Antiprostate carcinoma monoclonal antibody (D83.21) cross reacts with a membrane antigen expressed on cytomegalovirus‐transformed human fibroblasts

Abstract
Virological and epidemiological studies have implicated human cytomegalovirus (HCMV) as a possible etiological agent of prostate cancer. Because of the suspected associations, this laboratory tested the reactivity of a prostate-associated monoclonal antibody with HCMV-transformed cells. This mouse monoclonal antibody, D83.21, reacts with a membrane antigen on prostate and bladder tumor cells and does not bind to a variety of other malignant or normal cells. The results of this study indicated that the prostate-associated antibody bound to a membrane antigen on HCMV-transformed cells as detected by radioimmunoassay, immunofluorescence, and complemented-dependent cytotoxicity. This cross-reactivity appeared to be specific for HCMV-transformed cells and did not react with HCMV-infected cells or those transformed by other viruses. Antibody affinity chromatography, used to isolate the D83.21-reactive protein, revealed two peptides of 60 and 28 kd on both prostate tumor and HCMV-transformed cells. The results suggest that D83.21 reacts with a common cell surface protein expressed on HCMV-transformed cells and urogenital tumors.