scholarly journals Stx2-Specific Human Monoclonal Antibodies Protect Mice against Lethal Infection with Escherichia coli Expressing Stx2 Variants

2003 ◽  
Vol 71 (6) ◽  
pp. 3125-3130 ◽  
Author(s):  
Abhineet S. Sheoran ◽  
Susan Chapman ◽  
Pradeep Singh ◽  
Arthur Donohue-Rolfe ◽  
Saul Tzipori
Keyword(s):  
Escherichia Coli ◽  
Monoclonal Antibodies ◽  
Shiga Toxin ◽  
Human Monoclonal Antibodies ◽  
B Subunit ◽  
Lethal Infection ◽  
Uremic Syndrome ◽  
A Subunit ◽  
Spectrum Activity ◽  
Broad Spectrum Activity

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) strains are responsible for causing hemolytic-uremic syndrome (HUS), and systemic administration of Shiga toxin (Stx)-specific human monoclonal antibodies (HuMAbs) is considered a promising approach for prevention or treatment of the disease in children. The goal of the present study was to investigate the ability of Stx2-specific HuMAbs to protect against infections with STEC strains that produce Stx2 variants. Dose-response studies on five HuMAbs, using the mouse toxicity model, revealed that only the three directed against the A subunit were protective against Stx2 variants, and 5C12 was the most effective among the three tested. Two HuMAbs directed against the B subunit, while highly effective against Stx2, were ineffective against Stx2 variants. In a streptomycin-treated mouse model, parenteral administration of 5C12 significantly protected mice up to 48 h after oral bacterial challenge. We conclude that 5C12, reactive against the Stx2 A subunit, is an excellent candidate for immunotherapy against HUS and that antibodies directed against the A subunit of Stx2 have broad-spectrum activity that includes Stx2 variants, compared with those directed against the B subunit.

scholarly journals AB5Preassembly Is Not Required for Shiga Toxin Activity

2016 ◽  
Vol 198 (11) ◽  
pp. 1621-1630 ◽  
Author(s):  
Christine A. Pellino ◽  
Sayali S. Karve ◽  
Suman Pradhan ◽  
Alison A. Weiss
Keyword(s):  
Escherichia Coli ◽  
Enzymatic Activity ◽  
Hemolytic Uremic Syndrome ◽  
Shiga Toxin ◽  
Target Cells ◽  
Content Type ◽  
B Subunit ◽  
Uremic Syndrome ◽  
A Subunit ◽  
B Subunits

ABSTRACTShiga toxin (Stx)-producingEscherichia coli(STEC) is a major cause of foodborne illness, including the life-threatening complication hemolytic-uremic syndrome. The German outbreak in 2011 resulted in nearly 4,000 cases of infection, with 54 deaths. Two forms of Stx, Stx1 and Stx2, differ in potency, and subtype Stx2a is most commonly associated with fatal human disease. Stx is considered to be an AB5toxin. The single A (enzymatically active) subunit inhibits protein synthesis by cleaving a catalytic adenine from the eukaryotic rRNA. The B (binding) subunit forms a homopentamer and mediates cellular association and toxin internalization by binding to the glycolipid globotriaosylceramide (Gb3). Both subunits are essential for toxicity. Here we report that unlike other AB5toxin family members, Stx is produced by STEC as unassembled A and B subunits. A preformed AB5complex is not required for cellular toxicity orin vivotoxicity to mice, and toxin assembly likely occurs at the cell membrane. We demonstrate that disruption of A- and B-subunit association by use of A-subunit peptides that lack enzymatic activity can protect mice from lethal doses of toxin. Currently, no treatments have been proven to be effective for hemolytic-uremic syndrome. Our studies demonstrate that agents that interfere with A- and B-subunit assembly may have therapeutic potential. Shiga toxin (Stx) produced by pathogenicEscherichia coliis considered to be an AB5heterohexamer; however, no known mechanisms ensure AB5assembly. Stx released byE. coliis not in the AB5conformation and assembles at the receptor interface. Thus, unassembled Stx can impart toxicity. This finding shows that preventing AB5assembly is a potential treatment for Stx-associated illnesses.IMPORTANCEComplications due to Shiga toxin are frequently fatal, and at present, supportive care is the only treatment option. Furthermore, antibiotic treatment is contraindicated due to the ability of antibiotics to amplify bacterial expression of Shiga toxin. We report, contrary to prevailing assumptions, that Shiga toxin produced by STEC circulates as unassembled A and B subunits at concentrations that are lethal to mice. Similar to the case for anthrax toxin, assembly occurs on receptors expressed on the surfaces of mammalian target cells. Disruption of Shiga toxin assembly by use of A-subunit peptides that lack enzymatic activity protects mice from lethal challenge with Shiga toxin, suggesting a new approach for development of therapeutics.

