CEACAMs serve as toxin-stimulated receptors for enterotoxigenic Escherichia coli

Significance Enterotoxigenic Escherichia coli (ETEC), a leading cause of acute watery diarrheal illness in children, have also been linked to nondiarrheal sequelae including malnutrition. ETEC produce heat-labile toxin (LT) to stimulate the production of cellular cAMP, ultimately modulating ion channels to release salt and water into the intestinal lumen, resulting in diarrhea. Given the importance of cAMP as a “second messenger,” we reasoned that cellular features could be altered by LT to benefit the bacteria. Interestingly, we found that LT-mediated increases in cAMP stimulate production of CEACAMs, a family of cell surface glycoproteins, which then serve as receptors for ETEC. Collectively, our findings may have implications for our understanding of toxin-mediated illness as well as sequelae associated with these important pathogens.