Granulomatous lesions in the lung induced by inhalation of mold spores

Abstract

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 AspergilIus versicoIor 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)-I, 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.

Characterization and pro‐inflammatory potential of indoor mold particles

“…Spores of A versicolor are frequently present in the indoor air. One month after exposure to spores of A versicolor via aspiration, germ‐free rats had high proliferation rate of cells in lymphoid tissues, increased foamy alveolar macrophages, increased expression of IL‐1 and frequent granulomatous lesions . In another study, mice were exposed via intra‐tracheal instillation to various single doses of A versicolor spores.…”

“…This article is protected by copyright. All rights reserved rate of cells in lymphoid tissues, increased foamy alveolar macrophages, increased expression of IL-1 and frequent granulomatous lesions (226). In another study, mice were exposed via intratracheal instillation to various single doses of A. versicolor spores.…”

“…One month after exposure to spores of A versicolor via aspiration, germ-free rats had high proliferation rate of cells in lymphoid tissues, increased foamy alveolar macrophages, increased expression of IL-1 and frequent granulomatous lesions. 226 In another study, mice were exposed via intra-tracheal instillation to various single doses of A versicolor spores. The highest TNF-α and IL-6 concentrations in lungs were measured at 6 hours after the dose, and they returned to the control level by 3 days.…”

Increased Antifungal Antibodies in Bronchoalveolar Lavage Fluid and Serum in Pulmonary Sarcoidosis

“…The development of granulomas can result from the inability of the immune system to destroy and present antigen and may accompany an immune response to foreign bodies (photocopier dust [7], aluminium [8] or talc [9]). Granulomatous inflammation may also occur in fungal infection [10] and mimic sarcoidosis [11]. Tercelj et al [12] demonstrated increased cytokine production by lymphocytes after glucan exposure in pulmonary sarcoidosis.…”

Acute effects ofAspergillus versicoloraerosols on murine airways

“…In addition to volatile metabolites ( Bjurman and Kristensson, 1992 ; Börjesson et al., 1992, 1993 ; Cailleux et al., 1992 ; Horner et al., 1999 ; Larsen and Frisvad, 1994 ; Pasanen et al., 1997 ; Sunesson et al., 1995 ; Wilkins and Larsen, 1995 ; Wilkins et al., 1997, 1999, 2000 ), A. versicolor can produce different non‐volatile metabolites (not studied in this investigation) of which one is carcinogenic ( Larsen and Frisvad, 1994 ; Nielsen et al., 1998, 1999 ; Samson et al., 1994 ; Tuomi et al., 2000 ). Some experimental data exists on the lung response of rats to the inhalation of A. versicolor spores ( Sumi et al., 1990, 1994 ). A continuous exposure of rat offspring up to 2 years to A. versicolor contamination in the isolator (the exposure concentrations were not reported) caused high incidence of pituitary tumors in these rats, and was concluded to result from the metabolites derived from the mold.…”