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Veisi R, Nazarian S, Fathi J, Hadi N. Expression and purification of TolC as a recombinant protein vaccine against Shigella flexneri and evaluation of immunogenic response in mice. Microb Pathog 2024; 188:106539. [PMID: 38211835 DOI: 10.1016/j.micpath.2024.106539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/30/2023] [Accepted: 01/04/2024] [Indexed: 01/13/2024]
Abstract
BACKGROUND Shigella is one of the major causes of dysenteric diarrhea, which is known shigelosis. Shigelosis causes 160,000 deaths annually of diarrheal disease in the global scale especially children less than 5 years old. No licensed vaccine is available against shigelosis, therefore, efforts for develop an effective and safe vaccine against Shigella as before needed. The reverse vaccinology (RV) is a novel strategy that evaluate genome or proteome of the organism to find a new promising vaccine candidate. In this study, immunogenicity of a designed-recombinant antigen is evaluated through the in silico studies and animal experiments to predict a new immunogenic candidate against Shigella. METHODS In the first step, proteome of Shigella flexneri was obtained from UniProtKB and then the outer membrane and extracellular proteins were predicted. In this study TolC as an outer membrane protein was selected and confirmed among candidates. In next steps, pre-selected protein was evaluated for transmembrane domains, homology, conservation, antigenicity, solubility, and B- and T-cell prediction by different online servers. RESULT TolC as a conserved outer membrane protein, using different immune-informatics tools had acceptable scores and was selected as the immunogenic antigen for animal experiment studies. Recombinant TolC protein after expression and purification, was administered to BALB/c mice over three intraperitoneal routes. The sera of mice was used to evaluate the IgG1 production assay by indirect-ELISA. The immunized mice depicted effective protection against 2LD50 of Shigella. Flexneri ATCC12022 (challenge study). CONCLUSION Therefore, the reverse vaccinology approach and experimental test results demonstrated that TolC as a novel effective and immunogenic antigen is capable for protection against shigellosis.
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Affiliation(s)
- Razieh Veisi
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Shahram Nazarian
- Department of Biological Sciences, Faculty of Science, Imam Hossein University, Tehran, Iran
| | - Javad Fathi
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Nahal Hadi
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
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Hossain MJ, Svennerholm AM, Carlin N, D’Alessandro U, Wierzba TF. A Perspective on the Strategy for Advancing ETVAX ®, An Anti-ETEC Diarrheal Disease Vaccine, into a Field Efficacy Trial in Gambian Children: Rationale, Challenges, Lessons Learned, and Future Directions. Microorganisms 2023; 12:90. [PMID: 38257916 PMCID: PMC10819518 DOI: 10.3390/microorganisms12010090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/22/2023] [Accepted: 12/23/2023] [Indexed: 01/24/2024] Open
Abstract
For the first time in over 20 years, an Enterotoxigenic Escherichia coli (ETEC) vaccine candidate, ETVAX®, has advanced into a phase 2b field efficacy trial for children 6-18 months of age in a low-income country. ETVAX® is an inactivated whole cell vaccine that has gone through a series of clinical trials to provide a rationale for the design elements of the Phase 2b trial. This trial is now underway in The Gambia and will be a precursor to an upcoming pivotal phase 3 trial. To reach this point, numerous findings were brought together to define factors such as safe and immunogenic doses for children, and the possible benefit of a mucosal adjuvant, double mutant labile toxin (dmLT). Considering the promising but still underexplored potential of inactivated whole cells in oral vaccination, we present a perspective compiling key observations from past ETVAX® trials that informed The Gambian trial design. This report will update the trial's status and explore future directions for ETEC vaccine trials. Our aim is to provide not only an update on the most advanced ETEC vaccine candidate but also to offer insights beneficial for the development of other much-needed oral whole-cell vaccines against enteric and other pathogens.
