Antigenicity of infectious pancreatic necrosis virus VP2 subviral particles expressed in yeast

Abstract

Infectious pancreatic necrosis (IPN) virus, the etiologic agent of infectious pancreatic necrosis in salmonid fish, causes significant losses to the aquaculture industry. The gene for the viral capsid protein (VP2) was cloned into a yeast expression vector and expressed in Saccharomyces cerevisae. Expression of the capsid gene in yeast resulted in formation of approximately 20nm subviral particles composed solely of VP2 protein. Anti-IPNV antibodies were detected in rainbow trout vaccinated either by injection of purified VP2-subviral particles (rVP2-SVP) or by feeding recombinant yeast expressing rVP2-SVP. Challenge of rVP2-SVP immunized trout with a heterologous IPNV strain and subsequent viral load determination demonstrated that both injection and orally vaccinated fish had lower IPNV loads than naive or sham-vaccinated fish. This study demonstrates the ability of rVP2-SVPs to induce a specific immune response and the ability of immunized fish to reduce the viral load after an experimentally induced IPNV infection.

Immunogenicity of Lactobacillus-expressing VP2 and VP3 of the infectious pancreatic necrosis virus (IPNV) in rainbow trout

“…Allnutt et al [22] utilized yeast as expressing host to construct IPNV VP2-based subviral particles (SVPs). The recombinant yeast were ground in liquid nitrogen then incorporated into a fish feed for oral vaccination.…”

Immunogenic and protective effects of an oral DNA vaccine against infectious pancreatic necrosis virus in fish

“…Other experimental approaches have since been attempted, such as expressing conserved IPNV-VP2-derived antigenic epitopes in bacteria to produce a subunit vaccine [11] or VP2-subviral particles expressed in yeast [12] that reduce the viral load. Recently DNA-based vaccines have been shown to be capable of producing antigens in vivo and they are potentially an ideal approach for vaccination against many diseases.…”

Viral vaccines for farmed finfish

“…When expressed, these capsid proteins formed VLPs that were similar in size to the native virus and induced a strong immune response in salmon [69,94]. A more recent paper described production of an IPN vaccine based on the VP2 protein of IPNV [2]. In this study, a subunit-based particle was made that was smaller (22 nm) than the native virus (60 nm) but induced a strong anti-IPNV response in rainbow trout, and this particle was referred to as a SVP.…”

“…A number of expression systems have been considered, but using yeast as a biofactory for vaccine production provides strong advantages over other systems: (1) The production of biologics in yeast is well understood in the industry and veterinary vaccine manufacturers are likely to subscribe to a system that does not require additional infrastructural modifications. (2) Since many yeast species and strains have generally regarded as safe status (GRAS), the regulatory barrier for vaccines made in yeast tend to be lower than other manufacturing platforms such as bacteria or insect-cell based system. (3) The cost of vaccine production in yeast-based manufacturing system is likely to be lower as the cost of virus purification from yeast will be lower than that of for insect cells.…”