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Hajra D, Nair AV, Chakravortty D. Decoding the invasive nature of a tropical pathogen of concern: The invasive non-Typhoidal Salmonella strains causing host-restricted extraintestinal infections worldwide. Microbiol Res 2023; 277:127488. [PMID: 37716125 DOI: 10.1016/j.micres.2023.127488] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/18/2023]
Abstract
Invasive-Non-Typhoidal Salmonella (iNTS) are the major cause of health concern in the low-income, under-developed nations in Africa and Asia that lack proper sanitation facilities. Around 5% of the NTS cases give rise to invasive, extraintestinal diseases leading to focal infections like osteomyelitis, meningitis, osteoarthritis, endocarditis and neonatal sepsis. iNTS serovars like S. Typhimurium, S. Enteritidis, S. Dublin, S. Choleraesuis show a greater propensity to become invasive than others which hints at the genetic basis of their emergence. The major risk factors attributing to the invasive diseases include immune-compromised individuals having co-infection with malaria or HIV, or suffering from malnutrition. The rampant use of antibiotics leading to the emergence of multi-drug resistant strains poses a great challenge in disease management. An extensive understanding of the iNTS pathogenesis and its epidemiology will open up avenues for the development of new vaccination and therapeutic strategies to restrict the spread of this neglected disease.
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Affiliation(s)
- Dipasree Hajra
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
| | - Abhilash Vijay Nair
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
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Elias SC, Muthumbi E, Mwanzu A, Wanjiku P, Mutiso A, Simon R, MacLennan CA. Complementary measurement of nontyphoidal Salmonella-specific IgG and IgA antibodies in oral fluid and serum. Heliyon 2023; 9:e12071. [PMID: 36704288 PMCID: PMC9871079 DOI: 10.1016/j.heliyon.2022.e12071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 10/07/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
Objectives Immuno-epidemiological studies of orally acquired, enteric pathogens such as nontyphoidal Salmonella (NTS) often focus on serological measures of immunity, ignoring potentially relevant oral mucosal responses. In this study we sought to assess the levels and detectability of both oral fluid and serum IgG and IgA to NTS antigens, in endemic and non-endemic populations. Methods IgG and IgA antibodies specific for Salmonella Typhimurium and Salmonella Enteritidis O antigen and phase 1 flagellin were assessed using Enzyme Linked Immunosorbent Assay (ELISA). Paired oral fluid and serum samples were collected from groups of 50 UK adults, Kenyan adults and Kenyan infants. Additionally, oral fluid alone was collected from 304 Kenyan individuals across a range of ages. Results Antigen-specific IgG and IgA was detectable in the oral fluid of both adults and infants. Oral fluid antibody increased with age, peaking in adulthood for both IgG and IgA but a separate peak was also observed for IgA in infants. Oral fluid and serum responses correlated for IgG but not IgA. Despite standardised collection the relationship between oral fluid volume and antibody levels varied with age and country of origin. Conclusions Measurement of NTS-specific oral fluid antibody can be used to complement measurement of serum antibody. For IgA in particular, oral fluid may offer insights into how protective immunity to NTS changes as individuals transition with age, from maternal to acquired systemic and mucosal immunity. This may prove useful in helping to guide future vaccine design.
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Affiliation(s)
- Sean C. Elias
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, UK
- Corresponding author.
| | - Esther Muthumbi
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- London School of Hygiene & Tropical Medicine, UK
| | - Alfred Mwanzu
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Agnes Mutiso
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
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Ji HJ, Jang AY, Song JY, Ahn KB, Han SH, Bang SJ, Jung HK, Hur J, Seo HS. Development of Live Attenuated Salmonella Typhimurium Vaccine Strain Using Radiation Mutation Enhancement Technology (R-MET). Front Immunol 2022; 13:931052. [PMID: 35898510 PMCID: PMC9310569 DOI: 10.3389/fimmu.2022.931052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
Salmonella enterica is a leading cause of food-borne diseases in humans worldwide, resulting in severe morbidity and mortality. They are carried asymptomatically in the intestine or gallbladder of livestock, and are transmitted predominantly from animals to humans via the fecal-oral route. Thus, the best preventive strategy is to preemptively prevent transmission to humans by vaccinating livestock. Live attenuated vaccines have been mostly favored because they elicit both cellular and humoral immunity and provide long-term protective immunity. However, developing these vaccines is a laborious and time-consuming process. Therefore, most live attenuated vaccines have been mainly used for phenotypic screening using the auxotrophic replica plate method, and new types of vaccines have not been sufficiently explored. In this study, we used Radiation-Mutation Enhancement Technology (R-MET) to introduce a wide variety of mutations and attenuate the virulence of Salmonella spp. to develop live vaccine strains. The Salmonella Typhimurium, ST454 strain (ST WT) was irradiated with Cobalt60 gamma-irradiator at 1.5 kGy for 1 h to maximize the mutation rate, and attenuated daughter colonies were screened using in vitro macrophage replication capacity and in vivo mouse infection assays. Among 30 candidates, ATOMSal-L6, with 9,961-fold lower virulence than the parent strain (ST454) in the mouse LD50 model, was chosen. This vaccine candidate was mutated at 71 sites, and in particular, lost one bacteriophage. As a vaccine, ATOMSal-L6 induced a Salmonella-specific IgG response to provide effective protective immunity upon intramuscular vaccination of mice. Furthermore, when mice and sows were orally immunized with ATOMSal-L6, we found a strong protective immune response, including multifunctional cellular immunity. These results indicate that ATOMSal-L6 is the first live vaccine candidate to be developed using R-MET, to the best of our knowledge. R-MET can be used as a fast and effective live vaccine development technology that can be used to develop vaccine strains against emerging or serotype-shifting pathogens.
