Enterotoxigenic Escherichia coli colonization factor antigen I fimbrial tip adhesin and heat-labile enterotoxin (CfaE-LT)

Enterotoxigenic Escherichia coli (ETEC) CFA/I fimbrial tip adhesin (CfaE) and heat-labile enterotoxin (LT) represent two primary virulence factors and therapeutic targets for preventing ETEC-mediated diarrhea. CfaE is the minor subunit located at the tip of the Colonization Factor Antigen I (CFA/I) fimbriae, which is responsible for the initial attachment of the bacteria to human intestinal receptors. The heat-labile enterotoxin is an AB5-type toxin that increases intracellular cyclic AMP levels, leading to massive fluid and electrolyte secretion into the intestinal lumen. Therapeutic strategies, particularly vaccines, often combine these two components to provide a dual-action defense: blocking bacterial colonization and neutralizing the secreted toxin. Modern vaccine candidates utilize detoxified versions of LT, such as dmLT, as both an antigen and a potent mucosal adjuvant to enhance the immune response against the CfaE adhesin.

Other names

CfaEHeat-labile enterotoxinLTCFA/I fimbrial tip adhesinETEC adhesin-toxin complexColonization factor antigen I subunit E

Vaccines targeting these components work by inducing neutralizing antibodies that block the CfaE-mediated attachment of ETEC to intestinal epithelial cells and neutralize the enzymatic activity of the heat-labile enterotoxin to prevent fluid secretion.