Investigation of the impact chromosomal integration of human herpes virus 6 (HHV6) has on telomere molecular biology.

Lead Research Organisation: University of Leicester
Department Name: Genetics

Abstract

Human chromosomes are capped by telomeres, which are DNA sequences bound by proteins and they are essential for the stability of the human genome. It is now well known that telomeres play important roles in cellular senescence, which contributes to ageing, and in cancer progression thus it is important to identify and characterise factors that influence telomeres. The human herpesvirus 6 (HHV-6) occurs in two subtypes, A and B, and unlike other human herpes viruses, HHV-6 can insert itself into a chromosome. When it does this it always inserts in or next to a telomere but it is not known if this affects telomere function or whether it contributes to an increased risk of disease. It has been estimated that 1% of the UK population carry an integrated copy of the HHV-6 virus (CI-HHV-6) that is often inherited from a parent and so it is present in all cells of the body. In this project we will determine the nature of the chromosomal insertion site and use the information to understand how the virus inserts and how frequently it achieves this in the germ-line. We will investigate how the human cell controls expression of the viral genes and we will also try to determine whether the presence of CI-HHV-6 affects telomere function in somatic cells and in the germ-line.

Technical Summary

Telomere maintenance and length regulation is central to genome stability and cell immortality and plays important roles both in cancer and ageing. It is therefore important to understand factors that influence telomere function, as deleterious affects can contribute to disease risk. The human herpesvirus 6 can be subdivided into two types, A and B. These viruses often cause a mild illness in early childhood and then persist lifelong in a latent form in some cells. Reactivation of the latent virus often occurs in immuno-compromised patients where it is can be pathogenic. Unlike other human herpesviruses both HHV-6A and 6B can integrate into the telomeric region of chromosomes and the chromosomally integrated form (CI-HHV-6) can be inherited. About 1% of the UK population are carriers for a full-length integrated copy at one chromosome end but the rate and mechanism of germ-line integration are poorly understood. Moreover it is not known whether the presence of CI-HHV-6 influences disease risk in carriers. It is reasonable to hypothesis that the insertion of the ~160kb HHV-6 genome into or near a telomere may affect chromatin organisation and also telomere function. We will conduct experiments to gain insight into the rate of viral insertion and the mechanism by which HHV-6 integrates. This will be achieved in part by the isolation and characterization of viral sequences at the insertion sites from unrelated individuals. If we find evidence of common ancestry it will indicate that the viral insertion rate in the germ-line is low. To determine whether the presence of an integrated virus affects telomere function, we will compare the length of the telomere associate with the CI-HHV-6 to other telomeres in somatic cells and in the germ-line. We will explore the chromatin organisation across the integrated virus to determine whether it is silenced by epigenetic modifications and how these compare to epigenetic modification at another telomere-adjacent region. We will also seek to determine whether components of the Shelterin protein complex bind to the telomere-like repeats present within the HHV-6 genome as this may also interfere with telomere function at this chromosome end.
 
Description MIBTP- PHD studnetship
Amount £76,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 10/2015 
End 09/2019
 
Title PCR based assays for HHV6 integration into any human telomere 
Description We have developed a PCR based method that allows amplification from an HHV6 (in any human chromosome) to the end of the telomere in which it has integrated. We have shown that this method works well in all the human DNA samples that we have tested from donors that carry a germ-line inherited integrated copy of HHV6. 
Type Of Material Technology assay or reagent 
Year Produced 2012 
Provided To Others? Yes  
Impact Has enables a PhD student at a different Institution to use the method in his research 
 
Description CI-HHV-6 - Barts 
Organisation Barts Health NHS Trust
Country United Kingdom 
Sector Public 
PI Contribution The CI-HHV-6 research project was designed and initiated by me. The experimental work and data analysis were conducted by members of my research team and me. PMID: 24057213 The project is ongoing.
Collaborator Contribution Our collaborator in the Department of Virology provided us with some cell lines from CI-HHV-6 carriers with known chromosomal integration sites. In addition this collaborator has given us expertise advice about Human herpes virus-6 molecular biology and pathology. PMID: 24057213
Impact PMID: 24057213
Start Year 2009
 
Description CI-HHV-6 British Isles population survey 
Organisation University of Oxford
Country United Kingdom 
Sector Academic/University 
PI Contribution The CI-HHV-6 research project was designed and initiated by me. The experimental work and data analysis were conducted by members of my research team and me. PMID: 24057213 The project is ongoing.
Collaborator Contribution Our collaborator at the University of Oxford kindly provided us with a panel of DNA samples from the Population of the British Isles. It was particularly valuable that our collaborator was then able to provide us with lymphoblastoid cells lines from CI-HHV-6 carriers we had identified in the screen. PMID: 24057213
Impact PMID: 24057213
Start Year 2011
 
Description CI-HHV-6 in Orkney 
Organisation University of Edinburgh
Department Centre for Population Health Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution The CI-HHV-6 research project was designed and initiated by me. The experimental work and data analysis were conducted by members of my research team and me. PMID: 24057213 The project is ongoing.
Collaborator Contribution Our collaborator at the University of Edinburgh kindly provided us with a panel of 2000 blood DNA samples, in 96 well plate format, form the Orkney population.
Impact PMID: 24057213
Start Year 2011
 
Description CI-HHV-6 in sperm 
Organisation University of Leicester
Department Department of Genetics
Country United Kingdom 
Sector Academic/University 
PI Contribution The CI-HHV-6 research project was designed and initiated by me. The experimental work and data analysis were conducted by members of my research team and me. PMID: 24057213 The project is ongoing.
Collaborator Contribution Our collaborator in the Department of Genetics provided us with a panel of sperm DNA samples that we screened for CI-HHV-6 carriers. We were then able to obtain sufficient DNA for germline telomere length analysis from CI-HHV-6 donors. PMID: 24057213
Impact PMID: 24057213
 
Description MDV - Pirbright Institute 
Organisation The Pirbright Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution Analysis of Marek's Disease Virus (MDV) integration site in telomeres using chicken and quail cell lines
Collaborator Contribution Provides cell lines and DNA samples for analysis . Provides expertise on MDV as a pathogen.
Impact Grant application in development. The collaboration is multi-disciplinary. Pirbright Institute provide expertise in chicken virology. University group has expertise in telomere molecular biology.
Start Year 2015
 
Description Ruth Jarrett and Andrew Davison 
Organisation University of Glasgow
Department MRC - University of Glasgow Centre for Virus Research
Country United Kingdom 
Sector Academic/University 
PI Contribution We generated the HHV-6 DNA templates that were sent for next-generation-sequencing. We contributed the method for generating overlapping amplicons covering iciHHV-6 genomes to Jarrett's group.
Collaborator Contribution Next generation sequencing using Illumina MiSeq. Some droplet digital PCR analysis.
Impact Scientific Reports
Start Year 2013
 
Title Simple PCR based method for detection of chromosomal integration of HHV-6B 
Description Through sequence analysis of integrated copies of HHV6B we have identified a sequence that is present in 98.3% (57/58) copies of CI-HHV6B but absent from the full length consensus sequences of HHV-6B strains that are not integrated (HST and Z29). We have developed a simple PCR assay, based on this sequence, that detects integrated HHV-6B and strains that are capable of integration. 
Type Diagnostic Tool - Non-Imaging
Current Stage Of Development Refinement. Non-clinical
Year Development Stage Completed 2012
Development Status On hold
Impact This assay has the potential to simplify identification of donors or patients with an inherited copy of CI-HHV-6B (currently done using real time PCR to measure copy number of HHV6) but also to facilitate detection of CI-HHV6 following somatic integration, the consequences of which are currently unknown. 
 
Description Flagship lecture 1st year undergraduates 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact Approximately 280 first year undergraduates in Biological Sciences attended a flagship lecture entitled: Genetics, Ageing & Telomeres: the ends insight
Year(s) Of Engagement Activity 2016
 
Description Masterclass giving laboratory training in allele specific PCR based methods 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Type Of Presentation Workshop Facilitator
Geographic Reach Regional
Primary Audience Postgraduate students
Results and Impact Five postgraduates (1st year PhD students) from three different universities took part in the laboratory based practical training class (3 days, full time) . These students learned about allele specific PCR and hybridisation techniques and applications.

Not known at this time.
Year(s) Of Engagement Activity 2012
 
Description Members of my research group contribute to outreach activites for schools 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Type Of Presentation Workshop Facilitator
Geographic Reach Local
Primary Audience Schools
Results and Impact Support for hands on activities designed to increase year 9 pupils knowledge about genetic inheritance. These activities are organised by GENIE (University of Leicester)

Not known
Year(s) Of Engagement Activity 2010,2011,2012
 
Description News feature on HHV-6 Foundation web site 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact It is difficult to quantify the effect of the news article at this time.

It is difficult to measure the impact of the news article at this time. However our paper has been highlighed on a variety of web sites and blogs in multiple languages.
Year(s) Of Engagement Activity 2013
URL http://hhv-6foundation.org/featured/should-transplant-patients-donors-be-screened-for-cihhv-6-an-int...
 
Description Press release - iciHHV-6 ancient 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Press release attracted interest on social media - Twitter etc
Year(s) Of Engagement Activity 2017
 
Description Press release -accomanying a publication in NAR 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Type Of Presentation Paper Presentation
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact It is difficult to quantify the effect of the press release at this time. However our paper has been highlighted on a variety of web sites and blogs in multiple languages.

It is difficult to measure the impact of the press release at this time.
Year(s) Of Engagement Activity 2013
URL http://www2.le.ac.uk/offices/press/press-releases/2013/september/new-research-on-inherited-herpesvir...
 
Description Publication in International Innovation 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact The Article ' Testing telomeres' was about our recent work on chromosomally-integrated human herpesvirus-6.
It stimulated interest from Biotech companies.
Since then has also been used to engage members of the public in our research.

It stimulated preliminary interest from several Biotech companies.
Year(s) Of Engagement Activity 2014
URL http://www.internationalinnovation.com/testing-telomeres/
 
Description Short talk at Genetics 50th Celebrations: Open Day 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Talk stimulated interest, evidenced by comments received following the event

Not measured
Year(s) Of Engagement Activity 2014
 
Description Supporting families with cancer (Health Education Reaching Out, Leicester Oct2012) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Type Of Presentation Poster Presentation
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact 92 attendees of which 55 patients+relatives and 37 stakeholders/speakers/ organisers. We engaged in discussions with families with high cancer risk and with other stakeholders about our research and the potential benefits in the future

Stimulated interest in a screen that we plan to undertake using buccal samples.
Year(s) Of Engagement Activity 2012
 
Description TEN-UK 2018 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Other audiences
Results and Impact Royle from the University of Leicester and two other colleagues, from Univeristy of Sussex and University of Newcastle, organised the first Telomere-network-UK (TEN-UK) 2 day workshop, in Newcastle, Sept 2018. The purpose was to bring together UK research group leaders; potsdoctoral research associates and PhD students who investigate telomeres in a wide variety of species. The workshop promoted interacting between groups and gave early career researchers the opportunity to presnt their work and develop their own networks.
Year(s) Of Engagement Activity 2018