title: Glycosylated F4 (K88) fimbrial adhesin FaeG expressed in barley endosperm induces ETEC-neutralizing antibodies in mice.
abstract: The F4-positive enterotoxigenic Escherichia coli (ETEC) strains are a frequent cause of porcine post-weaning diarrhea. Orally administered F4 fimbriae or FaeG, the major subunit and adhesin of F4, induce a protective mucosal immune response in F4 receptor-positive piglets. Feed plants carrying immunogenic subunit proteins can offer great advantages for oral vaccination of domestic animals. Here, we describe high-level endosperm-specific production (1% of total soluble proteins) of FaeG in the crop plant barley. The endoplasmic reticulum-targeted recombinant endospermic FaeG (erFaeG) was shown to be heterogeneously glycosylated. The erFaeG showed resistance at digestive conditions simulating piglet gastric fluid. Glycosylation did not abolish the immunogenic character of the FaeG protein, since erFaeG was able to induce F4 fimbria-specific antibodies in mice. Biological activity of these anti-F4 antibodies was demonstrated in vitro by blocking the attachment of the F4+ ETEC to the F4 receptors present on porcine intestinal enterocytes.
authors.affiliation: Department of Applied Biology, University of Helsinki, P.O. Box 27, FIN-00014, Helsinki, Finland. jussi.joensuu@helsinki.fi
authors.forename: Jussi J
authors.initials: JJ
authors.lastname: Joensuu
authors.forename: Mirkka
authors.initials: M
authors.lastname: Kotiaho
authors.forename: Teemu H
authors.initials: TH
authors.lastname: Teeri
authors.forename: Leena
authors.initials: L
authors.lastname: Valmu
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Nuutila
authors.forename: Kirsi-Marja
authors.initials: KM
authors.lastname: Oksman-Caldentey
authors.forename: Viola
authors.initials: V
authors.lastname: Niklander-Teeri
mesh_terms: D018830:Adhesins, Escherichia coli / Q000737:chemistry*; D000818:Animals; D001422:Bacterial Adhesion; D001428:Bacterial Vaccines; D020895:Enterocytes / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D005260:Female; D006031:Glycosylation; D001467:Hordeum / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008957:Models, Genetic; D009693:Nucleic Acid Hybridization; D013552:Swine
chemical_list: D018830:Adhesins, Escherichia coli; D001428:Bacterial Vaccines; C494388:FaeG protein, E coli