Les herpèsvirus bovins : biologie et implications

Part of book (1994)

Madin Darby Bovine Kidney Cell Synchronization by Lovastatin: Application to Bovine Herpesvirus-1 Gene Expression

in Veterinary Research (1994), 25(6), 555-67

The number of investigations involving cell proliferation has increased rapidly in the last years. One of the major difficulties in studying cell-cycle-related events is obtaining highly synchronous cell ... [more ▼]

The number of investigations involving cell proliferation has increased rapidly in the last years. One of the major difficulties in studying cell-cycle-related events is obtaining highly synchronous cell populations without metabolic imbalance. This study demonstrates that the Madin Darby bovine kidney (MDBK) cells, a commonly used cell line in veterinary research, can be effectively synchronized using lovastatin (Lov), a drug used to treat hypercholesteremia in humans. This was demonstrated by the following results: (i) Lov inhibits cell proliferation in a dose-dependent manner; (ii) Lov synchronizes MDBK cells mainly in the G1 and secondarily in the G2+M cell-cycle phases; (iii) the cytostatic effect of Lov can be specifically inhibited by addition of mevalonate (Mev) (Lov inhibits the synthesis of Mev); (iv) removal of Lov from G1-arrested cultures, followed by addition of Mev, resulted in the synchronous recovery of DNA synthesis; and (v) 5-bromo2'-deoxyuridine incorporation experiments revealed that MDBK cells synchronization by Lov can be followed for at least 3 cycles after removal of Lov and addition of Mev. Furthermore, as an application of investigations based on the availability of synchronized MDBK, we showed that bovine herpesvirus-1 gene expression is independent on the cell cycle. [less ▲]

Attachment of the Gammaherpesvirus Bovine Herpesvirus 4 Is Mediated by the Interaction of Gp8 Glycoprotein with Heparinlike Moieties on the Cell Surface

in Virology (1993), 196(1), 232-40

Cell surface heparan sulfate serves as the initial receptor for several alphaherpesviruses and at least one betaherpesvirus. This study shows that during the process of adsorption of the gammaherpesvirus ... [more ▼]

Cell surface heparan sulfate serves as the initial receptor for several alphaherpesviruses and at least one betaherpesvirus. This study shows that during the process of adsorption of the gammaherpesvirus bovine herpesvirus 4 (BHV-4), the viral glycoprotein gp8 interacts with heparinlike moieties of cell surface. This conclusion is based on the following findings. (i) Soluble heparin was capable of blocking BHV-4 infection of Georgia bovine kidney cells by inhibition of viral attachment. (ii) Nevertheless, after virus adsorption to Georgia bovine kidney cells, heparin was partially capable of removing adsorbed virus. (iii) Enzymatic digestion of cell surface heparan sulfate but not of chondroitin sulfates A, B, and C reduced the binding of the virus to the cells, and rendered the cells partially resistant to infection. (iv) Radiolabeled purified BHV-4 bound to wild-type Chinese hamster ovary cells, whereas binding of the virus to mutant Chinese hamster ovary cell lines that where deficient in either all glycosaminoglycans or only heparan sulfate was significantly impaired. (v) Using heparin-affinity chromatography, gp8 glycoprotein was shown to bind specifically to immobilized heparin and to elute in the presence of soluble heparin. These data together showed that the gammaherpesvirus BHV-4, like alphaherpesviruses and one betaherpesvirus, adsorbs to cells by binding to cell surface heparin-like moieties. Therefore, this study extends the group of herpesviruses interacting with heparinlike moieties at the cell surface to a member of the gammaherpesvirinae subfamily. [less ▲]

Molecular Biology of Bovine Herpesvirus Type 4

in Veterinary Microbiology (1992), 33(1-4), 79-92

Bovine herpesvirus type 4 (BHV-4) is a ubiquitous virus of cattle. Its genome is a 144 +/- 6 kb double-stranded DNA consisting of a unique central part (L-DNA) flanked at both ends by tandem repeats ... [more ▼]

Bovine herpesvirus type 4 (BHV-4) is a ubiquitous virus of cattle. Its genome is a 144 +/- 6 kb double-stranded DNA consisting of a unique central part (L-DNA) flanked at both ends by tandem repeats called polyrepetitive DNA (prDNA or H-DNA). The overall arrangement of genes has been obtained by the analysis of homologies between short BHV-4 DNA sequences and corresponding genes of Epstein-Barr virus (EBV) and herpesvirus saimiri (HVS). The gene expression is temporally regulated. Glycoprotein precursor p (gp10/gp17) is expressed as gamma 1 polypeptide. Glycoproteins gp1, gp8, gp11 and their precursors are gamma 2 proteins. The analysis of strain variations allows the definition of two types of strains, based on the DNA patterns: the Movar 33/63-like and the DN 599-like strains. Only the M40 strain, isolated in India, fails to fit this classification. The genomic variations have been compiled to build a dendrogram showing three levels of divergence between BHV-4 strains or isolates. The available molecular data indicate that the BHV-4 genome shares much similarity with the DNA of EBV and HVS, two representative members of the gammaherpesvirinae. BHV-4 may therefore be classified in the subfamily gammaherpesvirinae. [less ▲]