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Affiliation(s)
- M. Jahangir Hossain
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, Banjul P.O. Box 273, The Gambia
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology, Gothenburg University Research Institute (GUVAX), Gothenburg University, 40530 Gothenburg, Sweden
| | - Nils Carlin
- Scandinavian Biopharma, Industrivägen 1, 17148 Solna, Sweden
| | - Umberto D’Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, Banjul P.O. Box 273, The Gambia
| | - Thomas F. Wierzba
- Section on Infectious Diseases, Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
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Rim S, Sakkestad ST, Zhou F, Gullaksen SE, Skavland J, Chauhan SK, Steinsland H, Hanevik K. Dynamics of circulating lymphocytes responding to human experimental enterotoxigenic Escherichia coli infection. Eur J Immunol 2023; 53:e2250254. [PMID: 37102399 DOI: 10.1002/eji.202250254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 03/11/2023] [Accepted: 04/24/2023] [Indexed: 04/28/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is an important cause of children's and travelers' diarrhea, with no licensed vaccine. This study aimed to explore the role of cellular immunity in protection against human ETEC infection. Nine volunteers were experimentally infected with ETEC, of which six developed diarrhea. Lymphocytes were collected from peripheral blood buffy coats, before and 3, 5, 6, 7, 10, and 28 days after dose ingestion, and 34 phenotypic and functional markers were examined by mass cytometry. Thirty-three cell populations, derived by manually merging 139 cell clusters from the X-shift unsupervised clustering algorithm, were analyzed. Initially, the diarrhea group responded with increased CD56dim CD16+ natural killer cells, dendritic cells tended to rise, and mucosal-associated invariant T cells decreased. On day 5-7, an increase in plasmablasts was paralleled by a consistent rise in CD4+ Th17-like effector memory and regulatory cell subsets. CD4+ Th17-like central memory cells peaked on day 10. All Th17-like cell populations showed increased expression of activation, gut-homing, and proliferation markers. Interestingly, in the nondiarrhea group, these same CD4+ Th17-like cell populations expanded earlier, normalizing around day 7. Earlier development of these CD4+ Th17-like cell populations in the nondiarrhea group may suggest a recall response and a potential role in controlling ETEC infections.
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Affiliation(s)
- Sehee Rim
- Department of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Sunniva T Sakkestad
- Department of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Fan Zhou
- Department of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Stein-Erik Gullaksen
- Department of Clinical Science, Centre of Cancer Biomarkers (CCBIO), University of Bergen, Bergen, Norway
- Hematology Section, Department of Internal Medicine, Helse Bergen, Bergen, Norway
| | - Jørn Skavland
- Department of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Sudhir K Chauhan
- Division of Cancer Medicine, Department of Cancer Immunology, Oslo University Hospital, Oslo, Norway
| | - Hans Steinsland
- Department of Global Public Health and Primary Care, Faculty of Medicine, Centre for Intervention Science in Maternal and Child Health (CISMAC), Centre for International Health, University of Bergen, Bergen, Norway
- Department of Biomedicine, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Kurt Hanevik
- Department of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
- Department of Medicine, Norwegian National Advisory Unit on Tropical Infectious Diseases, Haukeland University Hospital, Bergen, Norway
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Nasser A, Mosadegh M, Azimi T, Shariati A. Molecular mechanisms of Shigella effector proteins: a common pathogen among diarrheic pediatric population. Mol Cell Pediatr 2022; 9:12. [PMID: 35718793 PMCID: PMC9207015 DOI: 10.1186/s40348-022-00145-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 05/06/2022] [Indexed: 12/16/2022] Open
Abstract
Different gastrointestinal pathogens cause diarrhea which is a very common problem in children aged under 5 years. Among bacterial pathogens, Shigella is one of the main causes of diarrhea among children, and it accounts for approximately 11% of all deaths among children aged under 5 years. The case-fatality rates for Shigella among the infants and children aged 1 to 4 years are 13.9% and 9.4%, respectively. Shigella uses unique effector proteins to modulate intracellular pathways. Shigella cannot invade epithelial cells on the apical site; therefore, it needs to pass epithelium through other cells rather than the epithelial cell. After passing epithelium, macrophage swallows Shigella, and the latter should prepare itself to exhibit at least two types of responses: (I) escaping phagocyte and (II) mediating invasion of and injury to the recurrent PMN. The presence of PMN and invitation to a greater degree resulted in gut membrane injuries and greater bacterial penetration. Infiltration of Shigella to the basolateral space mediates (A) cell attachment, (B) cell entry, (C) evasion of autophagy recognition, (D) vacuole formation and and vacuole rapture, (E) intracellular life, (F) Shiga toxin, and (G) immune response. In this review, an attempt is made to explain the role of each factor in Shigella infection.
