Construction of Attenuated Strains for Red-Spotted Grouper Nervous Necrosis Virus (RGNNV) via Reverse Genetic System

Yingying Lei; Yu Xiong; Dagang Tao; Tao Wang; Tianlun Chen; Xufei Du; Gang Cao; Jiagang Tu; Jinxia Dai

doi:10.3390/v14081737

Construction of Attenuated Strains for Red-Spotted Grouper Nervous Necrosis Virus (RGNNV) via Reverse Genetic System

Viruses. 2022 Aug 6;14(8):1737. doi: 10.3390/v14081737.

Authors

Yingying Lei^{1

2}, Yu Xiong^{1

2}, Dagang Tao^{1

2}, Tao Wang¹, Tianlun Chen^{3

4}, Xufei Du³, Gang Cao^{1

2}, Jiagang Tu⁵, Jinxia Dai^{1

2}

Affiliations

¹ State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
² College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
³ Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Chinese Academy of Sciences, Shanghai 200031, China.
⁴ University of Chinese Academy of Sciences, Beijing 100049, China.
⁵ College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.

Abstract

The nervous necrosis virus (NNV) mainly attacks the central nervous system of fish to cause viral nervous necrosis, which is an acute and serious prevalent disease in fish. Among different genotypes of NNV, red-spotted grouper nervous necrosis virus (RGNNV) is the most widely reported, with the highest number of susceptible species. To better understand the pathogenicity of RGNNV, we first developed a reverse genetic system for recombinant RGNNV rescue using B7GG and striped snakehead (SSN-1) cells. Furthermore, we constructed attenuated RGNNV strains rRGNNV-B2-M1 and rRGNNV-B2-M2 with the loss of B2 protein expression, which grew slower and induced less Mx1 expression than that of wild-type RGNNV. Moreover, rRGNNV-B2-M1 and rRGNNV-B2-M2 were less virulent than the wild-type RGNNV. Our study provides a potential tool for further research on the viral protein function, virulence pathogenesis, and vaccine development of RGNNV, which is also a template for the rescue of other fish viruses.

Keywords: B2 protein; RGNNV; reverse genetics; synonymous mutation.

Publication types

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

MeSH terms

Animals
Bass* / genetics
Fish Diseases*
Necrosis
Nodaviridae* / genetics
RNA Virus Infections* / veterinary
Reverse Genetics

Grants and funding

This work was supported by the Key Research and Development Program of Guangdong Province (grant 2019B020211003), the National Natural Science Foundation of China (Grant No. 31972832 and 31902240), the China Postdoctoral Science Foundation (Grant No. 2018M640718).