scholarly journals The Glycoprotein B Cytoplasmic Domain Lysine Cluster Is Critical for Varicella-Zoster Virus Cell-Cell Fusion Regulation and Infection

2016 ◽  
Vol 91 (1) ◽  
Author(s):  
Edward Yang ◽  
Ann M. Arvin ◽  
Stefan L. Oliver
Keyword(s):  
Varicella Zoster Virus ◽  
Cell Fusion ◽  
Postherpetic Neuralgia ◽  
Positive Charge ◽  
Syncytium Formation ◽  
Wild Type ◽  
Painful Condition ◽  
Varicella Zoster ◽  
Multinuclear Cells ◽  
Cell Cell

ABSTRACT The conserved glycoproteins gB and gH-gL are essential for herpesvirus entry and cell-cell fusion induced syncytium formation, a characteristic of varicella-zoster virus (VZV) pathology in skin and sensory ganglia. VZV syncytium formation, which has been implicated in the painful condition of postherpetic neuralgia, is regulated by the cytoplasmic domains of gB (gBcyt) via an immunoreceptor tyrosine-based inhibition motif (ITIM) and gH (gHcyt). A lysine cluster (K894, K897, K898, and K900) in the VZV gBcyt was identified by sequence alignment to be conserved among alphaherpesviruses, suggesting a functional role. Alanine and arginine substitutions were used to determine if the positive charge and susceptibility to posttranslational modifications of these lysines contributed to gB/gH-gL cell-cell fusion. Critically, the positive charge of the lysine residues was necessary for fusion regulation, as alanine substitutions induced a 440% increase in fusion compared to that of the wild-type gBcyt while arginine substitutions had wild-type-like fusion levels in an in vitro gB/gH-gL cell fusion assay. Consistent with these results, the alanine substitutions in the viral genome caused exaggerated syncytium formation, reduced VZV titers (−1.5 log10), and smaller plaques than with the parental Oka (pOka) strain. In contrast, arginine substitutions resulted in syncytia with only 2-fold more nuclei, a −0.5-log10 reduction in titers, and pOka-like plaques. VZV mutants with both an ITIM mutation and either alanine or arginine substitutions had reduced titers and small plaques but differed in syncytium morphology. Thus, effective VZV propagation is dependent on cell-cell fusion regulation by the conserved gBcyt lysine cluster, in addition to the gBcyt ITIM and the gHcyt. IMPORTANCE Varicella-zoster virus (VZV) is a ubiquitous pathogen that causes chickenpox and shingles. Individuals afflicted with shingles risk developing the painful condition of postherpetic neuralgia (PHN), which has been difficult to treat because the underlying cause is not well understood. Additional therapies are needed, as the current vaccine is not recommended for immunocompromised individuals and its efficacy decreases with the age of the recipient. VZV is known to induce the formation of multinuclear cells in neuronal tissue, which has been proposed to be a factor contributing to PHN. This study examines the role of a lysine cluster in the cytoplasmic domain of the VZV fusion protein, gB, in the formation of VZV induced multinuclear cells and in virus replication kinetics and spread. The findings further elucidate how VZV self-regulates multinuclear cell formation and may provide insight into the development of new PHN therapies.

scholarly journals Regulation of Varicella-Zoster Virus-Induced Cell-to-Cell Fusion by the Endocytosis-Competent Glycoproteins gH and gE

2004 ◽  
Vol 78 (6) ◽  
pp. 2884-2896 ◽  
Author(s):  
Tracy Jo Pasieka ◽  
Lucie Maresova ◽  
Kimiyasu Shiraki ◽  
Charles Grose
Keyword(s):  
Cell Surface ◽  
Varicella Zoster Virus ◽  
Cell Fusion ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Wild Type ◽  
Viral Glycoprotein ◽  
Transfected Cells ◽  
Varicella Zoster ◽  
Kolmogorov Smirnov

ABSTRACT The gH glycoprotein of varicella-zoster virus (VZV) is a major fusogen. The realigned short cytoplasmic tail of gH (18 amino acids) harbors a functional endocytosis motif (YNKI) that mediates internalization in both VZV-infected and transfected cells (T. J. Pasieka, L. Maresova, and C. Grose, J. Virol. 77: 4194-4202, 2003). During subsequent confocal microscopy studies of endocytosis-deficient gH mutants, we observed that cells transfected with the gH tail mutants exhibited marked fusion. Therefore, we postulated that VZV gH endocytosis served to regulate cell-to-cell fusion. Subsequent analyses of gH+gL transfection fusion assays by the Kolmogorov-Smirnov statistical test demonstrated that expression of the endocytosis-deficient gH mutants resulted in a statistically significant enhancement of cell-to-cell fusion (P < 0.0001) compared to wild-type gH. On the other hand, coexpression of VZV gE, another endocytosis-competent VZV glycoprotein, was able to temper the fusogenicity of the gH endocytosis mutants by facilitating internalization of the mutant gH protein from the cell surface. When the latter results were similarly analyzed, there was no longer any enhanced fusion by the endocytosis-deficient gH mutant protein. In summary, these studies support a role for gH endocytosis in regulating the cell surface expression of gH and thereby regulating gH-mediated fusion. The data also confirm and extend prior observations of a gE-gH interaction during viral glycoprotein trafficking in a VZV transfection system.

scholarly journals Dysregulated Glycoprotein B-Mediated Cell-Cell Fusion Disrupts Varicella-Zoster Virus and Host Gene Transcription during Infection

2016 ◽  
Vol 91 (1) ◽  
Author(s):  
Stefan L. Oliver ◽  
Edward Yang ◽  
Ann M. Arvin
Keyword(s):  
Varicella Zoster Virus ◽  
Cell Fusion ◽  
Cellular Responses ◽  
Melanoma Cells ◽  
Live Cell ◽  
Effective Vaccine ◽  
Viral Glycoprotein ◽  
Varicella Zoster ◽  
Multinucleated Cells ◽  
Cell Cell

ABSTRACT The highly conserved herpesvirus glycoprotein complex gB/gH-gL mediates membrane fusion during virion entry and cell-cell fusion. Varicella-zoster virus (VZV) characteristically forms multinucleated cells, or syncytia, during the infection of human tissues, but little is known about this process. The cytoplasmic domain of VZV gB (gBcyt) has been implicated in cell-cell fusion regulation because a gB[Y881F] substitution causes hyperfusion. gBcyt regulation is necessary for VZV pathogenesis, as the hyperfusogenic mutant gB[Y881F] is severely attenuated in human skin xenografts. In this study, gBcyt-regulated fusion was investigated by comparing melanoma cells infected with wild-type-like VZV or hyperfusogenic mutants. The gB[Y881F] mutant exhibited dramatically accelerated syncytium formation in melanoma cells caused by fusion of infected cells with many uninfected cells, increased cytoskeleton reorganization, and rapid displacement of nuclei to dense central structures compared to pOka using live-cell confocal microscopy. VZV and human transcriptomes were concurrently investigated using whole transcriptome sequencing (RNA-seq) to identify viral and cellular responses induced when gBcyt regulation was disrupted by the gB[Y881F] substitution. The expression of four vital VZV genes, ORF61 and the genes for glycoproteins gC, gE, and gI, was significantly reduced at 36 h postinfection for the hyperfusogenic mutants. Importantly, hierarchical clustering demonstrated an association of differential gene expression with dysregulated gBcyt-mediated fusion. A subset of Ras GTPase genes linked to membrane remodeling were upregulated in cells infected with the hyperfusogenic mutants. These data implicate gBcyt in the regulation of gB fusion function that, if unmodulated, triggers cellular processes leading to hyperfusion that attenuates VZV infection. IMPORTANCE The highly infectious, human-restricted pathogen varicella-zoster virus (VZV) causes chickenpox and shingles. Postherpetic neuralgia (PHN) is a common complication of shingles that manifests as prolonged excruciating pain, which has proven difficult to treat. The formation of fused multinucleated cells in ganglia might be associated with this condition. An effective vaccine against VZV is available but not recommended for immunocompromised individuals, highlighting the need for new therapies. This study investigated the viral and cellular responses to hyperfusion, a condition where the usual constraints of cell membranes are overcome and cells form multinucleated cells. This process hinders VZV and is regulated by a viral glycoprotein, gB. A combination of live-cell imaging and next-generation genomics revealed an alteration in viral and cellular responses during hyperfusion that was caused by the loss of gB regulation. These studies reveal mechanisms central to VZV pathogenesis, potentially leading to improved therapies.

scholarly journals Sialic Acids on Varicella-Zoster Virus Glycoprotein B Are Required for Cell-Cell Fusion

2015 ◽  
Vol 290 (32) ◽  
pp. 19833-19843 ◽  
Author(s):  
Tadahiro Suenaga ◽  
Maki Matsumoto ◽  
Fuminori Arisawa ◽  
Masako Kohyama ◽  
Kouyuki Hirayasu ◽  
...  
Keyword(s):  
Varicella Zoster Virus ◽  
Cell Fusion ◽  
Sialic Acids ◽  
Glycoprotein B ◽  
Varicella Zoster ◽  
Virus Glycoprotein ◽  
Cell Cell

scholarly journals Phosphorylation by the Varicella-Zoster Virus ORF47 Protein Serine Kinase Determines whether Endocytosed Viral gE Traffics to the trans-Golgi Network or Recycles to the Cell Membrane

2002 ◽  
Vol 76 (21) ◽  
pp. 10980-10993 ◽  
Author(s):  
T. K. Kenyon ◽  
Jeffrey I. Cohen ◽  
Charles Grose
Keyword(s):  
Varicella Zoster Virus ◽  
Cytoplasmic Tail ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Varicella Zoster ◽  
Virion Production ◽  
Golgi Network ◽  
Cell Spread ◽  
Cell Cell

ABSTRACT Like all alphaherpesviruses, varicella-zoster virus (VZV) infection proceeds by both cell-cell spread and virion production. Virions are enveloped within vacuoles located near the trans-Golgi network (TGN), while in cell-cell spread, surface glycoproteins fuse cells into syncytia. In this report, we delineate a potential role for serine/threonine phosphorylation of the cytoplasmic tail of the predominant VZV glycoprotein, gE, in these processes. The fact that VZV gE (formerly called gpI) is phosphorylated has been documented (E. A. Montalvo and C. Grose, Proc. Natl. Acad. Sci. USA 83:8967-8971, 1986), although respective roles of viral and cellular protein kinases have never been delineated. VZV ORF47 is a viral serine protein kinase that recognized a consensus sequence similar to that of casein kinase II (CKII). During open reading frame 47 (ORF47)-specific in vitro kinase assays, ORF47 phosphorylated four residues in the cytoplasmic tail of VZV gE (S593, S595, T596, and T598), thus modifying the known phosphofurin acidic cluster sorting protein 1 domain. CKII phosphorylated gE predominantly on the two threonine residues. In wild-type-virus-infected cells, where ORF47-mediated phosphorylation predominated, gE endocytosed and relocalized to the TGN. In cells infected with a VZV ORF47-null mutant, internalized VZV gE recycled to the plasma membrane and did not localize to the TGN. The mutant virus also formed larger syncytia than the wild-type virus, linking CKII-mediated gE phosphorylation with increased cell-cell spread. Thus, ORF47 and CKII behaved as “team players” in the phosphorylation of VZV gE. Taken together, the results showed that phosphorylation of VZV gE by ORF47 or CKII determined whether VZV infection proceeded toward a pathway likely involved with either virion production or cell-cell spread.

scholarly journals Calcineurin phosphatase activity regulates Varicella-Zoster Virus induced cell-cell fusion

2020 ◽  
Vol 16 (11) ◽  
pp. e1009022 ◽  
Author(s):  
Momei Zhou ◽  
Vivek Kamarshi ◽  
Ann M. Arvin ◽  
Stefan L. Oliver
Keyword(s):  
Varicella Zoster Virus ◽  
Host Cell ◽  
Phosphatase Activity ◽  
Cell Fusion ◽  
High Throughput Screening ◽  
Host Factors ◽  
Varicella Zoster ◽  
Calcineurin Phosphatase ◽  
Cell Cell

