Variation in human herpesvirus 6B telomeric integration, excision and transmission between tissues and individuals
- University of Leicester, United Kingdom
- MRC-University of Glasgow Centre for Virus Research, United Kingdom
- University of Groningen, Netherlands
- University of Manchester, United Kingdom
- Centre hospitalier de l'Université Laval, Canada
Abstract
Human herpesviruses 6A and 6B (HHV-6A/6B) are ubiquitous pathogens that persist lifelong in latent form and can cause severe conditions upon reactivation. They are spread by community-acquired infection of free virus (acqHHV6A/6B) and by germline transmission of inherited chromosomally-integrated HHV-6A/6B (iciHHV-6A/6B) in telomeres. We exploited a hypervariable region of the HHV-6B genome to investigate the relationship between acquired and inherited virus and revealed predominantly maternal transmission of acqHHV-6B in families. Remarkably, we demonstrate that some copies of acqHHV-6B in saliva from healthy adults gained a telomere, indicative of integration and latency, and that the frequency of viral genome excision from telomeres in iciHHV-6B carriers is surprisingly high and varies between tissues. In addition, newly formed short telomeres generated by partial viral genome release are frequently lengthened, particularly in telomerase-expressing pluripotent cells. Consequently, iciHHV-6B carriers are mosaic for different iciHHV-6B structures, including circular extra-chromosomal forms that have the potential to reactivate. Finally, we show transmission of an HHV-6B strain from an iciHHV-6B mother to her non-iciHHV-6B son. Altogether we demonstrate that iciHHV-6B can readily transition between telomere-integrated and free virus forms.
Data availability
Sequencing data have been deposited in GenBank under accession numbers: MW049313-MW049327.The HHV6 explorer is freely available at https://www.hhv6explorer.org/ and so The source code for the HHV6 explorer and HHV6 counter are available at https://github.com/colinveal/HHV6-Explorer.Other data generated or analysed during this study are included in the manuscript and supporting files.
Article and author information
Author details
Funding
Biotechnology and Biological Sciences Research Council (MIBTP 1645656)
- Michael L Wood
Medical Research Council (G0901657)
- Nicola J Royle
HHV-6 Foundation (Pilot grant)
- Nicola J Royle
Canadian Institutes of Health Research (MOP 123214)
- Louis Flamand
European Commission (FP7-242209- BIOSTAT-CHF)
- Adriaan A Voors
Medical Research Council (MC_UU_12014/3)
- Andrew J Davison
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: The study was conducted in accordance with the Declaration of Helsinki and with approval by the relevant ethics committees as follows:The University of Leicester's Research Ethics Committee (refs: 10553-njr-genetics; njr-61d3).The BIOSTAT-CHF study was approved by the relevant ethics committee in each centre, all participants gave their written, informed consent to participate (Voors et al, 2016).
Copyright
© 2021, Wood et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 1,290
- views
-
- 118
- downloads
-
- 11
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Variation in human herpesvirus 6B telomeric integration, excision and transmission between tissues and individuals
eLife 10:e70452.
https://doi.org/10.7554/eLife.70452
Further reading
-
- Genetics and Genomics
Resistance to anthelmintics, particularly the macrocyclic lactone ivermectin (IVM), presents a substantial global challenge for parasite control. We found that the functional loss of an evolutionarily conserved E3 ubiquitin ligase, UBR-1, leads to IVM resistance in Caenorhabditis elegans. Multiple IVM-inhibiting activities, including viability, body size, pharyngeal pumping, and locomotion, were significantly ameliorated in various ubr-1 mutants. Interestingly, exogenous application of glutamate induces IVM resistance in wild-type animals. The sensitivity of all IVM-affected phenotypes of ubr-1 is restored by eliminating proteins associated with glutamate metabolism or signaling: GOT-1, a transaminase that converts aspartate to glutamate, and EAT-4, a vesicular glutamate transporter. We demonstrated that IVM-targeted GluCls (glutamate-gated chloride channels) are downregulated and that the IVM-mediated inhibition of serotonin-activated pharynx Ca2+ activity is diminished in ubr-1. Additionally, enhancing glutamate uptake in ubr-1 mutants through ceftriaxone completely restored their IVM sensitivity. Therefore, UBR-1 deficiency-mediated aberrant glutamate signaling leads to ivermectin resistance in C. elegans.
-
- Genetics and Genomics
Osteoporosis, characterized by reduced bone density and strength, increases fracture risk, pain, and limits mobility. Established therapies of parathyroid hormone (PTH) analogs effectively promote bone formation and reduce fractures in severe osteoporosis, but their use is limited by potential adverse effects. In the pursuit of safer osteoporosis treatments, we investigated R25CPTH, a PTH variant wherein the native arginine at position 25 is substituted by cysteine. These studies were prompted by our finding of high bone mineral density in a hypoparathyroidism patient with the R25C homozygous mutation, and we explored its effects on PTH type-1 receptor (PTH1R) signaling in cells and bone metabolism in mice. Our findings indicate that R25CPTH(1–84) forms dimers both intracellularly and extracellularly, and the synthetic dimeric peptide, R25CPTH(1–34), exhibits altered activity in PTH1R-mediated cyclic AMP (cAMP) response. Upon a single injection in mice, dimeric R25CPTH(1–34) induced acute calcemic and phosphaturic responses comparable to PTH(1–34). Furthermore, repeated daily injections increased calvarial bone thickness in intact mice and improved trabecular and cortical bone parameters in ovariectomized (OVX) mice, akin to PTH(1–34). The overall results reveal a capacity of a dimeric PTH peptide ligand to activate the PTH1R in vitro and in vivo as PTH, suggesting a potential path of therapeutic PTH analog development.
