Generation and Characterization of Monoclonal Antibodies Against Red-Spotted Grouper Nervous Necrosis Virus (RGNNV)

Nervous necrosis virus (NNV) can infect more than 120 fish species worldwide and has caused high mortality and significant economic losses to the aquaculture industry. Among different genotypes of NNV, the red-grouper nervous necrosis virus (RGNNV) is the most widely distributed one with the highest number of susceptible fish species. In this study, the capsid protein (Cp) gene of RGNNV was recombined and expressed in Escherichia coli strain BL21 (DE3) and the recombinant Cp (rCp) was used as an immunogen to produce monoclonal antibodies (MAbs) through hybridoma cell fusion technology. Three MAbs were produced and characterized by indirect enzyme-linked immunosorbent assay (ELISA), western blotting, and immunofluorescence assay (IFA). Western blotting result showed that the MAbs could specifically react with the capsid protein of RGNNV. The result of IFA showed that the MAbs could recognize virions in RGNNV-infected grouper spleen (GS) cells. These results indicate that the MAbs can specifically recognize RGNNV virions and can be used to produce a rapid detection method. This study provides a foundation for further studies on the rapid diagnosis of RGNNV and its infection mechanisms.