scholarly journals Human Stx2-Specific Monoclonal Antibodies Prevent Systemic Complications of Escherichia coli O157:H7 Infection

2002 ◽  
Vol 70 (2) ◽  
pp. 612-619 ◽  
Author(s):  
Jean Mukherjee ◽  
Kerry Chios ◽  
Dianne Fishwild ◽  
Deborah Hudson ◽  
Susan O'Donnell ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Monoclonal Antibodies ◽  
Shiga Toxin ◽  
Cerebral Lesions ◽  
Systemic Complications ◽  
E Coli ◽  
B Subunit ◽  
Significant Prolongation ◽  
A Subunit

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 κ light chain loci (HuMAb___Mouse) were immunized with formalin-inactivated Stx2. Thirty-seven stable hybridomas secreting Stx2-specific HuMAbs were isolated: 33 IgG1κ A-subunit-specific and 3 IgG1κ and 1 IgG3κ B-subunit-specific antibodies. Six IgG1κ A-subunit-specific (1G3, 2F10, 3E9, 4H9, 5A4, and 5C12) and two IgG1κ B-subunit-specific (5H8 and 6G3) HuMAbs demonstrated neutralization of >95% activity of 1 ng of Stx2 in the presence of 0.04 μg of HuMAb in vitro and significant prolongation of survival of mice given 50 μg 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.

scholarly journals Production and Characterization of Protective Human Antibodies against Shiga Toxin 1

2002 ◽  
Vol 70 (10) ◽  
pp. 5896-5899 ◽  
Author(s):  
Jean Mukherjee ◽  
Kerry Chios ◽  
Dianne Fishwild ◽  
Deborah Hudson ◽  
Susan O'Donnell ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
Immunoglobulin M ◽  
B Subunit ◽  
Significant Prolongation ◽  
Uremic Syndrome ◽  
A Subunit ◽  
Light Chain Immunoglobulin ◽  
Subunit B

ABSTRACT Hemolytic-uremic syndrome (HUS) is a serious complication which is predominantly associated in children with infection by Shiga toxin-producing Escherichia coli (STEC). By using HuMAb-Mouse (Medarex) animals, human monoclonal antibodies (Hu-MAbs) were developed against Shiga toxin 1 (Stx1) for passive immunotherapy of HUS. Ten stable hybridomas comprised of fully human heavy- and light-chain immunoglobulin elements and secreting Stx1-specific Hu-MAbs (seven immunoglobulin M(κ) [IgM(κ)] elements [one specific for the A subunit and six specific for the B subunit] and three IgG1(κ) elements specific for subunit B) were isolated. Two IgM(κ) Hu-MAbs (2D9 and 15G9) and three IgG1(κ) Hu-MAbs (5A4, 10F4, and 15G2), all specific for subunit B, demonstrated marked neutralization of Stx1 in vitro and significant prolongation of survival in a murine model of Stx1 toxicosis.

scholarly journals A New Family of Potent AB5 Cytotoxins Produced by Shiga Toxigenic Escherichia coli

