title: Enhanced immunogenicity induced by an alphavirus replicon-based pseudotyped baculovirus vaccine against porcine reproductive and respiratory syndrome virus.
abstract: Pseudotyped baculovirus has emerged as a promising vector for vaccine development and gene therapy. Alphaviruses, such as Semliki Forest virus (SFV), have also received considerable attention for use as expression vectors because of their self-replicating properties. In this study, pseudotyped baculovirus containing the hybrid cytomegalovirus (CMV) promoter/SFV replicon was used as a vector to co-express the GP5 and M proteins of porcine reproductive and respiratory syndrome virus (PRRSV). The immunogenicity of the resulting recombinant baculovirus (BV-SFV-5m6) was compared with the pseudotyped baculovirus vaccine (BV-CMV-5m6), in which the expression of GP5 and M were driven by the CMV promoter only. In vitro, BV-SFV-5m6 exhibited enhanced expression of foreign proteins and also caused apoptosis in transduced cells. After immunization in BALB/c mice, BV-SFV-5m6 induced strong GP5-specific ELISA antibodies and neutralizing antibodies against homologous and heterologous viruses, along with dose sparing. Further analysis of the cell-mediated immune response showed that BV-SFV-5m6 elicited a Th1-dominant immune response that was greater than that elicited by BV-CMV-5m6. Taken together, the results of this study indicate that a baculovirus containing the hybrid CMV promoter/alphavirus replicon can be utilized as an alternative strategy to develop an efficacious vaccine against PRRSV infection.
authors.affiliation: Division of Animal Infectious Diseases, State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Qunfeng
authors.initials: Q
authors.lastname: Wu
authors.forename: Fengqin
authors.initials: F
authors.lastname: Xu
authors.forename: Liurong
authors.initials: L
authors.lastname: Fang
authors.forename: Jinfang
authors.initials: J
authors.lastname: Xu
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Jiang
authors.forename: Huanchun
authors.initials: H
authors.lastname: Chen
authors.forename: Shaobo
authors.initials: S
authors.lastname: Xiao
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D016367:Baculoviridae / Q000235:genetics; D004337:Drug Carriers / Q000008:administration & dosage*; D005260:Female; D005822:Genetic Vectors; D051379:Mice; D008807:Mice, Inbred BALB C; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics / Q000276:immunology*; D012672:Semliki forest virus / Q000235:genetics; D018417:Th1 Cells / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D014763:Viral Matrix Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D004337:Drug Carriers; C525999:M protein, porcine reproductive and respiratory syndrome virus; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins; D014763:Viral Matrix Proteins; D014765:Viral Vaccines; C114789:glycoprotein 5, PRRSV