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Affiliation(s)
- Hyun Jung Ji
- Research Division for Radiation Science, Korea Atomic Energy Research Institute, Jeongeup, South Korea
- Department of Oral Microbiology and Immunology, and Dental Research Institute (DRI), School of Dentistry, Seoul National University, Seoul, South Korea
| | - A-Yeung Jang
- Department of Internal Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Joon Young Song
- Department of Internal Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Ki Bum Ahn
- Research Division for Radiation Science, Korea Atomic Energy Research Institute, Jeongeup, South Korea
| | - Seung Hyun Han
- Department of Oral Microbiology and Immunology, and Dental Research Institute (DRI), School of Dentistry, Seoul National University, Seoul, South Korea
| | - Seok Jin Bang
- Research and Development Center, HONGCHEON CTCVAC Co., Ltd., Hongcheon, South Korea
| | - Ho Kyoung Jung
- Research and Development Center, HONGCHEON CTCVAC Co., Ltd., Hongcheon, South Korea
| | - Jin Hur
- Department of Veterinary Public Health, College of Veterinary Medicine, Jeonbuk National University, Iksan, South Korea
- *Correspondence: Jin Hur, ; Ho Seong Seo,
| | - Ho Seong Seo
- Research Division for Radiation Science, Korea Atomic Energy Research Institute, Jeongeup, South Korea
- Department of Radiation Science, University of Science and Technology, Daejeon, South Korea
- *Correspondence: Jin Hur, ; Ho Seong Seo,
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Abstract
Polysaccharides are often the most abundant antigens found on the extracellular surfaces of bacterial cells. These polysaccharides play key roles in interactions with the outside world, and for many bacterial pathogens, they represent what is presented to the human immune system. As a result, many vaccines have been or currently are being developed against carbohydrate antigens. In this review, we explore the diversity of capsular polysaccharides (CPS) in Salmonella and other selected bacterial species and explain the classification and function of CPS as vaccine antigens. Despite many vaccines being developed using carbohydrate antigens, the low immunogenicity and the diversity of infecting strains and serovars present an antigen formulation challenge to manufacturers. Vaccines tend to focus on common serovars or have changing formulations over time, reflecting the trends in human infection, which can be costly and time-consuming. We summarize the approaches to generate carbohydrate-based vaccines for Salmonella, describe vaccines that are in development and emphasize the need for an effective vaccine against non-typhoidal Salmonella strains.
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Andersson DI, Balaban NQ, Baquero F, Courvalin P, Glaser P, Gophna U, Kishony R, Molin S, Tønjum T. Antibiotic resistance: turning evolutionary principles into clinical reality. FEMS Microbiol Rev 2020; 44:171-188. [PMID: 31981358 DOI: 10.1093/femsre/fuaa001] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 01/24/2020] [Indexed: 02/06/2023] Open
Abstract
Antibiotic resistance is one of the major challenges facing modern medicine worldwide. The past few decades have witnessed rapid progress in our understanding of the multiple factors that affect the emergence and spread of antibiotic resistance at the population level and the level of the individual patient. However, the process of translating this progress into health policy and clinical practice has been slow. Here, we attempt to consolidate current knowledge about the evolution and ecology of antibiotic resistance into a roadmap for future research as well as clinical and environmental control of antibiotic resistance. At the population level, we examine emergence, transmission and dissemination of antibiotic resistance, and at the patient level, we examine adaptation involving bacterial physiology and host resilience. Finally, we describe new approaches and technologies for improving diagnosis and treatment and minimizing the spread of resistance.
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Affiliation(s)
- Dan I Andersson
- Department of Medical Biochemistry and Microbiology, University of Uppsala, BMC, Husargatan 3, 75237, Uppsala, Sweden
| | - Nathalie Q Balaban
- The Racah Institute of Physics, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Jerusalem, Israel
| | - Fernando Baquero
- Department of Microbiology, Ramón y Cajal Health Research Institute, Ctra. Colmenar Viejo Km 9,100 28034 - Madrid, Madrid, Spain
| | - Patrice Courvalin
- French National Reference Center for Antibiotics, Institut Pasteur, 25-28 Rue du Dr Roux, 75015 Paris, Paris, France
| | - Philippe Glaser
- Ecology and Evolution of Antibiotic Resistance, Institut Pasteur, 25-28 Rue du Dr Roux, 75015 Paris, Paris, France
| | - Uri Gophna
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, 121 Jack Green building, Tel-Aviv University, Ramat-Aviv, 6997801, Tel Aviv, Israel
| | - Roy Kishony
- Faculty of Biology, The Technion, Technion City, Haifa 3200003, Haifa, Israel
| | - Søren Molin
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet Building 220 2800 Kgs.Lyngby, Lyngby, Denmark
| | - Tone Tønjum
- Department of Microbiology, University of Oslo, OUS HF Rikshospitalet Postboks 4950 Nydalen 0424 Oslo, Oslo, Norway.,Oslo University Hospital, P. O. Box 4950 Nydalen N-0424 Oslo, Oslo, Norway
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Ahmed A, Akhade AS, Qadri A. Accessibility of O Antigens Shared between Salmonella Serovars Determines Antibody-Mediated Cross-Protection. THE JOURNAL OF IMMUNOLOGY 2020; 205:438-446. [PMID: 32540995 DOI: 10.4049/jimmunol.1900624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 05/05/2020] [Indexed: 11/19/2022]
Abstract
Pathogenic Salmonella serovars produce clinical manifestations ranging from systemic infection typhoid to invasive nontyphoidal Salmonella disease in humans. These serovars share a high degree of homology at the genome and the proteome level. However, whether infection or immunization with one serovar provides protection against other serovars has not been well studied. We show in this study that immunization of mice with live typhoidal serovar, Salmonella Typhi, generates cross-reactive immune responses, which provide far greater resistance against challenge with nontyphoidal serovar Salmonella Enteritidis than with another nontyphoidal serovar, Salmonella Typhimurium. Splenic T cells from these immunized mice produced similar levels of IL-2 and IFN-γ upon ex vivo stimulation with Ags prepared from S Enteritidis and S Typhimurium. In contrast, Abs against S Typhi interacted with live intact S Enteritidis but did not bind intact S Typhimurium. These pathogen-reactive Abs were largely directed against oligosaccharide (O)-antigenic determinant of LPS that S Typhi shares with S Enteritidis. Abs against the O determinant, which S Typhi shares with S Typhimurium, were present in the sera of immunized mice but did not bind live intact Salmonella because of surface inaccessibility of this determinant. Similar accessibility-regulated interaction was seen with Abs generated against S Typhimurium and S Enteritidis. Our results suggest that the ability of protective Abs elicited with one Salmonella serovar to engage with and consequently provide protection against another Salmonella serovar is determined by the accessibility of shared O Ags. These findings have significant and broader implications for immunity and vaccine development against pathogenic Salmonellae.
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Affiliation(s)
- Anees Ahmed
- Hybridoma Laboratory, National Institute of Immunology, New Delhi 110067, India
| | - Ajay Suresh Akhade
- Hybridoma Laboratory, National Institute of Immunology, New Delhi 110067, India
| | - Ayub Qadri
- Hybridoma Laboratory, National Institute of Immunology, New Delhi 110067, India
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Zhi Y, Lin SM, Ahn KB, Ji HJ, Guo HC, Ryu S, Seo HS, Lim S. ptsI gene in the phosphotransfer system is a potential target for developing a live attenuated Salmonella vaccine. Int J Mol Med 2020; 45:1327-1340. [PMID: 32323733 PMCID: PMC7138283 DOI: 10.3892/ijmm.2020.4505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 01/07/2020] [Indexed: 11/15/2022] Open
Abstract
Salmonella enterica serovar Typhimurium causes invasive non-typhoidal Salmonella diseases in animals and humans, resulting in a high mortality rate and huge economic losses globally. As the prevalence of antibiotic-resistant Salmonella has been increasing, vaccination is thought to be the most effective and economical strategy to manage salmonellosis. The present study aimed to investigate whether dysfunction in the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS), which is critical for carbon uptake and survival in macrophages, may be adequate to generate Salmonella-attenuated vaccine strains. A Salmonella strain (KST0555) was generated by deleting the ptsI gene from the PTS and it was revealed that this auxotrophic mutant was unable to efficiently utilize predominant carbon sources during infection (glucose and glycerol), reduced its invasion and replication capacity in macrophages, and significantly (P=0.0065) lowered its virulence in the setting of a mouse colitis model, along with a substantially decreased intestinal colonization and invasiveness compared with its parent strain. The reverse transcription-quantitative PCR results demonstrated that the virulence genes in Salmonella pathogenicity island-1 (SPI-1) and -2 (SPI-2) and the motility of KST0555 were all downregulated compared with its parent strain. Finally, it was revealed that when mice were immunized orally with live KST0555, Salmonella-specific humoral and cellular immune responses were effectively elicited, providing protection against Salmonella infection. Thus, the present promising data provides a strong rationale for the advancement of KST0555 as a live Salmonella vaccine candidate and ptsI as a potential target for developing a live attenuated bacterial vaccine strain.
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Affiliation(s)
- Yong Zhi
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Shun Mei Lin
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Ki Bum Ahn
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Hyun Jung Ji
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Hui-Chen Guo
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730049, P.R. China
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
| | - Ho Seong Seo
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Sangyong Lim
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
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Effective mucosal live attenuated Salmonella vaccine by deleting phosphotransferase system component genes ptsI and crr. J Microbiol 2018; 57:64-73. [PMID: 30552632 DOI: 10.1007/s12275-019-8416-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/20/2018] [Accepted: 10/02/2018] [Indexed: 12/21/2022]
Abstract
Salmonella enterica is a major human pathogen that causes invasive non-typhoidal Salmonellosis (iNTS), resulting in significant morbidity and mortality. Although a number of pre-clinical and clinical studies have reported on the feasibility of developing a safe and effective vaccine against iNTS, there have been no licensed Salmonella vaccines available to protect against NTS strains. Vaccine formulations of highest priority for NTS are live attenuated vaccines, which can elicit effective induction of intestinal mucosal and intracellular bacteria-specific cell mediated immune responses. Since glucose is crucial for intracellular survival and replication in host cells, we constructed strains with mutations in components of the glucose uptake system, called the phosphotransferase system (PTS), and compared the relative virulence and immune responses in mice. In this study, we found that the strain with mutations in both ptsI and crr (KST0556) was the most attenuated strain among the tested strains, and proved to be highly effective in inducing a mucosal immune response that can protect against NTS infections in mice. Thus, we suggest here that KST0556 (ΔptsIΔcrr) is a potential live vaccine candidate for NTS, and may also be a candidate for a live delivery vector for heterologous antigens. Moreover, since PTS is a well-conserved glucose transporter system in both Gramnegative and Gram-positive bacteria, the ptsI and crr genes may be potential targets for creating live bacterial vectors or vaccine strains.
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Pennington SH, Ferreira DM, Reiné J, Nyirenda TS, Thompson AL, Hancock CA, Wright AD, Gordon SB, Gordon MA. Longevity of duodenal and peripheral T-cell and humoral responses to live-attenuated Salmonella Typhi strain Ty21a. Vaccine 2018; 36:4725-4733. [PMID: 29958737 PMCID: PMC6041722 DOI: 10.1016/j.vaccine.2018.05.114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/08/2018] [Accepted: 05/31/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND We have previously demonstrated that polyfunctional Ty21a-responsive CD4+ and CD8+ T cells are generated at the duodenal mucosa 18 days following vaccination with live-attenuated S. Typhi (Ty21a). The longevity of cellular responses has been assessed in peripheral blood, but persistence of duodenal responses is unknown. METHODS We vaccinated eight healthy adults with Ty21a. Peripheral blood and duodenal samples were acquired after a median of 1.5 years (ranging from 1.1 to 3.7 years) following vaccination. Cellular responses were assessed in peripheral blood and at the duodenal mucosa by flow cytometry. Levels of IgG and IgA were also assessed in peripheral blood by enzyme-linked immunosorbent assay. RESULTS No T-cell responses were observed at the duodenal mucosa, but CD4+ T-cell responses to Ty21a and FliC were observed in peripheral blood. Peripheral anti-lipopolysaccharide IgG and IgA responses were also observed. Early immunoglobulin responses were not associated with the persistence of long-term cellular immune responses. CONCLUSIONS Early T-cell responses which we have previously observed at the duodenal mucosa 18 days following oral vaccination with Ty21a could not be detected at a median of 1.5 years. Peripheral responses were observed at this time. Immunoglobulin responses observed shortly after vaccination were not associated with cellular immune responses at 1.5 years, suggesting that the persistence of cellular immunity is not associated with the strength of the initial humoral response to vaccination.