2004 ◽  
Vol 200 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Adrienne W. Paton ◽  
Potjanee Srimanote ◽  
Ursula M. Talbot ◽  
Hui Wang ◽  
James C. Paton
Keyword(s):  
Escherichia Coli ◽  
Bacterial Toxin ◽  
Virulence Plasmid ◽  
B Subunit ◽  
New Family ◽  
Uremic Syndrome ◽  
A Subunit ◽  
K 12 ◽  
Ab5 Toxins ◽  
Subtilase Cytotoxin

The Shiga toxigenic Escherichia coli (STEC) O113:H21 strain 98NK2, which was responsible for an outbreak of hemolytic uremic syndrome, secretes a highly potent and lethal subtilase cytotoxin that is unrelated to any bacterial toxin described to date. It is the prototype of a new family of AB5 toxins, comprising a single 35-kilodalton (kD) A subunit and a pentamer of 13-kD B subunits. The A subunit is a subtilase-like serine protease distantly related to the BA_2875 gene product of Bacillus anthracis. The B subunit is related to a putative exported protein from Yersinia pestis, and binds to a mimic of the ganglioside GM2. Subtilase cytotoxin is encoded by two closely linked, cotranscribed genes (subA and subB), which, in strain 98NK2, are located on a large, conjugative virulence plasmid. Homologues of the genes are present in 32 out of 68 other STEC strains tested. Intraperitoneal injection of purified subtilase cytotoxin was fatal for mice and resulted in extensive microvascular thrombosis, as well as necrosis in the brain, kidneys, and liver. Oral challenge of mice with E. coli K-12–expressing cloned subA and subB resulted in dramatic weight loss. These findings suggest that the toxin may contribute to the pathogenesis of human disease.

scholarly journals Syntheses and Immunologic Properties ofEscherichia coli O157 O-Specific Polysaccharide and Shiga Toxin 1 B Subunit Conjugates in Mice

1999 ◽  
Vol 67 (11) ◽  
pp. 6191-6193 ◽  
Author(s):  
Edward Konadu ◽  
Arthur Donohue-Rolfe ◽  
Stephen B. Calderwood ◽  
Vince Pozsgay ◽  
Joseph Shiloach ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Shiga Toxin ◽  
Conjugate Vaccines ◽  
E Coli ◽  
B Subunit ◽  
Specific Polysaccharide ◽  
Uremic Syndrome ◽  
Adult Volunteers ◽  
Immunologic Properties

ABSTRACT Escherichia coli O157 is the major cause of diarrhea-associated hemolytic uremic syndrome (HUS). Strains causing HUS contain either Shiga toxin 1 (Stx1) or Stx2, or both. In adult volunteers, conjugate vaccines of detoxified lipopolysaccharide (LPS) elicited bactericidal antibodies to E. coli O157. Here, the detoxified LPS was conjugated with improved schemes to the nontoxic B subunit of Stx1. Mice injected with these bivalent conjugates elicited both bactericidal antibodies to E. coli O157 and neutralization antibodies to Stx1.

scholarly journals Whole-genome characterization of hemolytic uremic syndrome-causing Shiga toxin-producing Escherichia coli in Sweden

Virulence ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1296-1305
Author(s):  
Ying Hua ◽  
Milan Chromek ◽  
Anne Frykman ◽  
Cecilia Jernberg ◽  
Valya Georgieva ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Shiga Toxin ◽  
Whole Genome ◽  
Genome Characterization ◽  
Uremic Syndrome

scholarly journals An Atypical Case of Shiga Toxin Producing-Escherichia Coli Hemolytic and Uremic Syndrome (STEC-HUS) in a Lung Transplant Recipient

2019 ◽  
Vol 2019 ◽  
pp. 1-3
Author(s):  
Louis Manière ◽  
Camille Domenger ◽  
Boubou Camara ◽  
Diane Giovannini ◽  
Paolo Malvezzi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Kidney Function ◽  
Shiga Toxin ◽  
Lactate Dehydrogenase Level ◽  
Fresh Frozen Plasma ◽  
First Case ◽  
Maintenance Immunosuppression ◽  
Fresh Frozen ◽  
Uremic Syndrome ◽  
Frozen Plasma

