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Mathipa MG, Thantsha MS. Probiotic engineering: towards development of robust probiotic strains with enhanced functional properties and for targeted control of enteric pathogens. Gut Pathog 2017; 9:28. [PMID: 28491143 PMCID: PMC5422995 DOI: 10.1186/s13099-017-0178-9] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/27/2017] [Indexed: 12/19/2022] Open
Abstract
There is a growing concern about the increase in human morbidity and mortality caused by foodborne pathogens. Antibiotics were and still are used as the first line of defense against these pathogens, but an increase in the development of bacterial antibiotic resistance has led to a need for alternative effective interventions. Probiotics are used as dietary supplements to promote gut health and for prevention or alleviation of enteric infections. They are currently used as generics, thus making them non-specific for different pathogens. A good understanding of the infection cycle of the foodborne pathogens as well as the virulence factors involved in causing an infection can offer an alternative treatment with specificity. This specificity is attained through the bioengineering of probiotics, a process by which the specific gene of a pathogen is incorporated into the probiotic. Such a process will subsequently result in the inhibition of the pathogen and hence its infection. Recombinant probiotics offer an alternative novel therapeutic approach in the treatment of foodborne infections. This review article focuses on various strategies of bioengineered probiotics, their successes, failures and potential future prospects for their applications.
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Affiliation(s)
- Moloko Gloria Mathipa
- Department of Microbiology and Plant Pathology, University of Pretoria, New Agricultural Sciences Building, Pretoria, 0002 South Africa
| | - Mapitsi Silvester Thantsha
- Department of Microbiology and Plant Pathology, University of Pretoria, New Agricultural Sciences Building, Pretoria, 0002 South Africa
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Dubreuil JD, Isaacson RE, Schifferli DM. Animal Enterotoxigenic Escherichia coli. EcoSal Plus 2016; 7:10.1128/ecosalplus.ESP-0006-2016. [PMID: 27735786 PMCID: PMC5123703 DOI: 10.1128/ecosalplus.esp-0006-2016] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Indexed: 12/13/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is the most common cause of E. coli diarrhea in farm animals. ETEC are characterized by the ability to produce two types of virulence factors: adhesins that promote binding to specific enterocyte receptors for intestinal colonization and enterotoxins responsible for fluid secretion. The best-characterized adhesins are expressed in the context of fimbriae, such as the F4 (also designated K88), F5 (K99), F6 (987P), F17, and F18 fimbriae. Once established in the animal small intestine, ETEC produce enterotoxin(s) that lead to diarrhea. The enterotoxins belong to two major classes: heat-labile toxins that consist of one active and five binding subunits (LT), and heat-stable toxins that are small polypeptides (STa, STb, and EAST1). This review describes the disease and pathogenesis of animal ETEC, the corresponding virulence genes and protein products of these bacteria, their regulation and targets in animal hosts, as well as mechanisms of action. Furthermore, vaccines, inhibitors, probiotics, and the identification of potential new targets by genomics are presented in the context of animal ETEC.
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Affiliation(s)
- J Daniel Dubreuil
- Faculté de Médecine Vétérinaire, Université de Montréal, Québec J2S 7C6, Canada
| | - Richard E Isaacson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108
| | - Dieter M Schifferli
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
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YANG X, SKYBERG JA, CAO L, CLAPP B, THORNBURG T, PASCUAL DW. Progress in Brucella vaccine development. FRONTIERS IN BIOLOGY 2013; 8:60-77. [PMID: 23730309 PMCID: PMC3666581 DOI: 10.1007/s11515-012-1196-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 01/16/2012] [Indexed: 01/18/2023]
Abstract
Brucella spp. are zoonotic, facultative intracellular pathogens, which cause animal and human disease. Animal disease results in abortion of fetuses; in humans, it manifests flu-like symptoms with an undulant fever, with osteoarthritis as a common complication of infection. Antibiotic regimens for human brucellosis patients may last several months and are not always completely effective. While there are no vaccines for humans, several licensed live Brucella vaccines are available for use in livestock. The performance of these animal vaccines is dependent upon the host species, dose, and route of immunization. Newly engineered live vaccines, lacking well-defined virulence factors, retain low residual virulence, are highly protective, and may someday replace currently used animal vaccines. These also have possible human applications. Moreover, due to their enhanced safety and efficacy in animal models, subunit vaccines for brucellosis show great promise for their application in livestock and humans. This review summarizes the progress of brucellosis vaccine development and presents an overview of candidate vaccines.
