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Induction of type C virus‐related functions in normal rat embryo fibroblasts by treatment with 5‐iododeoxyuridine
Author(s) -
Verwoerd Daniel W.,
Sarma Padman S.
Publication year - 1973
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910120303
Subject(s) - embryo , biology , virus , uridine , cell culture , microbiology and biotechnology , virology , idoxuridine , antigen , rna , strain (injury) , enzyme , biochemistry , immunology , genetics , gene , anatomy
Secondary cultures of rat embryo fibroblasts, derived from six different strains of normal laboratory and wild rats, were treated with 5‐iododeoxyuridine in an attempt to establish the presence of endogenous type C viruses in rat cells. All the cell lines tested responded with a transient appearance of RNA‐dependent DNA polymerase (RDP) activity which reached a peak 3 days after the beginning of treatment. However, no viral particles or rat gs‐antigen could be detected at this stage. In the cells derived from two highly inbred strains, a spontaneous second burst of RDP activity was observed after 10–12 days, and on subculturing these cells a 20‐ to 40‐fold increase of enzyme activity could be obtained. During this peak of activity both gs‐antigen and viral particles capable of incorporating labelled uridine were detected. Electron microscopic examination revealed the presence of complete or immature virions in one cell strain. The virus induced was non‐infective for monolayer cultures of 10 different animal species. Attempts to rescue infective virus by complementation with murine leukemia or sarcoma viruses failed. Prolonged cultivation of treated cultures did yield cells with trasformed morphology, but no oncogenicity could be demonstrated for these cells.