Tolerance Induction via Antigen Inhalation: Isotype Specificity, Stability, and Involvement of Suppressor T Cells

Abstract

Mice were exposed to aerosolized ovalbumin (OA) once weekly for 5 min on 6 occasions, prior to systemic challenge with soluble or alum-adsorbed (AH-OA) antigen. Mice challenged with AH-OA manifested profound IgE isotype-specific tolerance; those challenged with soluble OA initially manifested anamnestic IgE/IgG responses, but secondary intraperitoneal immunization 13 days later with soluble OA revealed IgE isotype-specific tolerance. The tolerized mice contained splenic suppressor T cells which inhibited IgE but not IgG responses in an adoptive transfer assay. Tolerance was still demonstrable in mice 6 months after the cessation of aerosol exposures. Exposure of low IgE responder rat strains to aerosolized OA tolerized for both IgE and IgG responses.

Role of antibody and T cells in the long-term inhibition of IgE synthesis.

“…More recently, Chen (22) reported that the suppressive T cells were CD4-CD8+. It is uncertain whether the specificity of their suppressor cells was directed to isotype (IgE) or to antigen (KLH), since both the donors and recipients were immunized with KLH; it has been reported that antigen-specific suppression can be restricted to the IgE isotype (23)(24)(25)(26)(27). Also, Jardieu et al (28) have isolated T-cell clones that produce soluble factors which inhibit antigen-specific IgE production.…”

The respiratory tract in pigs and its immune system: a review

“…They remove foreign particles including microorganisms from the respiratory tract without producing inflammations or immune responses. Some types of specific immune responses are of a immunosuppressive character (Sedgwick and Holt 1985;Holt and Leivers 1982). This type of specific immune response has not been substantiated yet.…”

The role of alveolar macrophages and dendritic cells in allergic airway sensitization

“…"Natural" exposure of the healthy respiratory mucosal surface to inhalants produces a characteristic pattern of immune responsiveness, which follows initial transient specific low-level IgE antibody production, and finally results in selective suppression of DTH and IgE responses, with the concomitant preservation of variable degrees of allergen-specific IgA, IgG, and T-helper-cell reactivity (22,23). This tolerance is antigen specific and transferrable to naive recipient animals by T cells of the CD8 + suppressor/cytotoxic phenotype (24)(25)(26). T-suppressor cells appear to be initially generated in the draining lymph nodes of the upper respiratory tract (25,27).…”