The protoparvovirus early promoters, e.g. P4 of Minute Virus of Mice (MVM), play a critical role during infection.
View Article and Find Full Text PDFThe P4 promoter of the autonomous parvovirus Minute Virus of Mice (MVM) drives the production of its non-structural proteins, NS1 and NS2. The NS2 isoforms are without enzymatic activity but interact with cellular proteins. While NS2 is crucial to the viral life cycle in cultured murine cells, NS2-null mutant virus productively infects transformed host cells of other species.
View Article and Find Full Text PDFParvoviruses infect and kill tumor cells in vivo and in vitro more efficiently than normal cells. Infection of transformed cells by the parvovirus minute virus of mice (MVM) results in high expression of the major non-structural cytolytic viral protein NS1, which induces a cell death modulated by cellular factors. In this work, we show that MVMp infection and/or NS1 protein expression in permissive transformed rat fibroblast cells leads to apoptosis in wild type and p53(-/-) cells.
View Article and Find Full Text PDFParvovirus minute virus of mice (MVMp) is endowed with oncotropic properties so far ascribed only to the dependency of the virus life cycle on cellular factors expressed during S phase and/or modulated by malignant transformation. For other viruses oncotropism relies on their inability to circumvent type I interferon (IFN)-induced innate antiviral mechanisms, the first line of defense triggered by normal cells against viral infections. These agents propagate, therefore, preferentially in transformed/tumor cells, which often lack functional antiviral mechanisms.
View Article and Find Full Text PDFWell-defined tissue tropism makes Autonomous Parvoviruses a valuable model for studies of virus-cell interactions and gene therapy research. We developed a new Minute Virus of Mice variant, different from the known prototype (MVMp) and immunosuppressive (MVMi) strains. The new virus variant, designated F1, was isolated from the culture of semi-permissive Fisher Rat Fibroblasts, F111, infected with MVMp.
View Article and Find Full Text PDFPrion diseases are fatal neurodegenerative disorders characterized by long incubation periods. To investigate whether concurrent diseases can modify the clinical outcome of prion-affected subjects, we tested the effect of viral infection on the binding and internalization of PrP(Sc), essential steps of prion propagation. To this effect, we added scrapie brain homogenate or purified PrP(Sc) to fibroblasts previously infected with minute virus of mice (MVM), a mouse parvovirus.
View Article and Find Full Text PDFActivation of the minute virus of mice (MVM) P4 promoter is a key step in the life cycle of the virus and is completely dependent on host transcription factors. Since transcription-factor composition varies widely in different cell types, there is the possibility that only some cell types in the host organism have the capacity to initiate expression from the P4 promoter and therefore that the promoter may be a factor in determining the tropism of MVM. In this study, the ability of various cell types to activate P4, independent of the other virus-host interactions, was examined in transgenic mouse lines bearing a beta-galactosidase reporter sequence driven by the P4 promoter.
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