Induction of immunity to a human osteosarcoma-associated antigen in mice using anti-idiotypic antibodies

Abstract

Polyclonal rabbit anti-idiotypic antibodies (Ab 2) were produced and analyzed for their ability to stimulate humoral immunity against a human tumor-associated antigen (TAA) in BALB c mice. Murine monoclonal antibody (Mab) OSA-1 recognizes an 85,000-Da TAA present on both human osteosarcoma tissue and osteosarcoma cell lines. Rabbits were immunized with OSA-1 (Ab 1) to produce Ab 2. The polyclonal Ab 2 were shown to react against an idiotope located at or near the antigen combining site of Ab 1. Ab 2 were demonstrated to be potent inhibitors of TAA binding to Ab 1. BALB c mice were immunized with this Ab 2 preparation and then tested for the presence of osteosarcoma TAA reactive antibodies. Sera from Ab 2-immunized mice were shown by Western blot to contain antibodies whose specificity resembled Ab 1. Thus, immunization with polyclonal rabbit Ab 2 was shown to stimulate production of Ab 3 in mice which reacted against a human osteosarcoma TAA.