Genetic fusion of a non-toxic heat-stable enterotoxin-related decapeptide antigen to cholera toxin B-subunit.
A decapeptide highly homologous to the STa Escherichia coli heat-stable enterotoxin and to several other heat-stable enterotoxins was fused genetically to the amino-end of the B-subunit of cholera toxin (CTB) and the hybrid protein gene expressed from a tacP overexpression system. The STa-related decapeptide used, which was encoded by a synthetic oligodeoxynucleotide, contained a single mutation which substituted a disulfide-linked cysteine by alanine. After its fusion to CTB the decapeptide was able to both react with and to give rise to anti-STa antibodies. Expression of the decapeptide-CTB hybrid by non-toxigenic Vibrio cholerae resulted in its full secretion into the extracellular milieu from where it could then be readily purified by single-step affinity chromatography using immobilized GM1 ganglioside. Bacteria producing this non-toxic, immunogenic decapeptide-CTB toxoid might be useful for the development of oral vaccines against diarrhea caused by E. coli and other bacteria producing immunologically related heat-stable enterotoxins, and as a source of immunoreagents for methods used to diagnose disease caused by these bacteria.
Sanchez
J
J
Department of Medical Microbiology, University of Göteborg, Sweden.
Svennerholm
A M
AM
Holmgren
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics* / Q000633:toxicity; D001483:Base Sequence; D002772:Cholera Toxin / Q000235:genetics* / Q000633:toxicity; D003001:Cloning, Molecular; D004768:Enterotoxins / Q000235:genetics* / Q000633:toxicity; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015151:Immunoblotting; D051379:Mice; D008969:Molecular Sequence Data; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000633:toxicity
D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D011993:Recombinant Fusion Proteins; C034151:heat stable toxin (E coli); D002772:Cholera Toxin