MSK
Search
- Page Path
- HOME > Search
Journal Articles
- Increase in the genetic polymorphism of varicella-zoster virus after passaging in in vitro cell culture
- Hye Rim Hwang , Seok Cheon Kim , Se Hwan Kang , Chan Hee Lee
- J. Microbiol. 2019;57(11):1033-1039. Published online October 28, 2019
- DOI: https://doi.org/10.1007/s12275-019-9429-4
- 11 View
- 0 Download
- 2 Citations
-
Abstract
- Primary infections with the varicella-zoster virus (VZV) result in varicella, while latent reactivation leads to herpes zoster. Both varicella and zoster can be prevented by live attenuated vaccines. There have been reports suggesting that both clinical VZV strains and those in vaccine preparations are genetically polymorphic, containing mixtures of both wild-type and vaccine-type sequences at certain vaccine-specific sites. In this study, the genetic polymorphism of the VZV genome was examined by analyzing the frequencies of minor alleles at each nucleotide position. Next-generation sequencing of the clinical VZV strain YC02 passaged in an in vitro cell culture was used to identify genetically polymorphic sites (GPS), where the minor allele frequency (MAF) exceeded 5%. The number of GPS increased by 7.3-fold at high passages (p100) when compared to low passages (p17), although the average MAF remained similar. GPS were found in 6 open reading frames (ORFs) in p17, 35, and 54 ORFs in p60 and p100, respectively. GPS were found more frequently in the dispensable gene group than the essential gene group, but the average MAF was greater in the essential gene group. The most common two major/minor base pairs were A/g and T/c. GPS were found in all three passages at 16 positions, all located in the reiterated (R) region. The population diversity as measured by Shannon entropy increased in p60 and p100. However, the entropy remained unchanged in the R regions.
- Analysis of IE62 mutations found in Varicella-Zoster virus vaccine strains for transactivation activity
- Hyemin Ko , Gwang Myeong Lee , Ok Sarah Shin , Moon Jung Song , Chan Hee Lee , Young Eui Kim , Jin-Hyun Ahn
- J. Microbiol. 2018;56(6):441-448. Published online June 1, 2018
- DOI: https://doi.org/10.1007/s12275-018-8144-x
- 11 View
- 0 Download
- 2 Citations
-
Abstract
- Live attenuated vaccine strains have been developed for Varicella- Zoster virus (VZV). Compared to clinically isolated strains, the vaccine strains contain several non-synonymous mutations in open reading frames (ORFs) 0, 6, 31, 39, 55, 62, and 64. In particular, ORF62, encoding an immediate-early (IE) 62 protein that acts as a transactivator for viral gene expression, contains six non-synonymous mutations, but whether these mutations affect transactivation activity of IE62 is not understood. In this study, we investigated the role of non-synonymous vaccine-type mutations (M99T, S628G, R958G, V1197A, I1260V, and L1275S) of IE62 in Suduvax, a vaccine strain isolated in Korea, for transactivation activity. In reporter assays, Suduvax IE62 showed 2- to 4-fold lower transactivation activity toward ORF4, ORF28, ORF29, and ORF68 promoters than wild-type IE62. Introduction of individual M99T, S628G, R958G, or V1197A/ I1260V/L1275S mutations into wild-type IE62 did not affect transactivation activity. However, the combination of M99T within the N-terminal Sp transcription factor binding region and V1197A/I1260V/L1275S within the C-terminal serineenriched acidic domain (SEAD) significantly reduced the transactivation activity of IE62. The M99T/V1197A/I1260V/ L1275S mutant IE62 did not show considerable alterations in intracellular distribution and Sp3 binding compared to wild-type IE62, suggesting that other alteration(s) may be responsible for the reduced transactivation activity. Collectively, our results suggest that acquisition of mutations in both Met 99 and the SEAD of IE62 is responsible for the reduced transactivation activity found in IE62 of the VZV vaccine strains and contributes to attenuation of the virus.
- Characterization and phylogenetic analysis of Varicella-zoster virus strains isolated from Korean patients
- Min Ho Kim , Jeong Seon Jeon , In Kyo Kim , Ji Seon Park , Hosun Park , Ok Sarah Shin , Chan Hee Lee
- J. Microbiol. 2017;55(8):665-672. Published online July 28, 2017
- DOI: https://doi.org/10.1007/s12275-017-7171-3
- 15 View
- 0 Download
- 5 Citations
-
Abstract
- Varicella-zoster virus (VZV) is a causative agent of chickenpox in primary infection and shingles after its reactivation from latency. Complete or almost-complete genomic DNA sequences for various VZV strains have been reported. Recently, clinical VZV strains were isolated from Korean patients whose genome was sequenced using high-throughput sequencing technology. In this study, we analyzed single nucleotide polymorphism (SNP) of VZV strains to genetically characterize Korean clinical isolates. Phylogenetic analyses revealed that three Korean strains, YC01, YC02, and YC03, were linked to clade 2. Comprehensive SNP analysis identified 86 sites specific for the 5 VZV clades. VZV strains isolated from Korea did not form a phylogenetic cluster. Rather, YC02 and YC03 clustered strongly with Chinese strain 84-7 within clade 2, more specifically cluster 2a. Signature sequences for the cluster 2a were identified and found to play an important role in the separation of cluster 2a strains from other clade 2 strains, as shown in substitution studies. Further genetic analysis with additional strains isolated from Japan, China, and other Asian countries would provide a novel insight into the significance of two distinct subclades within clade 2.
First
Prev
TOP
