Varicella zoster virus (VZV), a ubiquitous neurotropic alphaherpesvirus that causes varicella (chickenpox), becomes latent in cranial nerve ganglia, dorsal root ganglia and autonomic ganglia along the entire neuraxis. VZV reactivation, mostly in elderly and immunocompromised individuals, causes zoster, often followed by postherpetic neuralgia, myelitis, meningoencephalitis, vasculopathy and ocular diseases. No other human herpesvirus causes such a wide spectrum of disease. Although zoster vaccine reduces the incidence of zoster by 51.3% within 3 years after immunization, nearly 400,000 Americans still develop zoster every year, of which about 200,000 experience PHN;others develop stroke, paralysis and blindness. None of these neurological disorders would occur if virus reactivation could be prevented. Although the molecular mechanism(s) of VZV reactivation is unknown, VZV is unique in that no less than 12 VZV transcripts are detected in latently infected human ganglia, whereas all other neurotropic alphaherpesviruses, including herpes simplex-1 (HSV-1), transcribe a single latency associated transcript (LAT). HSV-1 LAT facilitates virus reactivation, and its promoter is coated with histones containing post-translational modifications that enhance transcription (euchromatin). Promoters for other HSV-1 genes are bound by modified histones that repress transcription (heterochromatin). The mechanism by which histone modifications are maintained is unknown, but may involve physical separation of histone complexes by chromatin insulators. Overall, the ability of the HSV-1 LAT to facilitate reactivation of latent virus DNA provides a rationale for my hypothesis that one or more VZV genes transcribed in latently infected human ganglia facilitate reactivation of latent VZV through their effects on histone modification.
Two specific aims will test our hypothesis.
Aim 1 will identify post- translational modifications of histones on promoters of VZV genes expressed during latency.
Aim 2 will investigate the mechanism by which euchromatic and heterochromatic histone modification are maintained. We are uniquely qualified to conduct our proposed studies since we have a continuous supply of fresh human ganglia obtained at autopsy, decades of expertise studying both the latent and lytic VZV transcriptome, and have developed ChIP assays and PCR-based multiplex assays to analyze human ganglia latently infected with VZV. Armed with an understanding of the epigenetic regulation of VZV genes, we will be able to design therapeutic agents to combat virus reactivation and mitigate sever neurologic disease in the elderly.

Public Health Relevance

Varicella zoster virus (VZV) reactivation resulting in zoster (shingles) is a significant health concern, particularly since it is frequently followed by postherpetic neuralgia, chronic pain that lasts months to years, and often for the rest of the patient's life. Furthermore, VZV reactivation produces VZV vasculopathy (stroke), myelitis (paralysis and incontinence and blindness (retinitis and various other ocular disorders). Importantly, all neurologic disease caused by VZV reactivation can occur without rash, thus making diagnosis difficult. Essentially multiple ganglia of everyone who has had varicella (chickenpox) or varicella vaccine contain latent VZV from which virus can reactivate by an as yet unidentified mechanism. Our central hypothesis is that VZV gene transcription facilitates virus reactivation. These studies will identify how VZV gene transcription is regulated in latently infected human ganglia, and a possible mechanism by which virus reactivation is initiated. Through this understanding of latent VZV gene transcriptional regulation, we will identify molecular events (for example, histone modifications) that can be targeted to prevent VZV reactivation.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
1R01NS082228-01
Application #
8476910
Study Section
Clinical Neuroimmunology and Brain Tumors Study Section (CNBT)
Program Officer
Wong, May
Project Start
2013-02-15
Project End
2018-01-31
Budget Start
2013-02-15
Budget End
2014-01-31
Support Year
1
Fiscal Year
2013
Total Cost
$337,513
Indirect Cost
$118,763
Name
University of Colorado Denver
Department
Neurology
Type
Schools of Medicine
DUNS #
041096314
City
Aurora
State
CO
Country
United States
Zip Code
80045
Como, Christina N; Pearce, Catherine M; Cohrs, Randall J et al. (2018) Interleukin-6 and type 1 interferons inhibit varicella zoster virus replication in human neurons. Virology 522:13-18
Cohrs, Randall J; Badani, Hussain; Baird, Nicholas L et al. (2017) Induction of varicella zoster virus DNA replication in dissociated human trigeminal ganglia. J Neurovirol 23:152-157
Cohrs, Randall J; Lee, Katherine S; Beach, Addilynn et al. (2017) Targeted Genome Sequencing Reveals Varicella-Zoster Virus Open Reading Frame 12 Deletion. J Virol 91:
Keller, Amy C; Badani, Hussain; McClatchey, P Mason et al. (2016) Varicella zoster virus infection of human fetal lung cells alters mitochondrial morphology. J Neurovirol 22:674-682
Henderson, Heather H; Timberlake, Kensey B; Austin, Zoe A et al. (2016) Occupancy of RNA Polymerase II Phosphorylated on Serine 5 (RNAP S5P) and RNAP S2P on Varicella-Zoster Virus Genes 9, 51, and 66 Is Independent of Transcript Abundance and Polymerase Location within the Gene. J Virol 90:1231-43
Gilden, Don; Grose, Charles; White, Teresa et al. (2016) Successful antiviral treatment after 6years of chronic progressive neurological disease attributed to VZV brain infection. J Neurol Sci 368:240-2
Cohrs, Randall J; Badani, Hussain; Bos, Nathan et al. (2016) Alphaherpesvirus DNA replication in dissociated human trigeminal ganglia. J Neurovirol 22:688-694
Gershon, Anne A; Breuer, Judith; Cohen, Jeffrey I et al. (2015) Varicella zoster virus infection. Nat Rev Dis Primers 1:15016
Baird, Nicholas L; Bowlin, Jacqueline L; Hotz, Taylor J et al. (2015) Interferon Gamma Prolongs Survival of Varicella-Zoster Virus-Infected Human Neurons In Vitro. J Virol 89:7425-7
Goodwin, Thomas J; McCarthy, Maureen; Cohrs, Randall J et al. (2015) 3D tissue-like assemblies: A novel approach to investigate virus-cell interactions. Methods 90:76-84

Showing the most recent 10 out of 22 publications