Isolation and characterization of monoclonal antibodies specific for the extracellular domain of prostate specific membrane antigen.
OBJECTIVE
Monoclonal antibodies specific for protein epitopes of prostate specific membrane antigen (PSMA) expressed on the external surface of prostatic epithelial cells were prepared to provide material for use in the diagnosis or treatment of prostatic cancer.


METHODS
Mice were immunized with LNCaP cell membranes followed by purified PSMA before fusion. Hybridomas were screened by reactivity with purified PSMA. Resulting antibodies were characterized by enzyme-linked immunosorbent assay, Western blot and fluorescence-activated cell sorter analyses.


RESULTS
Monoclonal antibody producing hybridomas designated 3E11, 3C2, 4E10-1.14, 3C9 and 1G3 were obtained which displayed specificities for differing regions of the extracellular domain of the PSMA protein. These antibodies reacted strongly with PSMA from multiple sources and specifically stained unfixed PSMA expressing cells by flow cytometric analysis.


CONCLUSIONS
The antibodies obtained displayed strong reactivity and specificity for extracellular epitopes of PSMA. These antibodies will have value in future diagnostic and therapeutic applications focusing on PSMA as a target antigen.
Murphy
G P
GP
Northwest Hospital, Pacific Northwest Cancer Foundation and Northwest Biotherapeutics, Seattle, Washington, USA.
Greene
T G
TG
Tino
W T
WT
Boynton
A L
AL
Holmes
E H
EH
D000818:Animals; D000911:Antibodies, Monoclonal / Q000302:isolation & purification*; D015153:Blotting, Western; D002268:Carboxypeptidases / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D005110:Extracellular Space; D005260:Female; D043425:Glutamate Carboxypeptidase II; D051379:Mice; D008807:Mice, Inbred BALB C
D000911:Antibodies, Monoclonal; D000939:Epitopes; D002268:Carboxypeptidases; D043425:Glutamate Carboxypeptidase II