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Affiliation(s)
- Shaun H Pennington
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, UK; Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Daniela M Ferreira
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Jesús Reiné
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Tonney S Nyirenda
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Queen Elizabeth Central Hospital, Malawi
| | - Ameeka L Thompson
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, UK; Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Carole A Hancock
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Angela D Wright
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Stephen B Gordon
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Queen Elizabeth Central Hospital, Malawi
| | - Melita A Gordon
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Queen Elizabeth Central Hospital, Malawi.
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Stable Chromosomal Expression of Shigella flexneri 2a and 3a O-Antigens in the Live Salmonella Oral Vaccine Vector Ty21a. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00181-17. [PMID: 29046309 DOI: 10.1128/cvi.00181-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 09/28/2017] [Indexed: 11/20/2022]
Abstract
We have been exploring the use of the live attenuated Salmonella enterica serovar Typhi Ty21a vaccine strain as a versatile oral vaccine vector for the expression and delivery of multiple foreign antigens, including Shigella O-antigens. In this study, we separately cloned genes necessary for the biosynthesis of the Shigella flexneri serotype 2a and 3a O-antigens, which have been shown to provide broad cross-protection to multiple disease-predominant S. flexneri serotypes. The cloned S. flexneri 2a rfb operon, along with bgt and gtrII, contained on the SfII bacteriophage, was sufficient in Ty21a to express the heterologous S. flexneri 2a O-antigen containing the 3,4 antigenic determinants. Further, this rfb operon, along with gtrA, gtrB, and gtrX contained on the Sfx bacteriophage and oac contained on the Sf6 bacteriophage, was sufficient to express S. flexneri 3a O-antigen containing the 6, 7, and 8 antigenic determinants. Ty21a, with these plasmid-carried or chromosomally inserted genes, demonstrated simultaneous and stable expression of homologous S Typhi O-antigen plus the heterologous S. flexneri O-antigen. Candidate Ty21a vaccine strains expressing heterologous S. flexneri 2a or 3a lipopolysaccharide (LPS) elicited significant serum antibody responses against both homologous S Typhi and heterologous Shigella LPS and protected mice against virulent S. flexneri 2a or 3a challenges. These new S. flexneri 2a and 3a O-antigen-expressing Ty21a vaccine strains, together with our previously constructed Ty21a strains expressing Shigella sonnei or Shigella dysenteriae 1 O-antigens, have the potential to be used together for simultaneous protection against the predominant causes of shigellosis worldwide as well as against typhoid fever.
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Constructing novel chimeric DNA vaccine against Salmonella enterica based on SopB and GroEL proteins: an in silico approach. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2017. [DOI: 10.1007/s40005-017-0360-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Pakkanen SH, Kantele JM, Rombo L, Kantele A. Specific and Cross-reactive Plasmablast Response in Humans after Primary and Secondary Immunization with Vi Capsular Polysaccharide Typhoid Vaccine. Scand J Immunol 2017; 86:207-215. [DOI: 10.1111/sji.12583] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 06/27/2017] [Indexed: 11/28/2022]
Affiliation(s)
- S. H. Pakkanen
- Department of Bacteriology and Immunology; University of Helsinki; Helsinki Finland
| | - J. M. Kantele
- Occupational Health and Environmental Medicine; Department of Public Health; University of Turku; Turku Finland
| | - L. Rombo
- Department of Medicine/Solna; Unit for Infectious Diseases; Karolinska Institute; Stockholm Sweden
- Centre for Clinical Research; Sörmland County Council; Eskilstuna Sweden
- Uppsala University; Uppsala Sweden
| | - A. Kantele
- Department of Bacteriology and Immunology; University of Helsinki; Helsinki Finland
- Department of Medicine/Solna; Unit for Infectious Diseases; Karolinska Institute; Stockholm Sweden
- Department of Medicine; Clinicum; University of Helsinki; Helsinki Finland
- Division of Infectious Diseases; Inflammation Center; University of Helsinki and Helsinki University Hospital; Helsinki Finland
- Aava Travel Clinic; Medical Centre Aava; Helsinki Finland
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Carreño JM, Perez-Shibayama C, Gil-Cruz C, Lopez-Macias C, Vernazza P, Ludewig B, Albrich WC. Evolution of Salmonella Typhi outer membrane protein-specific T and B cell responses in humans following oral Ty21a vaccination: A randomized clinical trial. PLoS One 2017; 12:e0178669. [PMID: 28570603 PMCID: PMC5453566 DOI: 10.1371/journal.pone.0178669] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/17/2017] [Indexed: 11/23/2022] Open
Abstract
Vaccination against complex pathogens such as typhoidal and non-typhoidal Salmonella requires the concerted action of different immune effector mechanisms. Outer membrane proteins (Omps) of Salmonella Typhi are potent immunogens, which elicit long-lasting and protective immunity. Here, we followed the evolution of S. Typhi OmpC and F-specific T and B cell responses in healthy volunteers after vaccination with the vaccine strain Ty21a. To follow humoral and cellular immune responses, pre- and post-vaccination samples (PBMC, serum and stool) collected from 15 vaccinated and 5 non-vaccinated individuals. Immunoglobulin levels were assessed in peripheral blood by enzyme-linked immunosorbent assay. B cell and T cell activation were analyzed by flow cytometry. We observed a significant increase of circulating antibody-secreting cells and maximal Omp-specific serum IgG titers at day 25 post vaccination, while IgA titers in stool peaked at day 60. Likewise, Omp-specific CD4+ T cells in peripheral blood showed the highest expansion at day 60 post vaccination, concomitant with a significant increase in IFN-γ and TNFα production. These results indicate that S. Typhi Omp-specific B cell responses and polyfunctional CD4+ T cell responses evolve over a period of at least two months after application of the live attenuated vaccine. Moreover, these findings underscore the potential of S. Typhi Omps as subunit vaccine components. Trial registration:ISRCTN18360696
