Possible chromosomal and germline integration of human herpesvirus 7

J Gen Virol. 2017 Feb;98(2):266-274. doi: 10.1099/jgv.0.000692.

Abstract

Human herpesvirus 7 (HHV-7) is a betaherpesvirus, and is phylogenetically related to both HHV-6A and HHV-6B. The presence of telomeric repeat sequences at both ends of its genome should make it equally likely to integrate into the human telomere as HHV-6. However, numerous studies have failed to detect germline integration of HHV-7, suggesting an important difference between the HHV-6A/-6B and HHV-7 genomes. In search of possible germline integrated HHV-7, we developed a sensitive and quantitative real-time PCR assay and discovered that primers designed against some parts of the HHV-7 genome can frequently miss HHV-7 positive clinical samples even though they work efficiently in cell-culture-derived HHV-7 positive materials. Using a primer pair against the U90 ORF of HHV-7, we identified a possible case of germline integration of HHV-7 with one copy of viral genome per cell in both peripheral blood cells and hair follicles. Chromosomal integration of HHV-7 in these individuals was confirmed by fluorescence in situ hybridization analysis. Germline integration of HHV-7 was further confirmed by detection of ~2.6 copies of HHV-7 in the hair follicles of one of the parents. Our results shed light on the complex nature of the HHV-7 genome in human-derived materials in comparison to cell-culture-derived materials and show the need for stringent criteria in the selection of primers for epidemiological HHV-7 studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Cells / virology
  • Cell Line
  • Chromosomes, Human / virology*
  • Female
  • Genome, Viral
  • Germ Cells / virology*
  • Hair Follicle / virology
  • Herpesvirus 7, Human / genetics*
  • Herpesvirus 7, Human / physiology*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Male
  • Roseolovirus Infections / transmission
  • Roseolovirus Infections / virology*
  • Telomere / virology*
  • Virus Integration*