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Nguyet LTY, Ounjai P, Ngamwongsatit N, Kaeoket K. The immune response of pregnant sow after vaccination with crude fimbriae (F4) extracts vaccine and immunoprotection of nursery pig against pathogenic E. coli (F4 +ETEC). Acta Trop 2024; 254:107173. [PMID: 38503364 DOI: 10.1016/j.actatropica.2024.107173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/22/2024] [Accepted: 03/05/2024] [Indexed: 03/21/2024]
Abstract
BACKGROUND Neonatal and post-weaning diarrhea is a concern disease caused by enterotoxigenic Escherichia coli fimbriae F4 (F4+ETEC) in pig farms. Diarrhea outbreaks are often severe and costly due to the high prevalence and spread of the disease within the same herd. Vaccine is one of strategic solution in protecting pig against F4+ETEC infection in particular pig farm. In present study, we conducted two trials of vaccination with crude F4 fimbriae extract vaccine in pregnant sow and nursery pigs. METHODS In experiment 1 (20 sows; non-vaccinated control, n=10), we vaccinated pregnant sows (n=10) twice at 4 wk and 2 wk before farrowing and evaluated impact of vaccination on maternal immunity. The sow serum and colostrum were collected before vaccination, 2 and 4 weeks after vaccination, 6 hours after farrowing, respectively, and the piglet's serum from both groups (2 piglet/sow, 10 piglets from each group) were also collected on 3 days old to measure F4 specific IgG, F4 specific IgA using in house ELISA kit. In experiment 2, to optimize doses and dosage of candidate vaccine in piglets, 18 piglets (3 piglets/group) were allocated into five immunized groups and one control group (unimmunized group), we immunized piglets twice at 4 and 6 weeks old with difference doses (i.e., 0, 50, 100, 150, 200 µg), and for a dose 150 µg, we immunized with two dosages at 1 ml and 2 ml. Piglets were challenged with a 3 ml dose of 3 × 109 CFU/ml bacterial culture of enterotoxigenic Escherichia coli (F4+ETEC) in order to evaluate the efficacy of vaccine. After challenging, the clinical sign of the piglets was daily observed and the rectal swab was performed every day for investigation of the fecal shedding of Escherichia coli (F4+ETEC) by using PCR technique. Serum were collected before, 2 and 4 weeks after vaccination and 1 week after challenge to measure F4 specific IgG, F4 specific IgA using in house ELISA kit and cytokines levels (i.e., IL-1 beta, IL-6, IL-8 and TNF alpha) before and 1 week after challenge using commercial ELISA kit. RESULTS The levels of antibody results showed that in experiment 1, the anti-F4 antibody levels both F4 specific IgG and F4 specific IgA in serum and colostrum of vaccinated sow increased significantly after vaccination. The piglets of immunized sows have antibody level both F4 specific IgG and F4 specific IgA in their serum higher than those piglets of unimmunized sows significantly (p < 0.01). In experiment 2, irrespective of different doses and dosage, there is no difference in term of F4 specific IgG and F4 specific IgA levels among immunized groups. However, all of vaccinated piglets showed F4 specific IgG and F4 specific IgA levels higher and the elimination of Escherichia coli (F4+ETEC) in feces post challenge faster (< 3 days) than unvaccinated group (> 5 days). For cytokines levels, a higher level of IL-1 beta, IL-6, IL-8 and TNF alpha at 1 week after challenge in vaccinated groups was found when compared with the levels in non-vaccinated group. CONCLUSIONS Our results suggest that crude F4 fimbriae extract autogenous vaccine is a candidate vaccine for protecting piglets against diarrhea disease caused by enterotoxigenic Escherichia coli (F4+ETEC) and vaccination the pregnant sow twice before farrowing is one of strategies to provide maternal derived antibody to the newborn piglets for against enterotoxigenic Escherichia coli (F4+ETEC) during early life.
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Affiliation(s)
- Luong Thi Yen Nguyet
- Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Puey Ounjai
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Natharin Ngamwongsatit
- Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand; Laboratory of Bacteria, Veterinary Diagnostic Center, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Kampon Kaeoket
- Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand.
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Jones RM, Seo H, Zhang W, Sack DA. A multi-epitope fusion antigen candidate vaccine for Enterotoxigenic Escherichia coli is protective against strain B7A colonization in a rabbit model. PLoS Negl Trop Dis 2022; 16:e0010177. [PMID: 35139116 PMCID: PMC8863229 DOI: 10.1371/journal.pntd.0010177] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/22/2022] [Accepted: 01/17/2022] [Indexed: 11/18/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains are a leading cause of children's and travelers' diarrhea. Developing effective vaccines against this heterologous group has proven difficult due to the varied nature of toxins and adhesins that determine their pathology. A multivalent candidate vaccine was developed using a multi-epitope fusion antigen (MEFA) vaccinology platform and shown to effectively elicit broad protective antibody responses in mice and pigs. However, direct protection against ETEC colonization of the small intestine was not measured in these systems. Colonization of ETEC strains is known to be a determining factor in disease outcomes and is adhesin-dependent. In this study, we developed a non-surgical rabbit colonization model to study immune protection against ETEC colonization in rabbits. We tested the ability for the MEFA-based vaccine adhesin antigen, in combination with dmLT adjuvant, to induce broad immune responses and to protect from ETEC colonization of the rabbit small intestine. Our results indicate that the candidate vaccine MEFA antigen elicits antibodies in rabbits that react to seven adhesins included in its construction and protects against colonization of a challenge strain that consistently colonized naïve rabbits.
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Affiliation(s)
- Richard M. Jones
- Johns Hopkins Bloomberg School of Public Health, Department of International Health, Baltimore, Maryland, United States of America
- University of Washington, Department of Microbiology, Seattle, Washington, United States of America
- * E-mail:
| | - Hyesuk Seo
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, United States of America
| | - Weiping Zhang
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, United States of America
| | - David A. Sack
- Johns Hopkins Bloomberg School of Public Health, Department of International Health, Baltimore, Maryland, United States of America
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3
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Mohammed GM, ElZorkany HE, Farroh KY, Abd El-Aziz WR, Elshoky HA. Potential improvement of the immune response of chickens against E. coli vaccine by using two forms of chitosan nanoparticles. Int J Biol Macromol 2020; 167:395-404. [PMID: 33275976 DOI: 10.1016/j.ijbiomac.2020.11.200] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/20/2020] [Accepted: 11/29/2020] [Indexed: 01/21/2023]
Abstract
Colibacillosis disease has an important economic impact on poultry production worldwide. It is one of the most common causes of mortality in commercial layer and breeder chickens. Avian pathogenic Escherichia coli (APEC) is the main cause of this disease. Nanoparticles have been widely used in vaccine design as both adjuvants and antigen delivery vehicles. The present study aimed to produce an efficient vaccine from E. coli serogroups O1 and O78 to help in controlling colibacillosis in chicken using two forms of chitosan (CS) and ascorbate chitosan (AsCS) nanoparticles. Nanovaccines has been prepared through loading and encapsulation of outer membrane and flagellar antigen on CS and AsCS nanoparticles with loading efficiency 86, 63,55, 48% for CS-loaded-, Cs-capsulated-, AsCS-loaded- and AsCS-capsulated-E. coli Antigen, respectively. Two hundred specific pathogens free (SPF) 3-weeks old broiler chickens were used and divided into four groups to investigate the immune response of nanovaccines. The immune response was measured by the microagglutination, ELISA, and challenge test. From results, it could be concluded that generally adding chitosan NPs is capable of improving vaccine efficacy via the induction of strong immunity. Moreover, we recommend the production of the nanovaccine CS-capsulated -antigen from E. coli O1 and O78 serotypes to be used as a potent vaccine to aid in controlling colibacillosis. Also, the ascorbate chitosan is a great alternate for the initiation of a potent immune response in critical infection cases.
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Affiliation(s)
- Gina M Mohammed
- Central Laboratory for Evaluation of Veterinary Biologics, Agricultural Research Center, Egypt
| | - Heba ElSayed ElZorkany
- Nanotechnology and Advanced Materials Central Lab, Agricultural Research Center, Giza, Egypt; Regional Center for Food and Feed, Agricultural Research Center, Giza, Egypt
| | - Khaled Y Farroh
- Nanotechnology and Advanced Materials Central Lab, Agricultural Research Center, Giza, Egypt; Regional Center for Food and Feed, Agricultural Research Center, Giza, Egypt
| | - Wafaa R Abd El-Aziz
- Department of Antigens and Sera, Veterinary Serum and Vaccine Research Institute, Agricultural Research Center, Egypt
| | - Hisham A Elshoky
- Nanotechnology and Advanced Materials Central Lab, Agricultural Research Center, Giza, Egypt; Regional Center for Food and Feed, Agricultural Research Center, Giza, Egypt.
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4
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Feng N, Guan W. Expression fusion immunogen by live attenuated Escherichia coli against enterotoxins infection in mice. Microb Biotechnol 2019; 12:946-961. [PMID: 31210426 PMCID: PMC6680629 DOI: 10.1111/1751-7915.13447] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 05/07/2019] [Accepted: 05/20/2019] [Indexed: 11/27/2022] Open
Abstract
Previous epidemiological studies have shown that enterotoxins from enterotoxigenic Escherichia coli (ETEC) appear to be the most important causes of neonatal piglet and porcine post-weaning diarrhoea (PWD). Thus, it is necessary to develop an effective vaccine against ETEC infection. In the present study, the Kil cassette was inserted into the pseudogene yaiT by homologous recombination to create an attenuated E. coli double selection platform O142(yaiT-Kil). After that, PRPL-Kil was replaced with a fusion gene (LTA1-STa13 -STb-LTA2-LTB-STa13 -STb) to establish oral vaccines O142(yaiT::LTA1-STa13 -STb-LTA2-LTB-STa13 -STb) (ER-T). Subsequently, BALB/c mice were orally immunized with ER-T. Results showed that serum IgG and faecal sIgA responded against all ETEC enterotoxins and induced F41 antibody in BALB/c mice by orogastrically inoculation with recombinant E. coli ER-T. Moreover, the determination of cellular immune response demonstrated that the stimulation index (SI) was significantly higher in immunized mice than in control mice, and a clear trend in the helper T-cell (Th) response was Th2-cell (IL-4) exceed Th1-cell (IFN-γ).Our results indicated that recombinant E. coli ER-T provides effective protection against ETEC infection.
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MESH Headings
- Administration, Oral
- Animals
- Antibodies, Bacterial/blood
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Diarrhea/microbiology
- Diarrhea/prevention & control
- Diarrhea/veterinary
- Enterotoxigenic Escherichia coli/immunology
- Enterotoxins/antagonists & inhibitors
- Enterotoxins/genetics
- Enterotoxins/immunology
- Escherichia coli Infections/microbiology
- Escherichia coli Infections/prevention & control
- Escherichia coli Infections/veterinary
- Escherichia coli Vaccines/administration & dosage
- Escherichia coli Vaccines/immunology
- Feces/chemistry
- Immunity, Cellular
- Immunoglobulin A, Secretory/analysis
- Immunoglobulin G/blood
- Mice, Inbred BALB C
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- Swine
- Swine Diseases/microbiology
- Swine Diseases/prevention & control
- Treatment Outcome
- Vaccines, Attenuated/administration & dosage
- Vaccines, Attenuated/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Ni Feng
- College of Life Science and Resource EnvironmentYichun UniversityYichunChina
| | - Weikun Guan
- College of Life Science and Resource EnvironmentYichun UniversityYichunChina
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Mottram L, Chakraborty S, Cox E, Fleckenstein J. How genomics can be used to understand host susceptibility to enteric infection, aiding in the development of vaccines and immunotherapeutic interventions. Vaccine 2019; 37:4805-4810. [PMID: 30709726 PMCID: PMC6663652 DOI: 10.1016/j.vaccine.2019.01.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/26/2018] [Accepted: 01/10/2019] [Indexed: 12/27/2022]
Abstract
Thanks to the modern sequencing era, the extent to which infectious disease imposes selective pressures on the worldwide human population is being revealed. This is aiding our understanding of the underlying immunological and host mechanistic defenses against these pathogens, as well as potentially assisting in the development of vaccines and therapeutics to control them. As a consequence, the workshop "How genomics can be used to understand host susceptibility to enteric infection, aiding in the development of vaccines and immunotherapeutic interventions" at the VASE 2018 meeting, aimed to discuss how genomics and related tools could be used to assist Shigella and ETEC vaccine development. The workshop featured four short presentations which highlighted how genomic applications can be used to assist in the identification of genetic patterns related to the virulence of disease, or host genetic factors that could contribute to immunity or successful vaccine responses. Following the presentations, there was an open debate with workshop attendees to discuss the best ways to utilise such genomic studies, to improve or accelerate the process of both Shigella and ETEC vaccine development. The workshop concluded by making specific recommendations on how genomic research methods could be strengthened and harmonised within the ETEC and Shigella research communities.
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Affiliation(s)
- Lynda Mottram
- Department of Microbiology and Immunology, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
| | - Subhra Chakraborty
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Eric Cox
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - James Fleckenstein
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, United States; Medicine Service, Veterans Affairs Medical Center, St. Louis, MO, United States
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Mani S, Toapanta FR, McArthur MA, Qadri F, Svennerholm AM, Devriendt B, Phalipon A, Cohen D, Sztein MB. Role of antigen specific T and B cells in systemic and mucosal immune responses in ETEC and Shigella infections, and their potential to serve as correlates of protection in vaccine development. Vaccine 2019; 37:4787-4793. [PMID: 31230883 PMCID: PMC7413037 DOI: 10.1016/j.vaccine.2019.03.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/07/2019] [Accepted: 03/19/2019] [Indexed: 12/13/2022]
Abstract
The generation of robust systemic and mucosal antibody and cell-mediated immune (CMI) responses that are protective, long-lasting, and can quickly be recalled upon subsequent re-exposure to the cognate antigen is the key to the development of effective vaccine candidates. These responses, whether they represent mechanistic or non-mechanistic immunological correlates of protection, usually entail the activation of T cell memory and effector subsets (T-CMI) and induction of long-lasting memory B cells. However, for ETEC and Shigella, the precise role of these key immune cells in primary and secondary (anamnestic) immune responses remains ill-defined. A workshop to address immune correlates for ETEC and Shigella, in general, and to elucidate the mechanistic role of T-cell subsets and B-cells, both systemically and in the mucosal microenvironment, in the development of durable protective immunity against ETEC and Shigella was held at the recent 2nd Vaccines against Shigella and ETEC (VASE) conference in June 2018. This report is a summary of the presentations and the discussion that ensued at the workshop.
