MRL/MP-lpr/lpr mice are homozygous for the lpr mutation that results in the accumulation of phenotypically abnormal cells (CD3+CD4+CD8-) in all lymphoid issues. Although no major abnormalities in the T cell receptor repertoire expressed by such lpr cells have been reported, the lpr mutation is a major disease-accelerating factor. Finally, intravenous administration of irradiated lpr cells recovered from the hyperplastic lymph nodes of adult diseased animals to young MRL/Mp-lpr/lpr mice resulted in a highly significant amelioration of disease parameters. This "T cell vaccination" approach resulted in a selective depletion of cells expressing products of the V(beta)8.2 subfamily among lymph node T cells, in addition to eliciting a surge in peripheral T cells capable of conferring disease protection in adoptive transfer experiments. Thus, a strategy aimed at specifically reducing the frequency of lpr cells proved successful in mitigating the autoimmune process. These findings add to the involvement of lpr cells in the autoimmune process and constitute the first report that T cell vaccination may be beneficial to a spontaneously occurring autoimmune disease.