Shiga toxin 2 B subunit (Stx2B)

The Shiga toxin 2 B subunit (Stx2B) is the pentameric component of the AB5 holotoxin produced by Shiga toxin-producing Escherichia coli (STEC) [1]. Its primary biological role is to mediate the specific binding of the toxin to the host cell surface glycolipid receptor, globotriaosylceramide (Gb3/CD77), which is highly expressed on renal glomerular endothelial cells and certain neurons [2]. Following binding, the B subunit facilitates the endocytosis and retrograde transport of the toxic A subunit through the Golgi apparatus and endoplasmic reticulum to the cytosol [3]. In the context of disease, Stx2B is a critical virulence factor responsible for the development of life-threatening complications such as Hemolytic Uremic Syndrome (HUS) and hemorrhagic colitis [4]. Because the B subunit is essential for toxin entry into cells, it serves as a primary therapeutic target for neutralizing monoclonal antibodies and small-molecule inhibitors designed to prevent systemic toxicity [5]. Therapeutic strategies often focus on blocking the Stx2B-Gb3 interaction to mitigate the severe vascular and renal damage associated with STEC infections [6]. However, the timing of administration is critical, as the toxin must be neutralized before it binds to target tissues, and certain antibiotics can paradoxically increase toxin release [7, 8].

Other names

Shiga-like toxin 2 B subunitVerotoxin 2 B subunitStx2BSLT-2BVerocytotoxin 2 B subunit

Neutralization of the toxin by preventing the B subunit from binding to the host cell surface receptor globotriaosylceramide (Gb3/CD77), thereby blocking toxin internalization and subsequent cytotoxicity.