TD-12 workshop report: characterization of monoclonal antibodies to neuron-specific enolase

Twelve antibodies to neuron-specific enolase (NSE) have been evaluated by four working groups. Human brain γγ-enolase, neuroblastoma-derived αγ-enolase, and recombinant γγ-enolase were used to determine antibody specificity and binding kinetics. All antibodies were found to be specific for the γ-isoform. It was possible to assign 11 of the antibodies to at least five epitope groups based on cross-inhibition experiments, QCM and SPR technology, and immunoassay combinations. Antibodies 9601 and 9602 showed the highest affinity for both native and recombinant γγ-enolase. Immunometric assays for both γγ- and αγ-enolase could be made by pairing 9601 with most of the other ISOBM antibodies. Antibodies differed in their ability to recognize native αγ-enolase, native γγ-enolase, and recombinant γγ-enolase. Some immunometric assay combinations appear to favor the detection of heterodimeric αγ-enolase over the homodimeric γγ-enolase. Although the majority of the antibodies failed to detect human NSE or recombinant NSE in Western blots, mAb 9601 recognized both, while E17 and 18E5 were specific for human NSE.