LT is a hetero-oligomeric AB5 type enterotoxin composed of a 27 kDa A subunit with toxic ADP ribosyl transferase activity and a stable noncovalent-linked pentamer of 11.6 kDa B subunits. ETEC infection and colonization of the small intestine, and the production of LT, causes acute diarrhea that can be fatal without intervention (Moravec et al., 2007).
Immunized mice developed antibodies that were capable of detecting each recombinant subunit in addition to native CS6 protein and also protected the mice against ETEC challenge. (Zeinalzadeh et al., 2017)