RT Journal Article
SR Electronic
T1 Biochemical Nature and Mapping of PSMA Epitopes Recognized by Human Antibodies Induced after Immunization with Gene-based Vaccines
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 4727
OP 4732
VO 25
IS 6C
A1 K. TODOROVA
A1 S. ZOUBAK
A1 M. MINCHEFF
A1 S. KYURKCHIEV
YR 2005
UL http://ar.iiarjournals.org/content/25/6C/4727.abstract
AB 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. Copyright© 2005 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved