Comprehensive analysis of human endogenous retrovirus group HERV-W locus transcription in multiple sclerosis brain lesions by high-throughput amplicon sequencing

J Virol. 2013 Dec;87(24):13837-52. doi: 10.1128/JVI.02388-13. Epub 2013 Oct 9.

Abstract

Human endogenous retroviruses (HERVs) of the HERV-W group comprise hundreds of loci in the human genome. Deregulated HERV-W expression and HERV-W locus ERVWE1-encoded Syncytin-1 protein have been implicated in the pathogenesis of multiple sclerosis (MS). However, the actual transcription of HERV-W loci in the MS context has not been comprehensively analyzed. We investigated transcription of HERV-W in MS brain lesions and white matter brain tissue from healthy controls by employing next-generation amplicon sequencing of HERV-W env-specific reverse transcriptase (RT) PCR products, thus revealing transcribed HERV-W loci and the relative transcript levels of those loci. We identified more than 100 HERV-W loci that were transcribed in the human brain, with a limited number of loci being predominantly transcribed. Importantly, relative transcript levels of HERV-W loci were very similar between MS and healthy brain tissue samples, refuting deregulated transcription of HERV-W env in MS brain lesions, including the high-level-transcribed ERVWE1 locus encoding Syncytin-1. Quantitative RT-PCR likewise did not reveal differences in MS regarding HERV-W env general transcript or ERVWE1- and ERVWE2-specific transcript levels. However, we obtained evidence for interindividual differences in HERV-W transcript levels. Reporter gene assays indicated promoter activity of many HERV-W long terminal repeats (LTRs), including structurally incomplete LTRs. Our comprehensive analysis of HERV-W transcription in the human brain thus provides important information on the biology of HERV-W in MS lesions and normal human brain, implications for study design, and mechanisms by which HERV-W may (or may not) be involved in MS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Brain / virology*
  • Case-Control Studies
  • Endogenous Retroviruses / genetics*
  • Endogenous Retroviruses / isolation & purification
  • Genome, Human
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Multiple Sclerosis / genetics*
  • Multiple Sclerosis / virology*
  • Transcription, Genetic*

Associated data

  • GENBANK/HG421036
  • GENBANK/HG421037
  • GENBANK/HG421038
  • GENBANK/HG421039
  • GENBANK/HG421040
  • GENBANK/HG421041
  • GENBANK/HG421042
  • GENBANK/HG421043
  • GENBANK/HG421044
  • GENBANK/HG421045
  • GENBANK/HG421046
  • GENBANK/HG421047
  • GENBANK/HG421048
  • GENBANK/HG421049
  • GENBANK/HG421050
  • GENBANK/HG421051
  • GENBANK/HG421052
  • GENBANK/HG421053
  • GENBANK/HG421054
  • GENBANK/HG421055
  • GENBANK/HG421056
  • GENBANK/HG421057
  • GENBANK/HG421058
  • GENBANK/HG421059
  • GENBANK/HG421060
  • GENBANK/HG421061
  • GENBANK/HG421062
  • GENBANK/HG421063
  • GENBANK/HG421064
  • GENBANK/HG421065
  • GENBANK/HG421066
  • GENBANK/HG421067