A recombinant Escherichia coli heat-stable enterotoxin b (STb) fusion protein eliciting neutralizing antibodies.
STb is a heat-stable enterotoxin elaborated by enterotoxigenic Escherichia coli strains associated with weaning piglets and is responsible for diarrhoea in those animals. The maltose binding protein (MBP) of E. coli was used as a carrier for STb, a poorly immunogenic molecule. Constructions were produced where the gene coding for mature STb toxin (MBP-STb) and a fragment of the gene spanning the major epitopic region of STb (AA8-AA30) (MBP-STb2) were fused to malE gene coding for MBP. The fusion proteins accumulated in the periplasm and were detected with a polyclonal antibody raised against the purified toxin. MBP-STb induced secretion in the biological model whereas MBP-STb2 was non-toxic. Immunization of rabbits evoked an antibody response to STb for these two fusion proteins. However, only MBP-STb elicited antibodies that effectively neutralized the toxicity of pure STb toxin as determined in the rat loop assay.
Dubreuil
J D
JD
Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Montreal University, Que Canada. dubreuid@ere.umontreal.ca
Letellier
A
A
Harel
J
J
D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology; D004768:Enterotoxins / Q000235:genetics / Q000276:immunology*; D029968:Escherichia coli Proteins; D058619:Maltose-Binding Proteins; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins; D009500:Neutralization Tests; D033902:Periplasmic Binding Proteins; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000633:toxicity; D014614:Vaccines, Synthetic / Q000276:immunology
D018528:ATP-Binding Cassette Transporters; D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D002352:Carrier Proteins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C461619:MalE protein, E coli; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; D011993:Recombinant Fusion Proteins; D014614:Vaccines, Synthetic; C034151:heat stable toxin (E coli); C461599:maltose transport system, E coli