title: A novel in vivo inducible expression system in Edwardsiella tarda for potential application in bacterial polyvalence vaccine.
abstract: Recombinant bacterial vector vaccine is an attractive vaccination strategy to induce the immune response to a carried protective antigen, and the main concern of bacterial vector vaccine is to establish a stable antigen expression system in vector bacteria. Edwardsiella tarda is an important facultative intracellular pathogen of both animals and humans, and its attenuated derivates are excellent bacterial vectors for use in recombinant vaccine design. In this study, we design an in vivo inducible expression system in E. tarda and establish potential recombinant E. tarda vector vaccines. With wild type strain E. tarda EIB202 as a vector, 53 different bacteria-originated promoters were examined for iron-responsive transcription in vitro, and the promoters P(dps) and P(yncE) showed high transcription activity. The transcription profiles in vivo of two promoters were further assayed, and P(dps) revealed an enhanced in vivo inducible transcription in macrophage, larvae and adult zebra fish. The gapA34 gene, encoding the protective antigen GAPDH from the fish pathogen Aeromonas hydrophila LSA34, was introduced into the P(dps)-based protein expression system, and transformed into attenuated E. tarda strains. The resultant recombinant vector vaccine WED/pUTDgap was evaluated in turbot (Scophtalmus maximus). Over 60% of the vaccinated fish survived under the challenge with A. hydrophila LSA34 and E. tarda EIB202, suggesting that the P(dps)-based antigen delivery system had great potential in bacterial vector vaccine application.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Mu
authors.forename: Lingyu
authors.initials: L
authors.lastname: Guan
authors.forename: Yijian
authors.initials: Y
authors.lastname: Yan
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
authors.forename: Yuanxing
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D016980:Aeromonas hydrophila / Q000276:immunology; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D017756:Aquaculture; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology*; D020609:Edwardsiella tarda / Q000235:genetics* / Q000276:immunology*; D005393:Fish Diseases / Q000382:microbiology* / Q000517:prevention & control*; D005412:Flatfishes; D020869:Gene Expression Profiling; D005822:Genetic Vectors / Q000235:genetics / Q000276:immunology*; D016905:Gram-Negative Bacterial Infections / Q000517:prevention & control / Q000662:veterinary*; D007814:Larva / Q000276:immunology; D008264:Macrophages / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D014169:Transformation, Bacterial; D015027:Zebrafish
chemical_list: D000942:Antigens, Bacterial; D001428:Bacterial Vaccines