Assessment in mice of the therapeutic potential of tailored, multivalent Shiga toxin carbohydrate ligands

Abstract

The therapeutic potential of 2 soluble multivalent receptor-based inhibitors of Shiga toxin (Stx) 1 and Stx2 was determined in mice. One of these, Starfish, protected mice when it was injected subcutaneously in admixture with a lethal dose of Stx1 but not Stx2. Starfish also reduced the distribution of 125I-Stx1 but not 125I-Stx2 to the murine kidney and brain. A modified version of Starfish, called "Daisy," in which the Stx αGal(1,4)βGal(1,4)βGlc receptors were installed on the core glucose structure via a modified tethering strategy, protected mice against both Stx1 and Stx2. Daisy also protected streptomycin-treated mice from Escherichia coli O91:H21 and did not interfere with the ability of the murine immune system to produce Stx-specific protective antibodies. These results extend the possibility of using soluble carbohydrate-based receptor inhibitors to prevent Stx-mediated complications arising from infections with enterohemorrhagic E. coli serotypes.