IgD-binding factors from mouse T lymphocytes.

Incubation of normal mouse splenic lymphocytes with dimeric mouse IgD results in the formation of T-cell factors that selectively inhibit rosette formation of Fc delta receptor-positive lymphocytes with IgD-coated erythrocytes. The rosette-inhibiting factors bound to IgD-Sepharose and were recovered by elution at acid pH. The results indicate that the rosette-inhibiting factors are IgD-binding factors. Neither IgE-binding factors nor IgG-binding factors inhibited IgD rosettes. The IgD-binding factors induced by IgD consist of two species of molecular weight 78,000 and 37,000, respectively. The source of IgD-binding factors is Lyt-1+ T cells bearing Fc delta receptors. It appears that the binding of IgD to the receptors on the T cells induces the formation of IgD-binding factors.