title: Immunoprophylactic potential of cloned Shiga toxin 2 B subunit.
abstract: The Shiga toxins Stx1 and Stx2 contribute to the development of enterohemorrhagic O157:H7 Escherichia coli-mediated colitis and hemolytic-uremic syndrome in humans. The Stx2 B subunit, which binds to globotriaosylceramide (GB3) receptors on target cells, was cloned. This involved replacing the Stx2 B subunit leader peptide nucleotide sequences with those from the Stx1 B subunit. The construct was expressed in the TOPP3 E. coli strain. The Stx2 B subunits from this strain assembled into a pentamer and bound to a GB3 receptor analogue. The cloned Stx2 B subunit was not cytotoxic to Vero cells or apoptogenic in Burkitt's lymphoma cells. Although their immune response to the Stx2 B subunit was variable, rabbits that developed Stx2 B subunit-specific antibodies, as determined by immunoblot and in vitro cytotoxicity neutralization assays, survived a challenge with Stx2 holotoxin. This is thought to be the first demonstration of the immunoprophylactic potential of the Stx2 B subunit.
authors.affiliation: Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Marcato
authors.forename: G
authors.initials: G
authors.lastname: Mulvey
authors.forename: R J
authors.initials: RJ
authors.lastname: Read
authors.lastname: Vander Helm K
authors.forename: P N
authors.initials: PN
authors.lastname: Nation
authors.forename: G D
authors.initials: GD
authors.lastname: Armstrong
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D017209:Apoptosis; D002051:Burkitt Lymphoma; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay; D004927:Escherichia coli Infections / Q000517:prevention & control* / Q000821:virology; D019453:Escherichia coli O157 / Q000276:immunology* / Q000378:metabolism; D022361:Escherichia coli Vaccines / Q000276:immunology*; D006027:Glycosides / Q000633:toxicity; D007114:Immunization; D009500:Neutralization Tests; D010957:Plasmids / Q000235:genetics; D011817:Rabbits; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000633:toxicity; D022641:Shiga Toxin 2 / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism / Q000633:toxicity; D014315:Triterpenes / Q000633:toxicity; D014407:Tumor Cells, Cultured; D014709:Vero Cells
chemical_list: D000907:Antibodies, Bacterial; D022361:Escherichia coli Vaccines; D006027:Glycosides; D011994:Recombinant Proteins; D022641:Shiga Toxin 2; D014315:Triterpenes; C001883:stichoposide