title: Construction and expression of immunogenic hybrid enterotoxigenic Escherichia coli CFA/I and CS2 colonization fimbriae for use in vaccines.
abstract: Enterotoxigenic Escherichia coli (ETEC) are an important cause of diarrheal morbidity in developing countries, especially in children and also of traveler's diarrhea. Colonization factors (CFs) of ETEC, like CFA/I and CS2 which are genetically and structurally related, play a substantial role in pathogenicity, and since intestinal-mucosal immune responses against CFs appear to be protective, much effort has focused on the development of a CF-based ETEC vaccine. We have constructed hybrid operons in which the major CS2 subunit-encoding cotA gene was inserted into the CFA/I operon, either replacing (hybrid I) or being added to the major CFA/I subunit-encoding cfaB gene (hybrid II). Using specific monoclonal antibodies against the major subunits of CFA/I and CS2, high levels of surface expression of both fimbrial subunits were shown in E. coli carrying the hybrid II operon. Oral immunization of mice with formalin-killed bacteria expressing hybrid II fimbriae induced strong CFA/I- and CS2-specific serum IgG + IgM and fecal IgA antibody responses, which were higher than those achieved by similar immunization with the reference strains. Bacteria expressing hybrid fimbriae are potential candidate strains in an oral-killed CF-ETEC vaccine, and the approach represents an attractive and novel means of producing a broad-spectrum ETEC vaccine.
authors.affiliation: University of Gothenburg Vaccine Research Institute (GUVAX), 40530 Gothenburg, Sweden., Joshua.Tobias@microbio.gu.se
authors.forename: Joshua
authors.initials: J
authors.lastname: Tobias
authors.forename: Ann-Mari
authors.initials: AM
authors.lastname: Svennerholm
authors.forename: Jan
authors.initials: J
authors.lastname: Holmgren
authors.forename: Michael
authors.initials: M
authors.lastname: Lebens
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D054307:Enterotoxigenic Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D022361:Escherichia coli Vaccines / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D005260:Female; D036781:Fimbriae Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D015870:Gene Expression; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment
chemical_list: D029968:Escherichia coli Proteins; D022361:Escherichia coli Vaccines; D011993:Recombinant Fusion Proteins; C022924:colonization factor antigens; D036781:Fimbriae Proteins