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Branchu P, Bawn M, Kingsley RA. Genome Variation and Molecular Epidemiology of Salmonella enterica Serovar Typhimurium Pathovariants. Infect Immun 2018; 86:e00079-18. [PMID: 29784861 PMCID: PMC6056856 DOI: 10.1128/iai.00079-18] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Salmonella enterica serovar Typhimurium is one of approximately 2,500 distinct serovars of the genus Salmonella but is exceptional in its wide distribution in the environment, livestock, and wild animals. S Typhimurium causes a large proportion of nontyphoidal Salmonella (NTS) infections, accounting for a quarter of infections, second only to S. enterica serovar Enteritidis in incidence. S Typhimurium was once considered the archetypal broad-host-range Salmonella serovar due to its wide distribution in livestock and wild animals, and much of what we know of the interaction of Salmonella with the host comes from research using a small number of laboratory strains of the serovar (LT2, SL1344, and ATCC 14028). But it has become clear that these strains do not reflect the genotypic or phenotypic diversity of S Typhimurium. Here, we review the epidemiological record of S Typhimurium and studies of the host-pathogen interactions of diverse strains of S Typhimurium. We present the concept of distinct pathovariants of S Typhimurium that exhibit diversity of host range, distribution in the environment, pathogenicity, and risk to food safety. We review recent evidence from whole-genome sequencing that has revealed the extent of genomic diversity of S Typhimurium pathovariants, the genomic basis of differences in the level of risk to human and animal health, and the molecular epidemiology of prominent strains. An improved understanding of the impact of genome variation of bacterial pathogens on pathogen-host and pathogen-environment interactions has the potential to improve quantitative risk assessment and reveal how new pathogens evolve.
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Affiliation(s)
- Priscilla Branchu
- Quadram Institute Bioscience, Norwich Research Park, Colney, Norwich, United Kingdom
| | - Matt Bawn
- Quadram Institute Bioscience, Norwich Research Park, Colney, Norwich, United Kingdom
- Earlham Institute, Norwich Research Park, Colney, Norwich, United Kingdom
| | - Robert A Kingsley
- Quadram Institute Bioscience, Norwich Research Park, Colney, Norwich, United Kingdom
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52
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Abstract
Uropathogenic Escherichia coli (UPEC) is the most common cause of urinary tract infection, which in some patients can develop into life-threatening urosepsis. Serum resistance is a key virulence trait of strains that cause urosepsis. Recently, we identified a novel method of serum resistance in patients with Pseudomonas aeruginosa lung infections, where patients possessed antibodies that inhibited complement-mediated killing (instead of protecting against infection). These inhibitory antibodies were of the IgG2 subtype, specific to the O-antigen component of lipopolysaccharide (LPS) and coated the bacterial surface, preventing bacterial lysis by complement. As this mechanism could apply to any Gram-negative bacterial infection, we hypothesized that inhibitory antibodies may represent an uncharacterized mechanism of serum resistance in UPEC. To test this, 45 urosepsis patients with paired blood culture UPEC isolates were screened for serum titers of IgG2 specific for their cognate strain’s LPS. Eleven patients had sufficiently high titers of the antibody to inhibit serum-mediated killing of UPEC isolates by pooled healthy control sera. Depletion of IgG or removal of O-antigen restored sensitivity of the isolates to the cognate patient serum. Importantly, the isolates from these 11 patients were more sensitive to killing by serum than isolates from patients with no inhibitory antibodies. This suggests the presence of inhibitory antibodies may have allowed these strains to infect the bloodstream. The high prevalence of patients with inhibitory antibodies (24%) suggests that this phenomenon is an important mechanism of UPEC serum resistance. LPS-specific inhibitory antibodies have now been identified against three Gram-negative pathogens that cause disparate diseases. Despite improvements in the early detection and management of sepsis, morbidity and mortality are still high. Infections of the urinary tract are one of the most frequent sources of sepsis with Escherichia coli the main causative agent. Serum resistance is vital for bacteria to infect the bloodstream. Here we report a novel method of serum resistance found in patients with UPEC-mediated sepsis. Antibodies in sera usually protect against infection, but here we found that 24% of patients expressed “inhibitory antibodies” capable of preventing serum-mediated killing of their infecting isolate. Our data suggest that these antibodies would allow otherwise serum-sensitive UPEC strains to cause sepsis. The high prevalence of patients with inhibitory antibodies in this cohort suggests that this is a widespread mechanism of resistance to complement-mediated killing in urosepsis patients, invoking the potential for the application of new methods to prevent and treat sepsis.
