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We discovered a new HSV-1 protein, UL24.5, which corresponds to the C-terminal portion of UL24. In contrast to the replication defects observed with HSV-1 strains that do not express full-length UL24, the absence of UL24.5 did not affect viral replication in cell culture. Moreover, in mice, the absence of UL24.5 did not affect viral titers in epithelia or trigeminal ganglia during acute infection; however, it was associated with a prolonged persistence of signs of inflammation. Strikingly, the absence of UL24.5 also led to an increase in the incidence of severe neurological impairment compared to results for wild-type control viruses. This increase in pathogenicity is in stark contrast to the reduction in clinical signs associated with the absence of full-length UL24. Bioinformatic analyses suggest that UL24.5 is conserved among all human alphaherpesviruses and in some nonhuman alphaherpesviruses. Thus, we have identified UL24.5 as a new HSV-1 determinant of pathogenesis.
Slimane Dridi; Nicolas Richerioux; Carmen Elena Gonzalez Suarez; Marion Vanharen; Carolina Sanabria-Solano; Angela Pearson. A Mutation in the UL24 Gene Abolishes Expression of the Newly Identified UL24.5 Protein of Herpes Simplex Virus 1 and Leads to an Increase in Pathogenicity in Mice. Journal of Virology 2018, 92, 1 .
AMA StyleSlimane Dridi, Nicolas Richerioux, Carmen Elena Gonzalez Suarez, Marion Vanharen, Carolina Sanabria-Solano, Angela Pearson. A Mutation in the UL24 Gene Abolishes Expression of the Newly Identified UL24.5 Protein of Herpes Simplex Virus 1 and Leads to an Increase in Pathogenicity in Mice. Journal of Virology. 2018; 92 (20):1.
Chicago/Turabian StyleSlimane Dridi; Nicolas Richerioux; Carmen Elena Gonzalez Suarez; Marion Vanharen; Carolina Sanabria-Solano; Angela Pearson. 2018. "A Mutation in the UL24 Gene Abolishes Expression of the Newly Identified UL24.5 Protein of Herpes Simplex Virus 1 and Leads to an Increase in Pathogenicity in Mice." Journal of Virology 92, no. 20: 1.
Previous studies have shown that HSV-1 infection of lymphocytes induces the tyrosine phosphorylation of several proteins that might correspond to viral or host proteins. VP11/12, a viral tegument protein, is the major HSV-induced tyrosine phosphorylated protein identified thus far. In this report, we demonstrated that the cellular adaptor proteins Dok-2 and Dok-1 are tyrosine phosphorylated upon HSV-1 infection. In addition, HSV-1 induced the selective degradation of Dok-2. Finally, we provide evidence that Dok-2 interacts with VP11/12, and that HSV-induced tyrosine phosphorylation and degradation of Dok-2 require VP11/12. Inactivation of either the Src Family Kinases binding motifs or the SHC binding motif of VP11/12 eliminated the interaction of Dok-2 with VP11/12. Elimination of the binding of Dok-2 to VP11/12 prevented Dok-2 phosphorylation and degradation. We propose that HSV-induced Dok phosphorylation and Dok-2 degradation is an immune evasion mechanism to inactivate T cells that might play an important role in HSV pathogenesis.
Soumia Lahmidi; Ulrike Strunk; James R. Smiley; Angela Pearson; Pascale Duplay. Herpes simplex virus 1 infection of T cells causes VP11/12-dependent phosphorylation and degradation of the cellular protein Dok-2. Virology 2017, 511, 66 -73.
AMA StyleSoumia Lahmidi, Ulrike Strunk, James R. Smiley, Angela Pearson, Pascale Duplay. Herpes simplex virus 1 infection of T cells causes VP11/12-dependent phosphorylation and degradation of the cellular protein Dok-2. Virology. 2017; 511 ():66-73.
Chicago/Turabian StyleSoumia Lahmidi; Ulrike Strunk; James R. Smiley; Angela Pearson; Pascale Duplay. 2017. "Herpes simplex virus 1 infection of T cells causes VP11/12-dependent phosphorylation and degradation of the cellular protein Dok-2." Virology 511, no. : 66-73.
Dok-1 and Dok-2 negatively regulate responses downstream of several immune receptors in lymphoid and myeloid cells. Recent evidence showed that Dok proteins are essential in the formation of memory CD8 + T cells to an exogenous epitope expressed by vaccinia virus; however, the importance of Dok-1 and Dok-2 in the control of viral infection is unknown. Here, we investigated the role of Dok proteins in modulating the immune response against herpes simplex virus 1 (HSV-1) in a mouse model of ocular infection. During acute infection, viral titers in the eye were similar in wild-type (WT) and Dok-1 and Dok-2 double-knockout (DKO) mice, and the percentages of infiltrating leukocytes were similar in DKO and WT corneas and trigeminal ganglia (TG). DKO mice exhibited a diminished CD8 + T cell response to the immunodominant HSV-1 glycoprotein B (gB) epitope in the spleen and draining lymph nodes compared to WT mice during acute infection. Remarkably, gB-specific CD8 + T cells almost completely disappeared in the spleens of DKO mice during latency, and the reduction of CD8 + effector memory T (Tem) cells was more severe than that of CD8 + central memory T (Tcm) cells. The percentage of gB-specific CD8 + T cells in TG during latency was also dramatically reduced in DKO mice; however, they were phenotypically similar to those from WT mice. In ex vivo assays, reactivation was detected earlier in TG cultures from infected DKO versus WT mice. Thus, Dok-1 and Dok-2 promote survival of gB-specific CD8 + T cells in TG latently infected with HSV-1. IMPORTANCE HSV-1 establishes lifelong latency in sensory neurons of trigeminal ganglia (TG). In humans, HSV-1 is able to sporadically reactivate from latently infected neurons and establish a lytic infection at a site to which the neurons project. Most herpetic disease in humans is due to reactivation of HSV-1 from latency rather than to primary acute infection. CD8 + T cells are thought to play an important role in controlling recurrent infections. In this study, we examined the involvement of Dok-1 and Dok-2 signaling proteins in the control of HSV-1 infection. We provide evidence that Dok proteins are required to maintain a CD8 + T cell response against HSV-1 during latency—especially CD8 + Tem cells—and that they negatively affect HSV-1 reactivation from latency. Elucidating Dok-mediated mechanisms involved in the control of HSV-1 reactivation from latency might contribute to the development of therapeutic strategies to prevent recurrent HSV-1-induced pathology.
