scholarly journals Glycoprotein D or J Delivered in transBlocks Apoptosis in SK-N-SH Cells Induced by a Herpes Simplex Virus 1 Mutant Lacking Intact Genes Expressing Both Glycoproteins

2000 ◽  
Vol 74 (24) ◽  
pp. 11782-11791 ◽  
Author(s):  
Guoying Zhou ◽  
Veronica Galvan ◽  
Gabriella Campadelli-Fiume ◽  
Bernard Roizman

ABSTRACT We have made two stocks of a herpes simplex virus 1 mutant lacking intact US5 and US6 open reading frames encoding glycoproteins J (gJ) and D (gD), respectively. The stock designated gD−/+, made in cells carrying US6 and expressing gD, was capable of productively infecting cells, whereas the stock designated gD−/−, made in cells lacking viral DNA sequences, was known to attach but not initiate infection. We report the following. (i) Both stocks of virus induced apoptosis in SK-N-SH cells. Thus, annexin V binding to cell surfaces was detected as early as 8 h after infection. (ii) US5 or US6 cloned into the baculovirus under the human cytomegalovirus immediate-early promoter was expressed in SK-N-SH cells and blocked apoptosis in cells infected with either gD−/+ or gD−/− virus, whereas glycoprotein B, infected cell protein 22, or the wild-type baculovirus did not block apoptosis. (iii) In SK-N-SH cells, internalized, partially degraded virus particles were detected at 30 min after exposure to gD−/− virus but not at later intervals. (iv) Concurrent infection of cells with baculoviruses did not alter the failure of gD−/− virus from expressing its genes or, conversely, the expression of viral genes by gD−/+ virus. These results underscore the capacity of herpes simplex virus to initiate the apoptotic cascade in the absence of de novo protein synthesis and indicate that both gD and gJ independently, and most likely at different stages in the reproductive cycle, play a key role in blocking the apoptotic cascade leading to cell death.

2001 ◽  
Vol 75 (17) ◽  
pp. 7904-7912 ◽  
Author(s):  
Sunil J. Advani ◽  
Ryan Hagglund ◽  
Ralph R. Weichselbaum ◽  
Bernard Roizman

ABSTRACT The herpes simplex virus 1 (HSV-1) infected cell proteins 0 and 4 (ICP0 and ICP4) are multifunctional proteins extensively posttranscriptionally processed by both cellular and viral enzymes. We examined by two-dimensional separations the posttranslational forms of ICP0 and ICP4 in HEp-2 cells and in human embryonic lung (HEL) fibroblasts infected with wild-type virus, mutant R325, lacking the sequences encoding the US1.5 protein and the overlapping carboxyl-terminal domain of ICP22, or R7914, in which the aspartic acid 199 of ICP0 was replaced by alanine. We report the following (i) Both ICP0 and ICP4 were sequentially posttranslationally modified at least until 12 h after infection. In HEL fibroblasts, the processing of ICP0 shifted from A+B forms at 4 h to D+G forms at 8 h and finally to G, E, and F forms at 12 h. The ICP4 progression was from the A′ form noted at 2 h to B′ and C′ forms noted at 4 h to the additional D′ and E′ forms noted at 12 h. The progression tended to be toward more highly charged forms of the proteins. (ii) Although the overall patterns were similar, the mobility of proteins made in HEp-2 cells differed from those made in HEL fibroblasts. (iii) The processing of ICP0 forms E and F was blocked in HEL fibroblasts infected with R325 or with wild-type virus and treated with roscovitine, a specific inhibitor of cell cycle-dependent kinases cdc2, cdk2, and cdk5. R325-infected HEp-2 cells lacked the D′ form of ICP4, and roscovitine blocked the appearance of the most highly charged E′ form of ICP4. (iv) A characteristic of ICP0 is that it is translocated into the cytoplasm of HEL fibroblasts between 5 and 9 h after infection. Addition of MG132 to the cultures late in infection resulted in rapid relocation of cytoplasmic ICP0 back into the nucleus. Exposure of HEL fibroblasts to MG132 late in infection resulted in the disappearance of the highly charged ICP0 G isoform. The G form of ICP0 was also absent in cells infected with R7914 mutant. In cells infected with this mutant, ICP0 is not translocated to the cytoplasm. (v) Last, cdc2 was active in infected cells, and this activity was inhibited by roscovitine. In contrast, the activity of cdk2 exhibited by immunoprecipitated protein was reduced and resistant to roscovitine and may represent a contaminating kinase activity. We conclude from these results that the ICP0 G isoform is the cytoplasmic form, that it may be phosphorylated by cdc2, consistent with evidence published earlier (S. J., Advani, R. R. Weichselbaum, and B. Roizman, Proc. Natl. Acad. Sci. USA 96:10996–11001, 2000), and that the processing is reversed upon relocation of the G isoform from the cytoplasm into the nucleus. The processing of ICP4 is also affected by R325 and roscovitine. The latter result suggests that ICP4 may also be a substrate of cdc2 late in infection. Last, additional modifications are superimposed by cell-type-specific enzymes.