We herein describe the first case of thrombotic microangiopathy (TMA) which was related to Shiga toxin producing-Escherichia Coli Hemolytic and Uremic Syndrome (STEC-HUS) after lung transplantation. His maintenance immunosuppression relied on tacrolimus plus mycophenolic acid. TMA was treated with plasma exchanges (PE) (fresh frozen plasma substitution). After five days of PE, platelets count and lactate dehydrogenase level normalized, whereas hemoglobin continued to gradually decrease and no improvement in kidney function was observed. After seven PE sessions, all TMA biological signs resolved. However, kidney function did not improve, and the patient still required chronic dialysis.

scholarly journals HUS and the case for complement

Blood ◽  
2015 ◽  
Vol 126 (18) ◽  
pp. 2085-2090 ◽  
Author(s):  
Edward M. Conway
Keyword(s):  
Escherichia Coli ◽  
Renal Failure ◽  
Shiga Toxin ◽  
Complement Activation ◽  
Thrombotic Microangiopathy ◽  
Response To Treatment ◽  
Microangiopathic Hemolytic Anemia ◽  
New Knowledge ◽  
Uremic Syndrome

Abstract Hemolytic-uremic syndrome (HUS) is a thrombotic microangiopathy that is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and renal failure. Excess complement activation underlies atypical HUS and is evident in Shiga toxin–induced HUS (STEC-HUS). This Spotlight focuses on new knowledge of the role of Escherichia coli–derived toxins and polyphosphate in modulating complement and coagulation, and how they affect disease progression and response to treatment. Such new insights may impact on current and future choices of therapies for STEC-HUS.

scholarly journals Switching Shiga Toxin (Stx) Type from Stx2d to Stx2a but Not Stx2c Alters Virulence of Stx-Producing Escherichia coli (STEC) Strain B2F1 in Streptomycin (Str)-Treated Mice

Toxins ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 64
Author(s):  
Beth A. McNichol ◽  
Rebecca A. Bova ◽  
Kieron Torres ◽  
Lan N. Preston ◽  
Angela R. Melton-Celsa
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Oral Administration ◽  
Amino Acid Composition ◽  
Shiga Toxin ◽  
Vero Cells ◽  
Toxin B ◽  
B Subunit ◽  
Intestinal Mucus ◽  
Binding Subunit

Shiga toxin (Stx)-producing Escherichia coli (STEC) strain B2F1 produces Stx type 2d, a toxin that becomes more toxic towards Vero cells in the presence of intestinal mucus. STEC that make Stx2d are more pathogenic to streptomycin (Str)-treated mice than most STEC that produce Stx2a or Stx2c. However, purified Stx2d is only 2- or 7-fold more toxic by the intraperitoneal route than Stx2a or Stx2c, respectively. We hypothesized, therefore, that the toxicity differences among Stx2a, Stx2c, and Stx2d occur at the level of delivery from the intestine. To evaluate that hypothesis, we altered the toxin type produced by stx2d+ mouse virulent O91:H21 clinical isolate B2F1 to Stx2a or Stx2c. Because B2F1 encodes two copies of stx2d, we did these studies in a derivative of B2F1 in which stx2d1 was deleted. Although the strains were equivalently virulent to the Str-treated mice at the 1010 dose, the B2F1 strain that produced Stx2a was attenuated relative to the ones that produced Stx2d or Stx2c when administered at 103 CFU/mouse. We next compared the oral toxicities of purified Stx2a, Stx2c, and Stx2d. We found that purified Stx2d is more toxic than Stx2a or Stx2c upon oral administration at 4 µg/mouse. Taken together, these studies suggest that Stx2 toxins are most potent when delivered directly from the bacterium. Furthermore, because Stx2d and Stx2c have the identical amino acid composition in the toxin B subunit, our results indicate that the virulence difference between Stx2a and Stx2d and Stx2c resides in the B or binding subunit of the toxins.

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