Soumia Lahmidi; Mitra Yousefi; Slimane Dridi; Pascale Duplay; Angela Pearson. Dok-1 and Dok-2 Are Required To Maintain Herpes Simplex Virus 1-Specific CD8 + T Cells in a Murine Model of Ocular Infection. Journal of Virology 2017, 91, e02297-16 .
AMA StyleSoumia Lahmidi, Mitra Yousefi, Slimane Dridi, Pascale Duplay, Angela Pearson. Dok-1 and Dok-2 Are Required To Maintain Herpes Simplex Virus 1-Specific CD8 + T Cells in a Murine Model of Ocular Infection. Journal of Virology. 2017; 91 (15):e02297-16.
Chicago/Turabian StyleSoumia Lahmidi; Mitra Yousefi; Slimane Dridi; Pascale Duplay; Angela Pearson. 2017. "Dok-1 and Dok-2 Are Required To Maintain Herpes Simplex Virus 1-Specific CD8 + T Cells in a Murine Model of Ocular Infection." Journal of Virology 91, no. 15: e02297-16.
Cyclic GMP-AMP synthase (cGAS) is a newly identified DNA sensor that recognizes foreign DNA, including the genome of herpes simplex virus 1 (HSV-1). Upon binding of viral DNA, cGAS produces cyclic GMP-AMP, which interacts with and activates stimulator of interferon genes (STING) to trigger the transcription of antiviral genes such as type I interferons (IFNs), and the production of inflammatory cytokines. HSV-1 UL24 is widely conserved among members of the herpesviruses family and is essential for efficient viral replication. In this study, we found that ectopically expressed UL24 could inhibit cGAS-STING-mediated promoter activation of IFN-β and interleukin-6 (IL-6), and UL24 also inhibited interferon-stimulatory DNA-mediated IFN-β and IL-6 production during HSV-1 infection. Furthermore, UL24 selectively blocked nuclear factor κB (NF-κB) but not IFN-regulatory factor 3 promoter activation. Coimmunoprecipitation analysis demonstrated that UL24 bound to the endogenous NF-κB subunits p65 and p50 in HSV-1-infected cells, and UL24 was also found to bind the Rel homology domains (RHDs) of these subunits. Furthermore, UL24 reduced the tumor necrosis factor alpha (TNF-α)-mediated nuclear translocation of p65 and p50. Finally, mutational analysis revealed that the region spanning amino acids (aa) 74 to 134 of UL24 [UL24(74–134)] is responsible for inhibiting cGAS-STING-mediated NF-κB promoter activity. For the first time, UL24 was shown to play an important role in immune evasion during HSV-1 infection. IMPORTANCE NF-κB is a critical component of the innate immune response and is strongly induced downstream of most pattern recognition receptors (PRRs), leading to the production of IFN-β as well as a number of inflammatory chemokines and interleukins. To establish persistent infection, viruses have evolved various mechanisms to counteract the host NF-κB pathway. In the present study, for the first time, HSV-1 UL24 was demonstrated to inhibit the activation of NF-κB in the DNA sensing signal pathway via binding to the RHDs of the NF-κB subunits p65 and p50 and abolishing their nuclear translocation.
Haiyan Xu; Chenhe Su; Angela Pearson; Christopher H. Mody; Chunfu Zheng. Herpes Simplex Virus 1 UL24 Abrogates the DNA Sensing Signal Pathway by Inhibiting NF-κB Activation. Journal of Virology 2017, 91, e00025-17 .
AMA StyleHaiyan Xu, Chenhe Su, Angela Pearson, Christopher H. Mody, Chunfu Zheng. Herpes Simplex Virus 1 UL24 Abrogates the DNA Sensing Signal Pathway by Inhibiting NF-κB Activation. Journal of Virology. 2017; 91 (7):e00025-17.
Chicago/Turabian StyleHaiyan Xu; Chenhe Su; Angela Pearson; Christopher H. Mody; Chunfu Zheng. 2017. "Herpes Simplex Virus 1 UL24 Abrogates the DNA Sensing Signal Pathway by Inhibiting NF-κB Activation." Journal of Virology 91, no. 7: e00025-17.