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53
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Humoral immunity to memory antigens and pathogens is maintained in patients with chronic kidney disease. PLoS One 2018; 13:e0195730. [PMID: 29659606 PMCID: PMC5901993 DOI: 10.1371/journal.pone.0195730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 03/28/2018] [Indexed: 01/29/2023] Open
Abstract
Patients with chronic kidney disease (CKD) have an increased risk of infection and poorer responses to vaccination. This suggests that CKD patients have an impaired responsiveness to all antigens, even those first encountered before CKD onset. To examine this we evaluated antibody responses against two childhood vaccine antigens, tetanus (TT) and diphtheria toxoids (DT) and two common pathogens, cytomegalovirus (CMV) and Salmonella enterica serovar Enteritidis (SEn) in two independent cohorts consisting of age-matched individuals with and without CKD. Sera were evaluated for antigen-specific IgG titres and the functionality of antibody to SEn was assessed in a serum bactericidal assay. Surprisingly, patients with CKD and control subjects had comparable levels of IgG against TT and DT, suggesting preserved humoral memory responses to antigens encountered early in life. Lipopolysaccharide-specific IgG titres and serum bactericidal activity in patients with CKD were also not inferior to controls. CMV-specific IgG titres in seropositive CKD patients were similar or even increased compared to controls. Therefore, whilst responses to new vaccines in CKD are typically lower than expected, antibody responses to antigens commonly encountered prior to CKD onset are not. The immunodeficiency of CKD is likely characterised by failure to respond to new antigenic challenges and efforts to improve patient outcomes should be focussed here.
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Lê-Bury G, Niedergang F. Defective Phagocytic Properties of HIV-Infected Macrophages: How Might They Be Implicated in the Development of Invasive Salmonella Typhimurium? Front Immunol 2018; 9:531. [PMID: 29628924 PMCID: PMC5876300 DOI: 10.3389/fimmu.2018.00531] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/28/2018] [Indexed: 01/07/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) infects and kills T cells, profoundly damaging the host-specific immune response. The virus also integrates into memory T cells and long-lived macrophages, establishing chronic infections. HIV-1 infection impairs the functions of macrophages both in vivo and in vitro, which contributes to the development of opportunistic diseases. Non-typhoidal Salmonella enterica serovar Typhimurium has been identified as the most common cause of bacterial bloodstream infections in HIV-infected adults. In this review, we report how the functions of macrophages are impaired post HIV infection; introduce what makes invasive Salmonella Typhimurium specific for its pathogenesis; and finally, we discuss why these bacteria may be particularly adapted to the HIV-infected host.
