title: Human Stx2-specific monoclonal antibodies prevent systemic complications of Escherichia coli O157:H7 infection.
abstract: Hemolytic-uremic syndrome (HUS) is a serious complication predominantly associated with infection by enterohemorrhagic Escherichia coli (EHEC), such as E. coli O157:H7. EHEC can produce Shiga toxin 1 (Stx1) and/or Shiga toxin 2 (Stx2), both of which are exotoxins comprised of active (A) and binding (B) subunits. In piglets and mice, Stx can induce fatal neurological symptoms. Polyclonal Stx2 antiserum can prevent these effects in piglets infected with the Stx2-producing E. coli O157:H7 strain 86-24. Human monoclonal antibodies (HuMAbs) against Stx2 were developed as potential passive immunotherapeutic reagents for the prevention and/or treatment of HUS. Transgenic mice bearing unrearranged human immunoglobulin (Ig) heavy and kappa light chain loci (HuMAb___Mouse) were immunized with formalin-inactivated Stx2. Thirty-seven stable hybridomas secreting Stx2-specific HuMAbs were isolated: 33 IgG1kappa A-subunit-specific and 3 IgG1kappa and 1 IgG3kappa B-subunit-specific antibodies. Six IgG1kappa A-subunit-specific (1G3, 2F10, 3E9, 4H9, 5A4, and 5C12) and two IgG1kappa B-subunit-specific (5H8 and 6G3) HuMAbs demonstrated neutralization of > 95% activity of 1 ng of Stx2 in the presence of 0.04 microg of HuMAb in vitro and significant prolongation of survival of mice given 50 microg of HuMAb intraperitoneally (i.p.) and 25 ng of Stx2 intravenously. When administered i.p. to gnotobiotic piglets 6 or 12 h after infection with E. coli O157:H7 strain 86-24, HuMAbs 2F10, 3E9, 5H8, and 5C12 prolonged survival and prevented development of fatal neurological signs and cerebral lesions. The Stx2-neutralizing ability of these HuMAbs could potentially be used clinically to passively protect against HUS development in individuals infected with Stx-producing bacteria, including E. coli O157:H7.
authors.affiliation: Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA.
authors.forename: Jean
authors.initials: J
authors.lastname: Mukherjee
authors.forename: Kerry
authors.initials: K
authors.lastname: Chios
authors.forename: Dianne
authors.initials: D
authors.lastname: Fishwild
authors.forename: Deborah
authors.initials: D
authors.lastname: Hudson
authors.forename: Susan
authors.initials: S
authors.lastname: O'Donnell
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Rich
authors.forename: Arthur
authors.initials: A
authors.lastname: Donohue-Rolfe
authors.forename: Saul
authors.initials: S
authors.lastname: Tzipori
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000627:therapeutic use*; D000918:Antibody Specificity; D004195:Disease Models, Animal; D019453:Escherichia coli O157 / Q000276:immunology*; D005260:Female; D005856:Germ-Free Life; D006367:HeLa Cells; D006463:Hemolytic-Uremic Syndrome / Q000517:prevention & control*; D006801:Humans; D007116:Immunization, Passive / Q000379:methods; D007074:Immunoglobulin G / Q000276:immunology / Q000627:therapeutic use; D007132:Immunoglobulin Isotypes / Q000276:immunology; D007145:Immunoglobulin kappa-Chains / Q000276:immunology / Q000627:therapeutic use*; D051379:Mice; D009500:Neutralization Tests; D022641:Shiga Toxin 2 / Q000276:immunology*; D013552:Swine
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007145:Immunoglobulin kappa-Chains; D022641:Shiga Toxin 2