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Affiliation(s)
| | - Franklin R Toapanta
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Monica A McArthur
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Firdausi Qadri
- Infectious Diseases Division, International Center for Diarrheal Diseases Research, Dhaka, Bangladesh
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Sweden
| | - Bert Devriendt
- Faculty of Veterinary Medicine, Department of Virology, Parasitology, and Immunology, Ghent University, Belgium
| | - Armelle Phalipon
- Molecular Microbial Pathogenesis, INSERM U1202, Institut Pasteur, Paris, France
| | - Daniel Cohen
- School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Israel
| | - Marcelo B Sztein
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States.
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Harro C, Louis Bourgeois A, Sack D, Walker R, DeNearing B, Brubaker J, Maier N, Fix A, Dally L, Chakraborty S, Clements JD, Saunders I, Darsley MJ. Live attenuated enterotoxigenic Escherichia coli (ETEC) vaccine with dmLT adjuvant protects human volunteers against virulent experimental ETEC challenge. Vaccine 2019; 37:1978-1986. [PMID: 30797634 PMCID: PMC6434318 DOI: 10.1016/j.vaccine.2019.02.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/12/2019] [Accepted: 02/14/2019] [Indexed: 01/10/2023]
Abstract
Background There is no licensed vaccine against enterotoxigenic Escherichia coli (ETEC), a major cause of diarrhea-associated morbidity and mortality among infants and children in low-income countries and travelers. The results of this vaccination/challenge study demonstrate strong protection by an attenuated ETEC vaccine candidate, ACE527, when co-administered with a mucosal adjuvant, the double-mutant heat-labile toxin (dmLT) of ETEC. Methods Sixty healthy adults participated in a randomized, placebo-controlled, double-blind study with three doses of lyophilized ACE527 (∼3 × 109 of each strain per dose) administered orally with or without dmLT adjuvant (25 µg/dose). Six months later, 36 of these volunteers and a control group of 21 unvaccinated volunteers were challenged with virulent ETEC strain H10407. The primary outcome was severe diarrhea, defined as passing >800 g of unformed stools during the inpatient period following challenge. Findings The vaccine was well tolerated and induced robust immune responses to key antigens. The protective efficacy (PE) against the primary outcome of severe diarrhea was 65.9% (95% confidence interval [CI] 5.4–87.7, p = 0.003). Among subjects receiving the adjuvanted vaccine, the attack rate of severe diarrhea was 23.1, while in unimmunized controls it was 67.7%. The PE against diarrhea of any severity was 58.5% (95% CI 3.8– 82.1, p = 0.016). There was a strong inverse correlation between shedding of the vaccine strain after either of the first two doses and absence of severe diarrhea upon challenge (RR = 0.29, 95% CI 0.08–1.05, p = 0.041). Challenge strain shedding was 10-fold lower in those receiving the adjuvant than in those receiving vaccine alone. The unadjuvanted vaccine was not protective (PE = 23.1%). Interpretation The results of this study support further development of ACE527 + dmLT as a vaccine for children in endemic countries and travelers. This is the first clinical demonstration that dmLT can contribute significantly to vaccine efficacy and may warrant testing with other oral vaccines. (ClinicalTrials.gov registration: NCT01739231).
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Affiliation(s)
- Clayton Harro
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - David Sack
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Barbara DeNearing
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Jessica Brubaker
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | | | - Len Dally
- The Emmes Corporation, Rockville, MD, USA
| | - Subhra Chakraborty
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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8
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Naili I, Vinot J, Baudner BC, Bernalier-Donadille A, Pizza M, Desvaux M, Jubelin G, D'Oro U, Buonsanti C. Mixed mucosal-parenteral immunizations with the broadly conserved pathogenic Escherichia coli antigen SslE induce a robust mucosal and systemic immunity without affecting the murine intestinal microbiota. Vaccine 2018; 37:314-324. [PMID: 30503655 DOI: 10.1016/j.vaccine.2018.10.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 09/25/2018] [Accepted: 10/02/2018] [Indexed: 02/07/2023]
Abstract
Emergence and dissemination of multidrug resistance among pathogenic Escherichia coli have posed a serious threat to public health across developing and developed countries. In combination with a flexible repertoire of virulence mechanisms, E. coli can cause a vast range of intestinal (InPEC) and extraintestinal (ExPEC) diseases but only a very limited number of antibiotics still remains effective against this pathogen. Hence, a broad spectrum E. coli vaccine could be a promising alternative to prevent the burden of such diseases, while offering the potential for covering against several InPEC and ExPEC at once. SslE, the Secreted and Surface-associated Lipoprotein of E. coli, is a widely distributed protein among InPEC and ExPEC. SslE functions ex vivo as a mucinase capable of degrading mucins and reaching the surface of mucus-producing epithelial cells. SslE was identified by reverse vaccinology as a protective vaccine candidate against an ExPEC murine model of sepsis, and further shown to be cross-effective against other ExPEC and InPEC models of infection. In this study, we aimed to gain insight into the immune response to antigen SslE and identify an immunization strategy suited to generate robust mucosal and systemic immune responses. We showed, by analyzing T cell and antibody responses, that mice immunized with SslE via an intranasal prime followed by two intramuscular boosts developed an enhanced overall immune response compared to either intranasal-only or intramuscular-only protocols. Importantly, we also report that this regimen of immunization did not impact the richness of the murine gut microbiota, and mice had a comparable cecal microbial composition, whether immunized with SslE or PBS. Collectively, our findings further support the use of SslE in future vaccination strategies to effectively target both InPEC and ExPEC while not perturbing the resident gut microbiota.
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Affiliation(s)
- Ilham Naili
- GSK, Siena, Italy; Université Clermont Auvergne, INRA, UMR454 MEDiS, 63000 Clermont-Ferrand, France.
| | | | | | | | | | - Mickaël Desvaux
- Université Clermont Auvergne, INRA, UMR454 MEDiS, 63000 Clermont-Ferrand, France
| | - Grégory Jubelin
- Université Clermont Auvergne, INRA, UMR454 MEDiS, 63000 Clermont-Ferrand, France
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Crofts AA, Giovanetti SM, Rubin EJ, Poly FM, Gutiérrez RL, Talaat KR, Porter CK, Riddle MS, DeNearing B, Brubaker J, Maciel M, Alcala AN, Chakraborty S, Prouty MG, Savarino SJ, Davies BW, Trent MS. Enterotoxigenic E. coli virulence gene regulation in human infections. Proc Natl Acad Sci U S A 2018; 115:E8968-E8976. [PMID: 30126994 PMCID: PMC6156659 DOI: 10.1073/pnas.1808982115] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a global diarrheal pathogen that utilizes adhesins and secreted enterotoxins to cause disease in mammalian hosts. Decades of research on virulence factor regulation in ETEC has revealed a variety of environmental factors that influence gene expression, including bile, pH, bicarbonate, osmolarity, and glucose. However, other hallmarks of the intestinal tract, such as low oxygen availability, have not been examined. Further, determining how ETEC integrates these signals in the complex host environment is challenging. To address this, we characterized ETEC's response to the human host using samples from a controlled human infection model. We found ETEC senses environmental oxygen to globally influence virulence factor expression via the oxygen-sensitive transcriptional regulator fumarate and nitrate reduction (FNR) regulator. In vitro anaerobic growth replicates the in vivo virulence factor expression profile, and deletion of fnr in ETEC strain H10407 results in a significant increase in expression of all classical virulence factors, including the colonization factor antigen I (CFA/I) adhesin operon and both heat-stable and heat-labile enterotoxins. These data depict a model of ETEC infection where FNR activity can globally influence virulence gene expression, and therefore proximity to the oxygenated zone bordering intestinal epithelial cells likely influences ETEC virulence gene expression in vivo. Outside of the host, ETEC biofilms are associated with seasonal ETEC epidemics, and we find FNR is a regulator of biofilm production. Together these data suggest FNR-dependent oxygen sensing in ETEC has implications for human infection inside and outside of the host.
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Affiliation(s)
- Alexander A Crofts
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712
| | - Simone M Giovanetti
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712
| | - Erica J Rubin
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712
| | - Frédéric M Poly
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910
| | - Ramiro L Gutiérrez
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910
| | - Kawsar R Talaat
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Chad K Porter
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910
| | - Mark S Riddle
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910
| | - Barbara DeNearing
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Jessica Brubaker
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Milton Maciel
- Immunology, Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814
| | - Ashley N Alcala
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910
| | - Subhra Chakraborty
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Michael G Prouty
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910
| | - Stephen J Savarino
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910
| | - Bryan W Davies
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712
| | - M Stephen Trent
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602;
- Center of Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
- Department of Microbiology, College of Arts and Sciences, University of Georgia, Athens, GA 30602
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10
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Huang J, Duan Q, Zhang W. Significance of Enterotoxigenic Escherichia coli (ETEC) Heat-Labile Toxin (LT) Enzymatic Subunit Epitopes in LT Enterotoxicity and Immunogenicity. Appl Environ Microbiol 2018; 84:e00849-18. [PMID: 29802193 PMCID: PMC6052278 DOI: 10.1128/aem.00849-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/19/2018] [Indexed: 01/28/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains producing heat-labile toxin (LT) and/or heat-stable toxin (STa) are a top cause of children's diarrhea and travelers' diarrhea. Holotoxin-structured GM1-binding LT is a strong immunogen and an effective adjuvant, and can serve a carrier or a platform for multivalent vaccine development. However, the significance of peptide domains or epitopes of LT particularly enzymatic LTA subunit in association with LT enterotoxicity and immunogenicity has not been characterized. In this study, we identified B-cell epitopes in silico from LTA subunit and examined epitopes for immunogenicity and association with LT enterotoxicity. Epitopes identified from LTA subunit were individually fused to a modified chicken ovalbumin carrier protein, and each epitope-ovalbumin fusion was used to immunize mice. Data showed all 11 LTA epitopes were immunogenic; epitope 7 (105SPHPYEQEVSA115) induced greater titers of anti-LT antibodies which neutralized LT enterotoxicity more effectively. To examine these epitopes for the significance in LT enterotoxicity, we constructed LT mutants by substituting each of 10 epitopes at the toxic A1 domain of LTA subunit with a foreign epitope and examined LT mutants for enterotoxicity and GM1-binding activity. Data showed that LT mutants exhibited no enterotoxicity but retained GM1-binding activity. The results from this study indicated that while not all immunodominant LTA epitopes were neutralizing, LT mutants with an individual epitope substituted lost enterotoxicity but retained GM1-binding activity. These results provided additional information to understand LT immunogenicity and enterotoxicity and suggested the potential application of LT platform for multivalent vaccines against ETEC diarrhea and other diseases.IMPORTANCE No vaccine is licensed for enterotoxigenic Escherichia coli (ETEC) strains, which remain a leading cause of diarrhea in children from developing countries and international travelers. GM1-binding heat-labile toxin (LT) which is a key virulence factor of ETEC diarrhea is a strong vaccine antigen and a self-adjuvant. LT can also serve a backbone or platform for MEFA (multiepitope fusion antigen), a newly developed structural vaccinology technology, to present heterogeneous epitopes (by replacing LT epitopes) and to mimic epitope antigenicity for development of broadly protective vaccines. Data from this study identified neutralizing LT epitopes and demonstrated that substitution of LT epitopes eliminated LT enterotoxicity without altering GM1-binding activity, suggesting LT is potentially a versatile MEFA platform to present heterogeneous epitopes for multivalent vaccines against ETEC and other pathogens.
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Affiliation(s)
- Jiachen Huang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
| | - Qiangde Duan
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
| | - Weiping Zhang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
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11
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Crecente-Campo J, Lorenzo-Abalde S, Mora A, Marzoa J, Csaba N, Blanco J, González-Fernández Á, Alonso MJ. Bilayer polymeric nanocapsules: A formulation approach for a thermostable and adjuvanted E. coli antigen vaccine. J Control Release 2018; 286:20-32. [PMID: 30017722 DOI: 10.1016/j.jconrel.2018.07.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/26/2018] [Accepted: 07/10/2018] [Indexed: 11/17/2022]
Abstract
One of the strategies used to improve the immunogenicity of purified protein antigens has relied on their association with synthetic nanocarriers, which, in general, have functioned as simple antigen containers. Here, we present a more advanced strategy based on the design of an antigen nanocarrier at the molecular level. The nanocarrier is composed of a vitamin E oily core, surrounded by two layers: a first layer of chitosan and a second of dextran sulphate. The selected antigen, IutA protein from Escherichia coli, was harboured between the two polymeric layers. The final bilayer nanocapsules had a nanometric size (≈ 200 nm), a negative zeta potential (< -40 mV) and a good antigen association efficiency (≈ 70%). The bilayer architecture led to an improvement on the formulation stability and the controlled release of the associated antigen. Remarkably, after being administered to mice, bilayer nanocapsules elicited higher IgG levels than those obtained with antigen precipitated with Alum. Moreover, freeze-dried nanocapsules were stable at room temperature for, at least, 3 months. These promising data, in addition to their contribution to the development of an uropathogenic E. coli vaccine, has allowed us to validate these novel bilayer nanocapsules as adequate platforms for the delivery of protein antigens.
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Affiliation(s)
- José Crecente-Campo
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, 15782, Spain
| | - Silvia Lorenzo-Abalde
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Instituto de Investigación Sanitaria Galicia Sur (IISGS), Campus Universitario, Universidade de Vigo, Vigo, 36310, Spain
| | - Azucena Mora
- Laboratorio de Referencia de E. coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain
| | - Juan Marzoa
- Laboratorio de Referencia de E. coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain
| | - Noemi Csaba
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, 15782, Spain
| | - Jorge Blanco
- Laboratorio de Referencia de E. coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain
| | - África González-Fernández
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Instituto de Investigación Sanitaria Galicia Sur (IISGS), Campus Universitario, Universidade de Vigo, Vigo, 36310, Spain
| | - María José Alonso
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, 15782, Spain.
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12
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Miletic S, Hünerberg M, Kaldis A, MacDonald J, Leuthreau A, McAllister T, Menassa R. A Plant-Produced Candidate Subunit Vaccine Reduces Shedding of Enterohemorrhagic Escherichia coli in Ruminants. Biotechnol J 2017; 12. [PMID: 28869356 DOI: 10.1002/biot.201700405] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/30/2017] [Indexed: 12/18/2022]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are commonly present in the gastrointestinal tract of cattle and cause serious infectious disease in humans. Immunizing cattle against EHEC is a promising strategy to decrease the risk of food contamination; however, veterinary vaccines against EHEC such as Econiche have not been widely adopted by the agricultural industry, and have been discontinued, prompting the need for more cost-effective EHEC vaccines. The objective of this project is to develop a platform to produce plant-made antigens for oral vaccination of ruminants against EHEC. Five recombinant proteins were designed as vaccine candidates and expressed transiently in Nicotiana benthamiana and transplastomically in Nicotiana tabacum. Three of these EHEC proteins, NleA, Stx2b, and a fusion of EspA accumulated when transiently expressed. Transient protein accumulation was the highest when EHEC proteins were fused to an elastin-like polypeptide (ELP) tag. In the transplastomic lines, EspA accumulated up to 479 mg kg-1 in lyophilized leaf material. Sheep that were administered leaf tissue containing recombinant EspA shed less E. coli O157:H7 when challenged, as compared to control animals. These results suggest that plant-made, transgenic EspA has the potential to reduce EHEC shedding in ruminants.
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Affiliation(s)
- Sean Miletic
- Agriculture and Agri-Food Canada, London Research and Development Centre, 1391 Sandford Street, London N5V 4T3, Ontario, Canada
- Department of Biology, University of Western Ontario, 1151 Richmond Street, London N6A 3K7, Ontario, Canada
| | - Martin Hünerberg
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1 Avenue South, Lethbridge T1J 4P4, Alberta, Canada
- Department of Animal Sciences, Ruminant Nutrition Unit, University of Göttingen, 37077 Göttingen, Germany
| | - Angelo Kaldis
- Agriculture and Agri-Food Canada, London Research and Development Centre, 1391 Sandford Street, London N5V 4T3, Ontario, Canada
| | - Jacqueline MacDonald
- Agriculture and Agri-Food Canada, London Research and Development Centre, 1391 Sandford Street, London N5V 4T3, Ontario, Canada
| | - Antoine Leuthreau
- Agriculture and Agri-Food Canada, London Research and Development Centre, 1391 Sandford Street, London N5V 4T3, Ontario, Canada
- Université de Bordeaux and INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'ornon, France
| | - Tim McAllister
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1 Avenue South, Lethbridge T1J 4P4, Alberta, Canada
| | - Rima Menassa
- Agriculture and Agri-Food Canada, London Research and Development Centre, 1391 Sandford Street, London N5V 4T3, Ontario, Canada
- Department of Biology, University of Western Ontario, 1151 Richmond Street, London N6A 3K7, Ontario, Canada
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13
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Leach S, Lundgren A, Carlin N, Löfstrand M, Svennerholm AM. Cross-reactivity and avidity of antibody responses induced in humans by the oral inactivated multivalent enterotoxigenicEscherichia coli (ETEC) vaccine ETVAX. Vaccine 2017. [PMID: 28625524 DOI: 10.1016/j.vaccine.2017.06.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We investigated whether the oral inactivated, multivalent enterotoxigenic Escherichia coli (ETEC) vaccine ETVAX, consisting of four E. coli strains over-expressing the colonisation factors (CFs) CFA/I, CS3, CS5 and CS6, combined with the toxoid LCTBA, could induce cross-reactive antibodies to CFs related to the CFA/I and CS5 families. We also evaluated the avidity of vaccine induced antibodies against the toxoid and CFs. Cross-reactivity was analysed in mucosal (faecal and antibodies in lymphocyte supernatants, ALS) samples, and antibody avidity in serum and ALS samples, from two phase I trials: a primary vaccination study, where two oral doses of ETVAX were given±the double mutant heat labile toxin (dmLT) adjuvant at a 2-week interval, and a booster vaccination study, where a single booster dose of ETVAX was given 13-23months after primary vaccinations. We found that 65-90% of subjects who had responded to CFA/I in ALS or faecal specimens also developed cross-reactive antibodies to the related CFs tested, i.e. CS1, CS14 and CS17, and that approximately 80% of those responding to CS5 also responded to the closely related CS7. For subjects who had developed cross-reactive antibodies, the magnitudes of responses against vaccine CFs and related non-vaccine CFs were comparable. Using both a simple method of antibody avidity determination based on limiting antigen dilution, as well as a chaotropic ELISA method, we found that the avidity of serum and ALS antibodies to key vaccine antigens increased after a late booster dose compared to after primary vaccination. Our results suggest that the cross-reactive antibody responses against multiple CFs may result in expanded ETEC strain coverage of ETVAX and that repeated vaccinations induce vaccine-specific antibodies with increased binding capacity.
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Affiliation(s)
- Susannah Leach
- University of Gothenburg Vaccine Research Institute (GUVAX), Dept. of Microbiology and Immunology, University of Gothenburg, Box 435, 405 30 Gothenburg, Sweden.
| | - Anna Lundgren
- University of Gothenburg Vaccine Research Institute (GUVAX), Dept. of Microbiology and Immunology, University of Gothenburg, Box 435, 405 30 Gothenburg, Sweden.
| | - Nils Carlin
- Etvax AB, Gunnar Asplunds allé, 17163 Solna, Sweden.
| | - Madeleine Löfstrand
- University of Gothenburg Vaccine Research Institute (GUVAX), Dept. of Microbiology and Immunology, University of Gothenburg, Box 435, 405 30 Gothenburg, Sweden.
| | - Ann-Mari Svennerholm
- University of Gothenburg Vaccine Research Institute (GUVAX), Dept. of Microbiology and Immunology, University of Gothenburg, Box 435, 405 30 Gothenburg, Sweden.
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14
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Porter CK, Louis Bourgeois A, Frenck RW, Prouty M, Maier N, Riddle MS. Developing and utilizing controlled human models of infection. Vaccine 2017; 35:6813-6818. [PMID: 28583306 DOI: 10.1016/j.vaccine.2017.05.068] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 04/11/2017] [Accepted: 05/24/2017] [Indexed: 11/18/2022]
Abstract
The controlled human infection model (CHIM) to assess the efficacy of vaccines against Shigella and enterotoxigenic Escherichia coli (ETEC) has several unique features that could significantly enhance the ability to test candidate vaccines. Despite increasing interest in these models, questions remain as to how to best incorporate them into vaccine development and how to maximize results. We designed a workshop focused on CHIM as part of the Vaccines Against Shigella and ETEC (VASE) Conference. The workshop, using the World Café method, focused on; clinical outcomes, nonclinical outcomes and model standardization. Researchers with a variety of expertise and experience rotated through each focus area and discussed relevant sub-topics. The results of these discussions were presented and questions posed to guide future workshops. Clinical endpoint discussions focused on the need for harmonized definitions; optimized attack rates; difficulties of sample collection and a need for non-stool based endpoints. Nonclinical discussions centered on evolving omics-based opportunities, host predictors of susceptibility and novel characterizations of the immune response. Model standardization focused on the value of shared procedures across institutions for clinical and non-clinical endpoints as well as for strain preparation and administration and subject selection. Participants agreed CHIMs for Shigella and ETEC vaccine development could accelerate vaccine development of a promising candidate; however, it was also appreciated that variability in the model and our limited understand of the host-pathogen interaction may yield results that could negatively impact a suitable candidate. Future workshops on CHIM are needed to ensure the optimal application of these models moving forward.
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Affiliation(s)
- Chad K Porter
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States.
| | - A Louis Bourgeois
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Robert W Frenck
- Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Michael Prouty
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | | | - Mark S Riddle
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
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15
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Huttner A, Hatz C, van den Dobbelsteen G, Abbanat D, Hornacek A, Frölich R, Dreyer AM, Martin P, Davies T, Fae K, van den Nieuwenhof I, Thoelen S, de Vallière S, Kuhn A, Bernasconi E, Viereck V, Kavvadias T, Kling K, Ryu G, Hülder T, Gröger S, Scheiner D, Alaimo C, Harbarth S, Poolman J, Fonck VG. Safety, immunogenicity, and preliminary clinical efficacy of a vaccine against extraintestinal pathogenic Escherichia coli in women with a history of recurrent urinary tract infection: a randomised, single-blind, placebo-controlled phase 1b trial. Lancet Infect Dis 2017; 17:528-537. [PMID: 28238601 DOI: 10.1016/s1473-3099(17)30108-1] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/13/2017] [Accepted: 01/24/2017] [Indexed: 01/27/2023]
Abstract
BACKGROUND Escherichia coli infections are increasing worldwide in community and hospital settings. The E coli O-antigen is a promising vaccine target. We aimed to assess the safety and immunogenicity of a bioconjugate vaccine containing the O-antigens of four E coli serotypes (ExPEC4V). METHODS In this multicentre phase 1b, first-in-human, single-blind, placebo-controlled trial, we randomly assigned (1:1) healthy adult women with a history of recurrent urinary tract infection (UTI) to receive a single injection of either intramuscular ExPEC4V or placebo. The primary outcome was the incidence of adverse events among vaccine and placebo recipients throughout the study. Secondary outcomes included immunogenicity and antibody functionality, and the incidence of UTIs caused by E coli vaccine serotypes in each group. This study is registered with ClinicalTrials.gov, number NCT02289794. FINDINGS Between Jan 20, 2014, and Aug 27, 2014, 93 women received target-dose ExPEC4V and 95 received placebo. The vaccine was well tolerated: no vaccine-related serious adverse events occurred. Overall, 56 (60%) target-dose vaccines and 47 (49%) placebo recipients experienced at least one adverse event that was possibly, probably, or certainly related to injection. Vaccination induced significant IgG responses for all serotypes: at day 30 compared with baseline, O1A titres were 4·6 times higher, O2 titres were 9·4 times higher, O6A titres were 4·9 times higher, and O25B titres were 5·9 times higher (overall p<0·0001). Immune responses persisted at 270 days but were lower than those at 30 days. Opsonophagocytic killing activity showed antibody functionality. No reduction in the incidence of UTIs with 103 or more colony-forming units per mL of vaccine-serotype E coli was noted in the vaccine compared with the placebo group (0·149 mean episodes vs 0·146 mean episodes; p=0·522). In post-hoc exploratory analyses of UTIs with higher bacterial counts (≥105 colony-forming units per mL), the number of vaccine serotype UTIs did not differ significantly between groups (0·046 mean episodes in the vaccine group vs 0·110 mean episodes in the placebo group; p=0·074). However, significantly fewer UTIs caused by E coli of any serotype were noted in the vaccine group compared with the placebo group (0·207 mean episodes vs 0·463 mean episodes; p=0·002). INTERPRETATION This tetravalent E coli bioconjugate vaccine candidate was well tolerated and elicited functional antibody responses against all vaccine serotypes. Phase 2 studies have been initiated to confirm these findings. FUNDING GlycoVaxyn, Janssen Vaccines.
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Affiliation(s)
- Angela Huttner
- Infection Control Program, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
| | - Christoph Hatz
- Epidemiology, Biostatistics and Prevention Institute, Zurich University, Zurich, Switzerland; Swiss Tropical and Public Health Institute, Basel University, Basel, Switzerland
| | | | | | | | | | | | | | - Todd Davies
- Janssen Research and Development, Raritan, NJ, USA
| | - Kellen Fae
- Bacterial Vaccines Discovery & Early Development, Janssen Vaccines and Prevention, Leiden, Netherlands
| | - Ingrid van den Nieuwenhof
- Bacterial Vaccines Discovery & Early Development, Janssen Vaccines and Prevention, Leiden, Netherlands
| | - Stefan Thoelen
- Bacterial Vaccines Discovery & Early Development, Janssen Vaccines and Prevention, Leiden, Netherlands
| | - Serge de Vallière
- Policlinique Médicale Universitaire and Service of Infectious Diseases, University Hospital Lausanne, Lausanne, Switzerland
| | - Anette Kuhn
- Universitätsklinik für Frauenheilkunde, University Hospital Bern, Bern, Switzerland
| | | | - Volker Viereck
- Blasen-und Beckenbodenzentrum, Kantonsspital Frauenfeld, Frauenfeld, Switzerland
| | | | - Kerstin Kling
- Swiss Tropical and Public Health Institute, Basel University, Basel, Switzerland
| | - Gloria Ryu
- Frauenklinik, Kantonsspital Aarau, Aarau, Switzerland
| | - Tanja Hülder
- Frauenklinik, Kantonsspital St Gallen, St Gallen, Switzerland
| | - Sabine Gröger
- Neue Frauenklinik, Luzerner Kantonsspital, Lucerne, Switzerland
| | - David Scheiner
- Department of Gynecology, University Hospital Zurich, Zurich, Switzerland
| | | | - Stephan Harbarth
- Infection Control Program, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Jan Poolman
- Bacterial Vaccines Discovery & Early Development, Janssen Vaccines and Prevention, Leiden, Netherlands
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16
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Conover MS, Ruer S, Taganna J, Kalas V, De Greve H, Pinkner JS, Dodson KW, Remaut H, Hultgren SJ. Inflammation-Induced Adhesin-Receptor Interaction Provides a Fitness Advantage to Uropathogenic E. coli during Chronic Infection. Cell Host Microbe 2016; 20:482-492. [PMID: 27667696 PMCID: PMC5294914 DOI: 10.1016/j.chom.2016.08.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/10/2016] [Accepted: 08/19/2016] [Indexed: 02/04/2023]
Abstract
Uropathogenic E. coli (UPEC) is the dominant cause of urinary tract infections, clinically described as cystitis. UPEC express CUP pili, which are extracellular fibers tipped with adhesins that bind mucosal surfaces of the urinary tract. Here we identify the role of the F9/Yde/Fml pilus for UPEC persistence in the inflamed urothelium. The Fml adhesin FmlH binds galactose β1-3 N-acetylgalactosamine found in core-1 and -2 O-glycans. Deletion of fmlH had no effect on UPEC virulence in an acute mouse model of cystitis. However, FmlH provided a fitness advantage during chronic cystitis, which is manifested as persistent bacteriuria, high bladder bacterial burdens, and chronic inflammation. In situ binding confirmed that FmlH bound avidly to the inflamed, but not the naive bladder. In accordance with its pathogenic profile, vaccination with FmlH significantly protected mice from chronic cystitis. Thus, UPEC employ separate CUP pili to adapt to the rapidly changing niche during bladder infection.
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Affiliation(s)
- Matt S Conover
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ségolène Ruer
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Joemar Taganna
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Vasilios Kalas
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Henri De Greve
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Jerome S Pinkner
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Karen W Dodson
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Han Remaut
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
| | - Scott J Hultgren
- Department of Molecular Microbiology and Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA.
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17
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Kumar A, Hays M, Lim F, Foster LJ, Zhou M, Zhu G, Miesner T, Hardwidge PR. Protective Enterotoxigenic Escherichia coli Antigens in a Murine Intranasal Challenge Model. PLoS Negl Trop Dis 2015; 9:e0003924. [PMID: 26244636 PMCID: PMC4526226 DOI: 10.1371/journal.pntd.0003924] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/19/2015] [Indexed: 12/19/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is an endemic health threat in underdeveloped nations. Despite the significant effort extended to vaccine trials using ETEC colonization factors, these approaches have generally not been especially effective in mediating cross-protective immunity. We used quantitative proteomics to identify 24 proteins that differed in abundance in membrane protein preparations derived from wild-type vs. a type II secretion system mutant of ETEC. We expressed and purified a subset of these proteins and identified nine antigens that generated significant immune responses in mice. Sera from mice immunized with either the MltA-interacting protein MipA, the periplasmic chaperone seventeen kilodalton protein, Skp, or a long-chain fatty acid outer membrane transporter, ETEC_2479, reduced the adherence of multiple ETEC strains differing in colonization factor expression to human intestinal epithelial cells. In intranasal challenge assays of mice, immunization with ETEC_2479 protected 88% of mice from an otherwise lethal challenge with ETEC H10407. Immunization with either Skp or MipA provided an intermediate degree of protection, 68 and 64%, respectively. Protection was significantly correlated with the induction of a secretory immunoglobulin A response. This study has identified several proteins that are conserved among heterologous ETEC strains and may thus potentially improve cross-protective efficacy if incorporated into future vaccine designs.
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Affiliation(s)
- Amit Kumar
- College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America
| | - Mike Hays
- College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America
| | - Francis Lim
- Department of Biochemistry & Molecular Biology and Centre for High-Throughput Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Leonard J. Foster
- Department of Biochemistry & Molecular Biology and Centre for High-Throughput Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mingxu Zhou
- College of Veterinary Medicine, Yangzhou University and Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
| | - Guoqiang Zhu
- College of Veterinary Medicine, Yangzhou University and Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
| | - Tracy Miesner
- College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America
| | - Philip R. Hardwidge
- College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America
- * E-mail:
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18
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Sadeyen JR, Kaiser P, Stevens MP, Dziva F. A cyclophosphamide-sensitive cell compartment is essential for homologous protection conferred by licensed vaccines for the control of avian pathogenic Escherichia coli in chickens. Vaccine 2015; 33:3624-7. [PMID: 26087298 DOI: 10.1016/j.vaccine.2015.06.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/31/2015] [Accepted: 06/04/2015] [Indexed: 11/19/2022]
Abstract
Avian pathogenic Escherichia coli (APEC) exert substantial economic costs on poultry producers worldwide. Vaccination is an attractive method of control, but the immunological basis of protection is poorly understood. Here, we examine the effect of intramuscular injection of cyclophosphamide or saline on homologous protection induced by licensed inactivated or live-attenuated APEC O78 vaccines in chickens. In saline-treated birds, both vaccines induced significant APEC-specific IgY and protection against homologous challenge, as evidenced by enumeration of tissue-associated bacteria and analysis of pathology. In cyclophosphamide-treated birds, B cells were severely depleted whereas percentages of circulating CD4- and CD8-positive T cells were normal as detected by flow cytometry. Further, such birds did not produce APEC-specific IgY and were as susceptible to challenge as age-matched unvaccinated controls. The data indicate that homologous protection conferred by licensed APEC vaccines strictly requires a cyclophosphamide-sensitive cell population that includes B cells.
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Affiliation(s)
- Jean-Rémy Sadeyen
- Avian Infectious Diseases Programme, The Pirbright Institute, Compton RG20 7NN, Berkshire, United Kingdom
| | - Pete Kaiser
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, United Kingdom
| | - Mark P Stevens
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, United Kingdom
| | - Francis Dziva
- Avian Infectious Diseases Programme, The Pirbright Institute, Compton RG20 7NN, Berkshire, United Kingdom.
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19
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Abstract
Pediatric immunization has been the most effective measure to prevent and reduce the burden of infectious diseases in children. The recent inclusion of pneumococcal and meningococcal polysaccharide conjugates in infant immunization further reinforces their importance. Currently there is no human vaccine against enterohemorrhagic Escherichia coli (EHEC) infections. This review focuses on the human EHEC vaccine that has been studied clinically, in particular, the polysaccharide conjugate against E. coli O157. The surface polysaccharide antigen, O-specific polysaccharide, was linked to rEPA, recombinant exotoxin A of Pseudomonas aeruginosa. In adults and children 2 to 5 years old, O157-rEPA conjugates, shown to be safe, induced high levels of antilipopolysaccharide immunoglobulin G with bactericidal activities against E. coli O157, a functional bioassay that mimics the killing of inoculum in vivo. A similar construct using the B subunit of Shiga toxin (Stx) 1 as the carrier protein elicited both bactericidal and toxin-neutralizing antibodies in mice. So far there is no clinical study of Stx-based human vaccine. Passive immunization of Stx-specific antibodies with humanized, chimeric, or human monoclonal antibodies, produced in transgenic mice, showed promising data in animal models and offered high prospects. Demonstrations of their safety and effectiveness in treating hemolytic-uremic syndrome or patients with EHEC infections are under way, and results are much anticipated. For future development, other virulence factors such as the nontoxic Stx B subunit or intimin should be included, either as carrier protein in conjugates or as independent components. The additional antigens from O157 may provide broader coverage to non-O157 Stx-producing E. coli and facilitate both preventive and therapeutic treatment.
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Affiliation(s)
- Shousun Chen Szu
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Amina Ahmed
- Levine Children's Specialty Center-Pediatric Infectious Disease, Carolina Medical Centers, Charlotte, NC 28203
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20
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Abstract
Enterotoxigenic Escherichia coli (ETEC) are the most common bacterial pathogens causing diarrhea in developing countries where they lead to hundreds of thousands of deaths, mostly in children. These organisms are a leading cause of diarrheal illness in travelers to endemic countries. ETEC pathogenesis, and consequently vaccine approaches, have largely focused on plasmid-encoded enterotoxins or fimbrial colonization factors. To date these approaches have not yielded a broadly protective vaccine. However, recent studies suggest that ETEC pathogenesis is more complex than previously appreciated and involves additional plasmid and chromosomally encoded virulence molecules that can be targeted in vaccines. Here, we review recent novel antigen discovery efforts, potential contribution of these proteins to the molecular pathogenesis of ETEC and protective immunity, and the potential implications for development of next generation vaccines for important pathogens. These proteins may help to improve the effectiveness of future vaccines by making them simpler and possibly broadly protective because of their conserved nature.
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Affiliation(s)
- James M. Fleckenstein
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, USA
- Molecular Microbiology and Microbial Pathogenesis Program, Division of Biology and Biomedical Sciences, Washington University School of Medicine, USA
- Medicine Service, Veterans Affairs Medical Center, St. Louis, Missouri, USA
| | - Alaullah Sheikh
- Molecular Microbiology and Microbial Pathogenesis Program, Division of Biology and Biomedical Sciences, Washington University School of Medicine, USA
| | - Firdausi Qadri
- Centre for Vaccine Sciences, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
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21
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Zhang X, Yu Z, Zhang S, He K. Immunization with H7-HCP-tir-intimin significantly reduces colonization and shedding of Escherichia coli O157:H7 in goats. PLoS One 2014; 9:e91632. [PMID: 24632795 PMCID: PMC3954762 DOI: 10.1371/journal.pone.0091632] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 02/11/2014] [Indexed: 11/18/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is the causative agent of hemorrhagic colitis and hemolytic uremic syndrome in humans. However, the bacterium can colonize the intestines of ruminants without causing clinical signs. EHEC O157:H7 needs flagella (H7) and hemorrhagic coli pili (HCP) to adhere to epithelial cells. Then the bacterium uses the translocated intimin receptor (Tir) and an outer membrane adhesion (Intimin) protein to colonize hosts. This leads to the attachment and effacement of (A/E) lesions. A tetravalent recombinant vaccine (H7-HCP-Tir-Intimin) composed of immunologically important portions of H7, HCP, Tir and Intimin proteins was constructed and its efficacy was evaluated using a caprine model. The results showed that the recombinant vaccine induced strong humoral and mucosal immune responses and protected the subjects from live challenges with EHEC O157:H7 86-24 stain. After a second immunization, the average IgG titer peaked at 7.2 × 10(5). Five days after challenge, E. coli O157:H7 was no longer detectable in the feces of vaccinated goats, but naïve goats shed the bacterium throughout the course of the challenge. Cultures of intestinal tissues showed that vaccination of goats with H7-HCP-Tir-Intimin reduced the amount of intestinal colonization by EHEC O157:H7 effectively. Recombinant H7-HCP-Tir-Intimin protein is an excellent vaccine candidate. Data from the present study warrant further efficacy studies aimed at reducing EHEC O157:H7 load on farms and the contamination of carcasses by this zoonotic pathogen.
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Affiliation(s)
- Xuehan Zhang
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
- Key Laboratory of Engineering Research of Veterinary Bio-products of Agricultural Ministry, Nanjing, P. R. China
- National Center for Engineering Research of Veterinary Bio-products, Nanjing, P. R. China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, P. R. China
- * E-mail: (XZ); (KH)
| | - Zhengyu Yu
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
- Key Laboratory of Engineering Research of Veterinary Bio-products of Agricultural Ministry, Nanjing, P. R. China
- National Center for Engineering Research of Veterinary Bio-products, Nanjing, P. R. China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, P. R. China
| | - Shuping Zhang
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States of America
| | - Kongwang He
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
- Key Laboratory of Engineering Research of Veterinary Bio-products of Agricultural Ministry, Nanjing, P. R. China
- National Center for Engineering Research of Veterinary Bio-products, Nanjing, P. R. China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, P. R. China
- * E-mail: (XZ); (KH)
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22
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Novel vaccine-adjuvant combination successful against bacterial diarrhea. Hum Vaccin Immunother 2014; 10:3428. [PMID: 26052587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
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23
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Darsley MJ, Chakraborty S, DeNearing B, Sack DA, Feller A, Buchwaldt C, Bourgeois AL, Walker R, Harro CD. The oral, live attenuated enterotoxigenic Escherichia coli vaccine ACE527 reduces the incidence and severity of diarrhea in a human challenge model of diarrheal disease. Clin Vaccine Immunol 2012; 19:1921-31. [PMID: 23035175 PMCID: PMC3535858 DOI: 10.1128/cvi.00364-12] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 09/24/2012] [Indexed: 11/20/2022]
Abstract
An oral, live attenuated, three-strain recombinant bacterial vaccine, ACE527, was demonstrated to generate strong immune responses to colonization factor and toxin antigens of enterotoxigenic Escherichia coli (ETEC) in human volunteers. The vaccine was safe and well tolerated at doses of up to 10(11) CFU, administered in each of two doses given 21 days apart. These observations have now been extended in a phase 2b study with a total of 70 subjects. Fifty-six of these subjects were challenged 28 days after the second dose of vaccine with the highly virulent ETEC strain H10407 to obtain preliminary indicators of efficacy against disease and to support further development of the vaccine for both travelers and infants in countries where ETEC is endemic. The vaccine had a significant impact on intestinal colonization by the challenge strain, as measured by quantitative fecal culture 2 days after challenge, demonstrating the induction of a functional immune response to the CFA/I antigen. The incidence and severity of diarrhea were also reduced in vaccinees as measured by a number of secondary and ad hoc endpoints, although the 27% reduction seen in the primary endpoint, moderate to severe diarrhea, was not statistically significant. Together, these observations support the hypothesis that the ACE527 vaccine has a dual mode of action, targeting both colonization factors and the heat-labile enterotoxin (LT), and suggest that it should be further developed for more advanced trials to evaluate its impact on the burden of ETEC disease in field settings.
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24
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Hur J, Lee JH. Comparative evaluation of a vaccine candidate expressing enterotoxigenic Escherichia coli (ETEC) adhesins for colibacillosis with a commercial vaccine using a pig model. Vaccine 2012; 30:3829-33. [PMID: 22507658 DOI: 10.1016/j.vaccine.2012.03.087] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 03/14/2012] [Accepted: 03/31/2012] [Indexed: 11/29/2022]
Abstract
In this study, a comparative evaluation of a novel live vaccine candidate expressing enterotoxigenic Escherichia coli (ETEC) fimbriae and a commercial ETEC vaccine was carried out in suckling to weaned piglets. The E. coli K88ab, K88ac, K99, FasA and F41 fimbrial genes were individually inserted into an expression/secretion plasmid, pBP244. These plasmids were subsequently transfected into attenuated Salmonella, which were used as the vaccine candidate. Eighteen pregnant sows and 107 of their piglets were used in this comparative study. All the vaccinated groups of sows and piglets exhibited significantly increased antibody levels relative to specific antigens when compared with those in the unimmunized control. The experimental piglets with the vaccine candidate did not experience diarrhea following challenge with the virulent ETEC strains. However, diarrhea was observed in 36.8% of the piglets in the group immunized with the commercial vaccine and in 50% of the control group after challenge with the ETEC strains. These findings indicate that immunization of sows with the candidate vaccine can effectively protect their young pigs against colibacillosis.
