Limits...
Stability of glycoprotein gene sequences of herpes simplex virus type 2 from primary to recurrent human infection, and diversity of the sequences among patients attending an STD clinic.

Haarr L, Nilsen A, Knappskog PM, Langeland N - BMC Infect. Dis. (2014)

Bottom Line: No nucleotide substitution was observed in any patient, indicating genetic stability.However, since the total number of nucleotides in these genes is only a small part of the total genome, we cannot rule out variation in other regions.We observed that several glycoprotein gene sequences are stable from primary to recurrent infection.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Clinical Science, The Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway. lars.haarr@k2.uib.no.

ABSTRACT

Background: Herpes simplex virus type 2 (HSV-2) is sexually transmitted, leading to blisters and ulcers in the genito-anal region. After primary infection the virus is present in a latent state in neurons in sensory ganglia. Reactivation and production of new viral particles can cause asymptomatic viral shedding or new lesions. Establishment of latency, maintenance and reactivation involve silencing of genes, continuous suppression of gene activities and finally gene activation and synthesis of viral DNA. The purpose of the present work was to study the genetic stability of the virus during these events.

Methods: HSV-2 was collected from 5 patients with true primary and recurrent infections, and the genes encoding glycoproteins B,G,E and I were sequenced.

Results: No nucleotide substitution was observed in any patient, indicating genetic stability. However, since the total number of nucleotides in these genes is only a small part of the total genome, we cannot rule out variation in other regions.

Conclusions: Although infections of cell cultures and animal models are useful for studies of herpes simplex virus, it is important to know how the virus behaves in the natural host. We observed that several glycoprotein gene sequences are stable from primary to recurrent infection. However, the virus isolates from the different patients were genetically different.

Show MeSH

Related in: MedlinePlus

Genetic relationship between the viruses included in the study. The tree is based upon the open reading frame nucleotide sequences of the genes encoding gB, gG, gI and gE.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3924402&req=5

Figure 1: Genetic relationship between the viruses included in the study. The tree is based upon the open reading frame nucleotide sequences of the genes encoding gB, gG, gI and gE.

Mentions: The four glycoprotein genes were sequenced in all HSV-2 isolates. Sequencing spanned the entire open reading frames and a variable number of nucleotides in the 5′- and 3′- untranscribed regions of each gene. When analysing the results from each patient separately, comparing sequences from primary to recurrent infection, no difference was detected in any patient, as indicated in Figure 1. One might not expect a substantial variation due to mutation, since proof reading during synthesis of HSV-DNA has been reported to be efficient and the rate of nucleotide substitution estimated to be 3 × 10-8 per site per year [34]. Similar genetic stability of HSV-2 has been observed under other conditions. Terhune et al. [35] studied isolates of HSV-2 propagated in cell culture and did not observe sequence variation in any of the genes encoding gB, gC and gD, respectively. Figure 1 also shows the genetic relationship between the viruses isolated from the 5 patients. All 5 isolates are clearly different.


Stability of glycoprotein gene sequences of herpes simplex virus type 2 from primary to recurrent human infection, and diversity of the sequences among patients attending an STD clinic.

Haarr L, Nilsen A, Knappskog PM, Langeland N - BMC Infect. Dis. (2014)

Genetic relationship between the viruses included in the study. The tree is based upon the open reading frame nucleotide sequences of the genes encoding gB, gG, gI and gE.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3924402&req=5

Figure 1: Genetic relationship between the viruses included in the study. The tree is based upon the open reading frame nucleotide sequences of the genes encoding gB, gG, gI and gE.
Mentions: The four glycoprotein genes were sequenced in all HSV-2 isolates. Sequencing spanned the entire open reading frames and a variable number of nucleotides in the 5′- and 3′- untranscribed regions of each gene. When analysing the results from each patient separately, comparing sequences from primary to recurrent infection, no difference was detected in any patient, as indicated in Figure 1. One might not expect a substantial variation due to mutation, since proof reading during synthesis of HSV-DNA has been reported to be efficient and the rate of nucleotide substitution estimated to be 3 × 10-8 per site per year [34]. Similar genetic stability of HSV-2 has been observed under other conditions. Terhune et al. [35] studied isolates of HSV-2 propagated in cell culture and did not observe sequence variation in any of the genes encoding gB, gC and gD, respectively. Figure 1 also shows the genetic relationship between the viruses isolated from the 5 patients. All 5 isolates are clearly different.

Bottom Line: No nucleotide substitution was observed in any patient, indicating genetic stability.However, since the total number of nucleotides in these genes is only a small part of the total genome, we cannot rule out variation in other regions.We observed that several glycoprotein gene sequences are stable from primary to recurrent infection.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Clinical Science, The Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway. lars.haarr@k2.uib.no.

ABSTRACT

Background: Herpes simplex virus type 2 (HSV-2) is sexually transmitted, leading to blisters and ulcers in the genito-anal region. After primary infection the virus is present in a latent state in neurons in sensory ganglia. Reactivation and production of new viral particles can cause asymptomatic viral shedding or new lesions. Establishment of latency, maintenance and reactivation involve silencing of genes, continuous suppression of gene activities and finally gene activation and synthesis of viral DNA. The purpose of the present work was to study the genetic stability of the virus during these events.

Methods: HSV-2 was collected from 5 patients with true primary and recurrent infections, and the genes encoding glycoproteins B,G,E and I were sequenced.

Results: No nucleotide substitution was observed in any patient, indicating genetic stability. However, since the total number of nucleotides in these genes is only a small part of the total genome, we cannot rule out variation in other regions.

Conclusions: Although infections of cell cultures and animal models are useful for studies of herpes simplex virus, it is important to know how the virus behaves in the natural host. We observed that several glycoprotein gene sequences are stable from primary to recurrent infection. However, the virus isolates from the different patients were genetically different.

Show MeSH
Related in: MedlinePlus