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Affiliation(s)
- Xinghong YANG
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - Jerod A. SKYBERG
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - Ling CAO
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - Beata CLAPP
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - Theresa THORNBURG
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
| | - David W. PASCUAL
- Department of Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA
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Suo Z, Yang X, Deliorman M, Cao L, Avci R. Capture efficiency of Escherichia coli in fimbriae-mediated immunoimmobilization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:1351-1359. [PMID: 22149536 PMCID: PMC3260392 DOI: 10.1021/la203348j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Capturing pathogens on a sensor surface is one of the most important steps in the design of a biosensor. The efficiency of a biosensor at capturing pathogens has direct bearing on its sensitivity. In this work we investigated the capturing of Escherichia coli on substrates modified with antibodies targeting different types of fimbriae: K88ab (F4), K88ac (F4), K99 (F5), 987P (F6), F41, and CFA/I. The results suggest that all these fimbriae can be used for the efficient immobilization of living E. coli cells. The immobilization efficiency was affected by the purity and clone type of the antibody and the fimbriae expression level of the bacteria. For a specific fimbriae type, a higher immobilization efficiency was often observed with the monoclonal antibodies. Immunoimmobilization was utilized in an antibody microarray immersed in a mixed culture of pathogens to demonstrate the rapid and simultaneous label-free detection of multiple pathogens within less than 1 h using a single test. The capture rate of living pathogens exceeds a single bacterium per 100 × 100 μm(2) area per 0.5 h of incubation for a bulk concentration of 10(5) cfu/mL.
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Affiliation(s)
- Zhiyong Suo
- Department of Physics, Montana State University, Bozeman, Montana 59717
| | - Xinghong Yang
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana 59717
| | | | - Ling Cao
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana 59717
| | - Recep Avci
- Department of Physics, Montana State University, Bozeman, Montana 59717
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Kochetkova I, Trunkle T, Callis G, Pascual DW. Vaccination without autoantigen protects against collagen II-induced arthritis via immune deviation and regulatory T cells. THE JOURNAL OF IMMUNOLOGY 2008; 181:2741-52. [PMID: 18684965 DOI: 10.4049/jimmunol.181.4.2741] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Anti-inflammation immunotherapy has been successfully applied for the treatment of autoimmune diseases. Mucosal vaccines against autoimmune disorders are beneficial by influencing the regulatory compartment of gut and systemic adaptive immune systems. A Salmonella vector expressing colonization factor Ag I (CFA/I), shown to behave as an anti-inflammatory vaccine, stimulates the production of CD4(+)CD25(+) T cells and regulatory cytokines. In this work, we queried whether Salmonella-CFA/I can protect DBA/1 mice from collagen-induced arthritis. The incidence of arthritis and cartilage loss in vaccinated DBA/1 mice was remarkably lower when compared with unprotected mice. Clinical findings were accompanied by the suppression of inflammatory cytokines TNF-alpha, IL-1beta, IL-6, and IL-27. Vaccination evoked a multi-tier response consisting of IL-4 producing Th2 cells, an increased production of TGF-beta by CD4(+) T cells, and suppression of collagen II-specific CD4(+) T cell proliferation. To assess the contribution of Salmonella-CFA/I-primed CD4(+) T cells, adoptive transfer studies with total CD4(+), CD4(+)CD25(-), or CD4(+)CD25(+) T cells were performed 15 days postchallenge. Mice receiving either subset showed reduced disease incidence and low clinical scores; however, mice receiving total CD4(+) T cells showed delayed disease onset by 10 days with reduced clinical scores, reduced IL-17 and IL-27, but enhanced IL-4, IL-10, IL-13, and TGF-beta. Inhibition of TGF-beta or IL-4 compromised protective immunity. These data show that Salmonella-CFA/I vaccination of DBA/1 mice protects against collagen-induced arthritis by stimulating TGF-beta- and IL-4-producing regulatory CD4(+) T cells.
