γδ T cells affect IL-4 production and B-cell tolerance

gamma delta T cells can influence specific antibody responses. Here, we report that mice deficient in individual. gamma delta T- cell subsets have altered levels of serum antibodies, including all major subclasses, sometimes regardless of the presence of alpha beta T cells. One strain with a partial.d deficiency that increases IgE antibodies also displayed increases in IL- 4- producing T cells (both residual.d T cells and aa T cells) and in systemic IL- 4 levels. Its B cells expressed IL- 4- regulated inhibitory receptors (CD5, CD22, and CD32) at diminished levels, whereas IL- 4- inducible IL- 4 receptor a and MHCII were increased. They also showed signs of activation and spontaneously formed germinal centers. These mice displayed IgE- dependent features found in hyper- IgE syndrome and developed antichromatin, antinuclear, and anticytoplasmic autoantibodies. In contrast, mice deficient in all.d T cells had nearly unchanged Ig levels and did not develop autoantibodies. Removing IL- 4 abrogated the increases in IgE, antichromatin antibodies, and autoantibodies in the partially gamma deficient mice. . Our data suggest that gamma delta T cells, controlled by their own cross- talk, affect IL- 4 production, B- cell activation, and B- cell tolerance.