title: Display of ISKNV orf086 protein on the surface of Aeromonas hydrophila and its immunogenicity in Chinese perch (Siniperca chuatsi).
abstract: Co-infection with infectious spleen and kidney necrosis virus (ISKNV) and Aeromonas hydrophila is becoming ever more widespread in Chinese perch (Siniperca chuatsi) aquaculture industry, so that it's necessary to develop the combined vaccine against ISKNV and A. hydrophila disease. The surface display of heterologous on bacteria using anchoring motifs from outer membranes proteins has already been explored as an effective delivery system of viral antigens. In present study, the ISKNV orf086 gene, which is verified as a protective antigen, was inserted into ompA gene cassette of A. hydrophila GYK1 strain by homologous recombination. And an ompA-orf086 fusion A. hydrophila mutant strain K28 was constructed. Then the ISKNV orf086 was verified to express on the surface of A. hydrophila K28 by RT-PCR, western blot and indirect immunofluorescence assay. Next, Chinese perch were intraperitoneally inoculated with formalin inactivated A. hydrophila k28 emulsified with ISA763 adjuvant with a dose of 9 × 10(8) CFU per fish. Transcriptional analysis of non-specific and specific immune related genes revealed that the expression levels of IRF-7, IRAK1, Mx, Viperin, Lysozyme and IgM were strongly up-regulated in Chinese perch post-inoculation. In addition, specific antibodies were detected by ELISA, and the results showed that antibody titer against ISKNV or A. hydrophila reached the highest with 1:800 or 1:1200 on 14dpv, respectively. Lymphocyte proliferation were detected by MTT methods, and the results showed that the SI values of AH-K28 vaccinated group to three different stimulators were significantly higher than those of control group. At last, protective efficacy were determined by challenge trials. The cumulative mortality rates of vaccinated groups were significantly lower than the control one (P < 0.05) after ISKNV or A. hydrophila challenge, and the relative percentage survival (RPS) value was 73.3% and 60%, respectively. This system provides a novel approach to the surface display of heterologous antigenic proteins on A. hydrophila and suggests the possibility to use the recombinant K28 strain as a combined vaccine against ISKNV and A. hydrophila infection.
authors.affiliation: Pearl River Fishery Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Fishery Drug Development, Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology, Guangzhou 510380, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Xiaozhe
authors.initials: X
authors.lastname: Fu
authors.affiliation: Pearl River Fishery Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Fishery Drug Development, Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology, Guangzhou 510380, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lin
authors.affiliation: Pearl River Fishery Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Fishery Drug Development, Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology, Guangzhou 510380, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Lihui
authors.initials: L
authors.lastname: Liu
authors.affiliation: Pearl River Fishery Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Fishery Drug Development, Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology, Guangzhou 510380, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Hongru
authors.initials: H
authors.lastname: Liang
authors.affiliation: Pearl River Fishery Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Fishery Drug Development, Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology, Guangzhou 510380, China.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Pearl River Fishery Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Fishery Drug Development, Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology, Guangzhou 510380, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China. Electronic address: liningq@126.com.
authors.forename: Ningqiu
authors.initials: N
authors.lastname: Li
mesh_terms: D016980:Aeromonas hydrophila / Q000235:genetics / Q000276:immunology*; D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology*; D060085:Coinfection / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary; D004266:DNA Virus Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary / Q000821:virology; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control* / Q000821:virology; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary; D007497:Iridoviridae / Q000276:immunology*; D030781:Organisms, Genetically Modified / Q000235:genetics / Q000276:immunology; D010473:Perciformes; D011897:Random Allocation; D017778:Vaccines, Combined / Q000276:immunology; D014764:Viral Proteins / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D001428:Bacterial Vaccines; D017778:Vaccines, Combined; D014764:Viral Proteins; D014765:Viral Vaccines
keywords: Aeromonas hydrophila; Combined vaccines; ISKNV; Siniperca chuatsi; Surface display of antigen; ompA