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Affiliation(s)
- Juan Manuel Carreño
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | | | - Cristina Gil-Cruz
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Constantino Lopez-Macias
- Medical Research Unit on Immunochemistry (UIMIQ), Specialties Hospital, National Medical Centre “Siglo XXI”, Mexican Social Security Institute (IMSS), Mexico City, Mexico
| | - Pietro Vernazza
- Division of Infectious Diseases and Hospital Epidemiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Burkhard Ludewig
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
- * E-mail:
| | - Werner C. Albrich
- Division of Infectious Diseases and Hospital Epidemiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
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Holmgren J, Parashar UD, Plotkin S, Louis J, Ng SP, Desauziers E, Picot V, Saadatian-Elahi M. Correlates of protection for enteric vaccines. Vaccine 2017; 35:3355-3363. [DOI: 10.1016/j.vaccine.2017.05.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/04/2017] [Accepted: 05/03/2017] [Indexed: 12/26/2022]
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Salmonella enterica Serovar Typhi Lipopolysaccharide O-Antigen Modification Impact on Serum Resistance and Antibody Recognition. Infect Immun 2017; 85:IAI.01021-16. [PMID: 28167670 PMCID: PMC5364305 DOI: 10.1128/iai.01021-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 01/30/2017] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica serovar Typhi is a human-restricted Gram-negative bacterial pathogen responsible for causing an estimated 27 million cases of typhoid fever annually, leading to 217,000 deaths, and current vaccines do not offer full protection. The O-antigen side chain of the lipopolysaccharide is an immunodominant antigen, can define host-pathogen interactions, and is under consideration as a vaccine target for some Gram-negative species. The composition of the O-antigen can be modified by the activity of glycosyltransferase (gtr) operons acquired by horizontal gene transfer. Here we investigate the role of two gtr operons that we identified in the S. Typhi genome. Strains were engineered to express specific gtr operons. Full chemical analysis of the O-antigens of these strains identified gtr-dependent glucosylation and acetylation. The glucosylated form of the O-antigen mediated enhanced survival in human serum and decreased complement binding. A single nucleotide deviation from an epigenetic phase variation signature sequence rendered the expression of this glucosylating gtr operon uniform in the population. In contrast, the expression of the acetylating gtrC gene is controlled by epigenetic phase variation. Acetylation did not affect serum survival, but phase variation can be an immune evasion mechanism, and thus, this modification may contribute to persistence in a host. In murine immunization studies, both O-antigen modifications were generally immunodominant. Our results emphasize that natural O-antigen modifications should be taken into consideration when assessing responses to vaccines, especially O-antigen-based vaccines, and that the Salmonellagtr repertoire may confound the protective efficacy of broad-ranging Salmonella lipopolysaccharide conjugate vaccines.
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16
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Dharmasena MN, Osorio M, Filipova S, Marsh C, Stibitz S, Kopecko DJ. Stable expression ofShigella dysenteriaeserotype 1 O-antigen genes integrated into the chromosome of liveSalmonellaoral vaccine vector Ty21a. Pathog Dis 2016; 74:ftw098. [DOI: 10.1093/femspd/ftw098] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Pennington SH, Thompson AL, Wright AKA, Ferreira DM, Jambo KC, Wright AD, Faragher B, Gilmour JW, Gordon SB, Gordon MA. Oral Typhoid Vaccination With Live-Attenuated Salmonella Typhi Strain Ty21a Generates Ty21a-Responsive and Heterologous Influenza Virus-Responsive CD4+ and CD8+ T Cells at the Human Intestinal Mucosa. J Infect Dis 2016; 213:1809-19. [PMID: 26810369 PMCID: PMC4857474 DOI: 10.1093/infdis/jiw030] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 01/06/2016] [Indexed: 01/15/2023] Open
Abstract
Background. Oral vaccination with live-attenuated Salmonella Typhi strain Ty21a is modestly efficacious, but the mechanisms of protection are currently unknown. While humoral and cellular immune responses are well described in peripheral blood, the cellular response at the intestinal mucosa has never been directly assessed. Methods. We vaccinated healthy adults with Ty21a and assessed humoral and cellular immunity in vaccinated volunteers and controls after 18 days. Immunoglobulin levels were assessed in peripheral blood by an enzyme-linked immunosorbent assay. Cellular responses were assessed in peripheral blood and at the duodenal and colonic mucosa by flow cytometry. Results. We demonstrate the generation of Ty21a-responsive and heterologous influenza virus–responsive CD4+ and CD8+ T cells at the duodenal mucosa. All duodenal responses were consistently correlated, and no responses were observed at the colonic mucosa. Peripheral anti-lipopolysaccharide immunoglobulin G and immunoglobulin A responses were significantly correlated with duodenal responses. The assessment of integrin β7 expression intensity among peripheral and duodenal T-cell subsets revealed varied capacities for mucosal homing and residence. Conclusions. The breadth of duodenal cellular responses was not reflected peripherally. The direct evaluation of mucosal immune defense may yield functional correlates of protection and could provide insight into mechanisms that may be manipulated to enhance vaccine immunogenicity.
