Development of a VP38 recombinant protein‐based indirect ELISA for detection of antibodies against grass carp reovirus genotype II (iELISA for detection of antibodies against GCRV II)

Abstract

Currently, serological assays for grass carp reovirus genotype II (GCRV‐II) diagnosis are not available. In this study, an indirect enzyme‐linked immunosorbent assay (ELISA) for the detection of antibodies against GCRV‐II was developed. The structural protein VP38 of GCRV‐II was used as the coating antigen. Monoclonal antibodies (mAb) against IgM of grass carp labelled with HRP were used as a secondary antibody. The antigen concentration and serum dilution were optimized using chess board titration. Furthermore, the specificity of indirect ELISA assay was confirmed by cross check with sera positive for other grass carp pathogens. In comparison with results obtained from indirect immunofluorescence assay (IFA) and Western blot by testing of 60 serum samples to evaluate the sensitivity and specificity of the ELISA, agreement between 90% and 96.7% was reached, respectively. A serological survey was performed using the assay with grass carp field serum samples. The seropositive rate of the 242 serum samples was 69.8%. In conclusion, the developed indirect ELISA is a very specific and sensitive test that will be useful for large‐scale serological surveys to detect indirectly GCRV II infections as well as to monitor the changes of antibody level after immunization.

Recombinant Baculovirus-Produced Grass Carp Reovirus Virus-Like Particles as Vaccine Candidate That Provides Protective Immunity against GCRV Genotype II Infection in Grass Carp

“…Chen et al (2018) vaccinated grass carp with a DNA vaccine consisting of the VP4, and the relative percentage of survival (RPS) was about 59.9% after the grass carp were challenged with GCRV [26,27]. VP38 can induce high titers of specific antibodies [28]. Therefore, these proteins encoded by those segments are good candidates to design GCRV vaccines.…”

Rapid detection of grass carp reovirus type 1 using RPA-based test strips combined with CRISPR Cas13a system

“…In fact, GCRV is usually diagnosed on the basis of viral genome and antibody detection. If viral antibody is detected, the majority of serological detection methods are conducted on the basis of enzyme-linked immunosorbent assay (ELISA) due to its straightforwardness and cost-effectiveness (Zeng et al, 2018). However, its sensitivity is limited in subacute or early infections because of the extended time it takes for antibody production after viral infection.…”

Development of Metal Nanoparticle-immobilized Microplate for High-throughput and Highly Sensitive Fluorescence Analysis

“…The procedure utilizing secondary antibodies is called indirect ELISA detection. 12 Although it has the advantages of high selectivity and easy availability of labeled secondary antibodies compared to the direct one, extra incubation steps as well as the elimination of nonspecific signals are usually required. 13,14 Therefore, an alternative method for enhancing the signal would be highly appreciated.…”