title: VscO, a putative T3SS chaperone escort of Vibrio alginolyticus, contributes to virulence in fish and is a target for vaccine development.
abstract: Type III secretion system (T3SS) in Vibrio alginolyticus is essential for its pathogenesis. VscO's homologous proteins FliJ, InvI and YscO have been suggested to be putative chaperone escorts although its function in V. alginolyticus is unclear. To investigate the physiological role of VscO, a mutant strain of V. alginolyticus with an in-frame deletion of the vscO gene was constructed in the present study. One finding was that the mRNA expression levels of SycD, VopB and VopD proteins decreased in the ΔvscO mutant. In addition, the ΔvscO mutant showed an attenuated swarming ability and a ten-fold decrease in the virulence to fish. However, the ΔvscO mutant showed no difference in the biofilm formation and ECPase activity. Complementation of the mutant strain with the vscO gene could restore the phenotypes of the wild-type strain. Finally, the recombinant VscO protein caused a high antibody titer and an effective protection against lethal challenge with the wild-type strain V. alginolyticus. These results indicated that VscO protein has a specific role in the pathogenesis of V. alginolyticus and it may be a candidate antigen for development of a subunit vaccine against vibriosis.
authors.affiliation: Fisheries College, Guangdong Ocean University, Zhanjiang, PR China; Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, PR China; Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Zhanjiang, PR China.
authors.forename: Zejun
authors.initials: Z
authors.lastname: Zhou
authors.forename: Huanying
authors.initials: H
authors.lastname: Pang
authors.forename: Yu
authors.initials: Y
authors.lastname: Ding
authors.forename: Jia
authors.initials: J
authors.lastname: Cai
authors.forename: Yucong
authors.initials: Y
authors.lastname: Huang
authors.forename: Jichang
authors.initials: J
authors.lastname: Jian
authors.forename: Zaohe
authors.initials: Z
authors.lastname: Wu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D058947:Bacterial Secretion Systems / Q000235:genetics; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology; D001483:Base Sequence; D018441:Biofilms / Q000254:growth & development; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli; D005393:Fish Diseases / Q000382:microbiology* / Q000517:prevention & control*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D005816:Genetic Complementation Test / Q000662:veterinary; D018832:Molecular Chaperones / Q000235:genetics*; D016296:Mutagenesis; D010473:Perciformes; D017422:Sequence Analysis, DNA / Q000662:veterinary; D014735:Vibrio Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D044149:Vibrio alginolyticus / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
chemical_list: D058947:Bacterial Secretion Systems; D001428:Bacterial Vaccines; D017931:DNA Primers; D018832:Molecular Chaperones
keywords: Protective immunity; Recombinant VscO; Type III secretion system; Vibrio alginolyticus; vscO mutant