p21(Waf1/Cip1) as a molecular sensor for BoHV-4 replication.
ABSTRACT BoHV-4 replication cycle is dependent on the S-phase of the cell-cycle at the stage of viral DNA synthesis. Because p21 is a rate-limiting regulator of the G1/S-phase transition and up-regulated by DNA-damaging agents, in this study p21 expression in BoHV-4 infected cells was investigated. The p21 promoter was found to be highly activated in a dose- and time-dependent manner following BoHV-4 infection only in cells which are permissive for BoHV-4 replication. Thus p21 expression reports on BoHV-4 replication and could represent a host cell defensive response to infection-associated cellular damage.
- SourceAvailable from: vir.sgmjournals.org[show abstract] [hide abstract]
ABSTRACT: Bovine herpesvirus-4 (BHV-4), a gammaherpesvirus lacking a clear disease association, productively infects multiple cell lines of various species and causes cell death. A human rhabdomyosarcoma cell line, RD-4, infected with BHV-4 produced low levels of early and late viral RNAs and infectious virus, but exhibited no cytopathic effect. Using a recombinant BHV-4 containing a neomycin-resistance gene, we established RD-4-derived cell lines persistently infected with BHV-4. The viral genome in these cells was predominantly circular. Because of drug selection, every cell contained a viral genome. In addition, all cells stained with a BHV-4-specific antiserum. Therefore, these cell lines are not carrier cultures. These cells produced infectious virus at all passages tested. Even though cells were selected and maintained at a concentration of geneticin at least 2.5 times that necessary to kill uninfected RD-4 cells, selected cells contained only approximately one viral genome per diploid host cell genome. Persistently infected cells grew more slowly than uninfected cells, even in the absence of drug. The slower growth of these cells suggests that any growth advantage conferred by multiple copies of the neomycin-gene-carrying viral genome might be offset by the detrimental effects of viral gene expression. This situation contrasts with other gammaherpesviruses, which are able to growth-transform cells.Journal of General Virology 08/2000; 81(Pt 7):1807-14. · 3.13 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: A comparative study was carried out to determine the relative sensitivities of eight different cell culture systems to six different herpesviruses of animals. The cells used were: OFL (ovine fetal lung), ML (mink lung), FK (ferret kidney), PTK-2 (potoroo kidney), TEK (turkey embryo kidney), ED (equine dermal), BT (bovine turbinate), and PK15 (porcine kidney). The viruses tested were: PRV (pseudorabies) of swine, CPHV (caprine herpesvirus), IBRV (infectious bovine rhinotracheitis virus), DN-599 strain of bovine herpesvirus type 4, EHV-1 (equine herpesvirus), and CHV (canine herpesvirus). On the basis of virus titers obtained and the time of appearance of CPE (cytopathic effects), ML cells were found to be the most useful because of their sensitivity to all six viruses tested. BT and OFL cells were also found to be highly sensitive to all viruses with the exception of CHV.Comparative Immunology Microbiology and Infectious Diseases 02/1988; 11(2):93-8. · 1.81 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Deregulation of cell proliferation is a hallmark of neoplastic transformation. Alteration in growth control pathways must translate into changes in the cell-cycle regulatory machinery, but the mechanism by which this occurs is largely unknown. Compared with normal human fibroblasts, cells transformed with a variety of viral oncoproteins show striking changes in the subunit composition of the cyclin-dependent kinases (CDKs). In normal cells, CDKs exist predominantly in multiple quaternary complexes, each containing a CDK, cyclin, proliferating cell nuclear antigen and the p21 protein. However, in many transformed cells, proliferating cell nuclear antigen and p21 are lost from these multiprotein enzymes. Here we have investigated the significance of this phenomenon by molecular cloning of p21 and in vitro reconstitution of the quaternary cell-cycle kinase complexes. We find that p21 inhibits the activity of each member of the cyclin/CDK family. Furthermore, overexpression of p21 inhibits the proliferation of mammalian cells. Our results indicate that p21 may be a universal inhibitor of cyclin kinases.Nature 01/1994; 366(6456):701-4. · 38.60 Impact Factor