Immunogenic properties of trivalent recombinant protein composed of B-subunits of LT, STX-2, and CT toxins

Abstract

Infectious diarrhoea remains an emerging problem in the world health program. Among diarrheagenic agents, Vibrio cholerae and enterotoxigenic and enterohemorrhagic Escherichia coli are critical enteropathogens. AB5 toxin produced by these bacteria, heat-labile enterotoxin (LT), cholera enterotoxin (CT), and shiga-like cytotoxin (STX) can target the immune system and are subunit vaccine candidates. A chemically-synthesized chimeric construct composed of the binding subunits of these toxins (LTB, STXB, and CTXB) was developed based on bioinformatics studies. The whole chimeric protein (rLSC) and each of the segments (rLTB, rSTXB, and rCTXB) were expressed in a prokaryotic expression system (E. coli), purified, and analysed for their immunogenic properties. The results indicate that these recombinant proteins were effectively able to present appropriate epitopes to an animal model of the immune system which could result in and increase IgG in serum and immune responses that protect against the binding activity of these toxins. The immunological assays revealed that the sera of immunized mice prevented toxins from binding to their specific receptors and neutralized their toxic effects. The proposed construct should be considered as a potent immunogen to prevent toxicity and diarrhoea.

Molecular characterization of virulence genes and antibiotic resistance among fecal Escherichia coli isolated from surface water of Wadi Shueib-Jordan

“…Among diarrheagenic bacteria, enterotoxigenic and enterohemorrhagic E. coli are important enteropathogens causing single and outbreaks of diarrhea following consumption of contamination of fresh food and drinks [22]. ETEC affects small intestine, and it is still a major cause of traveler diarrhea.…”

Molecular characterization of virulence genes and antibiotic resistance among fecal Escherichia coli isolated from surface water of Wadi Shueib-Jordan

“…Diarrhea caused by pathogenic types of E. coli is still a health care problem in devel oping countries including Jordan, mostly found in chil dren younger than five years old [11,20,21]. Among diarrheagenic bacteria, enterotoxigenic and enterohemorrhagic E. coli are important enteropathogens causing single and outbreaks of diarrhea following consumption of contamination of fresh food and drinks [22]. ETEC affects small intestine, and it is still a major cause of traveler diarrhea.…”

Production of Recombinant LSC Protein in Nicotiana tabacum Hairy Root: Direct vs. Indirect, a Comparison

“…The lsc gene construct was synthesized according to the previous studies. 17 In order to clone the lsc gene construct, the pUC57 vector containing this synthetic gene and the pBI121 vector were digested with XbaI/SacI restriction enzymes. The ligation of the lsc to pBI121 was performed and the construct was transformed to 2 strains of Agrobacterium by freezing and thawing.…”

“…In this regard, a serial dilution of 10 pg to 5 μg of the purified protein LSC and the antibody against this protein was prepared. 17 The endobiotic peroxidation activity in root tissues was stopped using 0.3% hydrogen peroxide. A protein solution from not-transformed hairy roots was used as negative control.…”

“…In our previous study, a three-partit gene construct containing the binding subunit of ltB-stxB-ctxB (LSC) after bioinformatics studies was synthesized. 17 Here, the expression ability of this chimeric gene in transgenic hairy roots of tobacco plant was investigated by direct and indirect transformation. Expression measurement of GUS enzyme and LSC chimeric protein in the tobacco hairy roots was conducted with the aim of producing an oral vaccine based on hairy roots and comparing two direct and indirect methods in transgenic hairy roots as a new method.…”