Interleukin-33 potentiates bleomycin-induced lung injury
Irina G Luzina1, Pavel Kopach, Virginia Lockatell
11 Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Maryland School of Medicine, Baltimore; and.
Summary
Full-length IL-33 (flIL-33) exacerbates lung disease by promoting inflammation and fibrosis, independent of its receptor. It synergistically increases cytokines and heat shock protein 70 (HSP70) in interstitial lung disease models.
Area of Science:
- Pulmonary Medicine
- Immunology
- Molecular Biology
Background:
- Interstitial lung disease (ILD) mechanisms are not fully understood.
- Elevated IL-33 levels are observed in ILD patients and animal models.
- Intracellular IL-33 suggests a role for the full-length (fl) protein.
Purpose of the Study:
- To investigate the role of full-length IL-33 (flIL-33) in lung injury and fibrosis.
- To assess the effects of flIL-33 alone and in combination with bleomycin injury.
- To explore the molecular mechanisms underlying flIL-33's effects on lung tissue.
Main Methods:
- Recombinant adenovirus-mediated gene delivery of flIL-33 in mice.
- Assessment of flIL-33 effects with and without bleomycin-induced lung injury.
- Analysis of cytokine profiles, cellular infiltration, collagen deposition, and heat shock protein (HSP) expression.
Main Results:
- flIL-33 combined with bleomycin synergistically increased pulmonary lymphocyte and collagen accumulation.
- Synergistic cytokine regulation involved TGF-β, IL-6, MCP-1, MIP-1α, and TNF-α, but not Th2 cytokines.
- flIL-33 significantly increased HSP expression, particularly HSP70, in lung tissue.
Conclusions:
- Full-length IL-33 acts as a synergistic proinflammatory and profibrotic regulator in lung injury.
- flIL-33's effects are mediated through non-Th2 cytokines and activation of HSP70.
- These findings highlight flIL-33 as a potential therapeutic target for ILD.
