Escherichia coli heat-labile enterotoxin (LT) is an extensively studied adjuvant of mucosal responses. Nevertheless, its mode of action as an adjuvant remains incompletely understood. In this study, we describe a simplified in vitro model with which to look at some aspects of immunoregulation by LT. The interaction of LT with the apical surface of a monolayer of CaCo-2 epithelial cells induces ...

Given recent evidence suggesting that the heat-labile enterotoxin (LT) provides a colonization advantage for enterotoxigenic Escherichia coli (ETEC) in vivo, we hypothesized that LT preconditions the host intestinal epithelium for ETEC adherence. To test this hypothesis, we used an in vitro model of ETEC adherence to examine the role of LT in promoting bacterium-host interactions. We present da...

Phenotypically nontoxinogenic mutants of Vibrio cholerae were isolated after infection with either of two mutagenic vibriophages, VcAI and VcA2ctsl. DNA isolated from these mutants was analyzed for toxin gene sequences by the Southern blotting method with 32P-labeled probes derived from the cloned A and B subunit genes for the heat-labile enterotoxin of Escherichia coli, designated LT. Several ...

The binding of class II Escherichia coli heat-labile enterotoxins (LT) to Y1 tissue-cultured cells and mouse intestinal cells was studied and compared with that of class I toxins, including cholera enterotoxin. All radioiodinated (125I) toxins retained their biological activities in both model systems, but only LTIIb could be shown to bind specifically to target cells. LTIIa could inhibit the b...

Enterotoxigenic Escherichia coli (ETEC)-induced diarrhoea is the second most commoncause of death in children in the developing countries. Heat labile toxin (LT) is responsible forETEC-induced diarrhoea. In the present study, a novel live ETEC vaccine based on subunitB of LT (LTB) expression in attenuated PhoPc Salmonella strain was developed. Herein, weaimed to compare the in-vitro activity of...

Enterotoxigenic Escherichia coli (ETEC)-induced diarrhoea is the second most commoncause of death in children in the developing countries. Heat labile toxin (LT) is responsible forETEC-induced diarrhoea. In the present study, a novel live ETEC vaccine based on subunitB of LT (LTB) expression in attenuated PhoPc Salmonella strain was developed. Herein, weaimed to compare the in-vitro activity of...