Development of a gene-deleted live attenuated candidate vaccine against fish virus (ISKNV) with low pathogenicity and high protection

Ruoyun Zeng; Weiqiang Pan; Yifan Lin; Jian He; Zhiyong Luo; Zhimin Li; Shaoping Weng; Jianguo He; Changjun Guo

doi:10.1016/j.isci.2021.102750

Development of a gene-deleted live attenuated candidate vaccine against fish virus (ISKNV) with low pathogenicity and high protection

iScience. 2021 Jun 19;24(7):102750. doi: 10.1016/j.isci.2021.102750. eCollection 2021 Jul 23.

Authors

Ruoyun Zeng^{1

2}, Weiqiang Pan¹, Yifan Lin², Jian He¹, Zhiyong Luo¹, Zhimin Li¹, Shaoping Weng², Jianguo He^{1

2}, Changjun Guo^{1

2}

Affiliations

¹ State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong 510006, PR China.
² Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.

Abstract

Aquaculture provides important food, nutrition, and income sources for humans. However, aquaculture industry is seriously threatened by viral diseases. Infectious spleen and kidney necrosis virus (ISKNV) disease causes high mortality and economic losses to the fish culture industry in Asia and has been listed as a certifiable disease by the International Epizootic Office. Vaccine development is urgent to control this disease. Here, a gene-deleted live attenuated candidate vaccine (ΔORF022L) against ISKNV with low pathogenicity and high protection was developed. ΔORF022L replicated well in mandarin fish fry-1 cells and showed similar structure with wild-type ISKNV. However, the pathogenicity was significantly lower as 98% of the mandarin fish infected with ΔORF022L survived, whereas all those infected with wild-type ISKNV died. Of importance, 100% of the ΔORF022L-infected fish survived the ISKNV challenge. ΔORF022L induced anti-ISKNV specific antibody response and upregulation of immune-related genes. This work could be beneficial to the control of fish diseases.

Keywords: Aquaculture diseases; Virology.