Construction and Characterization of a Recombinant Canine Adenovirus Expressing GP5 and M proteins of Porcine Reproductive and Respiratory Syndrome Virus

Abstract

ABSTRACT. The causative agent of porcine reproductive and respiratory syndrome (PRRS) is PRRS virus (PRRSV), which belongs to the family Arteriviridae. GP5/M protein complex of PRRSV binds to sialoadhesion expressed on the cells to infect the cells. In this study, we developed a canine adenovirus type 2 (CAV-2) recombinant, termed rCAV2-GP5/M, expressing GP5 and M proteins. To evaluate the immunogenicity of the recombinant virus, mice were inoculated subcutaneously with rCAV2-GP5/M, and specific antibodies against PRRSV in the sera were measured by enzyme-linked immunosorbent assay and the viral neutralization test. Two weeks post-immunization (w.p.i.), anti-PRRSV antibodies were detected in the sera, slightly increased by booster immunization at four w.p.i., and then gradually decreased. The viral neutralizing test showed that neutralizing antibodies were present in the sera collected at two w.p.i., increased by booster immunization, and reached the maximum titer at six w.p.i. Lymphocyte proliferation responding to PRRSV antigens was also observed from two w.p.i. Although further studies are needed to evaluate the usefulness of the recombinant virus to protect pigs from PPRSV, we succeeded in developing a candidate vaccine against PPRSV infection by using CAV-2 vector.KEY WORDS: GP5, immunogenicity, M, porcine reproductive and respiratory syndrome virus, recombinant canine adenovirus.

Porcine reproductive and respiratory syndrome virus vaccines: Immunogenicity, efficacy and safety aspects

“…These efforts reportedly included use of several adjuvants [40][41][42] , use of mixed strains of PRRSV [43,44] , and generation of alternative vaccines, i.e. DNA vaccine [45,46] , subunit vaccine [47,48] , synthetic peptide vaccine [13] , viral vector vaccines using adenovirus [49][50][51] , PRV [52,53] , poxvirus [54,55] , and transmissible gastroenteritis virus [56] as vectors, alphavirusderived replicon [57] , bacterial vector vaccine [58] , insect cellderived vaccine [59] , and plant-derived vaccine [60,61] (Table 4). These efforts, however, can achieve at best some, but not all, properties of an ideal PRRS vaccine.…”

Vaccination of Mice with <b><i>Listeria ivanovii</i></b> Expressing the Truncated M Protein of Porcine Reproductive and Respiratory Syndrome Virus Induces both Antigen-Specific CD4+ and CD8+ T Cell-Mediated Immunity

“…The M protein, encoded by the ORF6 gene, is the most conserved structural protein of PRRSV [Dokland, 2010]. It has been suggested that the M protein is capable of provoking cell-mediated immunity against PRRSV [Zheng et al, 2007;Cai et al, 2010]. Not recently, an unique CD8+ epitope (FGYMTFVHF) was also found in M protein [Zhang et al, 2011].…”

Production and Evaluation of Virus-Like Particles Displaying Immunogenic Epitopes of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)

“…However, PRRSV MLV vaccines have myriad concerns with respect to efficacy and safety, such as ineffective protection against heterologous strains, reversion of vaccine to pathogenic virus and shedding of infective virus upon vaccination. Several experimental vaccines have been reported, including mixed strain vaccines [ 22 , 23 ], recombinant subunit vaccines bearing different PRRSV structural proteins, such as DNA [ 24 , 25 ], bacteria [ 26 ], adenovirus [ 27 , 28 , 29 ], poxvirus [ 30 , 31 ], alphavirus [ 32 ], baculovirus [ 33 ] and gastroenteritis virus [ 34 ], plant-derived vaccines [ 35 , 36 , 37 ] and synthetic peptide vaccines [ 38 ]. These vaccines can confer protection at its best, but do not possess the characteristics of a universal PRRS vaccine.…”