title: Expression of EspA in Lactococcus lactis NZ9000 and the detection of its immune effect in vivo and vitro.
abstract: Enterhemorrhagic Escherichia coli (EPEC), an important cause of severe infantile diarrheal disease in many parts of the developing world, produced several recently described virulence determinations. Several of its virulence factors are secreted by type III secretion including EspA, which forms filamentous structures on bacterial surface bridging to the host cell's surface. These structures on bacterial surfaces may deliver other virulence factors directly into the host cell from EHEC. In this study, EspA was expressed in Lactococcus lactis NZ9000 (L. lactis NZ9000). BALB/C mice were immunized by recombinant EspA, and mice sera were assayed for the disruption of E. coli O157:H7 interaction with the host cell. BALB/C mice which were immunized with recombinant EspA produced specific antibody titers, and the difference between the control group and the immune group is marked (P<0.05). The polyclonal mice antisera blocked E. coli O157:H7-induced host cell actin rearrangement and could label E. coli O157:H7 EspA filaments in vitro. Our present findings suggest that L. lactis may be a good candidate to produce oral vaccine, and thus entertains the possibility of developing EspA-oral vaccine in the defense of E. coli O157:H7 infection.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong, People's Republic of China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Luan
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zhuang
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Kong
authors.initials: K
authors.lastname: Yun
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Peng George
authors.initials: PG
authors.lastname: Wang
mesh_terms: D000818:Animals; D019453:Escherichia coli O157 / Q000276:immunology*; D029968:Escherichia coli Proteins / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D022361:Escherichia coli Vaccines / Q000276:immunology*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D007114:Immunization; D013294:Lactococcus lactis / Q000235:genetics* / Q000254:growth & development; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D029968:Escherichia coli Proteins; D022361:Escherichia coli Vaccines; C102051:EspA protein, E coli; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic