egg-white and Bronchial-Hyperreactivity

The aim of this study was to investigate the role of immunoglobulin E (IgE) in the late phase reaction (LPR) of murine experimental asthma. Our model consisted of an implant of DNP-conjugated, heat-coagulated hen's egg white (DNP-EWI), followed 14 days later by an intratracheal challenge with aggregated DNP-ovalbumin. Airway inflammation was analyzed 48 h after challenge and compared with a similarly immunized group of mice with highly suppressed humoral response due to anti-micro and anti-delta antibody treatment. Total number of cells in the bronchoalveolar lavage (BAL) (with predominance of eosinophils) and EPO activity in the lung homogenate were increased in the DNP-EWI-immunized group compared with immunosuppressed or nonimmunized mice. However, the cellular infiltration and EPO activity observed in the immunosuppressed group were still significantly above those obtained in the nonimmunized group, indicating that inhibition of antibody production did not completely prevent the inflammatory manifestations in BAL and lung. Airway hyperresponsiveness to methacoline was obtained in DNP-EWI-immunized mice, but the respiratory mechanical parameters returned to normal levels in the immunosuppressed group. When these mice were reconstituted with monoclonal anti-DNP antibodies, only IgE, but not IgG1, restored lung inflammation and decreased the conductance of the respiratory system, therefore, increasing hyperresponsiveness. These results indicate that antibodies are not essential for induction of LPR in the lung. However, IgE enhances pulmonary inflammation and hyperresponsiveness.

Topics: Animals; Antibody Formation; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Cell Count; Dinitrophenols; Egg White; Eosinophil Peroxidase; Eosinophils; Immunoglobulin E; Immunoglobulins; Inflammation; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Peroxidases

The effects of denaturation of ovalbumin (OVA) on the induction of oral sensitization in guinea pigs were examined.. Guinea pig antibody and airway responses were assessed after 10 feedings of chemically or heat-denatured OVA or egg white (EW).. Their specific IgG, IgG1 and IgG2 antibody responses were orally sensitized by OVA or EW, but not by chemically or heat-denatured OVA or EW. When further exposed to 0.1% OVA or conalbumin aerosol, those fed OVA or EW, but not denatured OVA or EW, had increased pulmonary resistance and decreased tidal volume. On the other hand, in those fed denatured OVA, boiled EW or saline only, a second sensitization with 1% OVA aerosol generated antibody responses and airway hyperreactivity. Using a sandwich ELISA, guinea pig serum OVA was detected after feeding EW, but not chemically denatured or boiled EW.. It is likely that guinea pig gut absorption of OVA may result in oral sensitization. Chemical or heat denaturation of proteins may minimize their intestinal uptake and thus abrogates the induction of oral sensitization in guinea pigs.

Topics: Administration, Oral; Animals; Antibody Formation; Bronchial Hyperreactivity; Egg White; Guinea Pigs; Hot Temperature; Immune Tolerance; Immunization; Immunoglobulin G; Male; Ovalbumin; Protein Denaturation; Time Factors