We have studied the role of IgE in allergic asthma by using a mouse model of airway inflammation. BALB/c mice were primarily immunized with ovalbumin ( OVA ) in alum administered intraperitoneally; these mice were then challenged after 14 days with OVA in phosphate-buffered saline ( PBS ) given intranasally or through aerosol for 30 min, once a day for 3 or 6 days. Control mice received PBS only. Three or 24 hours after last challenge, the lung airways of these mice were lavaged via tracheal cannulation and bronchoalveolar lavage ( BAL ) fluid was collected. We discovered that significantly higher levels of IgE were present in BAL fluid from the antigen-challenged mice as compared to the control mice. Measured amount of IgE in antigen-challenged mice was 25 - 32 ng/ml BAL fluid, of which over 65% was antigen-specific. We, then, investigated the possible role of IgE in the airway inflammatory response. OVA-sensitized mice were challenged with anti-DNP IgE, TNP.OVA or TNP.OVA complexed to anti-DNP IgE. We found that mice challenged with IgE immune complexes developed significantly higher numbers of eosinophils and secreted higher amounts of IL-4 in their airways. These results suggest a hitherto unraveled role of IgE in antigen presentation during allergic airway inflammation. Antigen-specific IgE in airway secretions may contribute to antigen capturing and perpetuation of the allergic inflammatory responses.
|Original language||English (US)|
|State||Published - Mar 20 1998|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology