Preliminary study on the biological characteristics of the isolate of vaccinia virus Tiantan strain VG9
10.3760/cma.j.cn112309-20241112-00384
- VernacularTitle:痘苗病毒天坛广-9分离株的生物学特性初步研究
- Author:
Yunpeng WANG
1
;
Shouchun CAO
1
;
Xiaohong WU
1
;
Jia LI
1
;
Leitai SHI
1
;
Danhua ZHAO
1
;
Changgui LI
1
;
Qiang YE
1
Author Information
1. 中国食品药品检定研究院 中国医学科学院创新疫苗质量评价与标准化研究创新单元，北京 102629
- Publication Type:Journal Article
- Keywords:
Vaccinia virus;
Biological characteristics;
Immunofluorescence;
Next-generation sequencing;
Bioinformatics analysis
- From:
Chinese Journal of Microbiology and Immunology
2024;44(12):1059-1066
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To further study on the biological characteristics of vaccinia virus VG9 strain obtained by passaging from vaccinia virus Tiantan strain(VTT).Methods:The freeze-dried vaccinia virus VG9 strain was reconstituted and inoculated into Vero cells for recovery and sequential passaging. The strain was identified by indirect immunofluorescence and PCR amplification. The whole genome of VG9 was sequenced using next-generation sequencing technology. The sequencing results were compared with the reference sequence of VTT and the genome sequences of other 33 orthopoxviral strains, and a phylogenetic tree was drawn. A purified clone of VG9, namely VG9-V3-3, was obtained by terminal dilution method. Preliminary studies were conducted to characterize the biological properties of this clone, such as virus titer and intradermal virulence in rabbit.Results:VG9 could specifically bind to the rabbit antibody of VTT by indirect immunofluorescence identification, and the PCR amplification results proved that this strain contained the characteristic TK gene fragment of vaccinia virus. Whole-genome sequencing showed that the genome length of VG9 was 183 596 bp, including 165 150 bp in coding region. The sequencing results were compared with the NCBI core nucleotide database, and showed that the sequences of VG9 and multiple existing Tiantan isolates were highly homologous (consistency>99.5%). Sequence comparison revealed a total of 749 nucleotide site differences between the gene sequences of VG9 and TP5 isolate of VTT. The viral titer of the VG9-V3-3 isolate was 6.3 lg (PFU/ml), and the rabbit intradermal virulence assay showed that its virulence was significantly weakened compared with that of VTT.Conclusions:The biological characteristics of vaccinia virus VG9 strain are preliminarily studied and a purified clone strain named VG9-V3-3 is obtained. The viral titer of the isolate is basically stable, and the virulence is significantly weakened compared with that of VTT. In-depth study on the immunogenicity of VG9-V3-3 will be carried out in the future to explore its feasibility as a vaccine production strain.
