An Improved Immunochromatographic Strip Based on Plant-Derived E2 for Detection of Antibodies against Classical Swine Fever Virus

Abstract

The E2 protein of classical swine fever virus (CSFV) was expressed in transgenic rice endosperms as a diagnostic antigen for use with a rapid colloidal gold assay for the detection of antibodies (Abs) against CSFV. This improved test was used to monitor Abs against the E2 protein in both pigs and rabbits immunized with a live attenuated vaccine or E2 subunit vaccine.

Development of a dual immunochromatographic test strip to detect E2 and Erns antibodies against classical swine fever

“…However, ELISA procedures are time-consuming and require skilled personnel, which might not be suitable for rapid field testing if E2 and E rns antibody detection needs to be evaluated simultaneously with a large sample number in the field. Colloidal gold ICS have been established and are a valuable diagnostic tool for monitoring antibodies against CSFV in vaccinated pigs ( Li et al, 2012 ; Bai et al, 2022 ; Xu et al, 2022 ). Compared to alternative antibody detection methodologies such as SNT or ELISA, ICS is notably user-friendly, rapid, and easily transportable ( Li et al, 2012 ; Wang et al, 2020 ).…”

“…Compared to alternative antibody detection methodologies such as SNT or ELISA, ICS is notably user-friendly, rapid, and easily transportable ( Li et al, 2012 ; Wang et al, 2020 ). Thus far, ICS development has preferably focused on detecting antibodies against the CSFV E2 protein, a powerful tool for the CSFV antibody assessment ( Bai et al, 2022 ; Xu et al, 2022 ). Meanwhile, ICS development for CSFV E rns antibody detection for the DIVA diagnostic approach still has no specific innovation ( Wang et al, 2020 ).…”

“…In protein manipulation, previous studies have indicated that plant-derived transient expression enhances high protein expression and yield, immunogenicity in animal experiments, and high binding affinity for antibody detection absent in certain conventional expression systems ( Sohn et al, 2018 ; Yamamoto et al, 2018 ; Xu et al, 2022 ). Compared to the transgenic approach for CSFV E2 protein expression using baculovirus ( Wei et al, 2021 ; Bai et al, 2022 ), mammalian cells ( Ji et al, 2018 ; Chen et al, 2023 ), or the E. coli system ( Li et al, 2012 ; Yi et al, 2022 ), the CSFV E2-expressing transgenic plant-derived system was preferable in terms of a large amount and stable expression of the target protein and inexpensiveness, as in recent studies ( Sohn et al, 2018 ; Laughlin et al, 2019 ; Park et al, 2019 , 2020 ; Xu et al, 2022 ). This approach facilitated the purification of recombinant E2 from N. benthamiana extracts.…”

“…However, protein expression by the E. coli system can lead to protein misfolding, which may reduce antibody detection efficacy ( Bai et al, 2022 ). Several ICS studies have been performed to improve CSFV E2 antibody detection by enhancing the protein expression system, such as the baculovirus expression system ( Bai et al, 2022 ) or transgenic rice endosperm ( Xu et al, 2022 ). However, ICS for CSFV E2 antibody detection can only be used to monitor vaccination efficacy and early detection of antibody responses, whereas the DIVA test for detecting E rns antibody is lacking.…”

Different Types of Vaccines against Pestiviral Infections: “Barriers” for “Pestis”

“…Several CSF vaccines have been developed for oral immunization of wild boars [ 140 , 141 , 142 , 143 , 144 , 145 , 146 , 147 , 148 ]. For example, immunization with an oral bait vaccine based on C-strain proved to be safe and efficacious.…”