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Affiliation(s)
- Ahmad Nasser
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehrdad Mosadegh
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Taher Azimi
- Department of Bacteriology & Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Aref Shariati
- Molecular and medicine research center, Khomein University of Medical Sciences, Khomein, Iran
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TLR2-mediated mucosal immune priming boosts anti-rhabdoviral immunity in early vertebrates. Antiviral Res 2022; 203:105346. [DOI: 10.1016/j.antiviral.2022.105346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 04/19/2022] [Accepted: 05/17/2022] [Indexed: 11/19/2022]
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Berzosa M, Nemeskalova A, Zúñiga-Ripa A, Salvador-Bescós M, Larrañeta E, Donnelly RF, Gamazo C, Irache JM. Immune Response after Skin Delivery of a Recombinant Heat-Labile Enterotoxin B Subunit of Enterotoxigenic Escherichia coli in Mice. Pharmaceutics 2022; 14:pharmaceutics14020239. [PMID: 35213971 PMCID: PMC8875158 DOI: 10.3390/pharmaceutics14020239] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/18/2022] [Accepted: 01/18/2022] [Indexed: 02/07/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) infections have been identified as a major cause of acute diarrhoea in children in developing countries, associated with substantial morbidity and mortality rates. Additionally, ETEC remains the most common cause of acute diarrhea of international travellers to endemic areas. The heat-labile toxin (LT) is a major virulence factor of ETEC, with a significant correlation between the presence of antibodies against LT and protection in infected patients. In the present work, we constructed a recombinant LTB unit (rLTB) and studied the capacity of this toxoid incorporated in microneedles (rLTB-MN) to induce a specific immune response in mice. MN were prepared from aqueous blends of the polymer Gantrez AN® [poly (methyl vinyl ether-co-maleic anhydride)], which is not cytotoxic and has been shown to possess immunoadjuvant properties. The mechanical and dissolution properties of rLTB-MNs were evaluated in an in vitro Parafilm M® model and in mice and pig skin ex vivo models. The needle insertion ranged between 378 µm and 504 µm in Parafilm layers, and MNs fully dissolved within 15 min of application inside porcine skin. Moreover, female and male BALB/c mice were immunized through ear skin with one single dose of 5 μg·rLTB in MNs, eliciting significant fecal anti-LT IgA antibodies, higher in female than in male mice. Moreover, we observed an enhanced production of IL-17A by spleen cells in the immunized female mice, indicating a mucosal non-inflammatory and neutralizing mediated response. Further experiments will now be required to validate the protective capacity of this new rLTB-MN formulation against this deadly non-vaccine-preventable disease.
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Affiliation(s)
- Melibea Berzosa
- Department of Microbiology and Parasitology, Institute of Tropical Health, IDISNA, University of Navarra, 31008 Pamplona, Spain; (M.B.); (A.N.); (A.Z.-R.); (M.S.-B.)
| | - Alzbeta Nemeskalova
- Department of Microbiology and Parasitology, Institute of Tropical Health, IDISNA, University of Navarra, 31008 Pamplona, Spain; (M.B.); (A.N.); (A.Z.-R.); (M.S.-B.)
- Department of Analytical Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, Czech Republic
| | - Amaia Zúñiga-Ripa
- Department of Microbiology and Parasitology, Institute of Tropical Health, IDISNA, University of Navarra, 31008 Pamplona, Spain; (M.B.); (A.N.); (A.Z.-R.); (M.S.-B.)
| | - Miriam Salvador-Bescós
- Department of Microbiology and Parasitology, Institute of Tropical Health, IDISNA, University of Navarra, 31008 Pamplona, Spain; (M.B.); (A.N.); (A.Z.-R.); (M.S.-B.)
| | - Eneko Larrañeta
- Medical Biology Centre, School of Pharmacy, Queen’s University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK; (E.L.); (R.F.D.)
| | - Ryan F. Donnelly
- Medical Biology Centre, School of Pharmacy, Queen’s University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK; (E.L.); (R.F.D.)
| | - Carlos Gamazo
- Department of Microbiology and Parasitology, Institute of Tropical Health, IDISNA, University of Navarra, 31008 Pamplona, Spain; (M.B.); (A.N.); (A.Z.-R.); (M.S.-B.)
- Correspondence: (C.G.); (J.M.I.)
| | - Juan M. Irache
- Department of Pharmacy and Pharmaceutical Technology, University of Navarra, 31008 Pamplona, Spain
- Correspondence: (C.G.); (J.M.I.)
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Venkatesan MM, Ballou C, Barnoy S, McNeal M, El-Khorazaty J, Frenck R, Baqar S. Antibody in Lymphocyte Supernatant (ALS) responses after oral vaccination with live Shigella sonnei vaccine candidates WRSs2 and WRSs3 and correlation with serum antibodies, ASCs, fecal IgA and shedding. PLoS One 2021; 16:e0259361. [PMID: 34793505 PMCID: PMC8601580 DOI: 10.1371/journal.pone.0259361] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 10/18/2021] [Indexed: 12/15/2022] Open
Abstract
The levels of antigen-specific Antibodies in Lymphocyte Supernatant (ALS) using an ELISA are being used to evaluate mucosal immune responses as an alternate to measuring the number of Antibody Secreting Cells (ASCs) using an ELISpot assay. A recently completed trial of two novel S. sonnei live oral vaccine candidates WRSs2 and WRSs3 established that both candidates were safe, well tolerated and immunogenic in a vaccine dose-dependent manner. Previously, mucosal immune responses were measured by assaying IgA- and IgG-ASC in peripheral blood mononuclear cells (PBMCs). In this report, the magnitude of the S. sonnei antigen-specific IgA- and IgG-ALS responses was measured and correlated with previously described ASCs, serum antibodies, fecal IgA and vaccine shedding. Overall, the magnitude of S. sonnei anti-Invaplex50 ALS was higher than that of LPS or IpaB, and both vaccines demonstrated a more robust IgA-ALS response than IgG; however, compared to WRSs3, the magnitude and percentage of responders were higher among WRSs2 recipients for IgA- or IgG-ALS. All WRSs2 vaccinees at the two highest doses responded for LPS and Invaplex50-specific IgA-ALS and 63-100% for WRSs3 vaccinees responded. Regardless of the vaccine candidate, vaccine dose or detecting antigen, the kinetics of ALS responses were similar peaking on days 7 to 9 and returning to baseline by day 14. The ALS responses were vaccine-specific since no responses were detected among placebo recipients at any time. A strong correlation and agreement between responders/non-responders were noted between ALS and other mucosal (ASC and fecal IgA) and systemic (serum antibody) immune responses. These data indicate that the ALS assay can be a useful tool to evaluate mucosal responses to oral vaccination, an observation noted with trials of other bacterial diarrheal pathogens. Furthermore, this data will guide the list of immunological assays to be conducted for efficacy trials in different populations. It is hoped that an antigen-specific-ALS titer may be a key mucosal correlate of protection, a feature not currently available for any Shigella vaccines candidates. https://clinicaltrials.gov/show/NCT01336699.
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Affiliation(s)
- Malabi M. Venkatesan
- Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | | | - Shoshana Barnoy
- Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Monica McNeal
- Division of Infectious Diseases, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States of America
| | | | - Robert Frenck
- Division of Infectious Diseases, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States of America
| | - Shahida Baqar
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
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Qi L, Mao H, Lu X, Shi T, Wang J. Cinnamaldehyde Promotes the Intestinal Barrier Functions and Reshapes Gut Microbiome in Early Weaned Rats. Front Nutr 2021; 8:748503. [PMID: 34712688 PMCID: PMC8545821 DOI: 10.3389/fnut.2021.748503] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/16/2021] [Indexed: 01/04/2023] Open
Abstract
Cinnamaldehyde is an aromatic aldehyde isolated from the essential oil of cinnamon. It has been proved to possess various bioactivities such as anti-inflammation, anti-bacteria and antihypertensive. Nevertheless, early weaning could lead to intestinal stress, causing a range of intestinal health problems. The aim of this study is to explore the effects of cinnamaldehyde on gut barrier integrity, inflammatory responses, and intestinal microbiome of early weaned rats. In this study, treatment with cinnamaldehyde (100 or 200 mg/kg bodyweight/day) for 2 weeks significantly promoted the production of mucins in the colonic epithelial tissue of rats. Cinnamaldehyde supplementation significantly upregulated the expression of Muc2, TFF3 and the tight junction proteins (ZO-1, claudin-1, and occludin). Hematoxylin and eosin staining results showed that colonic histopathological changes were recovered by cinnamaldehyde supplementation. The mRNA expression of IL-6 and TNF-α were significantly decreased in the cinnamaldehyde groups while the TNF-α protein levels were significantly decreased in the two cinnamaldehyde groups. Cinnamaldehyde treatment obviously attenuated the activation of NF-κB signaling pathway in rat colonic tissue and suppressed the production of inflammatory cytokines. Furthermore, cinnamaldehyde supplementation remodeled the gut microbiome structure, at the genus level, Akkermansia, Bacteroides, Clostridium III, Psychrobacter, Intestinimonas were increased, whereas those of Ruminococcus, Escherichia/Shigella were obviously decreased in the cinnamaldehyde treated groups. These findings indicated that cinnamaldehyde could effectively enhance intestinal barrier integrity, ameliorate inflammatory responses and remodel gut microbiome in early weaned rats.
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Affiliation(s)
- Lili Qi
- School of Biological and Chemical Engineering, Ningbo Tech University, Ningbo, China
| | - Haiguang Mao
- School of Biological and Chemical Engineering, Ningbo Tech University, Ningbo, China
| | - Xiaohui Lu
- Ningbo Biomart Lifetech Co. Ltd, Ningbo, China
| | - Tingting Shi
- School of Biological and Chemical Engineering, Ningbo Tech University, Ningbo, China
| | - Jinbo Wang
- School of Biological and Chemical Engineering, Ningbo Tech University, Ningbo, China
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Zhao H, Xu Y, Li G, Liu X, Li X, Wang L. Protective efficacy of a novel multivalent vaccine in the prevention of diarrhea induced by enterotoxigenic Escherichia coli in a murine model. J Vet Sci 2021; 23:e7. [PMID: 34841745 PMCID: PMC8799940 DOI: 10.4142/jvs.21068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 08/26/2021] [Accepted: 09/05/2021] [Indexed: 11/23/2022] Open
Abstract
Background Enterotoxigenic Escherichia coli (ETEC) infection is a primary cause of livestock diarrhea. Therefore, effective vaccines are needed to reduce the incidence of ETEC infection. Objectives Our study aimed to develop a multivalent ETEC vaccine targeting major virulence factors of ETEC, including enterotoxins and fimbriae. Methods SLS (STa-LTB-STb) recombinant enterotoxin and fimbriae proteins (F4, F5, F6, F18, and F41) were prepared to develop a multivalent vaccine. A total of 65 mice were immunized subcutaneously by vaccines and phosphate-buffered saline (PBS). The levels of specific immunoglobulin G (IgG) and pro-inflammatory cytokines were determined at 0, 7, 14 and 21 days post-vaccination (dpv). A challenge test with a lethal dose of ETEC was performed, and the survival rate of the mice in each group was recorded. Feces and intestine washes were collected to measure the concentrations of secretory immunoglobulin A (sIgA). Results Anti-SLS and anti-fimbriae-specific IgG in serums of antigen-vaccinated mice were significantly higher than those of the control group. Immunization with the SLS enterotoxin and multivalent vaccine increased interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations. Compared to diarrheal symptoms and 100% death of mice in the control group, mice inoculated with the multivalent vaccine showed an 80% survival rate without any symptom of diarrhea, while SLS and fimbriae vaccinated groups showed 60 and 70% survival rates, respectively. Conclusions Both SLS and fimbriae proteins can serve as vaccine antigens, and the combination of these two antigens can elicit stronger immune responses. The results suggest that the multivalent vaccine can be successfully used for preventing ETEC in important livestock.
