Immunogenicity Properties of Authentic and Heterologously Synthesized Structural Protein VP2 of Infectious Pancreatic Necrosis Virus

Abstract

The sole coat protein VP2 of infectious pancreatic necrosis virus (IPNV) was isolated and purified from intact virions, propagated in CHSE-214 cells. Likewise was the full-length VP2 protein isolated and purified upon cloning and expression of the corresponding complete gene in E. coli. The two purified proteins of different synthetic origins carrying identical primary structures were utilized in an immunization program using a rabbit model. Sera obtained against both immunogens react equally well with authentic and recombinant VP2 in Western blots and ELISAs. Also, the total net binding forces as determined by avidity index (AI) calculations were high and of similar stature, exceeding 80. An IPNV infection of susceptible and permissive CHSE-214 cells could only be neutralized by IgG preparations obtained from rabbits immunized with authentic VP2. Only such antibodies were able to aggregate and sediment radiolabeled virions in glycerol gradients upon rate zonal centrifugations. The presence of sugar moieties on the authentic protein is suggested to be of pivotal importance in eliciting an immune response capable of preventing infection in cell cultures in vitro.

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

“…The basic reason was remained to be discussed further, may be depending on different inoculation routes. At the present time, most researches have been focusing on VP2 as model pathogen to develop novel vaccine against IPNV infection [10,23,25]. At the same time we found that Lactobacillus-derived VP3 also could induce neutralizing antidody in rainbow trout.…”

“…Segment A is the larger segment of about 3.1 kbp and it encodes VP2 and VP3, the two major structural proteins of the virus. Following capsid assembly, the pVP2 protein is cleaved further to produce VP2 [9] as protective antigen that induces neutralizing antibodies which protect susceptible fish from IPNV infection [10,11]. Although VP3 is believed to be a more internal capsid protein than VP2, some neutralizing epitopes have been mapped to it [12,13].…”

A review on the recent advances and application of vaccines against fish pathogens in aquaculture

“…Synthetic peptide vaccines can be used to serve like a subunit vaccine or as a suitable antigenic site (Tam 1988 ; Coeurdacier et al 2003 ). A few studies have been carried out by some researchers to demonstrate whether these peptides can be used for stimulating antibody production for pathogens like nodavirus, rhabdovirus, birnavirus, IHNV, infectious pancreatic necrosis virus (IPNV), and VHS (Emmenegger et al 1994 ; Coeurdacier et al 2003 ; Estepa et al 1999 ; Fridholm et al 2007 ). These reports suggested that fish vaccination by using peptides is possible although there is still a lack of the fundamental knowledge of fish immune mechanisms against various antigens (Dadar et al 2016 ).…”

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.…”