Varicella zoster virus: molecular controls of cell fusion-dependent pathogenesis

Summary

Principal Investigator: Ann Arvin
Abstract: DESCRIPTION (provided by applicant): Varicella-zoster virus (VZV) is a medically important human [unreadable]-herpesvirus that causes varicella (chickenpox) and leads to zoster (shingles) upon reactivation from latently infected sensory ganglia. Varicella can be serious and is life-threatening in immunocompromised patients. VZV exhibits tropism for T cells, skin and neurons during infection of the human host and overcomes the usual constraint against fusion between fully differentiated host cells to form multinucleated polykaryocytes, a hallmark of VZV pathogenesis. Glycoprotein B (gB) along with the gH/gL heterodimer is known to be critical for fusion of the virion envelope with the target cell membrane during herpesvirus entry. Our novel concept is that VZV mediates cell-cell fusion through a gB-dependent intracellular signaling function. This is based on our new evidence that preventing tyrosine phosphorylation of the gB cytoplasmic domain (gBcyt) leads to anomalies in cell-cell fusion and syncytia formation in vitro. Our application will investigate how the gBcyt modulates cell- cell fusion mechanisms via intracellular signaling pathways to produce the characteristic syncytia in vitro and fusion of epidermal cells and neuron-satellite cells caused by VZV infection of skin and ganglia in vivo. In Aim 1 we will determine how VZV modifies cellular regulation to favor transcription of genes that facilitate cell-cell fusion and syncytia formation by applying the high-throughput whole-transcriptome sequencing technology, RNA-seq, to our new fusion assay and our virus mutants, which carry mutations in the gBcyt residues that affect cell-cell fusion. To quantify the effects o tyrosine phosphorylation, the spatiotemporal evolution of syncytia formation will be measured in real-time for VZV and the gBcyt mutants. To determine the role of genes in cell fusion, as identified by RNA-seq, we will perform gene perturbation experiments to assess their biological significance in the context of VZV replication. Aim 2 will determine how the gBcyt regulates intracellular signaling events in cell fusion via post-translational modifications of tyrosine and/r lysine residues by cellular or viral proteins. Mass spectrometry will be used to identify cellular and viral proteins that interact with the gBcyt domain in its tyrosine-phosphorylated and non-phosphorylated forms. Lysine mutagenesis studies will be performed to assess the effects of acetylation and ubiquitination posttranslational modifications on VZV fusion and virulence. Finally, Aim 3 will establish whether the gBcyt modulates polykaryocyte formation to optimize VZV infection of skin and DRG. Our mutant viruses will be compared to wild type VZV for replication competencies in human skin and neuronal tissue using novel reporter viruses. We will establish the role of newly identified genes required for cell-cell fusion using a novel shRNA carrying virus. Given the significance of polykaryocyte formation for pathogenesis, deciphering how VZV regulates this process has the potential to yield new strategies for vaccine virus attenuation and antiviral drug design to ease the burden on vulnerable populations.
Funding Period: 2012-06-01 - 2017-05-31
more information: NIH RePORT

Top Publications

  1. pmc An immunoreceptor tyrosine-based inhibition motif in varicella-zoster virus glycoprotein B regulates cell fusion and skin pathogenesis
    Stefan L Oliver
    Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
    Proc Natl Acad Sci U S A 110:1911-6. 2013
  2. pmc Molecular mechanisms of varicella zoster virus pathogenesis
    Leigh Zerboni
    Departments of Pediatrics and of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
    Nat Rev Microbiol 12:197-210. 2014

Detail Information

Publications2

  1. pmc An immunoreceptor tyrosine-based inhibition motif in varicella-zoster virus glycoprotein B regulates cell fusion and skin pathogenesis
    Stefan L Oliver
    Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
    Proc Natl Acad Sci U S A 110:1911-6. 2013
    ....
  2. pmc Molecular mechanisms of varicella zoster virus pathogenesis
    Leigh Zerboni
    Departments of Pediatrics and of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
    Nat Rev Microbiol 12:197-210. 2014
    ..In this Review, we discuss how these models have improved our understanding of VZV pathogenesis. ..

Research Grants30

  1. Rocky Mountain Regional Center of Excellence or Biodefense and Emerging Infectiou
    John T Belisle; Fiscal Year: 2013
    ..abstract_text> ..
  2. Varicella zoster virus-Induced Pain in a Rat Model of Post-Herpetic Neuralgia
    Paul R Kinchington; Fiscal Year: 2013
    ..The project may also identify new methods to alleviate PHN using gene therapy approaches. ..
  3. Immunobioogy for Marrow Allografts for Leukemia
    RICHARD JOHN O'REILLY; Fiscal Year: 2013
    ..The 3 cores include: Core A which provides all patient samples and evaluate grafts pre and post HSCT, Core B Biostatistics and Core C administrative support and oversight. ..
  4. Autophagy and ER stress during varicella infection
    CHARLES F GROSE; Fiscal Year: 2013
    ..The results are relevant not only to our understanding of varicella vaccination but also the debilitating zoster-related illness called post-herpetic neuralgia. ..
  5. Pacific NorthWest Regional Center of Excellence (PNWRCE)
    Jay A Nelson; Fiscal Year: 2013
    ..pseudomallei host pathogen response during both the septicemic as well as the intracellular phases of the disease. ..
  6. New England Regional Center of Excellence in Biodefense and Emerging Infectious D
    Dennis L Kasper; Fiscal Year: 2013
    ..NERCE will also continue its Developmental Projects program and Career Development in Biodefense program in an effort to initiate new research efforts and to attract new investigators to this field. ..
  7. Northeast Biodefense Center
    W Ian Lipkin; Fiscal Year: 2013
    ..As a Center based in a School of Public Health and a State Department of Health, the NBC has a firm commitment to and practical understanding of Emergency Preparedness. ..
  8. Varicella-Zoster Virus: T Cell/Skin Tropism &Immunity
    Ann Arvin; Fiscal Year: 2013
    ..abstract_text> ..
  9. Pacific Southwest RCE for Biodefense &Emerging Infectious Diseases Research
    Alan G Barbour; Fiscal Year: 2013
    ..abstract_text> ..