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Affiliation(s)
- Hong Zhao
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Yongping Xu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China.,Dalian SEM Bio-Engineering Technology Co. Ltd., Dalian 116620, China
| | - Gen Li
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Xin Liu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Xiaoyu Li
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Lili Wang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China.
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Fleckenstein JM. Confronting challenges to enterotoxigenic Escherichia coli vaccine development. FRONTIERS IN TROPICAL DISEASES 2021; 2:709907. [PMID: 35937717 PMCID: PMC9355458 DOI: 10.3389/fitd.2021.709907] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023] Open
Abstract
The enterotoxigenic Escherichia coli (ETEC) are a diverse and genetically plastic pathologic variant (pathovar) of E. coli defined by their production of heat-labile (LT) and heat-stable (ST) enterotoxins. These pathogens, which came to recognition more than four decades ago in patients presenting with severe cholera-like diarrhea, are now known to cause hundreds of millions of cases of symptomatic infection annually. Children in low-middle income regions of the world lacking access to clean water and basic sanitation are disproportionately affected by ETEC. In addition to acute diarrheal morbidity, these pathogens remain a significant cause of mortality in children under the age of five years and have also been linked repeatedly to sequelae of childhood malnutrition and growth stunting. Vaccines that could prevent ETEC infections therefore remain a high priority. Despite several decades of effort, a licensed vaccine that protects against the breadth of these pathogens remains an aspirational goal, and the underlying genetic plasticity of E. coli has posed a fundamental challenge to development of a vaccine that can encompass the complete antigenic spectrum of ETEC. Nevertheless, novel strategies that include toxoids, a more complete understanding of ETEC molecular pathogenesis, structural details of target immunogens, and the discovery of more highly conserved antigens essential for virulence should accelerate progress and make a broadly protective vaccine feasible.
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Affiliation(s)
- James M. Fleckenstein
- Department of Medicine, Division of Infectious Diseases, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
- Medicine Service, Infectious Diseases, John Cochran Saint Louis Veterans Affairs Health Care System, Saint Louis, Missouri, USA
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Contribution of Noncanonical Antigens to Virulence and Adaptive Immunity in Human Infection with Enterotoxigenic E. coli. Infect Immun 2021; 89:IAI.00041-21. [PMID: 33558320 DOI: 10.1128/iai.00041-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 01/27/2021] [Indexed: 12/12/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) contributes significantly to the substantial burden of infectious diarrhea among children living in low- and middle-income countries. In the absence of a vaccine for ETEC, children succumb to acute dehydration as well as nondiarrheal sequelae related to these infections, including malnutrition. The considerable diversity of ETEC genomes has complicated canonical vaccine development approaches defined by a subset of ETEC pathovar-specific antigens known as colonization factors (CFs). To identify additional conserved immunogens unique to this pathovar, we employed an "open-aperture" approach to capture all potential conserved ETEC surface antigens, in which we mined the genomic sequences of 89 ETEC isolates, bioinformatically selected potential surface-exposed pathovar-specific antigens conserved in more than 40% of the genomes (n = 118), and assembled the representative proteins onto microarrays, complemented with known or putative colonization factor subunit molecules (n = 52) and toxin subunits. These arrays were then used to interrogate samples from individuals with acute symptomatic ETEC infections. Surprisingly, in this approach, we found that immune responses were largely constrained to a small number of antigens, including individual colonization factor antigens and EtpA, an extracellular adhesin. In a Bangladeshi cohort of naturally infected children <2 years of age, both EtpA and a second antigen, EatA, elicited significant serologic responses that were associated with protection from symptomatic illness. In addition, children infected with ETEC isolates bearing either etpA or eatA genes were significantly more likely to develop symptomatic disease. These studies support a role for antigens not presently targeted by vaccines (noncanonical) in virulence and the development of adaptive immune responses during ETEC infections. These findings may inform vaccine design efforts to complement existing approaches.
