Length variability of telomeric repeat sequences of human herpesvirus 6 DNA

Achour, Abla; Malet, Isabelle; Deback, Claire; Bonnafous, Pascale; Boutolleau, David; Gautheret‐Dejean, Agnès; Agut, Henri

doi:10.1016/j.jviromet.2009.03.002

Cited by 35 publications

(37 citation statements)

References 15 publications

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“…Surprisingly, analyses of all the clones revealed that the BACs, as well as the parental virus from SupT1-infected cells contained a short DR with a size of ϳ2.7 kb. Earlier reports concerning different viral strains have shown that DR sizes were from 8 to 10 kb in different viral isolates (2,19,24,46). Our finding of the ϳ2.7-kb DRs in the BAC clones and in viral replicating DNA raised the question whether the short DRs were an inherent property of the virus or resulted from DR shrinkage during laboratory passaging.…”

Section: Resultsmentioning

confidence: 55%

“…The unit-length DNA molecules are approximately 160 kb, composed of a 143-kb unique (U) segment flanked by left and right direct repeats (DR L and DR R , respectively) (19,24,27,46). The DRs are of sizes 8 to 10 kb in different viral isolates (2,19,24,46). In both the HHV-6A and HHV-6B genomes, the herpesvirus conserved cleavage/packaging signals pac-1 and pac-2 (9,15,17) are located at the left and the right termini of the DRs (17,19,46).…”

mentioning

confidence: 99%

“…The map continues with reiterated perfect hexanucleotide telomeric sequences (GGGTAA) n at positions 7655 to 8008 (19,43). The number of telomeric repeats was found to vary in different viral strains (2,43). The DR terminates with the pac-2 signal.…”

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confidence: 99%

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The DR1 and DR6 First Exons of Human Herpesvirus 6A Are Not Required for Virus Replication in Culture and Are Deleted in Virus Stocks That Replicate Well in T-Cell Lines

Borenstein

Zeigerman

Frenkel

2010

J Virol

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Section: Resultsmentioning

confidence: 55%

mentioning

confidence: 99%

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The DR1 and DR6 First Exons of Human Herpesvirus 6A Are Not Required for Virus Replication in Culture and Are Deleted in Virus Stocks That Replicate Well in T-Cell Lines

Borenstein

Zeigerman

Frenkel

2010

J Virol

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“…In addition to real-time PCR monitoring, viral isolation has been routinely carried out at our institute to demonstrate active HHV-6B infection in ES patients (27), transplant recipients (8), and DIHS patients (17). In contrast to the previous study (25), which used DNA extracted from PBMCs to identify latent HHV-6B infection, DNA extracted from clinical isolates was used in this study. Based on our findings, DNA extracted from clinical isolates was appropriate for determining whether mixed active HHV-6B infections (not latent infections) occurred in immunocompromised patients.…”

Section: Discussionmentioning

confidence: 99%

“…The numbers of copies of telomeric repeat sequences (TRS) that are located in direct repeats of the HHV-6 genome are highly variable among laboratory strains and clinical specimens (25). In order to determine whether mixed infections of HHV-6B occur in immunocompetent and immunocompromised individuals, we examined the TRS copy numbers of clinical isolates obtained from ES and DIHS patients and HSCT recipients by using PCR and direct sequencing of the PCR products.…”

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confidence: 99%

Copy Numbers of Telomeric Repeat Sequences of Human Herpesvirus 6B in Clinical Isolates: Possibility of Mixed Infections

et al. 2014

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In order to determine whether mixed infections of human herpesvirus 6B (HHV-6B) occur in immunocompetent and immunocompromised individuals, we examined the copy numbers of telomeric repeat sequences (TRS) of clinical isolates. In clinical isolates obtained from patients with exanthem subitum caused by primary HHV-6B infection, PCR products with HHV-6B TRS ranging between 400 and 800 bp were amplified. PCR products of various sizes were amplified in four clinical isolates from druginduced hypersensitivity syndrome (DIHS) patients and 15 isolates from hematopoietic stem cell transplant (HSCT) recipients with HHV-6B reactivation. Based on the sequence analysis of the PCR products, the copy numbers of TRS in DIHS and HSCT patients were between 42 and 82 and 22 and >90, respectively. For two of the HSCT recipients, HHV-6B TRS PCR products of different sizes were detected in several isolates from each patient, which suggests mixed HHV-6B infections. In two of the posttransplant HHV-6B encephalitis patients, the sizes of the TRS nested PCR products amplified from the reactivated virus detected in the central nervous system differed from those of the virus detected in initial isolates from peripheral blood mononuclear cells. Taken together, these results suggest that PCR analysis of TRS copy number is a reliable tool for the discrimination of HHV-6B clinical isolates. Additionally, mixed HHV-6B infections occurred in HSCT recipients, and in some cases, compartmentalization of the HHV-6B strains to the central nervous system versus the blood compartment occurred in posttransplant HHV-6B encephalitis patients. Primary human herpesvirus 6B (HHV-6B) infection presenting as exanthem subitum (ES) (1, 2) is considered a benign febrile illness and rarely causes neurological complications, such as febrile convulsion and encephalitis (3, 4). In addition to the primary infection, HHV-6 reactivation may be associated with acute graftversus-host disease (5-8), graft rejection (9), and encephalitis (10-13) in transplant recipients. Moreover, the virus can be reactivated in patients with drug-induced hypersensitivity syndrome (DIHS), which is a severe form of drug allergy that is characterized by fever, skin rash, lymphadenopathy, hepatitis, and leukocytosis (14-16). Active HHV-6B infection generally occurs only once throughout life (at the time of the primary infection) in immunocompetent individuals, but it may occur several times in transplant recipients (8) or DIHS patients (17). Frequent HHV-6B reactivation, as evidenced by the repeated isolation of the virus during an active viral infection, was observed in hematopoietic stem cell transplant (HSCT) recipients (8, 18).Previous reports detected mixed infections with multiple cytomegalovirus (CMV) strains in the same human herpesvirus subfamily (Betaherpesvirinae subfamily) as HHV-6B in a variety of patient populations, including immunocompetent and immunocompromised patients (19)(20)(21)(22). Furthermore, other studies have suggested that the genotype of the virus may be associate...

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Review, part 1: Human herpesvirus‐6‐basic biology, diagnostic testing, and antiviral efficacy

Flamand

Komaroff

Arbuckle

et al. 2010

Journal of Medical Virology

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Length variability of telomeric repeat sequences of human herpesvirus 6 DNA

Cited by 35 publications

References 15 publications

The DR1 and DR6 First Exons of Human Herpesvirus 6A Are Not Required for Virus Replication in Culture and Are Deleted in Virus Stocks That Replicate Well in T-Cell Lines

The DR1 and DR6 First Exons of Human Herpesvirus 6A Are Not Required for Virus Replication in Culture and Are Deleted in Virus Stocks That Replicate Well in T-Cell Lines

Copy Numbers of Telomeric Repeat Sequences of Human Herpesvirus 6B in Clinical Isolates: Possibility of Mixed Infections

Review, part 1: Human herpesvirus‐6‐basic biology, diagnostic testing, and antiviral efficacy

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