SUMMARY
Background: Typical murine models of allergic inflammation are
induced by the combination of ovalbumin and aluminum hydroxide. However,
accumulating evidence indicates that, in models of asthma and atopic
dermatitis, allergic inflammation can be generated in the absence of
aluminum hydroxide. Moreover, co-administration of S. aureusenterotoxin B with ovalbumin can enhance inflammation.
Objective: The objective of this study was to establish a rapid
and mast cell-dependent murine model of allergic inflammation by
inducing allergic peritonitis using ovalbumin and S. aureusenterotoxin B.
Methods: Allergic peritonitis was induced in C57BL/6 mice by
subcutaneous sensitization and intraperitoneal challenge with ovalbumin
and S. aureus enterotoxin B. Disease characteristics were
assessed by flow cytometry, ELISA, Trypan Blue exclusion and
colorimetric assays.
Results: Time course of the allergic peritonitis revealed a
peak of peritoneal inflammation 48h after challenge, as assessed by
total cells and eosinophil counts. Decrease of cell numbers started 96h
post challenge with complete clearance within 168h. Moreover,
significantly higher levels of tryptase and increased vascular
permeability were found 30 min following challenge. Allergic
inflammation induction by ovalbumin and S. aureus enterotoxin B
was impaired in mast cells deficient mice and partially restored by mice
reconstitution with bone marrow derived mast cells, indicating the mast
cell role in this model.
Conclusion: We present a novel model of allergic peritonitis
that is mast cell-dependent, simple and robust. Moreover, the use ofS. aureus enterotoxin B better resembles human allergic
inflammation, which is known to be characterized by the colonization ofStaphylococcus aureus .