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Updated: May 19, 2026
A Simple Fluorescence Assay for Quantification of Canine Neutrophil Extracellular Trap Release
Published on: November 21, 2016
Neutrophil extracellular traps are found at epithelial barriers in canine sinonasal aspergillosis
Pierre Janssen1,2, Constance de Meeûs3, Mutien-Marie Garigliany3
1Laboratory of Immunophysiology, Grappe Interdisciplinaire de Génoprotéomique Appliquée-Recherche (GIGA-R), Liege University, Liege, Belgium.
Introduction:
Sinonasal aspergillosis (SNA) is a frequent cause of chronic nasal discharge, predominantly caused by Aspergillus fumigatus. The infection is typically confined to the nasal cavity and/or frontal sinuses, characterized by superficial mucosal fungal plaques and associated with severe lymphoplasmacytic and neutrophilic inflammation of the mucosa. While Neutrophil Extracellular Traps (NETs) have been demonstrated to restrict fungal hyphal proliferation in animal models, their presence and role in canine SNA remain unexplored.
Methods:
In this study, we quantified the presence of NETs in nasal lavage fluid (NALf) or nasal mucosal biopsies from dogs diagnosed with SNA and healthy controls. To unambiguously detect NETs, we employed three detection techniques. The first method consisted in cell-free DNA detection in NAL. The second method measured myeloperoxidase (MPO)-DNA complexes in NAL by ELISA. The third method aimed to directly identify NETs in nasal biopsies by confocal microscopy and characterize histopathological lesions associated to NETs-enriched areas in corresponding adjacent hematoxylin-eosin tissue sections.
Results:
Interestingly, we were only able to detect NETs in biological samples of dogs with SNA but not in samples from control dogs. Furthermore, NETs-enriched areas were specifically restricted to the surface of the epithelial barrier, where they surrounded fungal spots.
Conclusion:
These results suggest that NETs are involved in the inflammatory response occurring in SNA and likely regulate disease progression. Whether they limit the fungal propagation or contribute to the pathogenesis of the disease remains to be determined, before assessing their role as potential therapeutic target.
Insights
Neutrophil extracellular traps (NETs) were detected in dogs with sinonasal aspergillosis (SNA), but not in healthy dogs. These NETs were found on the nasal surface, surrounding fungal elements, suggesting a role in canine SNA pathogenesis.
Area of Science:
- Veterinary Mycology
- Immunology
- Canine Pathology
Background:
- Sinonasal aspergillosis (SNA) is a common canine nasal condition caused by Aspergillus fumigatus.
- It presents as chronic nasal discharge with mucosal inflammation.
- Neutrophil extracellular traps (NETs) are known to combat fungal infections in animal models, but their role in canine SNA is unknown.
Purpose of the Study:
- To investigate the presence and location of NETs in canine SNA.
- To explore the potential role of NETs in the inflammatory response and disease progression of SNA.
Main Methods:
- NETs were quantified in nasal lavage fluid and biopsies from dogs with SNA and healthy controls.
- Detection methods included cell-free DNA analysis, MPO-DNA complex ELISA, and confocal microscopy of biopsies.
- Histopathological analysis characterized lesions in NETs-enriched areas.
Main Results:
- NETs were exclusively detected in dogs diagnosed with SNA.
- NETs were found on the epithelial surface, surrounding fungal plaques.
- No NETs were observed in samples from healthy control dogs.
Conclusions:
- The findings indicate NETs are present in canine SNA.
- NETs likely play a role in the inflammatory response within the nasal cavity during SNA.
- Further research is needed to determine if NETs limit fungal spread or contribute to disease pathogenesis, and their potential as a therapeutic target.
