The ICP22 protein selectively modifies the transcription of different kinetic classes of pseudorabies virus genes (original) (raw)
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Virus genes, 2017
The pseudorabies virus (PRV; also known as Suid herpesvirus-1) is a neurotropic herpesvirus of swine. The us7 and us8 genes of this virus encode the glycoprotein I and E membrane proteins that form a heterodimer that is known to control cell-to-cell spread in tissue culture and in animals. In this study, we investigated the effect of the deletion of the PRV us7 and us8 genes on the genome-wide transcription and DNA replication using a multi-time-point quantitative reverse transcriptase-based real-time PCR technique. Abrogation of the us7/8 gene function was found to exert a drastic but differential effect on the expression of PRV genes during lytic infection. In the mutant virus, all kinetic classes of viral genes were significantly down-regulated at the first 6 h of infection, while having been upregulated later. The level of upregulation was the highest in the immediate-early (IE) and the early (E) genes; lower in the early-late (E/L) genes; and the lowest in the late (L) genes. T...
The effects of viral load on pseudorabies virus gene expression
BMC Microbiology, 2010
Background: Herpesvirus genes are classified into distinct kinetic groups on the basis of their expression dynamics during lytic growth of the virus in cultured cells at a high, typically 10 plaque-forming units/cell multiplicity of infection (MOI). It has been shown that both the host response and the success of a pathogen are dependent on the quantity of particles infecting an organism. This work is a continuation of an earlier study , in which we characterized the overall expression of PRV genes following low-MOI infection. In the present study, we have addressed the question of whether viral gene expressions are dependent on the multiplicity of infection by comparing gene expressions under low and high-MOI conditions. Results: In the present study, using a real-time RT-PCR assay, we address the question of whether the expression properties of the pseudorabies virus (PRV) genes are dependent on the number of virion particles infecting a single cell in a culture. Our analysis revealed a significant dependence of the gene expression on the MOI in most of these genes. Specifically, we found that most of the examined viral genes were expressed at a lower level at a low MOI (0.1) than at a high MOI (10) experiment in the early stage of infection; however, this trend reversed by six hour post-infection in more than half of the genes. Furthermore, in the high-MOI infection, several PRV genes substantially declined within the 4 to 6-h infection period, which was not the case in the low-MOI infection. In the low-MOI infection, the level of antisense transcript (AST), transcribed from the antiparallel DNA strand of the immediate-early 180 (ie180) gene, was comparable to that of ie180 mRNA, while in the high-MOI experiment (despite the 10 times higher copy number of the viral genome in the infected cells) the amount of AST dropped by more than two log values at the early phase of infection. Furthermore, our analysis suggests that adjacent PRV genes are under a common regulation. This is the first report on the effect of the multiplicity of infection on genome-wide gene expression of large DNA viruses, including herpesviruses. Conclusion: Our results show a strong dependence of the global expression of PRV genes on the MOI. Furthermore, our data indicate a strong interrelation between the expressions of ie180 mRNA and AST, which determines the expression properties of the herpesvirus genome and possibly the replication strategy (lytic or latent infection) of the virus in certain cell types.
Gene, 2012
Real-time RT-PCR analysis was applied to evaluate the impact of deletion of the early protein 0 (EP0) gene of pseudorabies virus (PRV) on the global expression of the viral transcripts during lytic infection in cultured porcine kidney cells. Our analysis showed that EP0 exerted an inhibitory effect on the transcription of the PRV genes in the early stage of infection, and alternating stimulatory and inhibitory effects on the viral gene expressions in the late stage of infection. The data also suggested that a general function of EP0 might be to reverse the kinetics of expression of early viral genes. We also observed that EP0 facilitated the development of correlations in the transcription kinetics between the immediate early 180 gene and the PRV transcripts, indicating that a major function of EP0 could be to modify the effects of the IE180 protein on the PRV transcriptome.
