RESUMO
Eight monoclonal antibodies directed against Squamous Cell Carcinoma Antigens (A1 and A2) were collected and evaluated by three working groups. Recombinant antigens, fusion proteins and native antigens from normal tissue were used to evaluate antibody specificity. Five antibodies reacted with both A1 and A2. Two of these antibodies (K123 and K131) showed related binding characteristics, whereas SCC140, K182 and SCC111 demonstrated unique epitope specificity and were not related to the reference antibodies included (F1H3, F2H7 and SCC107). SCC111 reacted particularly well with antigen on Western blot, indicating that the epitope was partly hidden when the antigen was in solution. Two antibodies (SCC103 and SCC109) reacted only with A2 and the fusion protein A1/A2, indicating that they recognized an A2 epitope in exon 8. The A2-specific antibodies are unique in their binding to A2 and are different from the reference antibodies included (SCC104 and K122). SCC103 is probably the best A2-specific antibody available. One antibody, K136, was A1-specific and is related to reference antibody K135. The new antibodies can be used to establish immunometric assays for specific measurement of A1, A2 or both A1 and A2 together.
