Regulation of HSV-1 Gene Expression and Replication by Nuclear Hormone Receptors

Summary

Principal Investigator: SHAOCHUNG VICTOR HSIA
Abstract: DESCRIPTION (provided by applicant): HSV-1 is one of the most common viral infections affecting humans from mild cold sores to severe ocular keratitis and deadly encephalitis. The virus establishes a life-long latent infection within neurons of the trigeminal ganglia (TG). Literature showed that herpesvirus reactivation is correlated to hormone imbalance. Therefore we predict that hormone alteration may regulate the HSV-1 gene expression during reactivation. In searching for hormone responsive elements in HSV-1 genome, we identified thyroid hormone receptor responsive elements (TREs) in the regulatory regions of HSV-1 thymidine kinase (TK), latency-associated transcript (LAT), and infected cell protein 0 (ICP0). TREs are the binding sites where the thyroid hormone receptor (TR) binds/acts as a transcription factor. Our central hypothesis is that thyroid hormone (TH or T3) and its receptor (TR) can control HSV-1 latency and reactivation by regulating the HSV-1 key gene expression and thus influence the transcription and replication of virus within the latently-infected neurons. This hypothesis is supported by the literature and our observations: First, HSV-1 TK and ICP0 are important for efficient viral DNA replication and transcription within the infected neurons. Second, TR is present in sensory ganglia. Third, our results have shown that TR regulates expression of TK, LAT, and ICP0 in vitro. Fourth, our publication indicated that the level of T3 controls viral replication and the release of infectious viruses in vitro. Fifth, standard procedures used to induce HSV-1 reactivation, such as hyperthermia and dexamethasone treatment, also decrease TH levels. Together our published results demonstrate that the liganded receptor (T3/TR, the hormone-receptor complex) controls the expression of HSV-1 key genes and replication. N2aTR[unreadable] cell has been used for pilot study because of the advantages that 1) it is convenient to control the level of T3 by adding it into media, and 2) N2aTR[unreadable] cells can be differentiated by T3 after 3-days of treatment, mimicking the condition of differentiated neurons. In this project, we will further study the mechanisms by which T3/TR regulates HSV-1 replication/gene expression via the following Specific Aims. Specific Aim 1. To test the hypothesis that T3/TR control the transcription of thymidine kinase (TK) by chromatin regulation using silencing mediator of retinoid and thyroid receptors (SMRT) recruited by Nuclear Orphan Receptors (NORs) to the TK T3 Response Element (TRE) via TR. Our results indicated that liganded TR was recruited to the TK TRE, and NORs were up-regulated in T3-treated N2aTR[unreadable] cells. NOR is shown to interact with SMRT and repress promoter activity. In Aim 1, we will make a series of TRE mutants and test them using our T3 removal N2aTR[unreadable] cell culture model to investigate: 1) TR binding, 2) NOR/SMRT recruitment, and 3) their functions on viral replication/release by transient transfection and viral infection in neuronal and non-neuronal cells. Specific Aim 2. To test the hypothesis that T3 /TR modulate transcription of LAT and [unreadable] genes by recruiting multifunctional transcription factor Early Growth Response gene (Egr-1) and chromatin insulator CTCF to the key regulatory regions of HSV-1. In different studies we showed that Egr-1 and CTCF were induced by T3 /TR in neuronal cells upon infection. They both exhibit repressive effects on HSV-1 [unreadable] genes. In Aim 2, we will generate a series of mutant plasmids with partial deletion of HSV-1 Repeat Element-1 (RE-1) to study the boundary effect of CTCF on LAT and [unreadable] genes. Egr-1-mediated regulation will be further investigated by transfection assays as well as infections using recombinant virus over-expressing Egr-1 in neuronal and non-neuronal cells. Specific Aim 3: To test the hypothesis that Regulator of Chromosome Condensation 1 (RCC1) and RAs- related Nuclear protein (Ran) complex participated in the global epigenetic control of HSV-1 transcription/ replication by maintaining repressive chromatin structure on HSV-1 genome for gene silencing via T3/TR. RCC1/Ran complex is involved in the control of RNA translocation, DNA synthesis, and cell cycle progression via modulating effects on chromatin and nucleosomes. RCC1 is partially degraded in lytic infection but induced in neuronal cells by T3/TR upon infection (C.12, Fig. 7). In Aim 3, we will study the effects of RCC1/Ran complex on HSV-1 gene expression, replication, and virus release. Our laboratory has been working on HSV-1 biology through the support from NCRR/NIH, and we have three publications supporting the hypotheses. Additional studies are proposed in the Specific Aims based on our unpublished results. Our short-term mission is to establish an active research program at the School of Pharmacy at the University of Maryland Eastern Shore (UMES), a land-grant, historically black college and university (HBCU) so the students can study the current progress of virology, molecular biology, cell biology, neuroscience, and endocrinology. The long-term goal is to identify the regulatory mechanisms to assist in the development of novel therapeutic protocols for better treatments.
Funding Period: 2012-09-30 - 2017-08-31
more information: NIH RePORT

