Escherichia coli heat-labile enterotoxin B subunit (LT-B)

The Escherichia coli heat-labile enterotoxin B subunit is one of five identical binding subunits forming the pentameric ring of the heat-labile AB5 enterotoxin. This subunit is responsible for the high-affinity binding of the toxin complex to GM1 gangliosides on the surface of mammalian cells, enabling entry of the enzymatically active A subunit. The B subunit has no enzymatic activity but is essential for pathogenesis, as well as for its potent capacity to serve as a research and clinical adjuvant. Recombinant LT-B, lacking the toxic activity of the A subunit, is being explored for its ability to modulate immune responses, induce regulatory T cells, and act as a carrier or platform for antigens in vaccines. Its structure and function are closely related to the cholera toxin B subunit, but it has antigenic distinctions and unique binding properties.

Other names

LT-BETxBLTB subunitE. coli enterotoxin B subunit

Binds GM1 ganglioside receptors in host cell membranes, allowing uptake of the whole AB5 toxin complex. When used as an adjuvant or delivery tool, facilitates antigen uptake and T cell activation.