Whole-genome analysis of pseudorabies virus gene expression by real-time quantitative RT-PCR assay
BMC Genomics, 2009
Background: Pseudorabies virus (PRV), a neurotropic herpesvirus of pigs, serves as an excellent model system with which to investigate the herpesvirus life cycle both in cultured cells and in vivo. Real-time RT-PCR is a very sensitive, accurate and reproducible technique that can be used to detect very small amounts of RNA molecules, and it can therefore be applied for analysis of the expression of herpesvirus genes from the very early period of infection.
BMC Genomics, 2008
Background: Transcriptomic approaches are relevant for studying virus-host cell dialogues to better understand the physiopathology of infection and the immune response at the cellular level. Pseudorabies virus (PrV), a porcine Alphaherpesvirus, is a good model for such studies in pig. Since PrV displays a strong tropism for mucous epithelial cells, we developed a kinetics study of PrV infection in the porcine PK15 epithelial cell line. To identify as completely as possible, viral and cellular genes regulated during infection, we simultaneously analyzed PrV and cellular transcriptome modifications using two microarrays i.e. a laboratory-made combined SLA/PrV microarray, consisting of probes for all PrV genes and for porcine genes contained in the Swine Leukocyte Antigen (SLA) complex, and the porcine generic Qiagen-NRSP8 oligonucleotide microarray. We confirmed the differential expression of a selected set of genes by qRT-PCR and flow cytometry.
Journal of General Virology, 2004
Recombinant pseudorabies viruses (PRVs) gIS8 and N1aHTK were constructed by the insertion of a chimeric gene (a4-TK ) from herpes simplex virus type 1 (HSV-1) into wild-type PRV. HSV-1 TK expression by these recombinant viruses resulted in enhanced sensitivity to ganciclovir, compared to that of the wild-type PRV, and was similar to the sensitivity shown by HSV-1. Infection with gIS8 or N1aHTK recombinant viruses led to expression of HSV-1 TK mRNA as an immediate-early (IE) gene, observed by downregulation of the HSV-1 a4 promoter. This negative regulation was due to a PRV IE protein, IE180. IE180, however, does not have all the regulatory functions of the infected-cell protein ICP4, as it does not restore the growth of ICP4-deficient HSV-1 mutants.
2000
Recombinant pseudorabies viruses (PRVs) gIS8 and N1aHTK were constructed by the insertion of a chimeric gene (a4-TK ) from herpes simplex virus type 1 (HSV-1) into wild-type PRV. HSV-1 TK expression by these recombinant viruses resulted in enhanced sensitivity to ganciclovir, compared to that of the wild-type PRV, and was similar to the sensitivity shown by HSV-1. Infection with gIS8 or N1aHTK recombinant viruses led to expression of HSV-1 TK mRNA as an immediate-early (IE) gene, observed by downregulation of the HSV-1 a4 promoter. This negative regulation was due to a PRV IE protein, IE180. IE180, however, does not have all the regulatory functions of the infected-cell protein ICP4, as it does not restore the growth of ICP4-deficient HSV-1 mutants.
Archives of virology, 2017
Pseudorabies virus (PRV) is an animal alphaherpesvirus with a wide host range. PRV has 67 protein-coding genes and several non-coding RNA molecules, which can be classified into three temporal groups, immediate early, early and late classes. The ul54 gene of PRV and its homolog icp27 of herpes simplex virus have a multitude of functions, including the regulation of viral DNA synthesis and the control of the gene expression. Therefore, abrogation of PRV ul54 function was expected to exert a significant effect on the global transcriptome and on DNA replication. Real-time PCR and real-time RT-PCR platforms were used to investigate these presumed effects. Our analyses revealed a drastic impact of the ul54 mutation on the genome-wide expression of PRV genes, especially on the transcription of the true late genes. A more than two hour delay was observed in the onset of DNA replication, and the amount of synthesized DNA molecules was significantly decreased in comparison to the wild-type v...