Detail Information

Research Grants31

  1. Development Structure and Function of Broadly Neutralizing anti-HIV Antibodies
    JEFFREY VICTOR RAVETCH; Fiscal Year: 2013
    ..The proposed research aims to develop an understanding of these antibodies with the long term goal of being able to elicit them de novo as a component of a vaccine to be used in un-infected individuals. ..
  2. University of Maryland Greenebaum Cancer Center Support Grant
    Kevin J Cullen; Fiscal Year: 2013
    ..Reflecting our remarkable and continued growth, UMGCC seeks to renew its CCSG to enhance and expand its efforts in high-quality and clinically relevant cancer research. ..
  3. Serotonin as a Regulator of Bone Mass Accrual: Basic and Clinical
    Gerard Karsenty; Fiscal Year: 2013
    ..Together our studies should provide important and novel insights in the genetic and molecular control of bone remodeling as well as in the pathogenesis and treatment of osteoporosis, a major disease of aging. ..
  4. B-cell Biology of Mucosal Immune Protection from SIV Challenge
    Eric Hunter; Fiscal Year: 2013
    ....
  5. PROTON RADIATION THERAPY RESEARCH
    Thomas F DeLaney; Fiscal Year: 2013
    ..abstract_text> ..
  6. Modulation of histone deacetylase activity by a gammaherpesviral kinase
    Bryan C Mounce; Fiscal Year: 2013
    ..Several orf36 functions are conserved in other gammaherpesviral kinases;thus, the results of our studies are expected to translate to human pathogens. ..
  7. Center for Molecular Imaging Research at MGH/HMS
    Ralph Weissleder; Fiscal Year: 2013
    ....
  8. VIRAL AND HOST FACTORS IN HERPETIC REACTIVATION
    David A Leib; Fiscal Year: 2013
    ..If successful, these aims will bring an improved understanding of host and viral factors involved in HSV pathogenesis. ..
  9. HSV latency and reactivation and the novel neuronal regulation of VP16 in vivo.
    Nancy M Sawtell; Fiscal Year: 2013
    ..The outcomes of this work will identify transcription factors or protein modifying enzymes that could be targets for future development of therapeutic interventions for HSV reactivation. ..
  10. Regulation of lytic and latent infection by HSV-1 encoded miRNAs
    David C Bloom; Fiscal Year: 2013
    ....
  11. Chromatin and Herpes Simplex Virus Latency
    David M Knipe; Fiscal Year: 2013
    ....
  12. 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. ..
  13. Endothelial Injury and Repair: CardioPulmonary Vascular Biology COBRE
    SHARON IRENE SMITH ROUNDS; Fiscal Year: 2013
    ..abstract_text> ..
  14. Pacific Southwest RCE for Biodefense &Emerging Infectious Diseases Research
    Alan G Barbour; Fiscal Year: 2013
    ..abstract_text> ..
  15. Rocky Mountain Regional Center of Excellence or Biodefense and Emerging Infectiou
    John T Belisle; Fiscal Year: 2013
    ..abstract_text> ..
  16. Targeting the DNA damage response pathway for the treatment of HSV esophagitis
    Oleg Alekseev; Fiscal Year: 2013
    ..These studies will impact our understanding of the molecular pathways underlying HSV-1 infection and reactivation from latency, potentially identifying novel therapeutic targets for the treatment of herpes esophagitis. ..
  17. REPRESSION AND ACTIVATION OF PERSISTING HSV GENOMES
    Neal A DeLuca; Fiscal Year: 2013
    ..The completion of these studies will provide a better understanding of the repression and activation of latent genomes. ..
  18. Prevention of VZV Reactivation
    Randall J Cohrs; Fiscal Year: 2013
    ..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. ..
  19. BIOLOGY OF NEUROENDOCRINE PEPTIDES
    Marc R Montminy; Fiscal Year: 2013
    ..Specifying the contributions of the CRF family of ligands and receptors to the maintenance of homeostasis and to stress-linked allostasis may improve our ability to manage diseases, including mood and metabolic disorders ..
  20. Molecular Genetics of HSV Reactivation
    David C Bloom; Fiscal Year: 2013
    ..In addition this work may provide new insight into novel mechanisms of PRC regulation of cellular genes. ..