title: The swine CD81 enhances E2-based DNA vaccination against classical swine fever.
abstract: Classical swine fever (CSF) is a highly contagious and economically important viral disease that affects the pig industry worldwide. The glycoprotein E2 of CSFV can induce neutralizing antibodies and protective immunity, and is widely used for novel vaccine development. The objective of this study was to explore whether a tetraspanin molecule CD81 could improve the immune responses of an E2-based DNA vaccine. Plasmids pVAX-CD81, pVAX-E2 and pVAX-CD81-E2 were constructed and the expression of target proteins was confirmed in BHK-21 cells by indirect immunofluorescence assay. BALB/c mice were divided into 5 groups and immunized with different plasmids (pVAX-E2, pVAX-CD81-E2, pVAX-E2+pVAX-CD81, pVAX-CD81 and PBS) three times with two weeks interval. The results showed that the introduction of CD81 promoted higher humoral and cellular immune responses than E2 expression alone (P<0.05). In addition, immunization with pVAX-CD81-E2 induced stronger immune responses than pVAX-E2+pVAX-CD81. Furthermore, four groups of pigs were immunized with pVAX-E2, pVAX-CD81-E2, pVAX-CD81 and PBS, respectively. Humoral and cellular immune responses detection showed similar results with those in mice. Compared to pVAX-E2, pVAX-CD81-E2 induced higher titers of neutralizing antibodies after viral challenge and conferred stronger protection. These results confirmed the capacity of swine CD81 enhancing the humoral and cellular responses with an adjuvant effect on CSFV DNA vaccine. This is the first report demonstrating the adjuvant effect of CD81 to enhance the DNA vaccination for swine pathogen.
authors.affiliation: Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences; Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture; National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China. Electronic address: kfliwenliang@163.com.
authors.forename: Wenliang
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences; Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture; National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China.
authors.forename: Li
authors.initials: L
authors.lastname: Mao
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences; Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture; National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences; Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture; National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China.
authors.forename: Leilei
authors.initials: L
authors.lastname: Yang
authors.affiliation: Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences; Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture; National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences; Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture; National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China. Electronic address: 1776556843@qq.com.
authors.forename: Jieyuan
authors.initials: J
authors.lastname: Jiang
mesh_terms: D000276:Adjuvants, Immunologic / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D006691:Classical Swine Fever / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D005260:Female; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D008807:Mice, Inbred BALB C; D012720:Severity of Illness Index; D013552:Swine; D060225:Tetraspanin 28 / Q000235:genetics / Q000378:metabolism*; D014611:Vaccination / Q000379:methods*; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D060225:Tetraspanin 28; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C087086:glycoprotein E2, classical swine fever virus
keywords: Adjuvant; CD81; CSFV; DNA vaccine; E2 glycoprotein