Induction or elimination of tumor-specific immunity against a chemically-induced rat tumor using auto-anti-idiotypic immunity

Abstract

DA rat sarcomas P, and P, were induced by dimethylbenz (a) anthracene. A tumor-specific immune response of DA rats against P₁-tumor cells could be demonstrated at the humoral and cellular level. DA anti-P₁ antibodies were purified on fixed Prtumor cells and used as autoimmunogen in DA rats for the production of antiidiotypic antibodies. Such antiidiotypic antibodies could be demonstrated by using a solid-phase radioimmunoassay and by their ability to induce secondary type of DA anti-P₁ responses in vitro. In addition, such antibodies were able to induce cytotoxic T lymphocytes capable of eliminating P₁-tumor cells but not control tumor cells. In some of the auto-immunized DA rats enhanced P₁-tumor growth could be observed, indicating that the anti-idiotypic immune response had led to a selective ablation of idiotypic, potential anti-P₁ reactive T cells.