Escherichia coli producing heat-labile enterotoxin is responsible for numerous cases of diarrhea worldwide, leading to considerable morbidity and mortality. The B subunits of this toxin are responsible for the binding to the receptor, the complex ganglioside GM1 which has galactose as its terminal sugar. In this study we showed that analogs of galactose (gal) and N-acetylgalactosamine (GalNAc) ...

The cholera toxin B pentamer (CtxB(5)), which belongs to the AB(5) toxin family, is used as a model study for protein assembly. The effect of the pH on the reassembly of the toxin was investigated using immunochemical, electrophoretic and spectroscopic methods. Three pH-dependent steps were identified during the toxin reassembly: (i) acquisition of a fully assembly-competent fold by the CtxB mo...

Hybridization probes derived from the A and B subunit genes of the heat-labile enterotoxin (LT) of Escherichia coli were used to analyze DNA from Vibrio cholera strain 569B for cholera toxin gene sequences. Southern blot analysis indicated that the cholera toxin A and B subunit genes were each duplicated in the strain. One of the two toxin subunit gene pairs was cloned as a 5.1-kilobase DNA ins...

A modification of the enzyme-linked immunosorbent assay for a sensitive and rapid visual detection of heat-labile enterotoxins from Escherichia coli and Vibrio cholerae is described. Small amounts of bacterial supernatant fluids are bound to nitrocellulose filters which are used as sorbents in the nitrocellulose enzyme-linked immunosorbent assay. The test is based on the immunological similarit...

Multiple vaccination strategies have been devised against HIV-1 including delivery of HIV moieties in attenuated or replication defective recombinant microbial agents alone or in combination with priming agents in form of soluble proteins or naked DNA. For the priming agents to be effective, adjuvants might be essential in directing the immune response to a desired outcome. E. coli enterotoxin ...

Heat-labile enterotoxin of Escherichia coli pathogenic for humans (LTh) or for piglets (LTp) and Vibrio cholerae enterotoxin (CT) are structurally and functionally similar toxins. We have determined the complete nucleotide sequence of the toxA gene which encodes the subunit A of LTh (LTh A). The deduced amino acid sequence consists of 258 residues including a signal peptide of 18 residues. Acco...

Escherichia coli strain 86, isolated from a piglet with diarrhea, carries plasmid-linked genes for resistance to tetracycline, streptomycin, and sulfonamides and for production of heat-labile and heat-stable enterotoxin. Results of (i) genetic experiments involving conjugal transfer and phage P1-mediated transduction and (ii) physical experiments involving electron microscopic examination of pl...

Treatments to limit T cell activation are essential for managing autoimmune and inflammatory disorders. The B subunit of Escherichia coli heat-labile enterotoxin (EtxB) is known to ameliorate inflammatory disease in vivo but the mechanism by which this is mediated is not well understood. Here, we show that following intranasal administration, EtxB acts on two key cellular regulators of T cell a...