Abstract
Purified immunoglobulin from the serum of mice hyperimmunized with syngeneic tumour cells was compared with a monoclonal anti-idiotope antibody, obtained by immunizing mice with antibody to the same tumour. Both the immunoglobulin and the monoclonal antibody were specifically immunogenic in syngeneic (BALB/c) mice as tested by in vitro and in vivo assays of cell-mediated immunity. In both cases the reactivity was absent in immunoglobulin heavy chain gene complex-1 -(Igh) allotype congenic (CB.20) mice, indicating Igh-restriction of immunogenicity. The active material in hyperimmune serum thus has the properties of auto-anti-idiotypic antibody, complementary to T cell idiotopes.