Modification of immediate hypersensitivity responses by staphyloccocal enterotoxin B

Abstract

The staphylococcal enterotoxins have been termed superantigens based on their ability to stimulate polyclonal proliferative responses of murine and human T lymphocytes expressing particular T-cell receptor Vβ gene products. Certain of these toxins have been shown both to activate and to induce anergy in reactive T cells. Staphylococcal enterotoxin B is known to interact with murine T cells bearing Vβ3, −7, −8.1, −8.2, −8.3, and −17. In BALB/c mice Vβ3⁺ and Vβ17⁺ T cells are deleted; Vβ7⁺ T cells are low in frequency. BALB/c mice sensitized to ovalbumin via the skin and airways develop immediate hypersensitivity including IgE/IgGl antiovalbumin antibodies, immediate cutaneous reactivity to ovalbumin and, increased airway responsiveness. In bothin vitro andin vivo studies, the development of these responses has been associated with the Vβ8⁺ subset of T cells and controlled by Vβ2⁺ T cells. In view of the central role of Vβ8⁺ T cells in these responses, we tested the effects of staphylococcal enterotoxin B on the development of immediate hypersensitivity in this system. Intradermal injection of staphylococcal enterotoxin B prevented the development of these responses in the absence of a major deletion of Vβ8⁺ T cells. The data suggest that the administration of staphylococcal enterotoxin B prevented the antigen-induced expansion of Vβ8⁺ T cells resulting in a state of unresponsiveness or anergy, thus preventing the manifestations of immediate hypersensitivity. Bacterial toxins may provide a novel approach to intervention in allergic or autoimmune diseases.