heat-labile enterotoxin (R192G)

heat-labile enterotoxin (R192G) is a genetically detoxified derivative of the heat-labile enterotoxin (LT) produced by *Escherichia coli*, specifically engineered for use as a potent mucosal and systemic vaccine adjuvant. The molecule is a member of the AB5 toxin family, consisting of an A subunit with enzymatic activity and a B subunit pentamer responsible for cell binding. The R192G mutation replaces an arginine with a glycine at the trypsin-sensitive cleavage site of the A subunit, which prevents the proteolytic activation required for the toxin's ADP-ribosyltransferase activity. This modification eliminates the enterotoxicity (diarrheagenic potential) while retaining the molecule's ability to bind to GM1 ganglioside receptors on the surface of immune and epithelial cells. By facilitating antigen uptake and modulating local cytokine environments, LT(R192G) enhances both humoral (notably secretory IgA) and cellular immune responses to co-administered antigens. It has been primarily developed for vaccines targeting enterotoxigenic *E. coli* (ETEC) and respiratory pathogens.

Other names

mutant heat-labile enterotoxinEscherichia coli heat-labile enterotoxin (R192G)m-LT