Regulation of endogenous virus production by bromodeoxyuridine and dibutyryl cyclic AMP in Chinese hamster ovary cells.

Either dibutyryl cyclic AMP or bromodeoxyuridine can enhance RNA type-C virus production in Chinese hamster ovary cells. The resultant effect of simultaneous treatment of cells with 1 mM cyclic AMP and 65 muM bromodeoxyuridine is greater than their additive effects when used separately. The increase in virus production does not seem to involve viral gene amplification, but correlates with an increase in viral RNA transcription. The virus is also shown immunologically to be unique to the Chinese hamster cells and does not appear to be a result of external infection by other common laboratory type-C viruses. The control of this endogenous viral genomic expression may therefore by proposed to be under the normal Chinese hamster gene regulatory mechanism.