Characterization of human cells persistently infected with cytomegalovirus and exposed to a chemical carcinogen

✍ Scribed by Jui-Lien H. Li; Thomas Albrecht

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: French
• Weight: 873 KB
• Volume: 29
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910290109

✦ Synopsis

Abstract

A non‐productive, persistent human cytomegalovirus (CMV) infection was developed in human embryo lung (LU) cells by initially using supraoptimal temperatures to restrict the replication of a recent CMV isolate (76‐24). Although CMV replication was observed in some cells within a few weeks of shifting the cultures to 37°C and subculturing, CMV cytopathic effects and infectious CMV were not detected with further subculturing during the next 5 weeks. CMV‐specific nuclear antigens were, however, observed in most cells (designated LU‐76‐24) for 38 additional culture passages made during the following 12 months. Although the LU‐76‐24 cells were morphologically distinct from LU cell cultures carried in parallel as controls, the LU‐76‐24 were contact‐inhibited in spite of a somewhat disoriented growth pattern. Treatment of LU‐76‐24 cells with 0.05 μ/ml of the chemical carcinogen 4‐nitroquinoline I‐oxide (NQO) induced a lytic CMV infection from which a clone of cells (designated LUC‐NQO) was isolated. No effect was seen when LU cells were treated with the same dose of NQO. LUC‐NQO cells were morphologically altered from LU‐76‐24 cells and had lost contact inhibition. Even though CMV‐specific nuclear antigens were observed in LUC‐NQO cells, infectious CMV was not detected in lysates of these cells, nor was CMV rescued by co‐cultivation of these cells with susceptible cells or by induction with 5‐iodo‐2′‐deoxyuridine. LUC‐NQO, but not LU or LU‐76‐24 cells, plated with good efficiency in semi‐solid medium. The results indicate that long‐term, non‐productive, persistent CMV infections can be established in vitro and suggest that such cells may be more susceptible than non‐infected cells to the action of chemical carcinogens.