Mouse in Vivo Neutralization of Escherichia coli Shiga Toxin 2 with Monoclonal Antibodies

Abstract

Shiga toxin-producing Escherichia coli (STEC) food contaminations pose serious health concerns, and have been the subject of massive food recalls. STEC has been identified as the major cause of the life-threatening complication of hemolytic uremic syndrome (HUS). Besides supportive care, there currently are no therapeutics available. The use of antibiotics for combating pathogenic E. coli is not recommended because they have been shown to stimulate toxin production. Clearing Stx2 from the circulation could potentially lessen disease severity. In this study, we tested the in vivo neutralization of Stx2 in mice using monoclonal antibodies (mAbs). We measured the biologic half-life of Stx2 in mice and determined the distribution phase or t1/2 α to be 3 min and the clearance phase or t1/2 β to be 40 min. Neutralizing mAbs were capable of clearing Stx2 completely from intoxicated mouse blood within minutes. We also examined the persistence of these mAbs over time and showed that complete protection could be passively conferred to mice 4 weeks before exposure to Stx2. The advent of better diagnositic methods and the availability of a greater arsenal of therapeutic mAbs against Stx2 would greatly enhance treatment outcomes of life threatening E. coli infections.

Development and Characterization of Recombinant Antibody Fragments That Recognize and Neutralize In Vitro Stx2 Toxin from Shiga Toxin-Producing Escherichia coli

“…Four rounds of panning were performed. The monoclonal phage particles were grown and tested by ELISA [ 18 ] and positive clones were then sequenced.…”

“…One alternative treatment for STEC infection and possibly for HUS is neutralizing anti-Stx antibody therapy. Monoclonal antibodies (mAb) against Stx have been evaluated in animal models [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. One in particular, urtoxazumab showed better prospects in HUS therapy, as it appears to be a safe therapeutic tool [ 24 ].…”

Serum Shiga toxin 2 values in patients during acute phase of diarrhoea‐associated haemolytic uraemic syndrome

“…Serum samples were collected from patients with proven HUS on admission to the clinic and were frozen at À20°C (patients 1-14 and 18) or at À80°C (patients 15, 16 and 17). Ten patients were of Italian origin (patients 1-10), four were German (patients [11][12][13][14], three were Dutch (patients [15][16][17], and one was Belgian (patient 18). Patients five and nine were not included in the final analysis as there was not enough serum available, leaving 16 patients.…”

Hydrogel Retaining Toxin‐Absorbing Nanosponges for Local Treatment of Methicillin‐Resistant Staphylococcus aureus Infection

“…[3] These toxins disrupt cells by forming pores on cellular membranes and altering their permeability for bioactivity. [4] However, the majority of current toxin targeting strategies, such as antisera, [5] monoclonal antibodies, [6, 7] small-molecule inhibitors, [8, 9] and molecularly imprinted polymers, [10] relies primarily on structure-specific epitopic binding and custom synthesis is required to match specific toxins. As a result, the enormous diversity of PFTs presents a serious challenge to devise an effective detoxification platform against bacterial infections.…”