Biochemical nature and mapping of PSMA epitopes recognized by human antibodies induced after immunization with gene-based vaccines.
Biochemical nature and mapping of PSMA epitopes recognized by human antibodies induced after immunization with gene-based vaccines.
Related Articles Biochemical nature and mapping of PSMA epitopes recognized by human antibodies induced after immunization with gene-based vaccines. Anticancer Res. 2005 Nov-Dec;25(6C):4727-32 Authors: Todorova K, Zoubak S, Mincheff M, Kyurkchiev S BACKGROUND: A possible new target for immunotherapy is the prostate-specific membrane antigen (PSMA). The aim of the present study was to define potential PSMA epitopes for antibody binding using sera from patients immunized with gene-based anti-PSMA vaccines. MATERIALS AND METHODS: Sera from prostate cancer patients, immunized repeatedly with plasmid and adenoviral vectors, each encoding for the extracellular portion of human PSMA, were tested for anti-PSMA antibodies by Western blot. PSMA-producing LNCaP cells were used as a control. Recombinant PSMA protein cleaved with different proteinases was used for epitope mapping. Different enzymes were used to cleave the PSMA molecule. RESULTS: Specific anti-PSMA antibodies were detected in the studied patients' sera, mainly against the PSMA protein core. An alignment of the predicted enzyme-cleavage fragments was compared with Western blot results and several antibody epitopes were determined. CONCLUSION: These data demonstrate that multiple gene-based vaccinations induce an anti-PSMA humoral immune response. The antibodies are predominantly specific for the PSMA protein core. PMID: 16334167 [PubMed - indexed for MEDLINE]