Regulation of IgE responses to inhaled antigen in mice by antigen-specific gamma delta T cells.

Indirect evidence implicates gamma delta T cells in the cross-regulation of CD4 alpha beta T cell responses. Adoptive transfer of small numbers of gamma delta T cells from ovalbumin (OVA)-tolerant mice selectively suppressed TH2-dependent immunoglobulin E (IgE) antibody production without affecting parallel IgG responses. Challenge of these gamma delta T cells in vitro with specific antigen resulted in production of high levels of interferon gamma. The effects of the gamma delta T cells may be mediated by direct inhibition of OVA-specific CD4+ TH2 cell proliferation or selection for specific CD4 TH2 cells.