International audienceUL24 is conserved among all Herpesviridae. In herpes simplex virus 1 (HSV-1), UL24 mutations lead to reduced viral titers both in cell culture and in vivo, and reduced pathogenicity. The human cytomegalovirus ortholog of UL24 has a gene regulatory function; however, it is not known whether other UL24 orthologs also affect gene expression. We discovered that in co-transfection experiments, expression of UL24 correlated with a reduction in the expression of several viral proteins and transcripts. Substitution mutations targeting conserved residues in UL24 impaired this function. Reduced transcript levels did not appear attributable to changes in mRNA stability. The UL24 ortholog of Herpes B virus exhibited a similar activity. An HSV-1 mutant that does not express UL24 produced more viral R1 and R2 transcripts than the wild type or rescue virus relative to the amount of viral DNA. These results reveal a new role for HSV-1UL24 in regulating viral mRNA accumulation
Carolina Sanabria-Solano; Carmen Elena Gonzalez; Nicolas Richerioux; Luc Bertrand; Slimane Dridi; Anthony Griffiths; Yves Langelier; Angela Pearson. Regulation of viral gene expression by the herpes simplex virus 1 UL24 protein (HSV-1 UL24 inhibits accumulation of viral transcripts). Virology 2016, 495, 148 -160.
AMA StyleCarolina Sanabria-Solano, Carmen Elena Gonzalez, Nicolas Richerioux, Luc Bertrand, Slimane Dridi, Anthony Griffiths, Yves Langelier, Angela Pearson. Regulation of viral gene expression by the herpes simplex virus 1 UL24 protein (HSV-1 UL24 inhibits accumulation of viral transcripts). Virology. 2016; 495 ():148-160.
Chicago/Turabian StyleCarolina Sanabria-Solano; Carmen Elena Gonzalez; Nicolas Richerioux; Luc Bertrand; Slimane Dridi; Anthony Griffiths; Yves Langelier; Angela Pearson. 2016. "Regulation of viral gene expression by the herpes simplex virus 1 UL24 protein (HSV-1 UL24 inhibits accumulation of viral transcripts)." Virology 495, no. : 148-160.
Herpes simplex virus 1 (HSV-1) infection induces changes to the host cell nucleus including relocalization of the cellular protein Upstream Binding Factor (UBF) from the nucleolus to viral replication compartments (VRCs). Herein, we tested the hypothesis that UBF is recruited to VRCs to promote viral DNA replication. Surprisingly, infection of UBF-depleted HeLa cells with HSV-1 or HSV-2 produced higher viral titers compared to controls. Reduced expression of UBF also led to a progressive increase in the relative amount of HSV-1 DNA versus controls, and increased levels of HSV-1 ICP27 and TK mRNA and protein, regardless of whether viral DNA replication was inhibited or not. Our results suggest that UBF can inhibit gene expression from viral DNA prior to its replication. A similar but smaller effect on viral titers was observed in human foreskin fibroblasts. This is the first report of UBF having a restrictive effect on replication of a virus.
Gabriel Ouellet Lavallée; Angela Pearson. Upstream binding factor inhibits herpes simplex virus replication. Virology 2015, 483, 108 -116.
AMA StyleGabriel Ouellet Lavallée, Angela Pearson. Upstream binding factor inhibits herpes simplex virus replication. Virology. 2015; 483 ():108-116.
Chicago/Turabian StyleGabriel Ouellet Lavallée; Angela Pearson. 2015. "Upstream binding factor inhibits herpes simplex virus replication." Virology 483, no. : 108-116.
Herpes simplex virus 1 initially infects epithelial cells of the mucosa, and then goes on to infect sensory neurons leading ultimately to a latent infection in trigeminal ganglia (TG). UL24 is a core herpesvirus gene that has been identified as a determinant of pathogenesis in several alphaherpesvirinae, though the underlying mechanisms are unknown. In a mouse model of ocular infection, a UL24-deficient virus exhibits a reduction in viral titers in tear films of 1 log10 while titers in TG are often below the level of detection. Moreover, the efficiency of reactivation from latency is also severely reduced. Herein, we investigated how UL24 contributes to acute infection of TG. Our results comparing the impact of UL24 on viral titers in eye tissue versus in tearfilms did not reveal a general defect in virus release from the cornea. We also found that the impairment of replication seen in mouse primary embryonic neurons with a UL24-deficient virus was not more severe than that observed in an epithelial cell line. Rather, in situ histological analyses revealed that infection with a UL24-deficient virus led to a significant reduction in the number of acutely infected neurons at three days post-infection. Moreover, there was a significant reduction in the number of neurons positive for viral DNA at 2 days post-infection for the UL24-deficient virus as compared to that observed for wild-type or a rescue virus. Our results support a model whereby UL24 functions in the dissemination of acute infection from the cornea to neurons in the TG.
Pierre-Alexandre Rochette; Amélie Bourget; Carolina Sanabria-Solano; Soumia Lahmidi; Gabriel Ouellet Lavallée; Angela Pearson. Mutation of UL24 impedes the dissemination of acute herpes simplex virus 1 infection from the cornea to neurons of trigeminal ganglia. Journal of General Virology 2015, 96, 2794 -2805.
AMA StylePierre-Alexandre Rochette, Amélie Bourget, Carolina Sanabria-Solano, Soumia Lahmidi, Gabriel Ouellet Lavallée, Angela Pearson. Mutation of UL24 impedes the dissemination of acute herpes simplex virus 1 infection from the cornea to neurons of trigeminal ganglia. Journal of General Virology. 2015; 96 (9):2794-2805.
Chicago/Turabian StylePierre-Alexandre Rochette; Amélie Bourget; Carolina Sanabria-Solano; Soumia Lahmidi; Gabriel Ouellet Lavallée; Angela Pearson. 2015. "Mutation of UL24 impedes the dissemination of acute herpes simplex virus 1 infection from the cornea to neurons of trigeminal ganglia." Journal of General Virology 96, no. 9: 2794-2805.
