Human herpesvirus 6 integrates within telomeric regions as evidenced by five dif

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J Med Virol. 2008 Nov;80(11):1952-8. Links

Human herpesvirus 6 integrates within telomeric regions as evidenced

by five different chromosomal sites.Nacheva EP, Ward KN, Brazma D,

Virgili A, J, Leong HN, DA.

Department of Haematology, Royal Free & University College Medical

School (Hampstead Campus), London, United Kingdom. e.nacheva@...

Fluorescent in situ hybridization (FISH) was used to investigate the

chromosomal integration sites of human herpesvirus 6 (HHV-6) in

phytohemagglutinin-stimulated leukocytes and B lymphocytes from

Epstein-Barr virus transformed lymphoblastoid cell lines (LCLs). Five

different chromosomal integration sites were found in nine

individuals. Only one site was identified in each individual, each

site was in the vicinity of the telomeric region and was on either

the p or q arm of only one of the two chromosome homologues. The

sites were 9q34.3, 10q26.3, 11p15.5, 17p13.3, and 19q 13.4, of which

three have not been previously identified. For 9q34.3 the site of

integration was further mapped using a locus-specific probe for

9q34.3 together with a pan-telomeric probe and both co-localized with

the HHV-6 signal. Similarly an arm-specific telomeric probe for 19q

co-localized with the HHV-6 signal. It was therefore concluded that

the site of integration is actually within the telomere. The number

of viral DNA copies/cell was calculated in blood, LCL cells and hair

follicles and was one or more in every case for each of the nine

individuals. This result was confirmed by FISH where 100% of cells

gave an HHV-6 signal. These findings add to previous reports

suggesting that integrated HHV-6 DNA is found in every cell in the

body and transmitted vertically. Finally, including our data,

worldwide seven different chromosomal sites of HHV-6 integration have

now been identified. Large epidemiological studies of chromosomal

integration are required to identify further telomeric sites,

geographical or racial variation and possible clinical consequences.

2008 Wiley-Liss, Inc.