title: Interleukin-8 holds promise to serve as a molecular adjuvant in DNA vaccination model against Streptococcus iniae infection in fish.
abstract: DNA vaccines had been widely used in animal models against various viral infections, while it was not so convincing for many infectious diseases especially bacterial disease in aquaculture. Interleukin-8(IL-8) as one of the CXC chemokines, its immunological role and adjuvant potential which had been proved in mammals were rarely reported in fish species. In this study, recombination plasmid pcDNA3.1/IL-8(pcIL-8) was conducted and the capacity of IL-8 as molecular adjuvant was explored from several aspects by co-injecting with a DNA vaccine encoding α-enolase(pcENO) against Streptococcus iniae infection in channel catfish. The results suggested that co-injection of pcIL-8 with DNA vaccine increased the innate immunity and specific antibody levels, as well as increased the immune-related genes involving in pro-inflammatory response, humoral and cellular immunity. Moreover, pcIL-8 enhanced the immunoprotection of pcENO with the relative percent survival(RPS) of 60% to 80% against S.iniae infection at 4 week post vaccination(p.v.), with the significantly higher RPS of 73.33% in pcENO+pcIL-8 group compared with that of pcENO alone(53.33%) at challenge test of 8 weeks p.v. Taken together, these results indicate pcIL-8 as a molecular adjuvant co-injected with DNA vaccine not only improves the immunoprotection but also maintains long period of immunity for channel catfish against S.iniae infection. Our study signifies that IL-8 holds promise to serve as a potential adjuvant in DNA vaccines against bacterial infections for long time.
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Erlong
authors.initials: E
authors.lastname: Wang
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Long
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.|Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Kaiyu
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Xingli
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Defang
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.|Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Geng
authors.affiliation: Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Ouyang
authors.affiliation: Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Lai
mesh_terms: D000818:Animals; D017756:Aquaculture; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D029941:Fish Proteins / Q000235:genetics / Q000276:immunology*; D054884:Host-Pathogen Interactions; D007059:Ictaluridae / Q000235:genetics / Q000276:immunology / Q000382:microbiology*; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007113:Immunity, Innate; D000071497:Immunogenicity, Vaccine; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology*; D010751:Phosphopyruvate Hydratase / Q000235:genetics / Q000276:immunology*; D013290:Streptococcal Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D000070058:Streptococcus iniae / Q000276:immunology*; D013997:Time Factors; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
chemical_list: D029941:Fish Proteins; D016209:Interleukin-8; D019444:Vaccines, DNA; D010751:Phosphopyruvate Hydratase
keywords: DNA vaccine; Immune response; Immunity; Immunology and Microbiology Section; aquaculture; bacterial diseases; interleukin-8; molecular adjuvant