Herpes simplex virus 1 (HSV-1) is a neurotropic virus that causes skin lesions and goes on to enter a latent state in neurons of the trigeminal ganglia. Following stress, the virus may reactivate from latency leading to recurrent lesions. The in situ study of neuronal infections by HSV-1 is critical to understanding the mechanisms involved in the biology of this virus and how it causes disease; however, this normally requires fixation and sectioning of the target tissues followed by treatment with contrast agents to visualize key structures, which can lead to artifacts. To further our ability to study HSV-1 neuropathogenesis, we have generated a recombinant virus expressing a second generation red fluorescent protein (mCherry), which behaves like the parental virus in vivo. By optimizing the application of a multimodal non-linear optical microscopy platform, we have successfully visualized in unsectioned trigeminal ganglia of mice both infected cells by two-photon fluorescence microscopy, and myelinated axons of uninfected surrounding cells by coherent anti-Stokes Raman scattering (CARS) microscopy. These results represent the first report of CARS microscopy being combined with 2-photon fluorescence microscopy to visualize virus-infected cells deep within unsectioned explanted tissue, and demonstrate the application of multimodal non-linear optical microscopy for high spatial resolution biological imaging of tissues without the use of stains or fixatives.
Pierre-Alexandre Rochette; Mathieu Laliberté; Antony Bertrand-Grenier; Marie-Andrée Houle; Marie-Claire Blache; François Légaré; Angela Pearson. Visualization of Mouse Neuronal Ganglia Infected by Herpes Simplex Virus 1 (HSV-1) Using Multimodal Non-Linear Optical Microscopy. PLOS ONE 2014, 9, e105103 .
AMA StylePierre-Alexandre Rochette, Mathieu Laliberté, Antony Bertrand-Grenier, Marie-Andrée Houle, Marie-Claire Blache, François Légaré, Angela Pearson. Visualization of Mouse Neuronal Ganglia Infected by Herpes Simplex Virus 1 (HSV-1) Using Multimodal Non-Linear Optical Microscopy. PLOS ONE. 2014; 9 (8):e105103.
Chicago/Turabian StylePierre-Alexandre Rochette; Mathieu Laliberté; Antony Bertrand-Grenier; Marie-Andrée Houle; Marie-Claire Blache; François Légaré; Angela Pearson. 2014. "Visualization of Mouse Neuronal Ganglia Infected by Herpes Simplex Virus 1 (HSV-1) Using Multimodal Non-Linear Optical Microscopy." PLOS ONE 9, no. 8: e105103.
Mutations in UL24 of herpes simplex virus type 1 can lead to a syncytial phenotype. We hypothesized that UL24 affects the sub-cellular distribution of viral glycoproteins involved in fusion. In non-immortalized human foreskin fibroblasts (HFFs) we detected viral glycoproteins B (gB), gD, gH and gL present in extended blotches throughout the cytoplasm with limited nuclear membrane staining; however, in HFFs infected with a UL24-deficient virus (UL24X), staining for the viral glycoproteins appeared as long, thin streaks running across the cell. Interestingly, there was a decrease in co-localized staining of gB and gD with F-actin at late times in UL24X-infected HFFs. Treatment with chemical agents that perturbed the actin cytoskeleton hindered the formation of UL24X-induced syncytia in these cells. These data support a model whereby the UL24 syncytial phenotype results from a mislocalization of viral glycoproteins late in infection.
Nawel Ben Abdeljelil; Pierre-Alexandre Rochette; Angela Pearson. The UL24 protein of herpes simplex virus 1 affects the sub-cellular distribution of viral glycoproteins involved in fusion. Virology 2013, 444, 263 -273.
AMA StyleNawel Ben Abdeljelil, Pierre-Alexandre Rochette, Angela Pearson. The UL24 protein of herpes simplex virus 1 affects the sub-cellular distribution of viral glycoproteins involved in fusion. Virology. 2013; 444 (1-2):263-273.
Chicago/Turabian StyleNawel Ben Abdeljelil; Pierre-Alexandre Rochette; Angela Pearson. 2013. "The UL24 protein of herpes simplex virus 1 affects the sub-cellular distribution of viral glycoproteins involved in fusion." Virology 444, no. 1-2: 263-273.