2001 ◽  
Vol 75 (12) ◽  
pp. 5491-5497 ◽  
Author(s):  
Joshua Munger ◽  
Ana V. Chee ◽  
Bernard Roizman

ABSTRACT Earlier studies have shown that the d120 mutant of herpes simplex virus 1, which lacks both copies of the α4 gene, induces caspase-3-dependent apoptosis in HEp-2 cells. Apoptosis was also induced by the α4 rescuant but was blocked by the complementation of rescuant with a DNA fragment encoding the US3 protein kinase (R. Leopardi and B. Roizman, Proc. Natl. Acad. Sci. USA 93:9583–9587, 1996, and R. Leopardi, C. Van Sant, and B. Roizman, Proc. Natl. Acad. Sci. USA 94:7891–7896, 1997). To investigate its role in the apoptotic cascade, the US3 open reading frame was cloned into a baculovirus (Bac-US3) under the control of the human cytomegalovirus immediate-early promoter. We report the following. (i) Bac-US3 blocks processing of procaspase-3 to active caspase. Procaspase-3 levels remained unaltered if superinfected with Bac-US3 at 3 h afterd120 mutant infection, but significant amounts of procaspase-3 remained in cells superinfected with Bac-Us3 at 9 h postinfection with d120 mutant. (ii) The US3 protein kinase blocks the proapoptotic cascade upstream of mitochondrial involvement inasmuch as Bac-US3 blocks release of cytochrome c in cells infected with thed120 mutant. (iii) Concurrent infection of HEp-2 cells with Bac-US3 and the d120 mutant did not alter the pattern of accumulation or processing of ICP0, -22, or -27, and therefore US3 does not appear to block apoptosis by targeting these proteins.


2003 ◽  
Vol 77 (11) ◽  
pp. 6178-6187 ◽  
Author(s):  
Brunella Taddeo ◽  
Audrey Esclatine ◽  
Weiran Zhang ◽  
Bernard Roizman

ABSTRACT The accumulation of cellular transcripts from cells infected with herpes simplex virus 1 (HSV-1) as measured with the aid of Affymetrix microchips has been reported elsewhere. Among these transcripts were genes that respond to stress and that could have a noxious effect on viral replication. We have selected the stress-inducible cellular gene encoding the immediate-early response protein IEX-1 to verify and determine the significance of the accumulation of these transcripts in infected cells. We report that we verified the increase in accumulation of IEX-1 transcripts after infection by Northern analyses and real-time PCR. These transcripts reach peak levels between 3 and 7 h after infection and decrease thereafter. However, IEX-1 protein was detected in cells 1 h after infection but not at later intervals. Studies designed to elucidate the failure of IEX-1 protein to be synthesized revealed the following points. (i) IEX-1 RNA transported to the cytoplasm after 1 h of infection consisted of at least two populations, a partially degraded population and a population consisting of unspliced IEX-1 RNA. Neither of these RNAs could translate the authentic IEX-1 protein. (ii) The partially degraded IEX-1 RNA was not detected in the cytoplasm of cells infected with a mutant virus lacking the UL41 gene encoding the virion host shutoff protein (vhs). Although degradation of RNA mediated by vhs was reported to be 5′ to 3′, the partially degraded IEX-1 RNA lacked the 3′ sequences rather than the 5′ sequences. (iii) The unspliced pre-RNA form containing the IEX-1 intron sequences was detected in the cytoplasm of cell infected with wild-type virus but not in those infected with a mutant lacking the α27 gene encoding the infected cell protein No. 27. (iv) Overexpression of IEX-1 protein by transduction of the gene prior to infection with 1 PFU of HSV-1 per cell had no effect on the accumulation of late genes and virus yield. We conclude that the failure of IEX-1 to express its protein reflects the numerous mechanisms by which the virus thwarts the cells from expressing its genes after infection.


1998 ◽  
Vol 72 (3) ◽  
pp. 1731-1736 ◽  
Author(s):  
Yasushi Kawaguchi ◽  
Charles Van Sant ◽  
Bernard Roizman

