MONOCLONAL ANTIIDIOTYPIC ANTIBODIES AS PROBES FOR COMMON IDIOTOPES SHARED BY ANTI-BENZO(A)PYRENE-LIKE IGA OF CANCER-PATIENTS AND RABBIT ANTI-CONJUGATED BENZO(A)PYRENE ANTIBODIES

Anti-''benzo(a)pyrene [B(a)P]-like'' IgA [referred as idiotypic antibo dies (Ab1)] from cancer patients' sera were found to react with conjug ated B(a)P and a monoclonal anti-anti-conjugated B(A)P, internal image of conjugated B(a)P called AIB1 (referred to as Ab2 beta). These IgA were used to raise mouse monoclonal anti-idiotypic antibodies (Ab2). A monoclonal Ab2 called AIK1 was characterized as the internal image of a ''B(a)P-like'' structure. As shown by competitive experiments, AIK1 inhibited the reaction between Ab1 from a rabbit anti-conjugated B(a) P serum and its relevant internal image, AIB1. Furthermore, AIB1 inhib ited the reaction between AIK1 and anti-''B(a)P-like'' IgA from cancer patients' sera. These observations confirmed the cross-reactivity bet ween idiotypic determinants of human anti-''B(a)P-like'' IgA and rabbi t anti-conjugated B(a)P antibodies (Ab). This result was reinforced by a correlation between the anti-''B(a)P-like'' IgA levels found in can cer patients' sera using indirect ELISA method with conjugated B(a)P, AIB1 and AIK1 coated on well-plates.