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Affiliation(s)
- Shaun H Pennington
- Department of Clinical Infection, Microbiology, and Immunology, Institute of Infection and Global Health, University of Liverpool Department of Clinical Sciences, Liverpool School of Tropical Medicine
| | - Ameeka L Thompson
- Department of Clinical Infection, Microbiology, and Immunology, Institute of Infection and Global Health, University of Liverpool Department of Clinical Sciences, Liverpool School of Tropical Medicine
| | - Adam K A Wright
- Department of Clinical Sciences, Liverpool School of Tropical Medicine
| | | | - Kondwani C Jambo
- Department of Clinical Sciences, Liverpool School of Tropical Medicine
| | - Angela D Wright
- Department of Clinical Sciences, Liverpool School of Tropical Medicine
| | - Brian Faragher
- Department of Clinical Sciences, Liverpool School of Tropical Medicine
| | - Jill W Gilmour
- International AIDS Vaccine Initiative, Human Immunology Laboratory, Imperial College, London, United Kingdom
| | - Stephen B Gordon
- Department of Clinical Sciences, Liverpool School of Tropical Medicine
| | - Melita A Gordon
- Department of Clinical Infection, Microbiology, and Immunology, Institute of Infection and Global Health, University of Liverpool
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Tennant SM, Levine MM. Live attenuated vaccines for invasive Salmonella infections. Vaccine 2015; 33 Suppl 3:C36-41. [PMID: 25902362 PMCID: PMC4469493 DOI: 10.1016/j.vaccine.2015.04.029] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/06/2015] [Accepted: 04/08/2015] [Indexed: 02/04/2023]
Abstract
Salmonella enterica serovar Typhi produces significant morbidity and mortality worldwide despite the fact that there are licensed Salmonella Typhi vaccines available. This is primarily due to the fact that these vaccines are not used in the countries that most need them. There is growing recognition that an effective invasive Salmonella vaccine formulation must also prevent infection due to other Salmonella serovars. We anticipate that a multivalent vaccine that targets the following serovars will be needed to control invasive Salmonella infections worldwide: Salmonella Typhi, Salmonella Paratyphi A, Salmonella Paratyphi B (currently uncommon but may become dominant again), Salmonella Typhimurium, Salmonella Enteritidis and Salmonella Choleraesuis (as well as other Group C Salmonella). Live attenuated vaccines are an attractive vaccine formulation for use in developing as well as developed countries. Here, we describe the methods of attenuation that have been used to date to create live attenuated Salmonella vaccines and provide an update on the progress that has been made on these vaccines.
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Affiliation(s)
- Sharon M Tennant
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Myron M Levine
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA.
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Bridge DR, Whitmire JM, Gilbreath JJ, Metcalf ES, Merrell DS. An enterobacterial common antigen mutant of Salmonella enterica serovar Typhimurium as a vaccine candidate. Int J Med Microbiol 2015; 305:511-22. [PMID: 26070977 DOI: 10.1016/j.ijmm.2015.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 05/15/2015] [Accepted: 05/26/2015] [Indexed: 11/19/2022] Open
Abstract
Due to increasing rates of invasive Salmonella enterica serovar Typhimurium infection, there is a need for an effective vaccine to prevent this disease. Previous studies showed that a mutation in the first gene of the Enterobacterial common antigen biosynthetic pathway, wecA, resulted in attenuation of S. Typhimurium in a murine model of salmonellosis. Furthermore, immunization with a wecA(-) strain protected against lethal challenge with the parental wild type S. Typhimurium strain. Herein, we examined whether the S. Typhimurium wecA(-) strain could also provide cross-protection against non-parental strains of S. Typhimurium and S. Enteritidis. We found that intraperitoneal immunization (IP) with S. Typhimurium SL1344 wecA(-) resulted in a significant increase in survival compared to control mice for all Salmonella challenge strains tested. Oral immunization with SL1344 wecA(-) also resulted in increased survival; however, protection was less significant than with intraperitoneal immunization. The increase in survival of SL1344 wecA(-) immunized mice was associated with a Salmonella-specific IgG antibody response. Furthermore, analysis of sera from IP and orally immunized animals revealed cross-reactive antibodies to numerous Salmonella isolates. Functional analysis of antibodies found within the sera from IP immunized animals revealed agglutination and opsonophagocytic activity against all tested O:4 Salmonella serovars. Together these results indicate that immunization with a S. Typhimurium wecA(-) strain confers protection against lethal challenge with wild type S. Typhimurium and S. Enteritidis and that immunization correlates with functional antibody production.
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Affiliation(s)
- Dacie R Bridge
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
| | - Jeannette M Whitmire
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
| | - Jeremy J Gilbreath
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
| | - Eleanor S Metcalf
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
| | - D Scott Merrell
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
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Pakkanen SH, Kantele JM, Savolainen LE, Rombo L, Kantele A. Specific and cross-reactive immune response to oral Salmonella Typhi Ty21a and parenteral Vi capsular polysaccharide typhoid vaccines administered concomitantly. Vaccine 2015; 33:451-8. [DOI: 10.1016/j.vaccine.2014.11.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 11/05/2014] [Accepted: 11/17/2014] [Indexed: 01/02/2023]
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Sztein MB, Salerno-Goncalves R, McArthur MA. Complex adaptive immunity to enteric fevers in humans: lessons learned and the path forward. Front Immunol 2014; 5:516. [PMID: 25386175 PMCID: PMC4209864 DOI: 10.3389/fimmu.2014.00516] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/03/2014] [Indexed: 01/26/2023] Open
Abstract
Salmonella enterica serovar Typhi (S. Typhi), the causative agent of typhoid fever, and S. Paratyphi A and B, causative agents of paratyphoid fever, are major public health threats throughout the world. Although two licensed typhoid vaccines are currently available, they are only moderately protective and immunogenic necessitating the development of novel vaccines. A major obstacle in the development of improved typhoid, as well as paratyphoid vaccines is the lack of known immunological correlates of protection in humans. Considerable progress has been made in recent years in understanding the complex adaptive host responses against S. Typhi. Although the induction of S. Typhi-specific antibodies (including their functional properties) and memory B cells, as well as their cross-reactivity with S. Paratyphi A and S. Paratyphi B has been shown, the role of humoral immunity in protection remains undefined. Cell mediated immunity (CMI) is likely to play a dominant role in protection against enteric fever pathogens. Detailed measurements of CMI performed in volunteers immunized with attenuated strains of S. Typhi have shown, among others, the induction of lymphoproliferation, multifunctional type 1 cytokine production, and CD8(+) cytotoxic T-cell responses. In addition to systemic responses, the local microenvironment of the gut is likely to be of paramount importance in protection from these infections. In this review, we will critically assess current knowledge regarding the role of CMI and humoral immunity following natural S. Typhi and S. Paratyphi infections, experimental challenge, and immunization in humans. We will also address recent advances regarding cross-talk between the host's gut microbiota and immunization with attenuated S. Typhi, mechanisms of systemic immune responses, and the homing potential of S. Typhi-specific B- and T-cells to the gut and other tissues.
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Affiliation(s)
- Marcelo B Sztein
- Department of Pediatrics, Center for Vaccine Development (CVD), University of Maryland School of Medicine , Baltimore, MD , USA
| | - Rosangela Salerno-Goncalves
- Department of Pediatrics, Center for Vaccine Development (CVD), University of Maryland School of Medicine , Baltimore, MD , USA
| | - Monica A McArthur
- Department of Pediatrics, Center for Vaccine Development (CVD), University of Maryland School of Medicine , Baltimore, MD , USA
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Dougan G, Baker S. Salmonella entericaSerovar Typhi and the Pathogenesis of Typhoid Fever. Annu Rev Microbiol 2014; 68:317-36. [DOI: 10.1146/annurev-micro-091313-103739] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Gordon Dougan
- The Wellcome Trust Sanger Institute, The Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom;
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Program, Oxford University, Clinical Research Unit, Ho Chi Minh City, Vietnam;
- Centre for Tropical Medicine, Oxford University, Oxford OX3 7FZ, United Kingdom
- The London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom
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23
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MacLennan CA, Martin LB, Micoli F. Vaccines against invasive Salmonella disease: current status and future directions. Hum Vaccin Immunother 2014; 10:1478-93. [PMID: 24804797 PMCID: PMC4185946 DOI: 10.4161/hv.29054] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Though primarily enteric pathogens, Salmonellae are responsible for a considerable yet under-appreciated global burden of invasive disease. In South and South-East Asia, this manifests as enteric fever caused by serovars Typhi and Paratyphi A. In sub-Saharan Africa, a similar disease burden results from invasive nontyphoidal Salmonellae, principally serovars Typhimurium and Enteritidis. The existing Ty21a live-attenuated and Vi capsular polysaccharide vaccines target S. Typhi and are not effective in young children where the burden of invasive Salmonella disease is highest. After years of lack of investment in new Salmonella vaccines, recent times have seen increased interest in the area led by emerging-market manufacturers, global health vaccine institutes and academic partners. New glycoconjugate vaccines against S. Typhi are becoming available with similar vaccines against other invasive serovars in development. With other new vaccines under investigation, including live-attenuated, protein-based and GMMA vaccines, now is an exciting time for the Salmonella vaccine field.
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Affiliation(s)
- Calman A MacLennan
- Novartis Vaccines Institute for Global Health; Siena, Italy; Medical Research Council Centre for Immune Regulation and Clinical Immunology Service; Institute of Biomedical Research, School of Immunity and Infection; College of Medicine and Dental Sciences; University of Birmingham; Birmingham, UK
| | - Laura B Martin
- Novartis Vaccines Institute for Global Health; Siena, Italy
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Abstract
Attenuated Salmonella vaccines can be administered orally to deliver recombinant antigens to mucosal surfaces inducing a protective immune response against a variety of targeted pathogens. A number of exciting new approaches and technologies for attenuated Salmonella vaccines have been developed recently. However, a disconnect remains between results obtained with mice in preclinical studies and results obtained in human clinical trials. This is due to an incomplete understanding of Salmonella Typhi interactions with human hosts and inadequate animal models available for study. In this review, the authors describe recent progress in identifying important differences underlying S. Typhi-host interactions, the development of novel approaches to vaccine design and six recent clinical trials evaluating Salmonella-vectored vaccines.
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Affiliation(s)
- Kenneth L Roland
- The Biodesign Institute, Arizona State University, 1001 S. McAllister Avenue, Tempe, AZ 85287-5401, USA
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25
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Pakkanen SH, Kantele JM, Herzog C, Kantele A. Cross-reactive immune response elicited by parenteral Vi polysaccharide typhoid vaccine against non-typhoid Salmonellae. Vaccine 2013; 32:544-51. [PMID: 24342246 DOI: 10.1016/j.vaccine.2013.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 10/13/2013] [Accepted: 12/02/2013] [Indexed: 01/15/2023]
Abstract
BACKGROUND Despite 155000 deaths and over 90 million cases - and the current emergence of antimicrobial resistance - no vaccines are available against non-typhoid Salmonellae (NTS). We recently presented immunological arguments for using the oral Salmonella Typhi Ty21a as surrogate vaccine against NTS strains: Ty21a elicits intestinal antibodies against typhoidal O-9,12 antigen, and numerous NTS strains share one or both of these structures with S. Typhi. The Vi polysaccharide vaccine can, presumably because of contaminating typhoidal lipopolysaccharide, also elicit a humoral response to O-9,12, although a lower one in magnitude than the Ty21a. In this study, the Vi vaccine was explored for cross-reactive immune response to various NTS strains, and compared to that elicited by the Ty21a vaccine. MATERIALS AND METHODS Volunteers immunized with the Vi polysaccharide (Typherix(®); n=25) were investigated for circulating plasmablasts secreting antibodies reactive with six NTS serotypes. The results were compared to those for 25 age- and gender-matched volunteers vaccinated with Ty21a (Vivotif(®)), as partly presented in our previous study. The cross-reactive plasmablasts elicited by the Vi vaccine were also analyzed for homing receptor expressions. RESULTS 49 out of 50 vaccinees showed a cross-reactive plasmablast response against S. Enteritidis sharing both O-9 and O-12 antigens with S. Typhi (mean: 95%CI 37: 19-55 and 363: 234-493 plasmablasts/10(6) PBMC in the Vi and the Ty21a group, respectively). The response against strains only sharing O-12 was weaker (22: 8-38 and 222: 105-338 against S. Typhimurium). Strains without typhoidal O-antigens generated no significant reactivity. The cross-reactive plasmablasts elicited by the Vi vaccine had systemic homing properties. CONCLUSIONS The Vi vaccine elicited an immune response cross-reactive with several NTS strains. This response was lower than that in Ty21a-vaccinated volunteers. The clinical significance of these responses deserves further research with respect to both gastrointestinal and invasive NTS (iNTS) disease.
