Construction and characterization of a non-toxic mutant of the Escherichia coli heat-labile enterotoxin effective as an oral adjuvant

The heat-labile enterotoxin (LT) of Escherichia coli is immunologically and physiochemically related to the cholera enterotoxin (CT) produced by Vibrio cholerae. A number of studies have been performed to determine the relationship of the ADP-ribosylating enzymatic activity of these enterotoxins to toxicity and adjuvanticity. These studies have generally examined the effect of abolishing the ADP-ribosyltransferase activity of A...