Cell-cell fusion (abbreviated as cell fusion) is a characteristic pathology of medically important viruses, including varicella-zoster virus (VZV), the causative agent of chickenpox and shingles. Cell fusion is mediated by a complex of VZV glycoproteins, gB and gH-gL, and must be tightly regulated to enable skin pathogenesis based on studies with gB and gH hyperfusogenic VZV mutants. Although the function of gB and gH-gL in the regulation of cell fusion has been explored, whether host factors are directly involved in this regulation process is unknown. Here, we discovered host factors that modulated VZV gB/gH-gL mediated cell fusion via high-throughput screening of bioactive compounds with known cellular targets. Two structurally related non-antibiotic macrolides, tacrolimus and pimecrolimus, both significantly increased VZV gB/gH-gL mediated cell fusion. These compounds form a drug-protein complex with FKBP1A, which binds to calcineurin and specifically inhibits calcineurin phosphatase activity. Inhibition of calcineurin phosphatase activity also enhanced both herpes simplex virus-1 fusion complex and syncytin-1 mediated cell fusion, indicating a broad role of calcineurin in modulating this process. To characterize the role of calcineurin phosphatase activity in VZV gB/gH-gL mediated fusion, a series of biochemical, biological and infectivity assays was performed. Pimecrolimus-induced, enhanced cell fusion was significantly reduced by shRNA knockdown of FKBP1A, further supporting the role of calcineurin phosphatase activity in fusion regulation. Importantly, inhibition of calcineurin phosphatase activity during VZV infection caused exaggerated syncytia formation and suppressed virus propagation, which was consistent with the previously reported phenotypes of gB and gH hyperfusogenic VZV mutants. Seven host cell proteins that remained uniquely phosphorylated when calcineurin phosphatase activity was inhibited were identified as potential downstream factors involved in fusion regulation. These findings demonstrate that calcineurin is a critical host cell factor pivotal in the regulation of VZV induced cell fusion, which is essential for VZV pathogenesis.

scholarly journals Kestabilan Model Matematika Infeksi Primer Penyakit Varicella Dan Infeksi Rekuren Penyakit Herpes Zoster Oleh Virus Varicella Zoster

2020 ◽  
Vol 17 (1) ◽  
pp. 82-91
Author(s):  
Hardiyanti ◽  
R Ratianingsih ◽  
Hajar
Keyword(s):  
Herpes Zoster ◽  
Stability Analysis ◽  
Varicella Zoster Virus ◽  
Critical Point ◽  
Postherpetic Neuralgia ◽  
Primary Infection ◽  
Skin Diseases ◽  
Varicella Zoster ◽  
Stable Conditions ◽  
Disease Free

Varicella and herpes zoster are two infectious skin diseases of human that caused by varicella zoster virus, where varicella disease is a primary infection that often infected younger people while herpes zoster disease is a recurrent disease that often infected older people because of reactivation of latent varicella-zoster virus. If the pain caused by herpes zoster after recurrent phase is a appeared then the condition is known as postherpetic neuralgia. This study builds a mathematical model of primary infection (varicella disease) and recurrent infection (herpes zoster disease) developed from the SIR model (Susceptible, Infected, Recovered). The human population is divided into seven subpopulations, namely susceptible, infection, recovered of varicella, herpes zoster and postherpetic neuralgia subpopulation. Stability analysis at the critical point by linearization method gives a critical point 𝑇1 that guaranted to exist and unstable if 𝛼 𝜇(𝛽1+𝜇) 𝐴 , while the critical point 𝑇1 does not have any reqruitment. Stability analysis at the endemic disease-free critical point is represented 𝑇1 that will be unstable if 𝑇2 exist and stable 𝑇1 if 𝑇2 exist. Numerical simulations by simulated to describe such temporary disease-free conditions and an endemic stable conditions.

scholarly journals Contribution of Endocytic Motifs in the Cytoplasmic Tail of Herpes Simplex Virus Type 1 Glycoprotein B to Virus Replication and Cell-Cell Fusion

2007 ◽  
Vol 81 (24) ◽  
pp. 13889-13903 ◽  
Author(s):  
Igor Beitia Ortiz de Zarate ◽  
Lilia Cantero-Aguilar ◽  
Magalie Longo ◽  
Clarisse Berlioz-Torrent ◽  
Flore Rozenberg
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Cell Surface ◽  
Cell Fusion ◽  
Virus Replication ◽  
Herpes Simplex Virus Type ◽  
Wild Type ◽  
Simplex Virus ◽  
Cell Cell