Herpes simplex encephalitis (HSE) is a lethal neurological disease resulting from infection with Herpes Simplex Virus 1 (HSV-1). Loss-of-function mutations in the UNC93B1, TLR3, TRIF, TRAF3, and TBK1 genes have been associated with a human genetic predisposition to HSE, demonstrating the UNC93B-TLR3-type I IFN pathway as critical in protective immunity to HSV-1. However, the TLR3, UNC93B1, and TRIF mutations exhibit incomplete penetrance and represent only a minority of HSE cases, perhaps reflecting the effects of additional host genetic factors. In order to identify new host genes, proteins and signaling pathways involved in HSV-1 and HSE susceptibility, we have implemented the first genome-wide mutagenesis screen in an in vivo HSV-1 infectious model. One pedigree (named P43) segregated a susceptible trait with a fully penetrant phenotype. Genetic mapping and whole exome sequencing led to the identification of the causative nonsense mutation L3X in the Receptor-type tyrosine-protein phosphatase C gene (PtprcL3X), which encodes for the tyrosine phosphatase CD45. Expression of MCP1, IL-6, MMP3, MMP8, and the ICP4 viral gene were significantly increased in the brain stems of infected PtprcL3X mice accounting for hyper-inflammation and pathological damages caused by viral replication. PtprcL3X mutation drastically affects the early stages of thymocytes development but also the final stage of B cell maturation. Transfer of total splenocytes from heterozygous littermates into PtprcL3X mice resulted in a complete HSV-1 protective effect. Furthermore, T cells were the only cell population to fully restore resistance to HSV-1 in the mutants, an effect that required both the CD4+ and CD8+ T cells and could be attributed to function of CD4+ T helper 1 (Th1) cells in CD8+ T cell recruitment to the site of infection. Altogether, these results revealed the CD45-mediated T cell function as potentially critical for infection and viral spread to the brain, and also for subsequent HSE development. Herpes simplex encephalitis (HSE) is a lethal neurological disease resulting from infection with Herpes Simplex Virus 1 (HSV-1). Previous studies have demonstrated a human genetic predisposition to HSE. However, the gene mutations that have been suggested as critical in protective immunity to HSV-1, exhibit incomplete penetrance and represent only a minority of HSE cases, perhaps reflecting the effects of additional host genetics factors. In order to identify new host genes involved in HSV-1 and HSE susceptibility, we have implemented the first genome-wide mutagenesis screen in an in vivo HSV-1 infectious model. Using this large-scale approach, we have identified a loss-of-function mutation in the Receptor-type tyrosine-protein phosphatase C (Ptprc) gene. Mice carrying this mutation were characterized by defects in thymic and B cell development. Following infection, these mutant mice exhibited hyper-inflammation in their brains stems caused by viral replication. Transfer of total lymphocytes from resistant into mutant mice resulted in a complete HSV-1 protective effect. Furthermore, T lymphocytes were the only cell population to fully restore resistance to HSV-1 in the mutants. These findings revealed the T cell function as potentially critical for infection and viral spread to the brain, as well as to subsequent HSE development.
Grégory Caignard; Gabriel A. Leiva-Torres; Michael Leney-Greene; Benoit Charbonneau; Anne Dumaine; Nassima Fodil-Cornu; Michal Pyzik; Pablo Cingolani; Jeremy Schwartzentruber; Jeremy Dupaul-Chicoine; Huaijian Guo; Maya Saleh; André Veillette; Marc Lathrop; Mathieu Blanchette; Jacek Majewski; Angela Pearson; Silvia M. Vidal. Genome-Wide Mouse Mutagenesis Reveals CD45-Mediated T Cell Function as Critical in Protective Immunity to HSV-1. PLOS Pathogens 2013, 9, e1003637 .
AMA StyleGrégory Caignard, Gabriel A. Leiva-Torres, Michael Leney-Greene, Benoit Charbonneau, Anne Dumaine, Nassima Fodil-Cornu, Michal Pyzik, Pablo Cingolani, Jeremy Schwartzentruber, Jeremy Dupaul-Chicoine, Huaijian Guo, Maya Saleh, André Veillette, Marc Lathrop, Mathieu Blanchette, Jacek Majewski, Angela Pearson, Silvia M. Vidal. Genome-Wide Mouse Mutagenesis Reveals CD45-Mediated T Cell Function as Critical in Protective Immunity to HSV-1. PLOS Pathogens. 2013; 9 (9):e1003637.
Chicago/Turabian StyleGrégory Caignard; Gabriel A. Leiva-Torres; Michael Leney-Greene; Benoit Charbonneau; Anne Dumaine; Nassima Fodil-Cornu; Michal Pyzik; Pablo Cingolani; Jeremy Schwartzentruber; Jeremy Dupaul-Chicoine; Huaijian Guo; Maya Saleh; André Veillette; Marc Lathrop; Mathieu Blanchette; Jacek Majewski; Angela Pearson; Silvia M. Vidal. 2013. "Genome-Wide Mouse Mutagenesis Reveals CD45-Mediated T Cell Function as Critical in Protective Immunity to HSV-1." PLOS Pathogens 9, no. 9: e1003637.
International audienceWe recently provided evidence that the ribonucleotide reductase R1 subunits of herpes simplex virus types 1 and 2 (HSV-1 and -2) protect cells against tumor necrosis factor alpha- and Fas ligand-induced apoptosis by interacting with caspase 8. Double-stranded RNA (dsRNA) is a viral intermediate known to initiate innate antiviral responses. Poly(I * C), a synthetic analogue of viral dsRNA, rapidly triggers caspase 8 activation and apoptosis in HeLa cells. Here, we report that HeLa cells after HSV-1 and HSV-2 infection were quickly protected from apoptosis caused by either extracellular poly(I * C) combined with cycloheximide or transfected poly(I * C). Cells infected with the HSV-1 R1 deletion mutant ICP6Δ were killed by poly(I * C), indicating that HSV-1 R1 plays a key role in antiapoptotic responses to poly(I * C). Individually expressed HSV R1s counteracted caspase 8 activation by poly(I * C). In addition to their binding to caspase 8, HSV R1s also interacted constitutively with receptor-interacting protein 1 (RIP1) when expressed either individually or with other viral proteins during HSV infection. R1(1-834)-green fluorescent protein (GFP), an HSV-2 R1 deletion mutant protein devoid of antiapoptotic activity, did not interact with caspase 8 and RIP1, suggesting that these interactions are required for protection against poly(I * C). HSV-2 R1 inhibited the interaction between the Toll/interleukin-1 receptor domain-containing adaptor-inducing beta interferon (IFN-β) (TRIF) and RIP1, an interaction that is essential for apoptosis triggered by extracellular poly(I * C) plus cycloheximide or TRIF overexpression. TRIF silencing reduced poly(I * C)-triggered caspase 8 activation in mock- and ICP6Δ-infected cells, confirming that TRIF is involved in poly(I * C)-induced apoptosis. Thus, by interacting with caspase 8 and RIP1, HSV R1s impair the apoptotic host defense mechanism prompted by dsRNA
Florent Dufour; Luc Bertrand; Angela Pearson; Nathalie Grandvaux; Yves Langelier. The Ribonucleotide Reductase R1 Subunits of Herpes Simplex Virus 1 and 2 Protect Cells against Poly(I {middle dot} C)-Induced Apoptosis. Journal of Virology 2011, 85, 8689 -8701.
