title: Glycoprotein E2 of classical swine fever virus expressed by baculovirus induces the protective immune responses in rabbits.
abstract: Classical swine fever (CSF) caused by CSF virus (CSFV) is a highly contagious and devastating disease that affects the pig industry worldwide. The glycoprotein E2 of CSFV is the principal immunogenic protein that induces neutralizing antibodies and protective immunity. Several CSFV genotypes, including 1.1, 2.1, 2.2, and 2.3, have been identified in Mainland China. The glycoprotein E2 of genotypes 1.1 and 2.1 was expressed by using a baculovirus system and tested for its protective immunity in rabbits to develop novel CSF vaccines that elicit a broad immune response. Twenty CSFV seronegative rabbits were randomly divided into five groups. Each rabbit was intramuscularly immunized with E2 of genotypes 1.1 (CSFV-1.1E2), 2.1 (CSFV-2.1E2), or their combination (CSFV-1.1 + 2.1E2). A commercial CSF vaccine (C-strain) and phosphate-buffered saline (PBS) were used as positive or negative controls, respectively. All animals were challenged with CSFV C-strain at 4 weeks and then boosted with the same dose. All rabbits inoculated with CSFV-1.1E2, CSFV-2.1E2, and CSFV-1.1 + 2.1E2 elicited high levels of ELISA antibody, neutralizing antibody, and lymphocyte proliferative responses to CSFV. The rabbits inoculated with CSFV-1.1E2 and CSFV-1.1 + 2.1E2 received complete protection against CSFV C-strain. Two of the four rabbits vaccinated with CSFV-2.1E2 were completely protected. These results demonstrate that CSFV-1.1E2 and CSFV-1.1 + 2.1E2 not only elicit humoral and cell-mediated immune responses but also confer complete protection against CSFV C-strain in rabbits. Therefore, CSFV-1.1E2 and CSFV-1.1 + 2.1E2 are promising candidate subunit vaccines against CSF.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
authors.forename: Huawei
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Li
authors.forename: Guiqing
authors.initials: G
authors.lastname: Peng
authors.forename: Chenkai
authors.initials: C
authors.lastname: Tang
authors.forename: Shixuan
authors.initials: S
authors.lastname: Zhu
authors.forename: Suhong
authors.initials: S
authors.lastname: Qian
authors.forename: Jinfang
authors.initials: J
authors.lastname: Xu
authors.forename: Ping
authors.initials: P
authors.lastname: Qian
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D016367:Baculoviridae / Q000235:genetics; D049109:Cell Proliferation; D002681:China; D006691:Classical Swine Fever / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D006692:Classical Swine Fever Virus / Q000235:genetics / Q000276:immunology*; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D005822:Genetic Vectors; D007273:Injections, Intramuscular; D008214:Lymphocytes / Q000276:immunology; D009500:Neutralization Tests; D011817:Rabbits; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D013552:Swine; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C087086:glycoprotein E2, classical swine fever virus