The Influence of IgE-Enhancing and IgE-Suppressive γδ T Cells Changes with Exposure to Inhaled Ovalbumin

Abstract

It has been reported that the IgE response to allergens is influenced by γδ T cells. Intrigued by a study showing that airway challenge of mice with OVA induces in the spleen the development of γδ T cells that suppress the primary IgE response to i.p.-injected OVA-alum, we investigated the γδ T cells involved. We found that the induced IgE suppressors are contained within the Vγ4+ subset of γδ T cells of the spleen, that they express Vδ5 and CD8, and that they depend on IFN-γ for their function. However, we also found that normal nonchallenged mice harbor IgE-enhancing γδ T cells, which are contained within the larger Vγ1+ subset of the spleen. In cell transfer experiments, airway challenge of the donors was required to induce the IgE suppressors among the Vγ4+ cells. Moreover, this challenge simultaneously turned off the IgE enhancers among the Vγ1+ cells. Thus, airway allergen challenge differentially affects two distinct subsets of γδ T cells with nonoverlapping functional potentials, and the outcome is IgE suppression.