AMA StyleFlorent Dufour, Luc Bertrand, Angela Pearson, Nathalie Grandvaux, Yves Langelier. The Ribonucleotide Reductase R1 Subunits of Herpes Simplex Virus 1 and 2 Protect Cells against Poly(I {middle dot} C)-Induced Apoptosis. Journal of Virology. 2011; 85 (17):8689-8701.
Chicago/Turabian StyleFlorent Dufour; Luc Bertrand; Angela Pearson; Nathalie Grandvaux; Yves Langelier. 2011. "The Ribonucleotide Reductase R1 Subunits of Herpes Simplex Virus 1 and 2 Protect Cells against Poly(I {middle dot} C)-Induced Apoptosis." Journal of Virology 85, no. 17: 8689-8701.
UL24 of herpes simplex virus 1 (HSV-1) is widely conserved within the Herpesviridae family. Herein, we tested the hypothesis that UL24, which we have previously shown to induce the redistribution of nucleolin, also affects the localization of the nucleolar protein B23. We found that HSV-1-induced dispersal of B23 was dependent on UL24. The conserved N-terminal portion of UL24 was sufficient to induce the redistribution of B23 in transient transfection assays. Mutational analysis revealed that the endonuclease motif of UL24 was important for B23 dispersal in both transfected and infected cells. Nucleolar protein relocalization during HSV-1 infection was also observed in non-immortalized cells. Analysis of infected cells by electron microscopy revealed a decrease in the ratio of cytoplasmic versus nuclear viral particles in cells infected with a UL24-deficient strain compared to KOS-infected cells. Our results suggest that UL24 promotes nuclear egress of nucleocapsids during HSV-1 infection, possibly though effects on nucleoli
Maria H. Lymberopoulos; Amélie Bourget; Nawel Ben Abdeljelil; Angela Pearson. Involvement of the UL24 protein in herpes simplex virus 1-induced dispersal of B23 and in nuclear egress. Virology 2011, 412, 341 -348.
AMA StyleMaria H. Lymberopoulos, Amélie Bourget, Nawel Ben Abdeljelil, Angela Pearson. Involvement of the UL24 protein in herpes simplex virus 1-induced dispersal of B23 and in nuclear egress. Virology. 2011; 412 (2):341-348.
Chicago/Turabian StyleMaria H. Lymberopoulos; Amélie Bourget; Nawel Ben Abdeljelil; Angela Pearson. 2011. "Involvement of the UL24 protein in herpes simplex virus 1-induced dispersal of B23 and in nuclear egress." Virology 412, no. 2: 341-348.
Angela Pearson; Amélie Bourget; Nawel Ben Abdeljelil; Maria H Lymberopoulos. Role of the viral protein UL24 in nucleolar modifications induced by herpes simplex virus 1. BMC Proceedings 2011, 5, P102 -P102.
AMA StyleAngela Pearson, Amélie Bourget, Nawel Ben Abdeljelil, Maria H Lymberopoulos. Role of the viral protein UL24 in nucleolar modifications induced by herpes simplex virus 1. BMC Proceedings. 2011; 5 (1):P102-P102.
Chicago/Turabian StyleAngela Pearson; Amélie Bourget; Nawel Ben Abdeljelil; Maria H Lymberopoulos. 2011. "Role of the viral protein UL24 in nucleolar modifications induced by herpes simplex virus 1." BMC Proceedings 5, no. 1: P102-P102.
Luc Bertrand; Gabriel André Leiva-Torres; Huda Hyjazie; Angela Pearson. Conserved Residues in the UL24 Protein of Herpes Simplex Virus 1 Are Important for Dispersal of the Nucleolar Protein Nucleolin. Journal of Virology 2010, 84, 10436 -10436.
AMA StyleLuc Bertrand, Gabriel André Leiva-Torres, Huda Hyjazie, Angela Pearson. Conserved Residues in the UL24 Protein of Herpes Simplex Virus 1 Are Important for Dispersal of the Nucleolar Protein Nucleolin. Journal of Virology. 2010; 84 (19):10436-10436.
Chicago/Turabian StyleLuc Bertrand; Gabriel André Leiva-Torres; Huda Hyjazie; Angela Pearson. 2010. "Conserved Residues in the UL24 Protein of Herpes Simplex Virus 1 Are Important for Dispersal of the Nucleolar Protein Nucleolin." Journal of Virology 84, no. 19: 10436-10436.
Herpes simplex virus 1 (HSV-1) induces relocalization of several nucleolar proteins. We have found that, as for fibrillarin, the HSV-1-induced redistribution of two RNA polymerase I components, upstream binding factor (UBF) and RPA194, was independent of the viral protein UL24, which affects nucleolin localization. Nevertheless, the kinetics and sites of redistribution for fibrillarin and UBF differed. Interestingly, UBF remained associated with RPA194 during infection. Although UBF is redistributed to viral replication compartments during infection, we did not detect foci of UBF at early sites of viral DNA synthesis, suggesting that it may not be directly involved in this process at early times.
