Granulomatous lesions in the lung induced by inhalation of mold spores.
The health hazards associated with grain dust exposure have been recognized as a cause of lung diseases. In the present study, we used germ-free rats exposed to Aspergillus versicolor to elucidate the mechanism for the lung damage induced by grain dust exposure. One month after exposure to the mold, remarkable proliferation of bronchus-associated lymphoid tissues with germinal centres was induced by aspiration of mold spores. After 1 month, alveolar macrophages increased, becoming foamy macrophages by ingestion and digestion of mold spores. They expressed interleukin (IL)-1, Ia antigens and intercellular adhesion molecule-1 intensely and occasionally bound lymphocytes. Numerous lymphocytes infiltrated the granulomatous lesions which consisted of accumulated foamy macrophages and some T lymphocytes which carried IL-2 receptor. Granulomatous lesions were identified in the entire lung, especially around bronchioles. They extended from alveolar ducts to alveolar spaces for 6 months after exposure to the mold. The macrophage appears to be a key effector cell in granulomatous reactions to inhaled molds.
Sumi
Y
Y
Laboratory of Germfree Life, Nagoya University School of Medicine, Japan.
Nagura
H
H
Takeuchi
M
M
Miyakawa
M
M
D000818:Animals; D001228:Aspergillosis / Q000473:pathology*; D001230:Aspergillus; D004781:Environmental Exposure / Q000009:adverse effects*; D006099:Granuloma / Q000382:microbiology / Q000473:pathology*; D007375:Interleukin-1 / Q000378:metabolism; D008172:Lung Diseases, Fungal / Q000382:microbiology / Q000473:pathology*; D016676:Macrophages, Alveolar / Q000378:metabolism / Q000473:pathology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013047:Specific Pathogen-Free Organisms; D013172:Spores, Fungal; D013997:Time Factors
D007375:Interleukin-1