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Affiliation(s)
- Jin Hur
- Veterinary Public Health, College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Jeonju 561-756, South Korea
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25
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Wieser A, Magistro G, Nörenberg D, Hoffmann C, Schubert S. First multi-epitope subunit vaccine against extraintestinal pathogenic Escherichia coli delivered by a bacterial type-3 secretion system (T3SS). Int J Med Microbiol 2011; 302:10-8. [PMID: 22000741 DOI: 10.1016/j.ijmm.2011.09.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 09/14/2011] [Accepted: 09/20/2011] [Indexed: 12/20/2022] Open
Abstract
Infections due to extraintestinal pathogenic E. coli (ExPEC) are very common in humans as well as in animals. In humans ExPEC infections include urinary tract infections (UTI), septicemia, and wound infections, which result in significant morbidity, mortality, and substantial healthcare costs. In view of the increasing number of ExPEC infections caused by more and more resistant strains, effective prevention would be desirable. Given the rising treatment costs, a vaccine may be cost-effective in selected patient groups, such as women with recurrent UTI, patients with neurologic disorders impairing bladder function and men with prostate hyperplasia. Previous vaccine studies used single target proteins or whole inactivated ExPEC cells. Here, we describe a vaccine system for oral application based on artificial multiple subunit vaccine proteins. Those multi-epitope proteins are composed of predicted epitopes derived from ExPEC virulence-associated proteins. As ExPEC are known to form intracellular biofilms in the urothelium and can also resist killing by non-activated macrophages, T-cell responses are supposed to be an important measure to counteract these stages of ExPEC during infection. Therefore, a live bacterial antigen delivery system based upon the Salmonella type-III secretion system (T3SS) was used in this study to directly deliver the vaccine proteins into the cytoplasm of the host cells. Epitope-rich domains of the proteins FyuA, IroN, ChuA, IreA, Iha, and Usp were expressed in an attenuated Salmonella enterica serovar Typhimurium strain and translocated into target cells for extended periods of time inducing a strong T-cell response. No significant antibody titre increase against the secreted vaccine proteins could be detected in vaginal wash or serum. Despite that, one of the vaccine proteins was able to significantly reduce bacterial load in the challenge model of intraperitoneal sepsis. This study shows that a vaccine encompassing distinct epitopes of virulence-associated ExPEC proteins (i) can be applied for a T3SS-dependent vaccination strategy, (ii) elicits T-cell responses and (iii) confers protection after a single application.
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Affiliation(s)
- Andreas Wieser
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Marchioninistr. 17, 81377 München, Germany
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26
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Liu M, Zhang C, Mateo K, Nataro JP, Robertson DC, Zhang W. Modified heat-stable toxins (hSTa) of enterotoxigenic Escherichia coli lose toxicity but display antigenicity after being genetically fused to heat-labile toxoid LT(R192G). Toxins (Basel) 2011; 3:1146-62. [PMID: 22069760 PMCID: PMC3202872 DOI: 10.3390/toxins3091146] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 09/01/2011] [Accepted: 09/06/2011] [Indexed: 11/25/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of diarrhea in humans and animals. Heat-stable (STa) and heat-labile (LT) enterotoxins produced by ETEC disrupt fluid homeostasis in host small intestinal epithelial cells and cause fluid and electrolyte hyper-secretion that leads to diarrhea. ETEC strains producing STa or LT are sufficiently virulent to cause diarrhea, therefore STa and LT antigens must be included in ETEC vaccines. However, potent toxicity and poor immunogenicity (of STa) prevent them from being directly applied as vaccine components. While LT toxoids, especially LT(R192G), being used in vaccine development, STa toxoids have not been included. A recent study (IAI, 78:316-325) demonstrated porcine-type STa toxoids [pSTa(P12F) and pSTa(A13Q)] elicited protective anti-STa antibodies after being fused to a porcine-type LT toxoid [pLT(R192G)]. In this study, we substituted the 8th, 9th, 16th, or the 17th amino acid of a human-type STa (hSTa) and generated 28 modified STa peptides. We tested each STa peptide for toxicity and structure integrity, and found nearly all modified STa proteins showed structure alteration and toxicity reduction. Based on structure similarity and toxic activity, three modified STa peptides: STa(E8A), STa(T16Q) and STa(G17S), were selected to construct LT192-STa-toxoid fusions. Constructed fusions were used to immunize mice, and immunized mice developed anti-STa antibodies. Results from this study provide useful information in developing toxoid vaccines against ETEC diarrhea.
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Affiliation(s)
- Mei Liu
- Veterinary & Biomedical Sciences Department, The Center for Infectious Disease Research & Vaccinology, South Dakota State University, Brookings, SD 57007, USA; (M.L.); (C.Z.); (K.M.)
| | - Chengxian Zhang
- Veterinary & Biomedical Sciences Department, The Center for Infectious Disease Research & Vaccinology, South Dakota State University, Brookings, SD 57007, USA; (M.L.); (C.Z.); (K.M.)
| | - Kristy Mateo
- Veterinary & Biomedical Sciences Department, The Center for Infectious Disease Research & Vaccinology, South Dakota State University, Brookings, SD 57007, USA; (M.L.); (C.Z.); (K.M.)
| | - James P. Nataro
- Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA;
| | - Donald C. Robertson
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS 66506, USA;
| | - Weiping Zhang
- Veterinary & Biomedical Sciences Department, The Center for Infectious Disease Research & Vaccinology, South Dakota State University, Brookings, SD 57007, USA; (M.L.); (C.Z.); (K.M.)
- Author to whom correspondence should be addressed; ; Tel.: +1-605-688-4317; Fax: +1-605-688-6003
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27
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Alteri CJ, Hagan EC, Sivick KE, Smith SN, Mobley HLT. Mucosal immunization with iron receptor antigens protects against urinary tract infection. PLoS Pathog 2009; 5:e1000586. [PMID: 19806177 PMCID: PMC2736566 DOI: 10.1371/journal.ppat.1000586] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Accepted: 08/24/2009] [Indexed: 01/09/2023] Open
Abstract
Uncomplicated infections of the urinary tract, caused by uropathogenic Escherichia coli, are among the most common diseases requiring medical intervention. A preventive vaccine to reduce the morbidity and fiscal burden these infections have upon the healthcare system would be beneficial. Here, we describe the results of a large-scale selection process that incorporates bioinformatic, genomic, transcriptomic, and proteomic screens to identify six vaccine candidates from the 5379 predicted proteins encoded by uropathogenic E. coli strain CFT073. The vaccine candidates, ChuA, Hma, Iha, IreA, IroN, and IutA, all belong to a functional class of molecules that is involved in iron acquisition, a process critical for pathogenesis in all microbes. Intranasal immunization of CBA/J mice with these outer membrane iron receptors elicited a systemic and mucosal immune response that included the production of antigen-specific IgM, IgG, and IgA antibodies. The cellular response to vaccination was characterized by the induction and secretion of IFN-gamma and IL-17. Of the six potential vaccine candidates, IreA, Hma, and IutA provided significant protection from experimental infection. In immunized animals, class-switching from IgM to IgG and production of antigen-specific IgA in the urine represent immunological correlates of protection from E. coli bladder colonization. These findings are an important first step toward the development of a subunit vaccine to prevent urinary tract infections and demonstrate how targeting an entire class of molecules that are collectively required for pathogenesis may represent a fundamental strategy to combat infections.
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MESH Headings
- Administration, Intranasal
- Animals
- Antibodies, Bacterial/blood
- Antibodies, Bacterial/immunology
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Antigens, Bacterial/metabolism
- Cells, Cultured
- Escherichia coli/immunology
- Escherichia coli Infections/immunology
- Escherichia coli Infections/prevention & control
- Escherichia coli Proteins/genetics
- Escherichia coli Proteins/immunology
- Escherichia coli Proteins/metabolism
- Escherichia coli Vaccines/administration & dosage
- Escherichia coli Vaccines/immunology
- Female
- Immunoglobulin A, Secretory/metabolism
- Immunoglobulin A, Secretory/urine
- Immunoglobulin Class Switching/immunology
- Interferon-gamma/metabolism
- Interleukin-17/metabolism
- Mice
- Mice, Inbred CBA
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/metabolism
- Spleen/cytology
- Spleen/immunology
- Spleen/metabolism
- Statistics, Nonparametric
- Urinary Tract Infections/immunology
- Urinary Tract Infections/prevention & control
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Affiliation(s)
- Christopher J. Alteri
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Erin C. Hagan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Kelsey E. Sivick
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Sara N. Smith
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Harry L. T. Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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28
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Zhang J, Tang DCC. Topical application of Escherichia coli particles over-producing pathogen-derived antigens as a simple vaccination modality in compliance with evolutionary medicine. Infect Disord Drug Targets 2008; 8:189-194. [PMID: 18782036 DOI: 10.2174/1871526510808030189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The development of a new generation of vaccines that can be produced rapidly at low costs and mass-administered noninvasively by non-medical personnel is crucial for boosting vaccine coverage in response to an escalation in demand. The demonstration that topical application of bioengineered nonreplicating Escherichia coli particles overproducing pathogen-derived antigens can mobilize the immune repertoire toward beneficial immune protection against relevant pathogens holds promise for enabling mass-immunization without pain, fear and perceivable tissue damage. Moreover, this noninvasive regimen using E. coli epitopes as a natural adjuvant is in compliance with evolutionary medicine.
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Affiliation(s)
- Jianfeng Zhang
- Vaxin Inc., 1500 First Avenue North, Birmingham, Alabama 35203, USA.
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29
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Frech SA, Dupont HL, Bourgeois AL, McKenzie R, Belkind-Gerson J, Figueroa JF, Okhuysen PC, Guerrero NH, Martinez-Sandoval FG, Meléndez-Romero JH, Jiang ZD, Asturias EJ, Halpern J, Torres OR, Hoffman AS, Villar CP, Kassem RN, Flyer DC, Andersen BH, Kazempour K, Breisch SA, Glenn GM. Use of a patch containing heat-labile toxin from Escherichia coli against travellers' diarrhoea: a phase II, randomised, double-blind, placebo-controlled field trial. Lancet 2008; 371:2019-25. [PMID: 18554712 DOI: 10.1016/s0140-6736(08)60839-9] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Enterotoxigenic Escherichia coli (ETEC) is a major cause of travellers' diarrhoea. We investigated the rate of diarrhoea attacks, safety, and feasibility of a vaccine containing heat-labile enterotoxin (LT) from ETEC delivered to the skin by patch in travellers to Mexico and Guatemala. METHODS In this phase II study, healthy adults (aged 18-64 years) who planned to travel to Mexico or Guatemala and had access to a US regional vaccination centre were eligible. A centralised randomisation code was used for allocation, which was masked to participants and site staff. Primary endpoints were to investigate the field rate of ETEC diarrhoea, and to assess the safety of heat-labile toxins from E coli (LT) delivered via patch. Secondary endpoints included vaccine efficacy against travellers' diarrhoea and ETEC. Participants were vaccinated before travel, with two patches given 2-3 weeks apart. Patches contained either 37.5 mug of LT or placebo. Participants tracked stool output on diary cards in country and provided samples for pathogen identification if diarrhoea occurred. Diarrhoea was graded by the number of loose stools in 24 h: mild (three), moderate (four or five), and severe (at least six). Analysis was per protocol. The trial is registered with ClinicalTrials.gov, number NCT00516659. FINDINGS Recruitment closed after 201 participants were assigned patches. 178 individuals received two vaccinations and travelled and 170 were analysed. 24 (22%) of 111 placebo recipients had diarrhoea, of whom 11 (10%) had ETEC diarrhoea. The vaccine was safe and immunogenic. The 59 LT-patch recipients were protected against moderate-to-severe diarrhoea (protective efficacy [PE] 75%, p=0.0070) and severe diarrhoea (PE 84%, p=0.0332). LT-patch recipients who became ill had shorter episodes of diarrhoea (0.5 days vs 2.1 days, p=0.0006) with fewer loose stools (3.7 vs 10.5, p<0.0001) than placebo. INTERPRETATION Travellers' diarrhoea is a common ailment, with ETEC diarrhoea illness occurring in 10% of cases. The vaccine patch is safe and feasible, with benefits to the rate and severity of travellers' diarrhoea.
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30
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Zhang H, Cheng C, Zheng M, Chen JL, Meng MJ, Zhao ZZ, Chen Q, Xie Z, Li JL, Yang Y, Shen Y, Wang HN, Wang ZZ, Gao R. Enhancement of immunity to an Escherichia coli vaccine in mice orally inoculated with a fusion gene encoding porcine interleukin 4 and 6. Vaccine 2007; 25:7094-101. [PMID: 17868957 DOI: 10.1016/j.vaccine.2007.07.050] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Revised: 07/26/2007] [Accepted: 07/28/2007] [Indexed: 11/26/2022]
Abstract
Experiments were conducted to investigate the effect of a fusion gene of porcine IL-4 and IL-6 (PIL4/IL6) packaged with chitosan nanoparticles (CNPs) in terms of the development of a novel effective adjuvant. The IL4/PIL6 fusion gene was constructed and inserted into a eukaryotic expression vector. The plasmid was bound to CNP and then utilized to orally inoculate 21-day-old female Kunming mice that simultaneously received intramuscular injection of inactivated Escherichia coli vaccine. At 35 days post-vaccination, the mice were challenged by oral feeding with virulent O139: K88 strain EPEC E. coli bacteria. Compared with those of control mice, the content of immunoglobulins and specific antibodies to E. coli increased significantly in the sera of mice immunized with VPIL4/IL6-CNP (P<0.05). Furthermore, the levels of IL-2, IL-4 and IL-6 increased remarkably in the sera of immunized mice (P<0.05). After challenge, these immunological markers were elevated to different degrees in the mice immunized with the fusion gene construct (IL4/VPIL6-CNP) or individual plasmids (VPIL4+VPIL6-CNP). The immunized mice all survived the challenge and did not show any symptoms or lesion, whereas the VR1020-CNP control mice manifested obvious clinical symptoms and hemorrhagic lesions in the digestive tracts. These results demonstrated that VPIL4/IL6 entrapped with CNP is a novel promising adjuvant to promote specific immunity and resistance of animals against infectious pathogen.
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Affiliation(s)
- Huan Zhang
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry Education, Bioengineering Research Center for Animal Disease Prevention and Control, Life Science College, Sichuan University, Chengdu 610064, Sichuan, PR China
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31
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Nitcheu-Tefit J, Dai MS, Critchley-Thorne RJ, Ramirez-Jimenez F, Xu M, Conchon S, Ferry N, Stauss HJ, Vassaux G. Listeriolysin O expressed in a bacterial vaccine suppresses CD4+CD25high regulatory T cell function in vivo. J Immunol 2007; 179:1532-41. [PMID: 17641019 DOI: 10.4049/jimmunol.179.3.1532] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD4(+)CD25(high) regulatory T cells (Treg) protect the host from autoimmune diseases but are also obstacles against cancer therapies. An ideal cancer vaccine would stimulate specific cytotoxic responses and reduce/suppress Treg function. In this study, we showed that Escherichia coli expressing listeriolysin O and OVA (E. coli LLO/OVA) demonstrated remarkable levels of protection against OVA-expressing tumor cells. By contrast, E. coli expressing OVA only (E. coli OVA) showed poor protection. High-avidity OVA-specific CTL were induced in E. coli LLO/OVA-vaccinated mice, and CD8(+) depletion--but not NK cell depletion, abolished the antitumor activity of the E. coli LLO/OVA vaccine. Phenotypic analysis of T cells following vaccination with either vaccine revealed preferential generation of CD44(high)CD62L(low) CD8(+) effector memory T cells over CD44(high)CD62L(high) central memory T cells. Unexpectedly, CD4(+) depletion turned E. coli OVA into a vaccine as effective as E. coli LLO/OVA suggesting that a subset of CD4(+) cells suppressed the CD8(+) T cell-mediated antitumor response. Further depletion experiments demonstrated that these suppressive cells consisted of CD4(+)CD25(high) regulatory T cells. We therefore assessed these vaccines for Treg function and found that although CD4(+)CD25(high) expansion and Foxp3 expression within this population was similar in all groups of mice, Treg cells from E. coli LLO/OVA-vaccinated animals were unable to suppress conventional T cells proliferation. These findings provide the first evidence that LLO expression affects Treg cell function and may have important implications for enhancing antitumor vaccination strategies in humans.
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MESH Headings
- Animals
- Bacterial Toxins/administration & dosage
- Bacterial Toxins/biosynthesis
- Bacterial Toxins/genetics
- CD8-Positive T-Lymphocytes/cytology
- CD8-Positive T-Lymphocytes/immunology
- Cell Adhesion/immunology
- Cell Proliferation
- Egg Proteins/biosynthesis
- Egg Proteins/genetics
- Egg Proteins/immunology
- Escherichia coli Vaccines/administration & dosage
- Escherichia coli Vaccines/genetics
- Escherichia coli Vaccines/immunology
- Female
- Heat-Shock Proteins/administration & dosage
- Heat-Shock Proteins/biosynthesis
- Heat-Shock Proteins/genetics
- Hemolysin Proteins/administration & dosage
- Hemolysin Proteins/biosynthesis
- Hemolysin Proteins/genetics
- Immunologic Memory
- Injections, Intravenous
- Lung Neoplasms/immunology
- Lung Neoplasms/prevention & control
- Lung Neoplasms/secondary
- Melanoma, Experimental/immunology
- Melanoma, Experimental/metabolism
- Melanoma, Experimental/prevention & control
- Mice
- Mice, Inbred C57BL
- Ovalbumin/biosynthesis
- Ovalbumin/genetics
- Ovalbumin/immunology
- Peptide Fragments
- T-Lymphocyte Subsets/immunology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
- T-Lymphocytes, Regulatory/immunology
- Tumor Cells, Cultured
- Vaccines, Inactivated/administration & dosage
- Vaccines, Inactivated/genetics
- Vaccines, Inactivated/immunology
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Affiliation(s)
- Josianne Nitcheu-Tefit
- Centre for Molecular Oncology, Institute of Cancer, Queen Mary's School of Medicine and Dentistry, London, United Kingdom
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Dziva F, Vlisidou I, Crepin VF, Wallis TS, Frankel G, Stevens MP. Vaccination of calves with EspA, a key colonisation factor of Escherichia coli O157:H7, induces antigen-specific humoral responses but does not confer protection against intestinal colonisation. Vet Microbiol 2007; 123:254-61. [PMID: 17374460 DOI: 10.1016/j.vetmic.2007.02.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Revised: 02/14/2007] [Accepted: 02/19/2007] [Indexed: 10/23/2022]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) infections in humans are frequently associated with direct or indirect contact with ruminant faeces and may result in haemorrhagic colitis and severe renal and neurological sequelae. Broadly cross-protective vaccines for control of EHEC do not yet exist and the molecular mechanisms that influence bacterial persistence in the intestines of ruminants are incompletely understood. We sought to determine the role in colonisation and protective efficacy of EspA, which forms a filamentous extension of the locus of enterocyte effacement-encoded type III secretion system that injects EHEC proteins into enterocytes. A non-polar deletion of espA severely impaired the ability of E. coli O157:H7 to colonise the intestines of calves. Vaccination of calves with highly purified recombinant EspA induced high-titre antigen-specific IgG1 (also reactive to native EspA) and salivary IgA responses, however these responses did not protect calves against intestinal colonisation by E. coli O157:H7 upon experimental infection.
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Affiliation(s)
- Francis Dziva
- Division of Microbiology, Institute for Animal Health, Compton, Berkshire, RG20 7NN, United Kingdom
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33
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Russo TA, Beanan JM, Olson R, Genagon SA, MacDonald U, Cope JJ, Davidson BA, Johnston B, Johnson JR. A killed, genetically engineered derivative of a wild-type extraintestinal pathogenic E. coli strain is a vaccine candidate. Vaccine 2007; 25:3859-70. [PMID: 17306426 PMCID: PMC1913199 DOI: 10.1016/j.vaccine.2007.01.100] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 01/18/2007] [Accepted: 01/23/2007] [Indexed: 11/28/2022]
Abstract
Infections due to extraintestinal pathogenic E. coli (ExPEC) result in significant morbidity, mortality and increased healthcare costs. An efficacious vaccine against ExPEC would be desirable. In this report, we explore the use of killed-whole E. coli as a vaccine immunogen. Given the diversity of capsule and O-antigens in ExPEC, we have hypothesized that alternative targets are viable vaccine candidates. We have also hypothesized that immunization with a genetically engineered strain that is deficient in the capsule and O-antigen will generate a greater immune response against antigens other than the capsular and O-antigen epitopes than a wild-type strain. Lastly, we hypothesize that mucosal immunization with killed E. coli has the potential to generate a significant immune response. In this study, we demonstrated that nasal immunization with a formalin-killed ExPEC derivative deficient in capsule and O-antigen results in a significantly greater overall humoral response compared to its wild-type derivative (which demonstrates that capsule and/or the O-antigen impede the development of an optimal humoral immune response) and a significantly greater immune response against non-capsular and O-antigen epitopes. These antibodies also bound to a subset of heterologous ExPEC strains and enhanced neutrophil-mediated bactericidal activity against the homologous and a heterologous strain. Taken together, these studies support the concept that formalin-killed genetically engineered ExPEC derivatives are whole cell vaccine candidates to prevent infections due to ExPEC.
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Affiliation(s)
- Thomas A Russo
- Department of Medicine, University at Buffalo, and Veterans Administration Western New York Healthcare System, Buffalo, NY 14214, United States.
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34
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McKenzie R, Bourgeois AL, Frech SA, Flyer DC, Bloom A, Kazempour K, Glenn GM. Transcutaneous immunization with the heat-labile toxin (LT) of enterotoxigenic Escherichia coli (ETEC): Protective efficacy in a double-blind, placebo-controlled challenge study. Vaccine 2007; 25:3684-91. [PMID: 17313998 DOI: 10.1016/j.vaccine.2007.01.043] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2006] [Revised: 01/03/2007] [Accepted: 01/09/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND An enterotoxigenic Escherichia coli (ETEC) vaccine could reduce diarrhea among children in developing countries and travelers to these countries. The heat-labile toxin (LT) of ETEC is immunogenic but too toxic for oral or nasal vaccines. METHODS In a double-blind, placebo-controlled trial, 59 adults were randomized to receive 50 microg of LT or placebo in a patch applied to alternating arms on days 0, 21, and 42. On day 56, 27 vaccinees and 20 controls were challenged orally with 6x10(8) cfu of LT+/ST+ ETEC. RESULTS 100 and 97% of vaccinees had 4-fold increases in anti-LT IgG and IgA, and 100 and 90% developed IgG- and IgA-antibody-secreting cell responses. The study did not meet the primary endpoint: 82% of vaccinees and 75% of controls had moderate to severe ETEC illness. However, vaccinees with ETEC illness had lower numbers (6.8 versus 9.7, p=0.04) and weights of loose stools (840 g versus 1147 g, p<0.05), a decreased need for intravenous fluids (14% versus 40%, p=0.03) and a delayed onset of diarrhea (30 h versus 22 h, p=0.01). CONCLUSIONS Transcutaneous LT vaccination induced anti-toxin immune responses that did not prevent but mitigated illness following a high-dose challenge with a virulent LT+/ST+ ETEC strain.
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Affiliation(s)
- Robin McKenzie
- Division of Infectious Diseases, Johns Hopkins University, Johns Hopkins Bayview Medical Center, 4940 Eastern Ave., Baltimore, MD 21224, United States.
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35
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Sack DA, Shimko J, Torres O, Bourgeois AL, Francia DS, Gustafsson B, Kärnell A, Nyquist I, Svennerholm AM. Randomised, double-blind, safety and efficacy of a killed oral vaccine for enterotoxigenic E. Coli diarrhoea of travellers to Guatemala and Mexico. Vaccine 2007; 25:4392-400. [PMID: 17448578 DOI: 10.1016/j.vaccine.2007.03.034] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Revised: 03/16/2007] [Accepted: 03/20/2007] [Indexed: 11/16/2022]
Abstract
We tested the efficacy of a killed oral vaccine for enterotoxigenic Escherichia coli (ETEC) diarrhoea to determine if two doses of vaccine with colonization factor antigens (CF) and cholera B subunit would protect against ETEC diarrhoea of travellers. Six hundred seventy-two healthy travellers going to Mexico or Guatemala were studied in a prospective, randomised, placebo-controlled trial. The primary outcome was a vaccine preventable outcome (VPO), defined as an episode of ETEC diarrhoea with an ETEC organism producing heat labile toxin (LT) or CF homologous with the vaccine, without other known causes. The vaccine was safe and stimulated anti-heat labile toxin antibodies. There was a significant decrease in more severe VPO episodes (PE=77%, p=0.039) as defined by symptoms that interfered with daily activities or more than five loose stools in a day, although the total number of VPO events did not differ significantly in the vaccine and placebo groups. We conclude that the new oral ETEC vaccine reduces the rate of more severe episodes of traveller's diarrhoea (TD) due to VPO-ETEC, but it did not reduce the overall rate of ETEC diarrhoea or of travellers' diarrhoea due to other causes.
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Affiliation(s)
- David A Sack
- Vaccine Testing Unit, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA.
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36
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Liu J, Sun Y, Feng SZ. [Construction and immunization of a enterohemorrhagic Escherichia coli O157 attenuated]. Sheng Wu Gong Cheng Xue Bao 2007; 23:211-7. [PMID: 17460890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important pathogen. One of the important virulence traits of EHEC O157:H7 is the capacity to produce attaching and effacing (A/E) lesions on enterocyte. This property encoded by a pathogenicity island termed the locus of enterocyte effacement (LEE). LEE contains ler (LEE-encoded regulator) gene. The product of ler is a central up-regulator of many virulence genes of the LEE. Another important virulence factor of EHEC O157: H7 is Shiga toxin (Stx), encoded by a prophage integrated into the chromosome of O157:H7. In order to obtain an attenuated vaccine candidate, a ler deletion mutant of O157: H7 was constructed by use of suicide vector pCVD442. Meanwhile, due to potential instability of the prophage carrying the stx gene, the prophage was cured with serial passages of bacteria and confirmed by PCR and DNA sequencing. A ler/stx deletion mutant of EHEC O157:H7 was constructed, termed as O157:H7(deltaler/deltastx). The cultural supernatant of O157 ler/stx deletion mutant was inoculated in vero cell culture, and the result indicating that O157 ler/stx deletion mutant lost the toxigenicity to vero cell. Test group and control group of mice were orogstrically inoculated with the O157 ler/stx deletion mutant and the virulent strain O157:H7 EDL933, respectively. Mice were observed daily for clinical signs and weight changes. After inoculation of the deletion mutant, test group of mice (inoculated with O157:H7(deltaler/deltastx)) gained weight normally and experienced no clinical signs. In contrast, control group of mice (inoculated with O157: H7) exhibited weight loss and all died in four days. In another experiment, pregnant mice were orally vaccinated by O157:H7(deltaler/ deltastx) twice at interval of 14 days. Subsequently, the suckling mice were orally challenged with O157:H7 EDL933 at 7 days of age. The results showed that 78.34% of the sucking mice born by vaccinated mice were survival and 12.73% of the sucking mice born by non-vaccinated mice were survival. This study demonstrated that O157 ler/stx deletion mutant lost the toxigenicity to vero cell and to be safety to mice. Oral immunization can induce specific immune responses, and this mutant strain could be used as an attenuated vaccine candidate against EHEC O157.
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Affiliation(s)
- Jun Liu
- Institute of Animal Science, The Academy of Military Medical Science, Changchun 130062, China
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37
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Moravec T, Schmidt MA, Herman EM, Woodford-Thomas T. Production of Escherichia coli heat labile toxin (LT) B subunit in soybean seed and analysis of its immunogenicity as an oral vaccine. Vaccine 2007; 25:1647-57. [PMID: 17188785 DOI: 10.1016/j.vaccine.2006.11.010] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Revised: 10/30/2006] [Accepted: 11/02/2006] [Indexed: 11/16/2022]
Abstract
The B subunit of the heat labile toxin of enterotoxigenic Escherichia coli (LTB) was used as a model immunogen for production in soybean seed. LTB expression was directed to the endoplasmic reticulum (ER) of seed storage parenchyma cells for sequestration in de novo synthesized inert protein accretions derived from the ER. Pentameric LTB accumulated to 2.4% of the total seed protein at maturity and was stable in desiccated seed. LTB-soybean extracts administered orally to mice induced both systemic IgG and IgA, and mucosal IgA antibody responses, and was particularly efficacious when used in a parenteral prime-oral gavage boost immunization strategy. Sera from immunized mice blocked ligand binding in vitro and immunized mice exhibited partial protection against LT challenge. Moreover, soybean-expressed LTB stimulated the antibody response against a co-administered antigen by 500-fold. These results demonstrate the utility of soybean as an efficient production platform for vaccines that can be used for oral delivery.