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Affiliation(s)
- Irina Kochetkova
- Veterinary Molecular Biology, Montana State University, Bozeman, MT 59717, USA
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Ochoa-Repáraz J, Rynda A, Ascón MA, Yang X, Kochetkova I, Riccardi C, Callis G, Trunkle T, Pascual DW. IL-13 production by regulatory T cells protects against experimental autoimmune encephalomyelitis independently of autoantigen. THE JOURNAL OF IMMUNOLOGY 2008; 181:954-68. [PMID: 18606647 DOI: 10.4049/jimmunol.181.2.954] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Treatment with an anti-inflammatory Salmonella vaccine expressing enterotoxigenic Escherichia coli colonization factor Ag 1 (CFA/I) proved effective in stimulating protective, potent CD25(+)CD4(+) regulatory T (T(reg)) cells in susceptible mice challenged with experimental autoimmune encephalomyelitis (EAE). Because the Salmonella vector was considerably less protective, we questioned whether altering fimbrial subunit expression to resemble conventional Salmonella expression may impact T(reg) cell potency. The Salmonella-CFA/I vaccine was modified to limit fimbrial subunit expression to the intracellular compartment (Salmonella-CFA/I(IC)). SJL mice were challenged with proteolipid protein peptide 139-151 to induce EAE and orally treated with one of three Salmonella vaccines 6 days postchallenge. Treatment with Salmonella-CFA/I(IC) greatly reduced clinical disease, similarly as Salmonella-CFA/I, by subduing IL-17 and IL-21; however, mechanisms of protection differed as evident by increased IL-13 and IFN-gamma but diminished TGF-beta production by T(reg) cells from Salmonella-CFA/I(IC)-treated mice. Adoptive transfer of T(reg) cells from both CFA/I-expressing constructs was equivalent in protecting against EAE, showing minimal disease. Although not as potent in its protection, CD25(-)CD4(+) T cells from Salmonella-CFA/I(IC) showed minimal Th2 cells, but vaccination did prime these Th2 cells rendering partial protection against EAE challenge. In vivo IL-13 but not IFN-gamma neutralization compromised protection conferred by adoptive transfer with Salmonella-CFA/I(IC)-induced T(reg) cells. Thus, the Salmonella-CFA/I(IC) vaccine elicits T(reg) cells with attributes from both the Salmonella vector and Salmonella-CFA/I vaccines. Importantly, these T(reg) cells can be induced to high potency by simply vaccinating against irrelevant Ags, offering a novel approach to treat autoimmune diseases independently of the autoantigen.
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Abstract
Regulatory T (T(reg)) cells show promise for treating autoimmune diseases, but their induction to elevated potency has been problematic when the most optimally derived cells are from diseased animals. To circumvent reliance on auto-antigen reactive T(reg) cells, stimulation to vaccine antigens (Ags) may offer a viable alternative while maintaining potency to protect against proinflammatory diseases. Our Salmonella vaccine expressing colonization factor Ag I (CFA/I) possesses anti-inflammatory properties, evident by elevated Th2 cell responses, reduced inflammatory cell infiltrates in the Peyer's patches, and an absence of proinflammatory cytokine production by infected macrophages. Given these findings, we hypothesized whether this vaccine would be protective against experimental autoimmune encephalomyelitis (EAE). As such, Salmonella-CFA/I protected in both prophylactic and therapeutic paradigms against proteolipid protein (PLP(139-151))-mediated EAE in SJL mice. The protected mice showed significantly reduced clinical disease and subsequent resolution when compared to PBS-treated controls. Histopathological studies showed reduced demyelination and no inflammation of spinal cords when compared to PBS- or Salmonella vector-treated mice. To ascertain whether the observed immune deviation was in part supported by T(reg) cells, analysis revealed involvement of FoxP3(+) CD25(+) CD4(+) T cells. Adoptive transfer of induced TGF-beta (+) T(reg) cells from vaccinated mice showed complete protection against PLP(139-151) challenge, but not by naive T(reg) cells. Partial protection to EAE was also achieved by the adoptive transfer of CD25(-) CD4(+) T cells, suggesting that Th2 cells also contributed. Thus, these data show that T(reg) cells are induced by oral vaccination with Salmonella-CFA/I contributing to the efficacious treatment of autoimmune disease.
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Affiliation(s)
- D W Pascual
- Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717-3610, USA.
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