ABSTRACT The use of endocytic pathways by viral glycoproteins is thought to play various functions during viral infection. We previously showed in transfection assays that herpes simplex virus type 1 (HSV-1) glycoprotein B (gB) is transported from the cell surface back to the trans-Golgi network (TGN) and that two motifs of gB cytoplasmic tail, YTQV and LL, function distinctly in this process. To investigate the role of each of these gB trafficking signals in HSV-1 infection, we constructed recombinant viruses in which each motif was rendered nonfunctional by alanine mutagenesis. In infected cells, wild-type gB was internalized from the cell surface and concentrated in the TGN. Disruption of YTQV abolished internalization of gB during infection, whereas disruption of LL induced accumulation of internalized gB in early recycling endosomes and impaired its return to the TGN. The growth of both recombinants was moderately diminished. Moreover, the fusion phenotype of cells infected with the gB recombinants differed from that of cells infected with the wild-type virus. Cells infected with the YTQV-mutated virus displayed reduced cell-cell fusion, whereas giant syncytia were observed in cells infected with the LL-mutated virus. Furthermore, blocking gB internalization or impairing gB recycling to the cell surface, using drugs or a transdominant negative form of Rab11, significantly reduced cell-cell fusion. These results favor a role for endocytosis in virus replication and suggest that gB intracellular trafficking is involved in the regulation of cell-cell fusion.

scholarly journals Herpes Zoster and Postherpetic Neuralgia: Past, Present and Future

2009 ◽  
Vol 14 (4) ◽  
pp. 275-282 ◽  
Author(s):  
Gary J Bennett ◽  
C Peter N Watson
Keyword(s):  
Herpes Zoster ◽  
Varicella Zoster Virus ◽  
Recent Work ◽  
Postherpetic Neuralgia ◽  
Current Understanding ◽  
Varicella Zoster

OBJECTIVES: The history behind the current understanding of the varicella-zoster virus and its relationship to the pain conditions caused by shingles and postherpetic neuralgia are reviewed. The framework for the current conceptualization is Hope-Simpson’s latency hypothesis. Data from recent work in virology, neuroanatomy and epidemiology are reviewed, as is work using varicella-zoster virus-infected animals. The recent data largely confirm Hope-Simpson’s hypothesis and extend it significantly.

scholarly journals Varicella Vaccine Meningitis as a Complication of Herpes Zoster in Twice-Immunized Immunocompetent Adolescents

2020 ◽  
Vol 35 (13) ◽  
pp. 889-895 ◽  
Author(s):  
Veena Ramachandran ◽  
Stephen C. Elliott ◽  
Kathie L. Rogers ◽  
Randall J. Cohrs ◽  
Miles Weinberger ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Herpes Zoster ◽  
Varicella Zoster Virus ◽  
Varicella Vaccine ◽  
The United States ◽  
Vaccine Virus ◽  
Virus Reactivation ◽  
Wild Type ◽  
Varicella Zoster ◽  
Intravenous Acyclovir

Varicella-zoster virus vaccination is recommended for virtually all young children in the United States, Canada, and several other countries. Varicella vaccine is a live attenuated virus that retains some of its neurotropic properties. Herpes zoster caused by vaccine virus still occurs in immunized children, although the rate is much lower than in children who had wild-type varicella. It was commonly thought that 2 varicella vaccinations would protect children against the most serious complication of meningitis following herpes zoster; however, 2 meningitis cases have already been published. We now report a third case of varicella vaccine meningitis and define risk factors shared by all 3 immunized adolescents. The diagnosis in cerebrospinal fluid in this third case was verified by amplifying and sequencing portions of the viral genome, to document fixed alleles found only in the vaccine strain. Viral antibody was also detected in the cerebrospinal fluid by confocal microscopy. When compared with the other 2 cases, remarkably all 3 were 14 years old when meningitis occurred. All 3 were treated with intravenous acyclovir, with complete recovery. The adolescent in our case report also had recurrent asthma, which was treated with both prednisone tablets and beclomethasone inhaler before onset of meningitis. When the 3 cases were considered together, they suggested that immunity to varicella-zoster virus may be waning sufficiently in some twice-immunized adolescents to make them vulnerable to varicella vaccine virus reactivation and subsequent meningitis. This complication rarely happens in children after wild-type varicella.

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