The identification, isolation and characterization of a 67 kilodalton, PNA-reactive autoantigen commonly expressed in human adenocarcinomas.

In an attempt to characterize a Peanut Agglutinin (PNA) autoantigen widely expressed in common human adenocarcinomas, monoclonal antibodies (MAbs) were made against PNA-affinity purified glycoproteins from pooled breast cancer membrane biopsy materials. Two IgM MAbs, 167H.1 and 167H.4, were found to react strongly with frozen tissue sections of various adenocarcinomas and the antigen was characterized further. By immunoprecipitation, western blotting, and gel filtration, both MAbs were found to react with a 67 kilodalton (kD) antigen. The 67 kD antigen was purified and determined to be specifically PNA reactive and naturally occurring antibodies were demonstrated to the purified antigen. In conclusion, the 167H.1 and 167H.4 MAbs identify a non-mucinous, PNA-reactive autoantigen widely expressed in human adenocarcinomas.