Maria H. Lymberopoulos; Angela Pearson. Relocalization of Upstream Binding Factor to Viral Replication Compartments Is UL24 Independent and Follows the Onset of Herpes Simplex Virus 1 DNA Synthesis. Journal of Virology 2010, 84, 4810 -4815.
AMA StyleMaria H. Lymberopoulos, Angela Pearson. Relocalization of Upstream Binding Factor to Viral Replication Compartments Is UL24 Independent and Follows the Onset of Herpes Simplex Virus 1 DNA Synthesis. Journal of Virology. 2010; 84 (9):4810-4815.
Chicago/Turabian StyleMaria H. Lymberopoulos; Angela Pearson. 2010. "Relocalization of Upstream Binding Factor to Viral Replication Compartments Is UL24 Independent and Follows the Onset of Herpes Simplex Virus 1 DNA Synthesis." Journal of Virology 84, no. 9: 4810-4815.
The UL24 gene of herpes simplex virus 1 (HSV-1) is widely conserved among all subfamilies of the Herpesviridae. It is one of only four HSV-1 genes for which mutations have been mapped that confer a syncytial plaque phenotype. In a mouse model of infection, UL24-deficient viruses exhibit reduced titres, particularly in neurons, and an apparent defect in reactivation from latency. There are several highly conserved residues in UL24; however, their importance in the role of UL24 in vivo is unknown. In this study, we compared virus strains with substitution mutations corresponding to the PD-(D/E)XK endonuclease motif of UL24 (vUL24-E99A/K101A) or a substitution of another highly conserved residue (vUL24-G121A). Both mutant viruses cause the formation of syncytial plaques at 39 °C; however, we found that the viruses differed dramatically when tested in a mouse model of infection. vUL24-E99A/K101A exhibited titres in the eye that were 10-fold lower than those of the wild-type virus KOS, and titres in trigeminal ganglia (TG) that were more than 2 log10 lower. Clinical signs were barely detectable with vUL24-E99A/K101A. Furthermore, the percentage of TG from which virus reactivated was also significantly lower for this mutant than for KOS. In contrast, vUL24-G121A behaved similarly to the wild-type virus in mice. These results are consistent with the endonuclease motif being important for the role of UL24 in vivo and also imply that the UL24 temperature-dependent syncytial plaque phenotype can be separated genetically from several in vivo phenotypes.
Gabriel André Leiva-Torres; Pierre-Alexandre Rochette; Angela Pearson. Differential importance of highly conserved residues in UL24 for herpes simplex virus 1 replication in vivo and reactivation. Journal of General Virology 2010, 91, 1109 -1116.
AMA StyleGabriel André Leiva-Torres, Pierre-Alexandre Rochette, Angela Pearson. Differential importance of highly conserved residues in UL24 for herpes simplex virus 1 replication in vivo and reactivation. Journal of General Virology. 2010; 91 (5):1109-1116.
Chicago/Turabian StyleGabriel André Leiva-Torres; Pierre-Alexandre Rochette; Angela Pearson. 2010. "Differential importance of highly conserved residues in UL24 for herpes simplex virus 1 replication in vivo and reactivation." Journal of General Virology 91, no. 5: 1109-1116.
The UL24 family of proteins is widely conserved among herpesviruses. We demonstrated previously that UL24 of herpes simplex virus 1 (HSV-1) is important for the dispersal of nucleolin from nucleolar foci throughout the nuclei of infected cells. Furthermore, the N-terminal portion of UL24 localizes to nuclei and can disperse nucleolin in the absence of any other viral proteins. In this study, we tested the hypothesis that highly conserved residues in UL24 are important for the ability of the protein to modify the nuclear distribution of nucleolin. We constructed a panel of substitution mutations in UL24 and tested their effects on nucleolin staining patterns. We found that modified UL24 proteins exhibited a range of subcellular distributions. Mutations associated with a wild-type localization pattern for UL24 correlated with high levels of nucleolin dispersal. Interestingly, mutations targeting two regions, namely, within the first homology domain and overlapping or near the previously identified PD-(D/E)XK endonuclease motif, caused the most altered UL24 localization pattern and the most drastic reduction in its ability to disperse nucleolin. Viral mutants corresponding to the substitutions G121A and E99A/K101A both exhibited a syncytial plaque phenotype at 39°C. vUL24-E99A/K101A replicated to lower titers than did vUL24-G121A or KOS. Furthermore, the E99A/K101A mutation caused the greatest impairment of HSV-1-induced dispersal of nucleolin. Our results identified residues in UL24 that are critical for the ability of UL24 to alter nucleoli and further support the notion that the endonuclease motif is important for the function of UL24 during infection.
Luc Bertrand; Gabriel André Leiva-Torres; Huda Hyjazie; Angela Pearson. Conserved Residues in the UL24 Protein of Herpes Simplex Virus 1 Are Important for Dispersal of the Nucleolar Protein Nucleolin. Journal of Virology 2010, 84, 109 -118.
AMA StyleLuc Bertrand, Gabriel André Leiva-Torres, Huda Hyjazie, Angela Pearson. Conserved Residues in the UL24 Protein of Herpes Simplex Virus 1 Are Important for Dispersal of the Nucleolar Protein Nucleolin. Journal of Virology. 2010; 84 (1):109-118.
Chicago/Turabian StyleLuc Bertrand; Gabriel André Leiva-Torres; Huda Hyjazie; Angela Pearson. 2010. "Conserved Residues in the UL24 Protein of Herpes Simplex Virus 1 Are Important for Dispersal of the Nucleolar Protein Nucleolin." Journal of Virology 84, no. 1: 109-118.
