Production of interleukin 1 by rat pleural leucocytes in culture after intratracheal instillation of crocidolite asbestos

Our plain-English summary of Production of interleukin 1 by rat pleural leucocytes in culture after intratracheal instillation of crocidolite asbestos, by X.Y. Li, D. Lamb, K. Donaldson (British Journal of Industrial Medicine, 1993).

The study

• Authors: X.Y. Li, D. Lamb, K. Donaldson
• Journal: British Journal of Industrial Medicine
• Published: 1993;50(1):90-4
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

This study was undertaken to investigate the production of interleukin 1 (IL-1) by pleural leucocytes in culture and to evaluate the influence of intratracheal instillation of crocidolite asbestos on this production. Normal pleural leucocytes spontaneously released IL-1 in culture and stimulation with lipopolysaccharide (LPS) dramatically increased production. Intratracheal instillation with crocidolite asbestos induced recruitment of pleural leucocytes in the longer term and changed IL-1 production by the leucocytes. Reduced production of IL-1 was found by one day after instillation of asbestos and this was correlated with the dose of asbestos. With increasing time after instillation, however, release of IL-1 by pleural leucocytes gradually recovered to normal until, one month after asbestos injection, the leucocytes produced augmented IL-1 in culture compared with control pleural leucocytes. Our data show that pleural leucocytes possess the potential to produce IL-1 in vitro and this capability is altered by intratracheal instillation of crocidolite asbestos. This may be relevant to development of pleural diseases associated with inhalation of asbestos.

In plain English

This was an animal experiment in rats. The authors studied whether white blood cells washed out of the pleural cavity (the space around the lungs) produced interleukin 1 (IL-1), a signalling protein, and how this changed after crocidolite asbestos was placed directly into the windpipe. PVG rats received 1 mg to 10 mg of UICC crocidolite. Their pleural cells were then grown in culture and IL-1 was measured. Cells from untreated rats released about 167 U/ml of IL-1 on their own, and about 268 U/ml when stimulated with a bacterial toxin (LPS). After 5 mg of crocidolite, the number of pleural cells rose over time and the share of eosinophils increased. IL-1 output fell significantly one day after instillation, and this fall was correlated with the dose. Output then recovered and was significantly higher than in control rats by 30 days. The authors noted that small amounts of endotoxin in the culture media may have contributed to background IL-1 release. They concluded that these complex changes are not understood but may be related to pleural disease seen after asbestos exposure.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: animal experiment (rats given asbestos into the windpipe, with pleural cells then studied in culture)
• Who was studied: Syngeneic PVG rats more than 12 weeks old, from the Institute of Occupational Medicine animal unit (Edinburgh). Groups were 5-7 rats per time point or dose, and 14 normal rats were used to describe normal pleural cells.
• Exposure: A single intratracheal instillation of UICC crocidolite asbestos (1 mg, 5 mg or 10 mg in 0.5 ml phosphate buffered saline). Rats were studied 1, 3, 14 and 30 days after the 5 mg dose, and 1 day after each dose.
• Main results:
  • Pleural cells from normal (untreated) rats released IL-1 in culture without stimulation, at about 167 U/ml.
  • When normal pleural cells were stimulated with 100 ng/ml of LPS, IL-1 activity reached about 268 U/ml.
  • After 5 mg crocidolite, total pleural cell numbers increased significantly over time compared with normal rats (mean 6.30 x 10^6 at day 3, 6.92 x 10^6 at day 14 and 6.96 x 10^6 at day 30, versus 4.51 in normal rats).
  • After 5 mg crocidolite, the percentage of macrophages declined (for example 72% at day 14 versus 82% in normal rats), and eosinophils increased significantly (for example 18% at day 14 versus 6% in normal rats).
  • At the 10 mg dose, a small number of neutrophils (2%) appeared in the pleural cells one day after instillation. There were no obvious differences in total cell numbers across doses.
  • In rats given 5 mg crocidolite, IL-1 activity from pleural cells decreased significantly one day after instillation.
  • In rats given 5 mg crocidolite, IL-1 activity recovered towards normal over time and was significantly higher than control values by 30 days after instillation.
  • One day after instillation, the decrease in IL-1 activity was correlated with the dose of crocidolite (1, 5 and 10 mg).
  • No detectable IL-2 was found in the pleural cell culture fluids. This was tested to rule out IL-2 as a factor in the IL-1 assay.
  • Small amounts of endotoxin were found in the culture media: 106 pg/ml in F10 + 2% BSA and 16 pg/ml in PBS.
• The authors' conclusion: The authors concluded that pleural cells showed a dose-dependent fall in IL-1 production soon after asbestos exposure and increased production later. They stated that these complex changes are not understood but may be related to the pleural disease seen after asbestos exposure.
• Limitations the authors state:
  • Low levels of endotoxin contamination in the culture materials may have contributed to the spontaneous IL-1 release by normal cells.
  • The changing IL-1 pattern could not be fully explained by changes in the types of pleural cells present.
  • The authors stated that the complex changes in IL-1 production are not understood.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Crocidolite.

Medical terms in this study, explained in our Lexicon: Crocidolite.

Related studies

• The production of TNF-alpha and IL-1-like activity by bronchoalveolar leucocytes after intratracheal instillation of crocidolite asbestos — X.Y. Li, D. Lamb, et al. (1993)
• Increased production of plasminogen activator inhibitor in vitro by pleural leukocytes from rats intratracheally instilled with crocidolite asbestos — X.Y. Li, G.M. Brown, et al. (1991)
• Intratracheal injection of crocidolite asbestos depresses the secretion of tumor necrosis factor by pleural leukocytes in vitro — X.Y. Li, D. Lamb, et al. (1992)
• Interleukin 1 production and accessory cell function of rat alveolar macrophages exposed to mineral dust particles — Y. Oghiso, Y. Kubota (1987)
• The ability of inflammatory bronchoalveolar leucocyte populations elicited with microbes or mineral dust to injure alveolar epithelial cells and degrade extracellular matrix in vitro — K. Donaldson, J. Slight, et al. (1988)
• Relative release of interleukin-1 beta and interleukin-1 receptor antagonist by alveolar macrophages. A study in asbestos-induced lung disease, sarcoidosis, and idiopathic pulmonary fibrosis — J.N. Kline, D.A. Schwartz, et al. (1993)

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