A high-throughput proteo-genomics method to identify antibody targets associated with malignant disease.

Identification of antibody targets associated with malignant disease is indispensable to developing passive and active antibody-based therapeutics or diagnostic agents. We have developed a novel technique combining Western blotting, genetic profiling, and mass spectroscopy that allows for the rapid and unambiguous identification of such antigens in a high-throughput manner. Herein, we demonstrate this technique, designated Ab SCAN, by deducing the known target of a monoclonal antibody and by identifying a new antigen that was observed to be the frequent target of humoral immune responses in prostate cancer patients. In both instances, a specific antigen emerged as the sole protein candidate. The newly identified antigen, mannose-6-phosphate/IGF II receptor, may be an important naturally immunogenic antigen involved in prostate cancer. The Ab SCAN technique is uniquely suited to the analysis of longitudinal serum samples from clinical studies and could be a powerful tool to correlate humoral immune responses directed against discreet antigens with clinical events.