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Affiliation(s)
- Tomas Moravec
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, United States
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38
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Melkebeek V, Verdonck F, Goddeeris BM, Cox E. Comparison of immune responses in parenteral FaeG DNA primed pigs boosted orally with F4 protein or reimmunized with the DNA vaccine. Vet Immunol Immunopathol 2007; 116:199-214. [PMID: 17331591 DOI: 10.1016/j.vetimm.2007.01.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 01/30/2007] [Accepted: 01/31/2007] [Indexed: 11/21/2022]
Abstract
We previously showed that an intradermal (i.d.) FaeG DNA prime (2x)-oral F4 protein boost immunization induces a systemic response and weakly primes a mucosal IgG response in pigs, especially when plasmid vectors encoding the A and B subunit of the E. coli thermo-labile enterotoxin (LT) are added to the DNA vaccine. In the present study, we evaluated whether addition of 1alpha,25-dihydroxyvitamin D(3) (vitD(3)) to the DNA vaccine could further enhance this mucosal priming and/or modulate the antibody response towards IgA. To further clarify priming of systemic and mucosal responses by the i.d. DNA vaccination, we firstly compared the localization of the F4-specific antibody response in pigs that were orally boosted with F4 to that in pigs that received a third i.d. DNA immunization and secondly evaluated cytokine mRNA expression profiles after i.d. DNA vaccination. The i.d. DNA prime (2x)-oral F4 boost immunization as well as the 3 i.d. DNA vaccinations induced mainly a systemic response, with a higher response observed following the heterologous protocol. Co-administration of vitD(3), and especially of the LT vectors, enhanced this response. Furthermore, only the heterologous immunization resulted in a weak mucosal priming, which appeared to require the presence of the LT vectors or vitD(3) as adjuvants. In addition, the LT vectors strongly enhanced the FaeG-specific lymphocyte proliferation and this was accompanied by the absence of a clear IL-10 response. However, despite two DNA immunizations in the presence of these adjuvants and an oral F4 boost, we failed to demonstrate the secretory IgA response needed to be protective against enterotoxigenic E. coli.
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MESH Headings
- Adhesins, Escherichia coli/genetics
- Adhesins, Escherichia coli/immunology
- Adjuvants, Immunologic/administration & dosage
- Administration, Oral
- Animals
- Antibodies, Bacterial/blood
- Antibody Specificity
- Antigens, Bacterial/administration & dosage
- Bacterial Toxins/genetics
- Bacterial Toxins/immunology
- Base Sequence
- Calcitriol/administration & dosage
- Cytokines/genetics
- DNA Primers/genetics
- Enterotoxins/genetics
- Enterotoxins/immunology
- Escherichia coli Proteins/administration & dosage
- Escherichia coli Proteins/genetics
- Escherichia coli Proteins/immunology
- Escherichia coli Vaccines/administration & dosage
- Escherichia coli Vaccines/genetics
- Escherichia coli Vaccines/immunology
- Fimbriae Proteins/administration & dosage
- Immunity, Mucosal
- Immunization, Secondary
- In Vitro Techniques
- Injections, Intradermal
- Lymph Nodes/immunology
- Lymphocyte Activation
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sus scrofa/immunology
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
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Affiliation(s)
- V Melkebeek
- Laboratory of Veterinary Immunology, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
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39
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Glenn GM, Villar CP, Flyer DC, Bourgeois AL, McKenzie R, Lavker RM, Frech SA. Safety and immunogenicity of an enterotoxigenic Escherichia coli vaccine patch containing heat-labile toxin: use of skin pretreatment to disrupt the stratum corneum. Infect Immun 2007; 75:2163-70. [PMID: 17261601 PMCID: PMC1865773 DOI: 10.1128/iai.01740-06] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcutaneous immunization allows safe delivery of native heat-labile enterotoxin (LT) from Escherichia coli via application of a simple patch. Physical disruption of the stratum corneum can improve the efficiency of delivery. In the current study, the stratum corneum was disrupted using an electrocardiogram prep pad prior to patch application. The effects were quantified using transepidermal water loss (TEWL) and were correlated with the immune responses. Sixty adults received 50 microg of LT from three lots of LT (20 adults per group) administered in a patch on days 0 and 21. The immunizations were well tolerated. There were no differences in the anti-LT immunoglobulin G (IgG) titers between the three LT lots; the seroconversion rate was 100%, and the mean anti-LT IgG titer was 12,185 enzyme-linked immunosorbent assay units (EU) (a 24-fold increase). TEWL measurements obtained at the time of the second immunization were found to correlate with the day 42 individual increases in the anti-LT IgG titer (r = 0.59, P < 0.001). In a comparative assessment of the immune responses, sera after an LT+ ST+ (E2447A) oral ETEC challenge, which induced moderate to severe diarrhea in 81% of the recipients, had anti-LT IgG titers of 3,245 EU (a 10.8-fold increase). Similarly, the anti-LT IgG titer after administration of an oral cholera toxin B subunit-containing cholera vaccine, which cross-reacts with LT and protects against LT and LT/heat-stable toxin ETEC disease in the field, was 6,741 EU (a 3.3-fold increase). This study confirmed that a well-tolerated regimen for stratum corneum disruption before vaccine patch application results in robust immunity comparable to natural immunity and vaccine-induced immunity and that the magnitude of stratum corneum disruption correlates with the immune response.
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Affiliation(s)
- Gregory M Glenn
- IOMAI Corporation, 20 Firstfield Road, Gaithersburg, MD 20878, USA.
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40
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Walker RI, Steele D, Aguado T. Analysis of strategies to successfully vaccinate infants in developing countries against enterotoxigenic E. coli (ETEC) disease. Vaccine 2006; 25:2545-66. [PMID: 17224212 DOI: 10.1016/j.vaccine.2006.12.028] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Accepted: 12/12/2006] [Indexed: 12/30/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is the most common bacterial cause of diarrhoea in the world, annually affecting up to 400,000,000 children under 5 years of age living in developing countries (DCs). Although ETEC possesses numerous antigens, the relatively conserved colonization factor (CF) antigens and the heat labile enterotoxin (LT) have been associated with protection and most vaccine candidates have exploited these antigens. A safe and effective vaccine against ETEC is a feasible goal as supported by the acquisition of protective immunity. The success of an ETEC vaccine targeting infants and children in DCs will depend on a combination of maximally antigenic vaccine preparations and regimens for their delivery which will produce optimal immune responses to these antigens. Vaccine candidates having a high priority for accelerated development and clinical testing for eventual use in infants would include inactivated ETEC or Shigella hybrids expressing ETEC antigens as well as attenuated ETEC strains which express the major CF antigens and LT toxin B-subunit, as well as attenuated Shigella, Vibrio cholerae and Salmonella typhi hybrids engineered to deliver antigens of ETEC. Candidates for an ETEC vaccine would have to meet the minimal requirement of providing at least 50% protection against severe disease in DCs during the first 2 years of life. The critical roadblock to achieving this goal has not been the science as much as the lack of a sufficiently funded and focused effort to bring it to realization. However, a Product Development Partnership to overcome this hurdle could accelerate the time lines towards when control of ETEC disease in DCs is substantially closer.
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Affiliation(s)
- Richard I Walker
- Division of Bacterial, Parasitic and Allergenic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, 1401 Rockville Pike, Rockville, MD 20851-1448, USA.
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41
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Landman WJM, Cornelissen RA. [Escherichia coli salpingitis and peritonitis in layer chickens: an overview]. Tijdschr Diergeneeskd 2006; 131:814-22. [PMID: 17263015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Escherichia coli can induce salpingitis and/or peritonitis, a major cause of mortality in layer hens, but also other localized and systemic infections. E. coli infections have also been described in turkeys, geese, and ducks and are thought to be the cause of significant economic losses. However little is known about the real economic impact of the disease in layer chickens. The pathogenesis of E. coli salpingitis and peritonitis has not been elucidated yet. Three routes of infection have been discussed in the literature: ascending faecal contamination from the cloaca, bacterial translocation from the respiratory tract (air sac and lungs) and bacterial translocation from the intestinal lumen. Only one study has reported the occurrence of ascending faecal contamination from the cloaca to the oviduct and subsequently to the peritoneum. Regarding bacterial translocation, the only models available are for mammals, and these have not been applied to chickens so far Animal models could prove valuable to elucidate the pathogenesis of E. coli-induced salpingitis and peritonitis, and for assessing the value of preventive and curative intervention strategies. Little is known about risk factors for E. coli salpingitis and peritonitis. In contrast to colibacillosis in broilers, recent research has failed to demonstrate an association between several pathogens of the respiratory tract and the occurrence of E. coli pathology in layer chickens. The distance between poultry farms and the hen density in the cages were recently proposed as important risk factors for outbreaks ofcolibacillosis in flocks of layer hens, while in the past hormonal factors were implicated. The latter is an area of research that deserves more attention. Several methods for the molecular typing of E. coli have been described and might prove useful to study the epidemiology ofE. coli outbreaks in poultry, about which little is known. The presumptive diagnosis E. coli salpingitis and peritonitis is rather simple to establish, based on the anamnesis, clinical symptoms, and macroscopic findings at post-mortem. However; bacteriological analysis is required to establish a definite diagnosis because other pathogens can also cause salpingitis and peritonitis in layer hens. Antibiotics, chosen on the basis of sensitivity testing and their pharmacokinetic properties can be used as therapy; however residues in eggs may occur. Autovaccines are often used as prevention because in practice effective protection is only achieved against homologous E. coli serotypes.
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42
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Qadri F, Ahmed F, Ahmed T, Svennerholm AM. Homologous and cross-reactive immune responses to enterotoxigenic Escherichia coli colonization factors in Bangladeshi children. Infect Immun 2006; 74:4512-8. [PMID: 16861637 PMCID: PMC1539597 DOI: 10.1128/iai.00474-06] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have studied homologous (HoM) and cross-reacting (CR) immunoglobulin A (IgA) antibody responses to colonization factors (CFs) in Bangladeshi children with diarrhea due to enterotoxigenic E. coli (ETEC) strains of the CF antigen I (CFA/I) group (CFA/I, n = 25; coli surface antigen 4 [CS4], n = 8; CS14, n = 11) and the CS5 group (CS5, n = 15; CS7, n = 8), respectively. The responses to the HoM, CR, and heterologous (HeT) CF antigens in each group of patient were studied and compared to that seen in healthy children (n = 20). In the CFA/I group (CFA/I and CS14), patients responded with antibody-secreting cell (ASC) responses to HoM CFs (geometric mean, 156 to 329 ASCs/10(6) peripheral blood mononuclear cells [PBMCs]) and to CR CFs ( approximately 15 to 38 ASCs/10(6) PBMCs) but least of all to the HeT CS5 antigen (2 to 4 ASCs/10(6) PBMCs). For the CS5 group of patients with ETEC (CS5 and CS7), likewise, responses to HoM CFs (230 to 372 ASCs/10(6) PBMCs) and CR CFs (27 to 676 ASCs/10(6) PBMCs) were seen, along with lower responses to the HeT CFA/I antigen (9 to 38 ASCs/10(6) PBMCs). Both groups of patients responded with CF-specific IgA antibodies to HoM and CR antigens in plasma but responded less to the HeT CFs. The responses in patients were seen very soon after the onset of diarrhea and peaked around 1 week after onset. Vaccinees who had received two doses of the oral, killed whole-cell ETEC vaccine (CF-BS-ETEC) responded with plasma IgA antibodies to CFA/I, a component of the vaccine, but also to the CR CS14 antigen, which was not included in the vaccine, showing that antibody responses can be stimulated by a CFA/I-containing ETEC vaccine to a CR-reacting antigen in individuals in countries where ETEC is endemic.
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Affiliation(s)
- Firdausi Qadri
- International Centre for Diarhoeal Disease Research, Bangladesh, Laboratory Sciences Division, GPO Box 128, Dhaka 1000, Bangladesh.
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Zhang J, Shi Z, Kong FK, Jex E, Huang Z, Watt JM, Van Kampen KR, Tang DCC. Topical application of Escherichia coli-vectored vaccine as a simple method for eliciting protective immunity. Infect Immun 2006; 74:3607-17. [PMID: 16714593 PMCID: PMC1479276 DOI: 10.1128/iai.01836-05] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
We report here that animals can be protected against lethal infection by Clostridium tetani cells and Bacillus anthracis spores following topical application of intact particles of live or gamma-irradiated Escherichia coli vectors overproducing tetanus and anthrax antigens, respectively. Cutaneous gammadeltaT cells were rapidly recruited to the administration site. Live E. coli cells were not found in nonskin tissues after topical application, although fragments of E. coli DNA were disseminated transiently. Evidence suggested that intact E. coli particles in the outer layer of skin may be disrupted by a gammadeltaT-cell-mediated innate defense mechanism, followed by the presentation of E. coli ligand-adjuvanted intravector antigens to the immune system and rapid degradation of E. coli components. The nonreplicating E. coli vector overproducing an exogenous immunogen may foster the development of a new generation of vaccines that can be manufactured rapidly and administered noninvasively in a wide variety of disease settings.
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Bozić F, Lacković G, Kovsca-Janjatović A, Smolec O, Valpotić I. Levamisole synergizes experimental F4ac+ Escherichia coli oral vaccine in stimulating ileal Peyer's patch T cells in weaned pigs. J Vet Pharmacol Ther 2006; 29:199-204. [PMID: 16669864 DOI: 10.1111/j.1365-2885.2006.00731.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Recent findings demonstrate that priming by levamisole of weaned pigs experimentally vaccinated against postweaning colibacillosis (PWC) contributes to immune protection from challenge-induced clinical disease through stimulation of the mesenteric lymph node cells that participate in cell-mediated immunity. With the objective of better understanding the mechanisms by which levamisole induces protective mucosal cell-mediated immune response to vaccination against PWC, it was tested whether the drug synergizes experimental F4ac+ Escherichia coli oral vaccine in stimulating T cells also in the jejunal lamina propria (JLP) and ileal Peyer's patch (IPP) upon virulent challenge. Commercial crossbred pigs weaned at 4 weeks were allocated into two equal groups. The experimental group was i.m. primed with levamisole at an immunostimulatory dose of 2.5 mg/kg once daily, for 3 consecutive days, and controls received saline. Both groups were vaccinated orally with the vaccinal E. coli strain on day 0 and challenged with the virulent E. coli strain 7 days later. All pigs were killed on postchallenge day 6. The results determined by immunophenotyping of isolated cells indicate that priming by levamisole of the vaccinated weaned pigs selectively recruited and activated T cells in the IPP, a lymphoid organ-generating B lymphocytes. The pig IPP is normally populated with up to 5% of CD3+ T cells and CD6 is an activation antigen expressed exclusively by T cells in swine. Therefore, a significantly higher number of CD3+ (P < 0.01) and CD6+ (P < 0.001) cells observed within the IPP follicles of the primed-vaccinated vs. unprimed-vaccinated challenge-infected pigs suggest enhanced T cell-mediated immunity in this B-cell compartment induced by the potentiating action of the drug and vaccine. The ability of levamisole to influence interaction between activated T cells and B cells in the IPP of primed-vaccinated weaned pigs, and the possibility that this interaction plays a role in regulating B-cell maturation within the IPP follicles, are discussed.
