Transfer of immediate hypersensitivity and airway hyperresponsiveness by IgE-positive B cells

The role of allergen-specific sIgE+ B cells in the development of airway hyperresponsiveness to electrical field stimulation was examined in a murine model of allergic sensitization. Ovalbumin (OVA)-specific B cells (OVA+) were isolated from mice that were sensitized to aerosolized OVA. The OVA+ B cell population was shown to be distinct from the remaining, non-OVA-responsive B cells (OVA-). There was a high frequency of sIgE+ B cells and a low frequency of sIgG+ B cells in the OVA+ population compared with the OVA- population, where the ratio was reversed. Although both populations produced immunoglobulin in vitro, only the OVA+ cells secreted anti-OVA antibodies. Transfer of 10(6) OVA+ B cells or as few as 5 x 10(4) OVA+/sIgE+ B cells was able to transfer the capability for anti-OVA IgE synthesis and cutaneous reactivity to OVA in naive recipients. Exposure to OVA via the airways in addition to transfer of OVA+ B cells was necessary for development of airway hyperresponsiveness, whereas recipients challenged with an irrelevant allergen, ragweed, had normal airway function. Transfer of up to 10(7) OVA- B cells failed to induce production of anti-OVA IgE. Despite production of polyclonal IgE, recipients of OVA- B cells did not develop airway hyperresponsiveness after OVA challenge. We conclude that both allergen-specific IgE production and local challenge via the airways with specific allergen are necessary to change airway function in this model.