Variations of telomerase activity in cultured mouse fibroblasts upon proliferation of polyomavirus

Telomerase plays a central role in various biological phenomena such as cell differentiation and proliferation, apoptosis, malignant transformation and virus infection, for instance HIV and papillomavirus. In addition, it has recently been shown that, in human fibroblasts transformed by monkey polyomavirus SV40, telomeres became stabilized as a consequence of telomerase activation. However, no information exists on the effects of acute infection by murine polyomavirus on the telomeres maintenance and telomerase activity in the host cell. In this paper we report on a differential activity of telomerase in productively infected cells. The results showed a decreased activity of the enzyme as assessed by the TRAP assay. The decrease had already occurred at a non-lytic time of infection and was observed both after infection and naked DNA transfection. Therefore nuclear decapsidation is not involved in the determination of the phenomenon that is attributed to the proliferation of the virus.