Antibody response against Escherichia coli heat-stable enterotoxin expressed as fusions to flagellin

Pereira, Cátia M.; Guth, Beatriz E. C.; Sbrogio-Almeida, Maria E.; Castilho, Beatriz A.

doi:10.1099/00221287-147-4-861

Cited by 30 publications

(23 citation statements)

References 37 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ST has also been genetically coupled to the S. aureus protein A ZZ fragment (28) and Salmonella flagellin (35). The ZZ-ST fusion peptide, where ST was fused to the N terminus of ZZ, elicited an immune response in rabbits with serum levels that were able to neutralize native ST in suckling mice.…”

Section: St Vaccinologymentioning

confidence: 99%

“…The toxicity of ZZ-ST was lower than that of native ST, and a polymeric form of ZZ-ST was about 100 times less toxic than the monomeric fusion protein (28). When ST was inserted into the hypervariable region of the Salmonella flagellin, a good antigenic response was observed only after two of the disulfide bonds were disrupted by substitution of cysteine residues (STh, Cys7Ala Cys18Ala) (35). The flagellin-ST fusion protein was delivered using an attenuated Salmonella strain.…”

Section: St Vaccinologymentioning

confidence: 99%

“…Detoxifying ST. Detoxification of ST can be achieved, at least in part, by genetic fusion or chemical conjugation, but it has often been combined with mutagenesis (2,35,39). Several mutants with effects on toxicity have been reported and are summarized in Fig.…”

Section: St Vaccinologymentioning

confidence: 99%

See 2 more Smart Citations

Heat-Stable Enterotoxin of EnterotoxigenicEscherichia colias a Vaccine Target

et al. 2010

View full text Add to dashboard Cite

5Enterotoxigenic Escherichia coli (ETEC) is responsible for 280 million to 400 million episodes of diarrhea and about 380,000 deaths annually. Epidemiological data suggest that ETEC strains which secrete heat-stable toxin (ST), alone or in combination with heat-labile toxin (LT), induce the most severe disease among children in developing countries. This makes ST an attractive target for inclusion in an ETEC vaccine. ST is released upon colonization of the small intestine and activates the guanylate cyclase C receptor, causing profuse diarrhea. To generate a successful toxoid, ST must be made immunogenic and nontoxic. Due to its small size, ST is nonimmunogenic in its natural form but becomes immunogenic when coupled to an appropriate large-molecular-weight carrier. This has been successfully achieved with several carriers, using either chemical conjugation or recombinant fusion techniques. Coupling of ST to a carrier may reduce toxicity, but further reduction by mutagenesis is desired to obtain a safe vaccine. More than 30 ST mutants with effects on toxicity have been reported. Some of these mutants, however, have lost the ability to elicit neutralizing immune responses to the native toxin. Due to the small size of ST, separating toxicity from antigenicity is a particular challenge that must be met. Another obstacle to vaccine development is possible cross-reactivity between anti-ST antibodies and the endogenous ligands guanylin and uroguanylin, caused by structural similarity to ST. Here we review the molecular and biological properties of ST and discuss strategies for developing an ETEC vaccine that incorporates immunogenic and nontoxic derivatives of the ST toxin.

show abstract

Section: St Vaccinologymentioning

confidence: 99%

Section: St Vaccinologymentioning

confidence: 99%

See 1 more Smart Citation

Heat-Stable Enterotoxin of EnterotoxigenicEscherichia colias a Vaccine Target

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Thus, E. coli, Salmonella and Shigella spp. expressing surface recombinant peptide antigens stimulate specific immune responses, 29,30 whereas rIL-10 released by Lactococcus lacti prevented the onset of colitis in experimental animal models. 31 Bacteria can be used to deliver DNA to eukaryotic cells.…”

