell compartments as early as 3 d after exposure; within 10 d of exposure, levels returned to baseline. The data suggest that the lung could be a sensitive target for inhaled xenobiotics, which might generate rapid immune local modifications that result in the maintenance of homeostasis.