Thermal Separation of the Synthesis of Papovavirus SV40 Tumor and Virus Antigens. ∗

Summary

The synthesis of papovavirus SV40 tumor (T) and virus (V) antigens in infected green monkey kidney cell cultures incubated at different temperatures was studied. At 37°C or higher (up to 43°), both T and V antigens were formed reaching peak titers in 2 to 4 days. However, at 23°C, there was hardly any development of V antigen, while the T antigen reached the same peak titer obtained in cultures incubated at 37°. The 23° cultures with peak amounts of T antigen appeared normal, but raising their temperature to 37° was followed by a rapid hundred-fold increase in V antigen and the appearance of cytopathic changes. These findings indicate that the synthesis of tumor antigen is less temperature dependent than is the synthesis of virus antigen. The thermal separation of the synthesis of tumor and virus antigen confirms the finding obtained previously with DNA inhibitors—that is, formation of tumor antigen is not dependent upon the synthesis of virus.