Genomic analysis of a Chinese MDV strain derived from vaccine strain CVI988 through recombination

Liangliang He; Jie Li; Peng Peng; Jingsong Nie; Jun Luo; Yongchang Cao; Chunyi Xue

doi:10.1016/j.meegid.2019.104045

Genomic analysis of a Chinese MDV strain derived from vaccine strain CVI988 through recombination

Infect Genet Evol. 2020 Mar:78:104045. doi: 10.1016/j.meegid.2019.104045. Epub 2019 Nov 4.

Authors

Liangliang He¹, Jie Li², Peng Peng¹, Jingsong Nie¹, Jun Luo³, Yongchang Cao¹, Chunyi Xue⁴

Affiliations

¹ State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.
² School of Biology and Food Engineering, Changshu Institute of Technology, Changshu 215500, China.
³ Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China; College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China.
⁴ State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China. Electronic address: xuechy@mail.sysu.edu.cn.

PMID: 31698116
DOI: 10.1016/j.meegid.2019.104045

Abstract

Disease caused by Marek's disease virus (MDV), a highly oncogenic alpha-herpesvirus, is controlled mainly by vaccination. Since 1990s, CVI988 has been widely used as vaccine strain. However, as an attenuated live vaccine, CVI988 has the potential of virulence enhancement and the risk of recombination that should be considered. In this study, we sequenced the whole genome of a Chinese strain HNLC503 and found the close relationship between HNLC503 and CVI988. Further study indicated that HNLC503 had undergone recombination in US region, the same position as that previously occurred in Eurasian strains isolated from 2010 to 2014. By comparing ORFs, it was found that non-synonymous mutations were introduced in US2, US3, SORF4 and gD genes by recombination, while natural mutations occurred in RLORF1, vIL-8, UL36, VP22 and gE, in HNLC503. In summary, our study revealed the phenomenon of MDV vaccine strain recombination, warning that vaccine strains have the potential to enhance virulence through recombination.

Keywords: Complete genome; MDV; Phylogenetic analysis; Recombination; Vaccine.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Line
Chick Embryo
Genome, Viral
High-Throughput Nucleotide Sequencing
Marek Disease Vaccines / genetics*
Mutation*
Recombination, Genetic*
Vaccines, Attenuated / genetics
Whole Genome Sequencing / methods*

Substances

Marek Disease Vaccines
Vaccines, Attenuated