Functional diversity of heat-labile toxins (LT) produced by enterotoxigenic Escherichia coli: differential enzymatic and immunological activities of LT1 (hLT) AND LT4 (pLT).

ABSTRACT: Heat-labile toxins (LTs) have ADP-ribosylation activity and induce the secretory diarrhea caused by enterotoxigenic Escherichia coli (ETEC) strains in different mammalian hosts. LTs also act as adjuvants following delivery via mucosal, parenteral, or transcutaneous routes. Previously we have shown that LT produced by human-derived ETEC strains encompass a group of 16 polymorphic variants, including the reference toxin (LT1 or hLT) produced by the H10407 strain and one variant that is found mainly among bacterial strains isolated from pigs (LT4 or pLT). Herein, we show that LT4 (with six polymorphic sites in the A (K4R, K213E, and N238D) and B (S4T, A46E, and E102K) subunits) displays differential in vitro toxicity and in vivo adjuvant activities compared with LT1. One in vitro generated LT

SUBMITTER: Rodrigues JF 

PROVIDER: S-EPMC3037635 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature