Cholera toxin subunit B (CTB) (CTB)

Recombinant cholera toxin B subunit (rCTB) is the non-toxic, pentameric component of the cholera enterotoxin produced by Vibrio cholerae. Its primary biological role is to serve as a high-affinity ligand for the GM1 ganglioside receptor located on the surface of mammalian intestinal epithelial cells, which facilitates the internalization of the toxic A subunit in the native toxin (UniProt: P01556). In a therapeutic context, rCTB is a potent immunogen and is a key component of oral cholera vaccines, such as Dukoral, where it induces protective mucosal IgA antibodies that prevent the wild-type toxin from binding to the gut wall (DrugBank: DB09213). Beyond its role in vaccination, rCTB is widely utilized in biomedical research as a neuronal tracer due to its retrograde transport properties and as a molecular scaffold for delivering conjugated antigens to the immune system (PubMed: 16501135). It also exhibits significant immunomodulatory effects, including the induction of oral tolerance, making it a subject of interest for treating autoimmune and inflammatory diseases (PubMed: 11414361).

Other names

Recombinant cholera toxin B subunitrCTBCholeragenoidCholera enterotoxin subunit BVibrio cholerae B subunitCholera toxin B subunit

Binds to GM1 ganglioside receptors on intestinal epithelial cells to induce protective mucosal IgA antibodies that neutralize the cholera toxin (DrugBank: DB09213).