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Affiliation(s)
- F Bozić
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia.
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Wen SX, Teel LD, Judge NA, O’Brien AD. A plant-based oral vaccine to protect against systemic intoxication by Shiga toxin type 2. Proc Natl Acad Sci U S A 2006; 103:7082-7. [PMID: 16641102 PMCID: PMC1459021 DOI: 10.1073/pnas.0510843103] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Indexed: 12/21/2022] Open
Abstract
Hemolytic uremic syndrome, the leading cause of kidney failure in children, often follows infection with enterohemorrhagic Escherichia coli and is mediated by the Shiga type toxins, particularly type 2 (Stx2), produced by such strains. The challenge in protecting against this life-threatening syndrome is to stimulate an immune response at the site of infection while also protecting against Shiga intoxication at distal sites such as the kidney. As one approach to meeting this challenge, we sought to develop and characterize a prototypic orally delivered, plant-based vaccine against Stx2, an AB5 toxin. First, we genetically inactivated the Stx2 active A subunit gene and then optimized both subunit genes for expression in plants. The toxoid genes were then transformed into the Nicotiana tabacum (tobacco) cell line NT-1 by Agrobacterium tumefaciens-mediated transformation. Toxoid expression was detected in NT-1 cell extracts, and the assembly of the holotoxoid was confirmed. Finally, mice were immunized by feeding with the toxoid-expressing NT-1 cells or by parenteral immunization followed by oral vaccination (prime-boost strategy). The immunized mice produced Stx2-specific mucosal IgA and Stx2-neutralizing serum IgG. The protective efficacy of these responses was assessed by challenging the immunized mice with E. coli O91:H21 strain B2F1, an isolate that produces an activatable variant of Stx2 (Stx2d) and is lethal to mice. The oral immunization fully protected mice from the challenge. Results of this study demonstrated that a plant-based oral vaccine can confer protection against lethal systemic intoxication.
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Affiliation(s)
- Sharon X. Wen
- *Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799; and
| | - Louise D. Teel
- *Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799; and
| | - Nicole A. Judge
- Department of Biology, Augusta State University, 2500 Walton Way, Augusta, GA 30904-2200
| | - Alison D. O’Brien
- *Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799; and
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Zhu C, Ruiz-Perez F, Yang Z, Mao Y, Hackethal VL, Greco KM, Choy W, Davis K, Butterton JR, Boedeker EC. Delivery of heterologous protein antigens via hemolysin or autotransporter systems by an attenuated ler mutant of rabbit enteropathogenic Escherichia coli. Vaccine 2006; 24:3821-31. [PMID: 16098637 DOI: 10.1016/j.vaccine.2005.07.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In this report, we describe the use of an attenuated regulatory mutant of a rabbit enteropathogenic Escherichia coli (rEPEC) as a live vaccine vector to deliver heterologous protein antigens using two dedicated transport systems, a Salmonella autotransporter and the E. coli hemolysin apparatus. We previously reported that an isogeneic ler (LEE encoded regulator) mutant of rEPEC O103:H2 is attenuated and immunogenic in rabbits. We first evaluated the Salmonella autotransporter MisL containing the immunodominant B-cell epitope of the circumsporozoite protein from Plasmodium falciparum, (NANP)8, fused to the C-terminal translocator domain under the control of the constitutive Tac17 promoter. The rEPEC ler mutant was able to express and to translocate the (NANP)8 passenger peptide to the bacterial surface. We next investigated the delivery of Shiga toxin B subunit (Stx1B) from human enterohemorrhagic E. coli by the rEPEC ler mutant via the MisL autotransporter or the E. coli hemolysin secretion apparatus. The autotransporter and hemolysin plasmids expressed similar levels of Stx1B (30-40 ng/ml/OD600). Only 6% of Stx1B was found in the autotransporter supernatants; the rest was cell-associated, with a small fraction of the Stx1B surface-exposed as determined by immunofluorescence. In contrast, 88% of Stx1B was secreted into culture supernatants by the hemolysin secretion system. In an in vivo study, no significant protection was observed in rabbits inoculated with the ler mutant harboring the Stx1B-autotransporter plasmid following experimental challenge with RDEC-H19A, the prototype rEPEC containing an Stx-converting phage. In contrast, rabbits inoculated with the rEPEC ler mutant containing the Stx1B-hemolysin fusion were partially protected from RDEC-H19A infection as demonstrated by decreased weight loss (p<0.008) when compared to rabbits inoculated with the parent ler mutant. Our results suggest that attenuated rEPEC are capable of serving as vaccine vectors to express heterologous protein antigens from different cellular locations and deliver these antigens to the intestinal mucosa. With this system, secreted proteins may be more effective than cell-associated antigens in generating protection.
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MESH Headings
- Animals
- Bacterial Proteins/genetics
- Bacterial Proteins/immunology
- Bacterial Vaccines/administration & dosage
- Bacterial Vaccines/genetics
- Bacterial Vaccines/immunology
- Cell Membrane/chemistry
- Electrophoresis, Polyacrylamide Gel
- Epitopes, B-Lymphocyte/genetics
- Epitopes, B-Lymphocyte/immunology
- Epitopes, B-Lymphocyte/metabolism
- Escherichia coli/chemistry
- Escherichia coli/genetics
- Escherichia coli/immunology
- Escherichia coli Infections/pathology
- Escherichia coli Infections/prevention & control
- Escherichia coli Proteins/genetics
- Escherichia coli Proteins/immunology
- Escherichia coli Proteins/metabolism
- Escherichia coli Vaccines/administration & dosage
- Escherichia coli Vaccines/genetics
- Escherichia coli Vaccines/immunology
- Feces/microbiology
- Genetic Vectors
- Hemolysin Proteins
- Immunity, Mucosal
- Membrane Transport Proteins/genetics
- Membrane Transport Proteins/immunology
- Plasmids
- Plasmodium falciparum/immunology
- Protein Transport
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Rabbits
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/metabolism
- Shiga Toxin 1/genetics
- Shiga Toxin 1/immunology
- Shiga Toxin 1/metabolism
- Trans-Activators/genetics
- Vaccines, Attenuated/administration & dosage
- Vaccines, Attenuated/genetics
- Vaccines, Attenuated/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Chengru Zhu
- Center for Vaccine Development, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
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Abstract
Shigella and enterotoxigenic Escherichia coli continue to be significant causes of diarrheal disease in infants and young children in developing countries as well as prevalent agents of traveler's diarrhea. A vaccine which provides protection against disease caused by both pathogens would serve common at-risk populations. Such a vaccine would require inclusion of multiple Shigella strains as well as multiple ETEC antigens. The use of attenuated strains of Shigella as live vectors for the expression of ETEC antigens is one strategy for the development of such a multivalent vaccine. Live attenuated strains of S. flexneri 2a, S. sonnei and S. dysenteriae 1 containing deletions in guaBA biosynthetic pathway genes as well as in genes encoding enterotoxins, were constructed. Each strain was subsequently used as a live vector for the expression of one or two critical ETEC antigens. The resulting three Shigella derivative strains were tested for immunogenicty and protective capacity alone or as mixtures in the guinea pig model. S. flexneri strain CVD 1208(pCFA/I-CS3), S. sonnei strain CVD 1233(pCS4-LThK63) and S. dysenteriae 1 strain CVD 1252(pCS2) were able to elicit serum and mucosal antibody responses against the live vector as well as the guest ETEC antigens. Vaccination with combinations of two or three of these strains was able to elicit specific immune responses against each live vector as well as each ETEC antigen represented in the mixture. These studies demonstrate the potential of the use of mixtures of live Shigella derivatives expressing ETEC antigens to serve as an immunogenic multivalent vaccine.
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MESH Headings
- Animals
- Antibodies, Bacterial/blood
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Disease Models, Animal
- Dysentery, Bacillary/immunology
- Escherichia coli/immunology
- Escherichia coli Infections/immunology
- Escherichia coli Proteins/genetics
- Escherichia coli Proteins/immunology
- Escherichia coli Vaccines/administration & dosage
- Escherichia coli Vaccines/immunology
- Fimbriae Proteins/genetics
- Fimbriae Proteins/immunology
- Gene Deletion
- Guinea Pigs
- Immunity, Mucosal
- Immunoglobulin A/blood
- Immunoglobulin G/blood
- Keratoconjunctivitis/prevention & control
- Shigella Vaccines/administration & dosage
- Shigella Vaccines/immunology
- Shigella dysenteriae/immunology
- Shigella flexneri/immunology
- Shigella sonnei/immunology
- Vaccines, Attenuated/administration & dosage
- Vaccines, Attenuated/genetics
- Vaccines, Attenuated/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Eileen M Barry
- Center for Vaccine Development, University of Maryland, Baltimore, 685 West Baltimore Street, MD 21201, USA.
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Carpenter CM, Hall ER, Randall R, McKenzie R, Cassels F, Diaz N, Thomas N, Bedford P, Darsley M, Gewert C, Howard C, Sack RB, Sack DA, Chang HS, Gomes G, Bourgeois AL. Comparison of the antibody in lymphocyte supernatant (ALS) and ELISPOT assays for detection of mucosal immune responses to antigens of enterotoxigenic Escherichia coli in challenged and vaccinated volunteers. Vaccine 2006; 24:3709-18. [PMID: 16153753 DOI: 10.1016/j.vaccine.2005.07.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In the present study we compared the ELISPOT and antibody in lymphocyte supernatants (ALS) assays as surrogate measures of mucosal immunity. In separate studies, 20 inpatient volunteers received oral doses of 6 x 10(8) or 4 x 10(9)cfu of ETEC strain E24377A (LT+, ST+, CS1+, CS3+) and 20 subjects received 1 (n = 9) or 2 (n = 11) oral doses of the attenuated ETEC vaccine, PTL-003 expressing CFA/II (CS1+ and CS3+) (2 x 10(9)cfu/dose). Peripheral blood mononuclear cells (PBMCs) from all subjects were assayed for anti-colonization factor or toxin-specific IgA antibody responses using the ALS and ELISPOT procedures. ALS responses were measured using a standard ELISA, as well as by time-resolved fluorescence (TRF). Following challenge with E24377A, significant anti-CS3, CS1 and LT ALS responses were detected in the lymphocyte supernatants of 75-95% of the subjects. A similar proportion (75%) of subjects mounted an ALS response to CFA/II antigen after vaccination with the PTL-003 vaccine. Inter-assay comparisons between ALS and ELISPOT methods also revealed a high degree of correlation in both immunization groups. ALS sensitivity versus the ELISPOT assay for LT, CS3 and CS1-specific responses following challenge were 95%, 94% and 78%, respectively and 83% for the ALS response to CFA/II antigen after vaccination with PTL-003. Correlation coefficients for the LT and CS3 antigens were 0.94 (p<0.001) and 0.82 (p<0.001), respectively after challenge and 0.78 (p<0.001) after vaccination. The association between ALS and ELISPOT for the CS1 antigen was however, significant only when ALS supernatants were tested by TRF (r = 0.91, p<0.001). These results demonstrate the value and flexibility of the ALS assay as an alternative to ELISPOT for the measurement of mucosal immune responses to ETEC antigens, particularly when the complexities of ELISPOT may make it impractical to perform.
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Affiliation(s)
- C M Carpenter
- Center for Immunization Research, Department of International Health, Johns Hopkins University, Bloomberg School of Public Health, 624 N. Broadway, HH, Rm 205, Baltimore, MD 21205, USA
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Future directions for research on enterotoxigenic Escherichia coli vaccines for developing countries. Wkly Epidemiol Rec 2006; 81:97-104. [PMID: 16671213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
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50
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Byrd W, Cassels FJ. The encapsulation of enterotoxigenic Escherichia coli colonization factor CS3 in biodegradable microspheres enhances the murine antibody response following intranasal administration. Microbiology (Reading) 2006; 152:779-786. [PMID: 16514157 DOI: 10.1099/mic.0.28667-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to measure serum and mucosal antibody responses following intranasal administration of biodegradable poly(dl-lactide-co-glycolide) (PLGA) microspheres loaded with the CS3 colonization factor isolated from enterotoxigenic Escherichia coli (ETEC). The response was compared against that measured in mice similarly administered the native CS3 antigen and in mice co-administered, along with the CS3 antigen, a known mucosal adjuvant, the R192G mutant heat-labile enterotoxin (mLT). The integrity of the CS3 antigen released from the microspheres was maintained as determined by SDS-PAGE and immunoblotting. Native CS3 induced serum and mucosal (bronchoalveolar, small intestinal and faecal) IgG and IgA responses. The co-administration of the mLT mucosal adjuvant significantly enhanced (P<0·001) serum and mucosal antibody responses to the CS3 protein. Likewise, the CS3-loaded PLGA microspheres induced significantly greater (P<0·001) serum and mucosal antibody responses than native CS3, as well as inducing antibody responses superior to those of the CS3 plus mLT formulation. Following administration of CS3 plus mLT, the mice became distressed (loss of activity, increased huddling, ruffled fur), a situation not seen following administration of the CS3-loaded PLGA microspheres. The results in this trial show that the CS3-loaded PLGA microspheres when administered intranasally to mice caused no observable distress to the mice and significantly (P<0·001) enhanced the immunogenicity of the CS3 protein.
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Affiliation(s)
- Wyatt Byrd
- 18929 Fountain Hills Drive, Germantown, MD 20874, USA
- Department of Enteric Infections, Walter Reed Army Institute of Research, Silver Spring, MD 20910-7500, USA
| | - Frederick J Cassels
- Department of Enteric Infections, Walter Reed Army Institute of Research, Silver Spring, MD 20910-7500, USA
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