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Adeleke VT, Adeniyi AA, Adeleke MA, Okpeku M, Lokhat D. The design of multiepitope vaccines from plasmids of diarrheagenic Escherichia coli against diarrhoea infection: Immunoinformatics approach. INFECTION GENETICS AND EVOLUTION 2021; 91:104803. [PMID: 33684568 DOI: 10.1016/j.meegid.2021.104803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 02/19/2021] [Accepted: 03/02/2021] [Indexed: 01/19/2023]
Abstract
Diarrhoea infection is a major global health public problem and is caused by many organisms including diarrheagenic Escherichia coli pathotypes. The common problem with diarrhoea is the drug resistance of pathogenic bacteria, the most promising alternative means of preventing drug resistance is vaccination. However, there has not been any significant success in the prevention of diarrhoea caused by E. coli through vaccination. Epitope-based vaccine is gaining more attention due to its safety and specificity. Sequence variation of protective antigens of the pathogen has posed a new challenge in the development of epitope-based vaccines against the infection, leading to the necessity of multiepitope based design. In this study, immunoinformatics tools were used to design multiepitope vaccine candidates from plasmid genome sequences of multiple pathotypes of E. coli species involved in diarrhoea infections. The ability of the identified epitopes to be used as a cross-protect multiepitope vaccine was achieved by identifying conserved, immunogenic and antigenic peptides that can elicit CD4+ T-cell, CD8+ T-cell and B-cell and bind to MHC I and II HLA alleles. The molecular docking results of T-cell epitopes showed their well binding affinity to receptive protein and with a wider population coverage. The different multiepitope-based vaccines (MEVCs) candidates were constructed and based on the types of epitope linker they contained. The MEVCs exhibited very good binding interactions with the human immune receptor. Among multiepitope vaccines constructed, MEVC6, MEVCA and MEVCB are more promising as potential vaccine candidates for cross-protection against gastrointestinal infections according to the computational study. It is also hoped that after validation and testing, the predicted multiepitope-based vaccine candidates will probably resolve the challenge of immunological heterogeneity facing enteric vaccine development.
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Affiliation(s)
- Victoria T Adeleke
- Discipline of Chemical Engineering, University of KwaZulu-Natal, Howard Campus, Durban 4041, South Africa.
| | - Adebayo A Adeniyi
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein, South Africa; Department of Industrial Chemistry, Federal University, Oye, Ekiti, Nigeria
| | - Matthew A Adeleke
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, P/Bag X54001, Durban 4000, South Africa
| | - Moses Okpeku
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, P/Bag X54001, Durban 4000, South Africa
| | - David Lokhat
- Discipline of Chemical Engineering, University of KwaZulu-Natal, Howard Campus, Durban 4041, South Africa
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Zhao H, Xu Y, Li G, Liu X, Li X, Wang L. Protective efficacy of a novel multivalent vaccine in the prevention of diarrhea induced by enterotoxigenic Escherichia coli in a murine model. J Vet Sci 2021. [DOI: 10.4142/jvs.2021.22.e90] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Hong Zhao
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Yongping Xu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
- Dalian SEM Bio-Engineering Technology Co. Ltd., Dalian 116620, China
| | - Gen Li
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Xin Liu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Xiaoyu Li
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Lili Wang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
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14
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The Intriguing Interaction of Escherichia coli with the Host Environment and Innovative Strategies To Interfere with Colonization: a Summary of the 2019 E. coli and the Mucosal Immune System Meeting. Appl Environ Microbiol 2020; 86:AEM.02085-20. [PMID: 33008822 DOI: 10.1128/aem.02085-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The third E. coli and the Mucosal Immune System (ECMIS) meeting was held at Ghent University in Belgium from 2 to 5 June 2019. It brought together an international group of scientists interested in mechanisms of colonization, host response, and vaccine development. ECMIS distinguishes itself from related meetings on these enteropathogens by providing a greater emphasis on animal health and disease and covering a broad range of pathotypes, including enterohemorrhagic, enteropathogenic, enterotoxigenic, enteroaggregative, and extraintestinal pathogenic Escherichia coli As it is well established that the genus Shigella represents a subspecies of E. coli, these organisms along with related enteroinvasive E. coli are also included. In addition, Tannerella forsythia, a periodontal pathogen, was presented as an example of a pathogen which uses its surface glycans for mucosal interaction. This review summarizes several highlights from the 2019 meeting and major advances to our understanding of the biology of these pathogens and their impact on the host.
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