title: Vaccination of plasmid DNA encoding ORF81 gene of CJ strains of KHV provides protection to immunized carp.
abstract: In order to construct the recombinant plasmid of pIRES-ORF81, the nucleic acid isolated from Koi herpes virus-CJ (KHV-CJ) strains was used as a template to insert the ORF81 gene fragments amplified by PCR into the pIRES-neo, a kind of eukaryotic expression vector. Using Western blotting analysis, it was verified that ORF81 gene protein can be expressed correctly by pIRES-ORF81, after MFC cells were transfected. The recombinant plasmid pIRES-ORF81 was set into three immunization dose gradients: 1, 10, and 50 μg/carp. Empty plasmid group, PBS group, and blank control group were set simultaneously. Giving intramuscular injections to healthy carps with an average body mass of 246 ± 20 g, indirect ELISA was used to regularly determine antibody levels after three times immunization injection. Neutralizing antibodies were detected by neutralization assay. The results of inoculation tests showed that the pIRES-ORF81 recombinant plasmid can induce the production of carp-specific antibodies. The differences of immune effect between the three different doses of immune gradients were not significant (P > 0.05), but they can induce the production of neutralizing antibodies. After 25 d of inoculation, carp mortality of pIRES-neo empty vector treatment groups was 85%, while the carp mortality of eukaryotic expression recombinant plasmid pIRES-ORF81 injected with three different doses of immune gradients was 20, 17.5, and 12.5%, respectively. Differences in comparison to the control group were highly significant (P < 0.01). However, histopathological section of immunohistochemistry organization revealed no significant changes. It demonstrated that the DNA vaccine pIRES-ORF81 constructed in the experiment displayed a good protective effect against KHV, which had the potential to industrial applications.
authors.affiliation: College of Animal Science and Technology, Key Laboratory of Animal Production and Safety of Ministry of Education, Jilin Agricultural University, Changchun, 130118, China.
authors.forename: Jingxiang
authors.initials: J
authors.lastname: Zhou
authors.forename: Jiangdong
authors.initials: J
authors.lastname: Xue
authors.forename: Qiuju
authors.initials: Q
authors.lastname: Wang
authors.forename: Xia
authors.initials: X
authors.lastname: Zhu
authors.forename: Xingwei
authors.initials: X
authors.lastname: Li
authors.forename: Wenliang
authors.initials: W
authors.lastname: Lv
authors.forename: Dongming
authors.initials: D
authors.lastname: Zhang
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D002347:Carps / Q000276:immunology* / Q000821:virology; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D006564:Herpesviridae / Q000276:immunology; D006566:Herpesviridae Infections / Q000276:immunology / Q000517:prevention & control* / Q000662:veterinary* / Q000821:virology; D016366:Open Reading Frames / Q000235:genetics; D010957:Plasmids / Q000235:genetics / Q000276:immunology; D011897:Random Allocation; D014611:Vaccination; D019444:Vaccines, DNA / Q000627:therapeutic use*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D019444:Vaccines, DNA