UL24 is widely conserved among herpesviruses but its function during infection is poorly understood. Previously, we discovered a genetic link between UL24 and the herpes simplex virus 1-induced dispersal of the nucleolar protein nucleolin. Here, we report that in the absence of viral infection, transiently expressed UL24 accumulated in both the nucleus and the Golgi apparatus. In the majority of transfected cells, nuclear staining for UL24 was diffuse, but a minor staining pattern, whereby UL24 was present in nuclear foci corresponding to nucleoli, was also observed. Expression of UL24 correlated with the dispersal of nucleolin. This dispersal did not appear to be a consequence of a general disaggregation of nucleoli, as foci of fibrillarin staining persisted in cells expressing UL24. The conserved N-terminal region of UL24 was sufficient to cause this change in subcellular distribution of nucleolin. Interestingly, a bipartite nuclear localization signal predicted within the C terminus of UL24 was dispensable for nuclear localization. None of the five individual UL24 homology domains was required for nuclear or Golgi localization, but deletion of these domains resulted in the loss of nucleolin-dispersal activity. We determined that a nucleolar-targeting signal was contained within the first 60 aa of UL24. Our results show that the conserved N-terminal domain of UL24 is sufficient to specifically induce dispersal of nucleolin in the absence of other viral proteins or virus-induced cellular modifications. These results suggest that UL24 directly targets cellular factors that affect the composition of nucleoli.
Luc Bertrand; Angela Pearson. The conserved N-terminal domain of herpes simplex virus 1 UL24 protein is sufficient to induce the spatial redistribution of nucleolin. Journal of General Virology 2008, 89, 1142 -1151.
AMA StyleLuc Bertrand, Angela Pearson. The conserved N-terminal domain of herpes simplex virus 1 UL24 protein is sufficient to induce the spatial redistribution of nucleolin. Journal of General Virology. 2008; 89 (5):1142-1151.
Chicago/Turabian StyleLuc Bertrand; Angela Pearson. 2008. "The conserved N-terminal domain of herpes simplex virus 1 UL24 protein is sufficient to induce the spatial redistribution of nucleolin." Journal of General Virology 89, no. 5: 1142-1151.
UL24 of herpes simplex virus 1 is important for efficient viral replication, but its function is unknown. We generated a recombinant virus, vHA-UL24, encoding UL24 with an N-terminal hemagglutinin tag. By indirect immunofluorescence at 9 h post-infection (hpi), we detected HA-UL24 in nuclear foci and in cytoplasmic speckles. HA-UL24 partially co-localized with nucleolin, but not with ICP8 or coilin, markers for nucleoli, viral replication compartments, and Cajal bodies respectively. HA-UL24 staining was often juxtaposed to that of another nucleolar protein, fibrillarin. Analysis of HSV-1-induced nucleolar modifications revealed that by 18 hpi, nucleolin staining had dispersed, and fibrillarin staining went from clusters of small spots to a few separate but prominent spots. Fibrillarin redistribution appeared to be independent of UL24. In contrast, cells infected with a UL24-deficient virus retained foci of nucleolin staining. Our results demonstrate involvement of UL24 in dispersal of nucleolin during infection.
Maria H. Lymberopoulos; Angela Pearson. Involvement of UL24 in herpes-simplex-virus-1-induced dispersal of nucleolin. Virology 2007, 363, 397 -409.
AMA StyleMaria H. Lymberopoulos, Angela Pearson. Involvement of UL24 in herpes-simplex-virus-1-induced dispersal of nucleolin. Virology. 2007; 363 (2):397-409.
Chicago/Turabian StyleMaria H. Lymberopoulos; Angela Pearson. 2007. "Involvement of UL24 in herpes-simplex-virus-1-induced dispersal of nucleolin." Virology 363, no. 2: 397-409.
The carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II (RNAP II) ordinarily exists in electrophoretically distinct hypophosphorylated and hyperphosphorylated forms. Human cytomegalovirus infection induced forms of this subunit whose electrophoretic mobilities were intermediate without decreases in abundance of the original forms. Phosphatase treatment nearly eliminated the intermediate migrating forms. In vitro, the viral protein kinase, UL97, phosphorylated this subunit, a recombinant protein containing the CTD, and peptides containing the CTD consensus sequence, YSPTSPS. Phosphorylation occurred predominantly on serine 5 and was substantially reduced when either serine 2 or 5 was already phosphorylated. The abundance of the intermediate and hypophosphorylated forms was reduced at most twofold during infections in which UL97 was genetically or pharmacologically inhibited. These results identify a new pattern of RNA polymerase II modification induced by virus infection and a viral enzyme that phosphorylates the CTD in vitro, but only possibly in vivo.
Moon-Chang Baek; Paula M Krosky; Angela Pearson; Donald M Coen. Phosphorylation of the RNA polymerase II carboxyl-terminal domain in human cytomegalovirus-infected cells and in vitro by the viral UL97 protein kinase. Virology 2004, 324, 184 -193.
AMA StyleMoon-Chang Baek, Paula M Krosky, Angela Pearson, Donald M Coen. Phosphorylation of the RNA polymerase II carboxyl-terminal domain in human cytomegalovirus-infected cells and in vitro by the viral UL97 protein kinase. Virology. 2004; 324 (1):184-193.
Chicago/Turabian StyleMoon-Chang Baek; Paula M Krosky; Angela Pearson; Donald M Coen. 2004. "Phosphorylation of the RNA polymerase II carboxyl-terminal domain in human cytomegalovirus-infected cells and in vitro by the viral UL97 protein kinase." Virology 324, no. 1: 184-193.