title: Possible chromosomal and germline integration of human herpesvirus 7.
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.
authors.affiliation: Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Bhupesh K
authors.initials: BK
authors.lastname: Prusty
authors.affiliation: Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Nitish
authors.initials: N
authors.lastname: Gulve
authors.affiliation: August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, 1069 Riga, Latvia.
authors.forename: Santa
authors.initials: S
authors.lastname: Rasa
authors.affiliation: August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, 1069 Riga, Latvia.
authors.forename: Modra
authors.initials: M
authors.lastname: Murovska
authors.affiliation: Hospital Clinico Universitario Lozano Blesa, 50009 Zaragoza, Spain.
authors.forename: Pilar Collado
authors.initials: PC
authors.lastname: Hernandez
authors.affiliation: HHV-6 Foundation, Santa Barbara, CA 93101, USA.
authors.forename: Dharam V
authors.initials: DV
authors.lastname: Ablashi
mesh_terms: D000328:Adult; D001773:Blood Cells / Q000821:virology; D002460:Cell Line; D002877:Chromosomes, Human / Q000821:virology*; D005260:Female; D016679:Genome, Viral; D005854:Germ Cells / Q000821:virology*; D018859:Hair Follicle / Q000821:virology; D016199:Herpesvirus 7, Human / Q000235:genetics* / Q000502:physiology*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D019349:Roseolovirus Infections / Q000635:transmission / Q000821:virology*; D016615:Telomere / Q000821:virology*; D016662:Virus Integration