The adjuvant-like activity of staphylococcal enterotoxin B in a murine asthma model is independent of IL-1R signaling.
BACKGROUND
Staphylococcal enterotoxin B (SEB) is a superantigen known to be a modulator of chronic airway inflammation in mice and humans, yet little is known about the mechanisms that regulate its interaction with the innate immune system. We investigated this mechanism in a murine model of allergic airway inflammation induced by OVA (ovalbumin) in the presence of SEB.


METHODS
Superantigen-induced allergic inflammation was studied in IL-1R knockout (KO) mice exposed to OVA+SEB. Multicolor flow cytometry was used to analyze the inflammatory cell profile in airways and lymph nodes. Production of IL-4, IL-5, IL-10, and IL-13 in lymph nodes was assessed by Luminex technology.


RESULTS
In wild-type mice, endonasal instillation of OVA+SEB induced a pulmonary inflammation, characterized by an increase in the number of eosinophils, T cells, and dendritic cells and in the production of Th2 cytokines and OVA-specific IgE. In IL-1R KO mice exposed to OVA+SEB, attraction of CD4+ cells and production of Th2 cytokines were reduced. However, knocking out IL-1R did not affect any of the features of allergic airway inflammation, such as bronchial eosinophilia, OVA-specific IgE production and goblet cell metaplasia.


CONCLUSIONS
We provide new insights into the mechanisms of airways allergy development in the presence of bacterial superantigen. The asthma features induced by OVA+SEB, such as bronchial eosinophilia, goblet cell proliferation, production of OVA-specific IgE and increase in inflammatory dendritic cells, are IL-1R independent. Yet, IL-1R signaling is crucial for CD4 cell accumulation and Th2 cytokine production.
Upper Airway Research Laboratory, Department of Oto-Rhino-Laryngology, Ghent University, Ghent, Belgium. Olga.Krysko@UGent.be
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Krysko
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Maes
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Plantinga
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Holtappels
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Imiru
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Vandenabeele
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Joos
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Krysko
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Bachert
D000276:Adjuvants, Immunologic; D000818:Animals; D001249:Asthma / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D002633:Chemotaxis / Q000235:genetics / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D004195:Disease Models, Animal; D004768:Enterotoxins / Q000276:immunology*; D004804:Eosinophils / Q000276:immunology; D020397:Goblet Cells / Q000473:pathology; D006965:Hyperplasia; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000276:immunology; D007249:Inflammation / Q000276:immunology; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D017472:Receptors, Interleukin-1 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D018418:Th2 Cells / Q000276:immunology
D000276:Adjuvants, Immunologic; D016207:Cytokines; D004768:Enterotoxins; D017472:Receptors, Interleukin-1; D007073:Immunoglobulin E; C031818:enterotoxin B, staphylococcal