ABSTRACT The translation elongation factor 1δ (EF-1δ) consists of two forms, a hypophosphorylated form (apparent M r, 38,000) and a hyperphosphorylated form (apparentM r, 40,000). Earlier Y. Kawaguchi, R. Bruni, and B. Roizman (J. Virol. 71:1019–1024, 1997) reported that whereas mock-infected cells accumulate the hypophosphorylated form, the hyperphosphorylated form of EF-1δ accumulates in cells infected with herpes simplex virus 1. We now report that the accumulation of the hyperphosphorylated EF-1δ is due to phosphorylation by UL13 protein kinase based on the following observations. (i) The relative amounts of hypo- and hyperphosphorylated EF-1δ in Vero cells infected with mutant virus lacking the UL13 gene could not be differentiated from those of mock-infected cells. In contrast, the hyperphosphorylated EF-1δ was the predominant form in Vero cells infected with wild-type viruses, a recombinant virus in which the deleted UL13 sequences were restored, or with a virus lacking the US3 gene, which also encodes a protein kinase. (ii) The absence of the hyperphosphorylated EF-1δ in cells infected with the UL13 deletion mutant was not due to failure of posttranslational modification of infected-cell protein 22 (ICP22)/US1.5 or of interaction with ICP0, inasmuch as preferential accumulation of hyperphosphorylated EF-1δ was observed in cells infected with viruses from which the genes encoding ICP22/US1.5 or ICP0 had been deleted. (iii) Both forms of EF-1δ were labeled by 32Pi in vivo, but the prevalence of the hyperphosphorylated EF-1δ was dependent on the presence of the UL13 protein. (iv) EF-1δ immunoprecipitated from uninfected Vero cells was phosphorylated by UL13 precipitated by the anti-UL13 antibody from lysates of wild-type virus-infected cells, but not by complexes formed by the interaction of the UL13 antibody with lysates of cells infected with a mutant lacking the UL13 gene. This is the first evidence that a viral protein kinase targets a cellular protein. Together with evidence that ICP0 also interacts with EF-1δ reported in the paper cited above, these data indicate that herpes simplex virus 1 has evolved a complex strategy for optimization of infected-cell protein synthesis.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
David Shahnazaryan ◽  
Rana Khalil ◽  
Claire Wynne ◽  
Caroline A. Jefferies ◽  
Joan Ní Gabhann-Dromgoole ◽  
...  

AbstractHerpes simplex keratitis (HSK), caused by herpes simplex virus type 1 (HSV-1) infection, is the commonest cause of infectious blindness in the developed world. Following infection the virus is initially suspended in the tear film, where it encounters a multi-pronged immune response comprising enzymes, complement, immunoglobulins and crucially, a range of anti-viral and pro-inflammatory cytokines. However, given that HSV-1 can overcome innate immune responses to establish lifelong latency throughout a susceptible individual’s lifetime, there is significant interest in understanding the mechanisms employed by HSV-1 to downregulate the anti-viral type I interferon (IFN) mediated immune responses. This study aimed to investigate the interactions between infected cell protein (ICP)0 and key elements of the IFN pathway to identify possible novel targets that contribute to viral immune evasion. Reporter gene assays demonstrated the ability of ICP0 to inhibit type I IFN activity downstream of pathogen recognition receptors (PRRs) which are known to be involved in host antiviral defences. Further experiments identified interferon regulatory factor (IRF)7, a driver of type I IFN, as a potential target for ICP0. These findings increase our understanding of the pathogenesis of HSK and suggest IRF7 as a potential therapeutic target.


2011 ◽  
Vol 7 (10) ◽  
pp. e1002278 ◽  
Author(s):  
Todd Wuest ◽  
Min Zheng ◽  
Stacey Efstathiou ◽  
William P. Halford ◽  
Daniel J. J. Carr

2006 ◽  
Vol 81 (4) ◽  
pp. 1980-1989 ◽  
Author(s):  
Alice P. W. Poon ◽  
Bernard Roizman

ABSTRACT Earlier studies have shown that the herpes simplex virus (HSV) US3 encodes two transcriptional units directing the synthesis of the US3 (residues 1 to 481) and US3.5 (residues 77 to 481) protein kinases. Both kinases phosphorylate histone deacetylase 1 (HDAC1) and HDAC2 and enable the expression of genes cotransduced into U2OS cells by recombinant baculoviruses, an activity designated the “helper function.” The two kinases differ with respect to antiapoptotic activity. In the studies reported here, we made a series of FLAG-tagged amino- and carboxyl-terminal truncations of US3 and these were tested for antiapoptotic activity, phosphorylation of HDAC1, and the helper function. We report the following. (i) HDAC1 phosphorylation and the helper function were expressed in cells transduced by the truncation encoding residues 182 to 481 but not in cells transduced by the truncation encoding residues 189 to 481 or the amino-terminal polypeptides encompassing the first 188 amino acids. (ii) The self-posttranslational modification requires residues 164 to 481. (iii) The antiapoptotic activity requires both the amino-terminal and the carboxyl-terminal domains, of which the truncated protein containing residues 1 to 163 and that containing residues 164 to 481, respectively, were the smallest fragments tested to be effective. The two domains need not be on the same molecule, but they must overlap. The smallest overlapping pair tested was the fragment containing residues 1 to 181 and that containing residues 164 to 481. Consistent with the hypothesis that the effective overlapping truncations form a heteromultimeric structure, antibody to FLAG coprecipitated untagged US3 from lysates of cells cotransduced with FLAG-tagged, truncated US3 constructs. Although US3 has been reported to be a monomeric enzyme, the results indicate that it can form enzymatically active multimeric structures.


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