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Affiliation(s)
- Sari H Pakkanen
- Department of Bacteriology and Immunology, Haartman Institute, POB 21, 00014 University of Helsinki, Helsinki, Finland; Department of Medicine, Division of Infectious Diseases, POB 348, 00029 Helsinki University Hospital, Helsinki, Finland.
| | - Jussi M Kantele
- Department of Medical Microbiology and Immunology, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland.
| | | | - Anu Kantele
- Department of Bacteriology and Immunology, Haartman Institute, POB 21, 00014 University of Helsinki, Helsinki, Finland; Department of Medicine, Division of Infectious Diseases, POB 348, 00029 Helsinki University Hospital, Helsinki, Finland; Institute of Clinical Medicine, Department of Medicine, POB 20, 00014 University of Helsinki, Helsinki, Finland.
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Yang Y, Wan C, Xu H, Wei H. Identification and characterization of OmpL as a potential vaccine candidate for immune-protection against salmonellosis in mice. Vaccine 2013; 31:2930-6. [PMID: 23643894 DOI: 10.1016/j.vaccine.2013.04.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 04/11/2013] [Accepted: 04/18/2013] [Indexed: 01/13/2023]
Abstract
Salmonella is gram-negative flagellated bacteria that can cause food and waterborne gastroenteritis and typhoid fever in humans. Despite the importance of Salmonella infections in human and animal health, the target antigens of Salmonella-specific immunity remain poorly defined, the effectiveness of the currently available vaccines is also limited. Outer membrane proteins (OMPs) of Salmonella have been considered possible candidates for conferring protection against salmonellosis. OMPs interface the cell with the environment, thus representing important potential vaccine candidate for pathogen infection. We showed that the outer membrane porin L (OmpL) is a transmembrane β barrel (TMBB) protein, which forms 12 transmembrane β-strands. OmpL of S. Typhimurium is highly immunogenic, OmpL could evoke humoral and cell-mediated immune responses, and confer 100% protection to immunized mice against challenge with very high doses of S. Typhimurium. Besides, very efficient clearance of bacteria from the reticuloendothelial systems of immunized mice was seen. The homology search further revealed that OmpL is widely distributed and conserved, homologous proteins were identified in S. Typhi and Paratyphi by RT-PCR and western blot. We also found that anti-rOmpL serum harber a high bactericidal activity for Salmonella serovars tested in this study. Therefore, OmpL provide a promising target for the development of a candidate vaccine against Salmonella infection.
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Affiliation(s)
- Youjun Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, PR China
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Kantele A, Pakkanen SH, Karttunen R, Kantele JM. Head-to-head comparison of humoral immune responses to Vi capsular polysaccharide and Salmonella Typhi Ty21a typhoid vaccines--a randomized trial. PLoS One 2013; 8:e60583. [PMID: 23593253 PMCID: PMC3620468 DOI: 10.1371/journal.pone.0060583] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 02/27/2013] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The two typhoid vaccines, the parenteral Vi capsular polysaccharide and the oral live whole-cell Salmonella Typhi Ty21a vaccine, provide similar levels of protection in field trials. Sharing no antigens, they are thought to confer protection by different mechanisms. This is the first head-to-head study to compare the humoral immune responses to these two vaccines. METHODS 50 age- and gender-matched volunteers were immunized, 25 with the Vi and 25 with the Ty21a vaccine. Circulating plasmablasts reactive with whole-cell Salmonella Typhi or one of the typhoidal antigenic structures, Vi, O-9,12, and H-d antigens, were identified as antibody-secreting cells (ASC) with ELISPOT. Homing receptor (HR) expressions were determined. These results were compared with ASC in four patients with typhoid fever. Antibodies to S. Typhi lipopolysaccharides were assessed in cultures of ALS (antibodies in lymphocyte supernatants) and in serum with ELISA. RESULTS In 49 out of 50 vaccinees, no typhoid-specific plasmablasts were seen before vaccination. On day 7, response to Vi antigen was mounted in 24/25 volunteers in the Vi, and none in the Ty21a group; response to S. Typhi and O-9,12 was mounted in 49/50 vaccinees; and to H-d in 3/50. The numbers of typhoid-specific plasmablasts (total of ASC to Vi, O-9,12 and H-d antigens) proved equal in the vaccination groups. The HR expressions indicated a mainly systemic homing in the Vi and intestinal in the Ty21a group, the latter resembling that in natural infection. Plasmablasts proved more sensitive than serum and ALS in assessing the immune response. CONCLUSIONS The typhoid-specific humoral responses to Vi and Ty21a vaccines are similar in magnitude, but differ in expected localization and antigen-specificity. The unforeseen O antigen-specific response in the Vi group is probably due to lipopolysaccharide contaminating the vaccine preparation. Only the response to Ty21a vaccine was found to imitate that in natural infection. TRIAL REGISTRATION Current Controlled Trials Ltd. c/o BioMed Central ISRCTN68125331.
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Affiliation(s)
- Anu Kantele
- Department of Medicine, Division of Infectious Diseases, Helsinki University Central Hospital, Helsinki, Finland
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland
- Institute of Clinical Medicine, Department of Medicine, University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Sari H. Pakkanen
- Department of Medicine, Division of Infectious Diseases, Helsinki University Central Hospital, Helsinki, Finland
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Riitta Karttunen
- Division of Clinical Microbiology, Department of Virology and Immunology, Helsinki University Hospital, Helsinki, Finland
| | - Jussi M. Kantele
- Department of Medical Microbiology and Immunology, University of Turku, Turku, Finland
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