Section: Discussionmentioning

confidence: 99%

Engineered E. coli delivers therapeutic genes to the colonic mucosa

et al. 2005

View full text Add to dashboard Cite

Taking advantage of the proximity of bowel mucosa to luminal bacteria, we have attempetd to deliver a therapeutic gene to the colonic mucosa by oral administration of an invasive and non-pathogenic Escherichia coli. E. coli diamenopimelate (dap) auxotroph, harboring plasmid pGB2Oinv-hly, express the inv gene from Yersinia pseudotubercolosis that confers the ability to invade nonprofessional phagocytic cells and the hly gene from Listeria monocytogenes that allows expression of lystreriolysin O, a perforin cytolysin able to perfore phagosomal membranes. This bacterial vector invades and transfers functional DNA to epithelial cells in vitro. We have shown that this strain carrying a therapeutic gene (pC1OTGF-b1) can significantly reduce the severity of experimental colitis in mice. However, as a consequence of mucosal barrier disruption during colitis, vector-specific mRNA transcripts could be recovered from the colon and also from extra-colonic tissues. We therefore replaced the constitutive CMV promoter in pC1OTGF-b1 by the inflammation-inducible interleukin-8 promoter generating plasmid pC1OTGF-b1 IND . Plasmid-specific TGF-b1 mRNA transcripts were detectable in mouse CMT-93 epithelial cells incubated with E. coli BM2710/pGB2Oinv-hly carrying pC1OTGF-b1 IND following exposure to inflammatory cytokines. Furthermore, the transcripts were detectable only within inflamed tissues and the therapeutic effects were comparable to those in animals treated with E. coli BM2710/ pGB2Oinv-hly+pC1OTGF-b1. In summary, engineered enteric bacteria can efficiently deliver in vivo therapeutic genes to the intact intestinal mucosa and regulation expression of the therapeutic gene by an inflammation-inducible promoter prevents its dissemination during colitis.

show abstract

“…Several strategies have been investigated to make STa immunogenic either through chemical conjugation [6,[31][32][33] or recombinant fusion protein [7,[34][35][36][37][38]. These approaches have been assessed based on antigenicity of the final product or complexity of the procedure.…”

Section: Discussionmentioning

confidence: 99%

Novel Heat-Stable Enterotoxin (STa) Immunogen Based on Cationic Nanoliposomes: Preparation, Characterization and Immunization

Aref¹,

Nasr²,

Osman³

2017

J Vaccines Vaccin

View full text Add to dashboard Cite

The novelties encountered in the field of formulation have provided promising solutions for the problematic vaccine development of hapten molecules. In the current study, the novel preparation of a cationic nanoliposomal immunogen of the heat stable enterotoxin (STa) was reported. STa was produced from clinically ETEC isolate of diarrheic neonatal calves and purified using RP-HPLC. STa was loaded into the cationic vesicles which were characterized for their particle size, surface charge, morphology, STa loading, and stability. The STa loaded cationic nanoliposome was used for mice immunization and the generation of STa antibody was monitored using ELISA. Results displayed the spherical nature of the STa loaded vesicles, their suitable size and homogeneity represented by a particle size of 228.1 nm and a PDI of 0.202. The surface charge of the STa nanoliposomes was +29.9, demonstrating sufficient stability during refrigeration storage. The STa loaded cationic nanoliposome was able to elicit specific STa antibody response, and to confer effective protection against STa challenge in mice. The STa antibody binding titer and neutralization capacity were 10 5 and 10 4 mouse units/ml serum, respectively. The developed system is a one-step procedure, which overcomes the disadvantage of the complexity of generation of the hapten-carrier conjugate. In conclusion, the developed STa-cationic nanoliposomal immunogen is feasible and has the potential to improve effectiveness against ETEC, suggesting its applicability in preventing the harmful effects of ETEC infection in neonatal calves.

show abstract

Antibody response against Escherichia coli heat-stable enterotoxin expressed as fusions to flagellin

Cited by 30 publications

References 37 publications

Heat-Stable Enterotoxin of EnterotoxigenicEscherichia colias a Vaccine Target

Heat-Stable Enterotoxin of EnterotoxigenicEscherichia colias a Vaccine Target

Engineered E. coli delivers therapeutic genes to the colonic mucosa

Novel Heat-Stable Enterotoxin (STa) Immunogen Based on Cationic Nanoliposomes: Preparation, Characterization and Immunization

Contact Info

Product

Resources

About