title: Immunogenicity of a plant-derived edible chimeric EspA, Intimin and Tir of Escherichia coli O157:H7 in mice.
abstract: Transgenic plants offer the possibility to produce and deliver an oral immunogen on a large-scale with low production costs and minimal purification or enrichment. Cattles are important reservoirs of Escherichia coli O157:H7 and developing a specific immunity in animals would be invaluable. Intimin, Tir, and EspA proteins are the virulence factors expressed by LEE locus of enterohemorrhagic E. coli. We hypothesized that the chimeric recombinant forms of these effectors delivered as an edible-base vaccine would reduce colonization of bacteria in mice. A synthetic gene (eit) composed of espA (e), eae (i) and tir (t) attached by linkers was constructed. The gene was codon optimized and cloned into plant expression vectors adjacent to CaMV35S and FAE promoters for expression in tobacco and canola plants. Of total soluble protein 0.2% and 0.3% (in average) were detected in transgenic tobacco leaves and canola seeds respectively. Mice immunized either subcutaneously or orally with recombinant EIT and challenged with E. coli O157:H7 significantly exhibited reduced bacterial shedding. Application of transgenic plants containing trivalent immunogen is an effective tool for protection against E. coli O157:H7.
authors.affiliation: Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran.
authors.forename: Jafar
authors.initials: J
authors.lastname: Amani
authors.forename: Seyed Latif
authors.initials: SL
authors.lastname: Mousavi
authors.forename: Sima
authors.initials: S
authors.lastname: Rafati
authors.forename: Ali Hatef
authors.initials: AH
authors.lastname: Salmanian
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000276:immunology*; D000818:Animals; D029688:Brassica napus / Q000235:genetics; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay; D019453:Escherichia coli O157 / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D029968:Escherichia coli Proteins / Q000235:genetics / Q000276:immunology*; D005260:Female; D056724:Immunity, Humoral; D018928:Immunity, Mucosal; D007114:Immunization / Q000379:methods*; D051379:Mice; D008807:Mice, Inbred BALB C; D030821:Plants, Genetically Modified / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D014026:Nicotiana / Q000235:genetics; D014170:Transformation, Genetic
chemical_list: D018829:Adhesins, Bacterial; D029968:Escherichia coli Proteins; C102051:EspA protein, E coli; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; C109287:Tir protein, E coli; C073819:eaeA protein, E coli