We induced typical interstitial nephritis with high titers of anti-tubular basement membrane (TBM) autoantibody in genetically resistant C57BL/6 mice by treating them with sodium aurothiomalate (gold) and immunizing them with syngeneic TBM antigen. When gold was not used, the T-cell fraction of nylon wool adherent splenic cells showed prominent suppressive activity against the proliferative response of nonadherent cells to TBM antigen. However, this suppressive activity was remarkably decreased by the gold treatment. TBM antigen sensitized thymocytes, a thymocyte extract, and a spleen cell extract were transferred to C57BL/6 mice which had been immunized with TBM antigen and treated with gold. This transfer clearly depressed the induction of autoimmune interstitial nephritis in an antigen-specific manner. These results indicate that TBM antigen-specific suppressor T cells and their soluble factor may play an important role in the negative regulation of interstitial nephritis in C57BL/6 mice.