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Allergen extracts directly mobilize and activate human eosinophils
Lena Svensson1, Anna Rudin, Christine Wennerås
1Department of Clinical Bacteriology, Göteborg University, Gothenburg, Sweden.
European Journal of Immunology
|May 27, 2004
Summary
Common allergens directly activate human eosinophils, triggering responses like degranulation and increased adhesion molecule expression. This suggests allergens play a direct role in allergic inflammation, beyond indirect signaling.
Area of Science:
- Immunology
- Allergy Research
- Cell Biology
Background:
- Allergic diseases involve eosinophils recruited by chemoattractants.
- The role of direct allergen-eosinophil interaction in allergic responses is not fully understood.
Purpose of the Study:
- To investigate whether common allergens can directly activate human eosinophils.
- To assess the effects of purified allergen extracts on eosinophil functions.
Main Methods:
- Isolated human eosinophils from healthy donors.
- Stimulated eosinophils with purified allergen extracts (house dust mite, cat, birch, grass).
- Assessed eosinophil chemotaxis, respiratory burst, degranulation (MBP, EPO release), and CR3 expression.
Main Results:
- House dust mite (HDM) and birch extracts induced eosinophil chemotaxis.
- HDM extract triggered major basic protein (MBP) release and CR3 up-regulation.
- Cat, birch, and grass allergens increased eosinophil peroxidase (EPO) release.
- Allergens did not induce eosinophilic cationic protein release or free oxygen radical production.
Conclusions:
- Common aeroallergens can directly activate human eosinophils in vitro.
- Direct allergen-eosinophil interaction may contribute to allergic inflammation in vivo.
- Eosinophil activation is not solely mediated by cytokines and chemokines.