Long-term persistence of cytomegalovirus genome in cultured human cells of prostatic origin

Cells from prostatic tissue obtained from a 3-year-old male donor exhibited scattered foci of cytopathology on primary culture. A virus was isolated and shown by serological analysis to be cytomegalovirus (CMV). After a number of cell culture passages, a cell line (disignated CMV-Mj-P) was obtained in which foci of infection could no longer be demonstrated, nor could virus be rescued. On continued passage the doubling time of the cells decreased markedly, and the fibroblastoid cells ceased to demonstrate contact inhibition. CMV-specific antigen(s) was detected on the surface of the cells by indirect immunofluorescence techniques after exposure of the cultures to iododeoxyuridine. Microcytotoxocity tests established that CMV-Mj-P cells, but not control human prostate cells or human embryonic lung cells, share a membrane antigen with hamster cells transformed by CMV. Nucleic acid hybridization studies revealed that virus genetic information was carried by the human prostate cells and that the cells contained an average of about 10 to 15 genome equivalents of CMV DNA. Karyotypic analysis confirmed that the CMV-Mj-P cells were of human male origin. These results indicate that the cells either have been transformed by CMV or are chronically infected with CMV and releasing virus at levels below detection.