Skip to main content

Interleukin-33 in asthma: insights into pro-inflammatory roles of airway structural cells


Interleukin-33 (IL-33) is a novel cytokine that triggers inflammatory immune responses, but evidence of its role in human asthma, a common allergic airway disease, is lacking. There is also a paucity of information regarding which cells express IL-33, and what conditions promote its expression. We sought to investigate whether IL-33 is expressed in the lung tissue from patients with asthma.


We obtained lung biopsy tissue specimens from asthmatic adults and from healthy control subjects, along with normal primary cells from human airways that were cultured in vitro. We studied expression of IL-33 in lung tissue specimens, and determined whether conditions seen in asthma promote IL-33 expression in vitro. We also assessed whether IL-33 expression is sensitive to glucocorticoid treatment.


Higher expression of IL-33 is detected in lung tissue from asthmatic patients compared to control subjects. IL-33 expression correlates TNF-α e.g. a hallmark of inflammation. Airway epithelium, smooth muscle cells and endothelium are all sources of IL-33. When exposed to inflammatory conditions, in vitro cultured bronchial smooth muscle and epithelial cells increased their IL-33 expression, which surprisingly remained intracellular. Finally, glucocorticoid did not significantly reduce TNF-α-induced IL-33 expression.


Our study first describes IL-33 expression in asthma; it is increased in the lungs from asthmatics, and is enhanced under asthma-like in vitro conditions. IL-33 originates from structural cells of the airways and its expression does not respond to classic anti-inflammatory drug, thus reinforcing its relevance as a potential therapeutic target to treat asthma.

Research funding sources

Severe Asthma Program – Richard & Edith Strauss Canada Foundation. J.T. Costello Memorial Research Fund. Fonds de Recherche en Santé du Québec.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Q Hamid.

Rights and permissions

Open Access This article is published under license to BioMed Central Ltd. This is an Open Access article is distributed under the terms of the Creative Commons Attribution 2.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Reprints and Permissions

About this article

Cite this article

Préfontaine, D., Al-Awan, L., Mogas, A. et al. Interleukin-33 in asthma: insights into pro-inflammatory roles of airway structural cells. All Asth Clin Immun 6 (Suppl 1), P20 (2010).

Download citation

  • Published:

  • DOI:


  • Asthma
  • Glucocorticoid
  • Lung Tissue
  • Airway Epithelium
  • Glucocorticoid Treatment