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Affiliation(s)
- Gabrielle Lê-Bury
- INSERM, U1016, Institut Cochin, Paris, France.,CNRS, UMR 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Florence Niedergang
- INSERM, U1016, Institut Cochin, Paris, France.,CNRS, UMR 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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55
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IgG Responses to Porins and Lipopolysaccharide within an Outer Membrane-Based Vaccine against Nontyphoidal Salmonella Develop at Discordant Rates. mBio 2018; 9:mBio.02379-17. [PMID: 29511082 PMCID: PMC5844998 DOI: 10.1128/mbio.02379-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Antibodies acquired after vaccination or natural infection with Gram-negative bacteria, such as invasive Salmonella enterica serovar Typhimurium, can protect against disease. Immunization with naturally shed outer membrane vesicles from Gram-negative bacteria is being studied for its potential to protect against many infections, since antigens within vesicles maintain their natural conformation and orientation. Shedding can be enhanced through genetic modification, and the resulting particles, generalized modules for membrane antigens (GMMA), not only offer potential as vaccines but also can facilitate the study of B-cell responses to bacterial antigens. Here we show that the response to immunization with GMMA from S. Typhimurium (STmGMMA) provides B-cell-dependent protection and induces antibodies to two immunodominant antigens, lipopolysaccharide (LPS) and porins. Antibodies to LPS O antigen (O-Ag) markedly enhance protection in the spleen, but this effect is less marked in the liver. Strikingly, IgG responses to LPS and porins develop with distinct kinetics. In the first week after immunization, there is a dramatic T-cell-independent B1b-cell-associated induction of all IgG isotypes, except IgG1, to porins but not to LPS. In contrast, production of IgG1 to either antigen was delayed and T cell dependent. Nevertheless, after 1 month, cells in the bone marrow secreting IgG against porins or LPS were present at a similar frequency. Unexpectedly, immunization with O-Ag-deficient STmGMMA did not substantially enhance the anti-porin response. Therefore, IgG switching to all antigens does not develop synchronously within the same complex and so the rate of IgG switching to a single component does not necessarily reflect its frequency within the antigenic complex. Vaccines save millions of lives, yet for some infections there are none. This includes some types of Salmonella infections, killing hundreds of thousands of people annually. We show how a new type of vaccine, called GMMA, that is made from blebs shed from the Salmonella cell wall, works to protect against infection in mice by inducing host proteins (antibodies) specifically recognizing bacterial components (antigens). The rate of development of IgG antibody to antigens within GMMA occurred with different kinetics. However, the antibody response to GMMA persists and is likely to provide prolonged protection for those who need it. These results help show how antibody responses to bacterial antigens develop and how vaccines like GMMA can work and help prevent infection.
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56
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Sebina I, Pepper M. Humoral immune responses to infection: common mechanisms and unique strategies to combat pathogen immune evasion tactics. Curr Opin Immunol 2018; 51:46-54. [PMID: 29477969 DOI: 10.1016/j.coi.2018.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 02/02/2018] [Accepted: 02/05/2018] [Indexed: 01/08/2023]
Abstract
Humoral immune responses are crucial for protection against invading pathogens and are the underlying mechanism of protection for most successful vaccines. Our understanding of how humoral immunity develops is largely based on animal models utilizing experimental immunization systems. While these studies have made enormous progress for the field and have defined many of the fundamental principles of B cell differentiation and function, we are only now beginning to appreciate the complexities of humoral immune responses induced by infection. Co-evolution of the adaptive immune system and the pathogenic world has created a diverse array of B cell responses to infections, with both shared and unique strategies. In this review, we consider the common mechanisms that regulate the development of humoral immune responses during infection and highlight recent findings demonstrating the evolution of unique strategies used by either host or pathogen for survival.
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Affiliation(s)
- Ismail Sebina
- Department of Immunology, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Marion Pepper
- Department of Immunology, University of Washington School of Medicine, Seattle, WA 98109, USA.
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57
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Juel HB, Thomaides-Brears HB, Darton TC, Jones C, Jones E, Shrestha S, Sie R, Eustace A, Galal U, Kurupati P, Van TT, Thieu NTV, Baker S, Blohmke CJ, Pollard AJ. Salmonella Typhi Bactericidal Antibodies Reduce Disease Severity but Do Not Protect against Typhoid Fever in a Controlled Human Infection Model. Front Immunol 2018; 8:1916. [PMID: 29387052 PMCID: PMC5776093 DOI: 10.3389/fimmu.2017.01916] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 12/14/2017] [Indexed: 01/12/2023] Open
Abstract
Effective vaccines against Salmonella Typhi, a major cause of febrile illness in tropical regions, can have a significant effect as a disease control measure. Earlier work has shown that immunization with either of two Salmonella Typhi vaccines, licensed Ty21a or candidate M01ZH09, did not provide full immunity in a controlled human infection model. Here, we describe the human humoral immune responses to these oral vaccines and their functional role in protection after challenge with S. Typhi. Serum, obtained from healthy volunteers before and after vaccination with Ty21a or M01ZH09 or placebo and before and after oral challenge with wild-type S. Typhi, was assessed for bactericidal activity. Single-dose vaccination with M01ZH09 induced an increase in serum bactericidal antibodies (p = 0.001) while three doses of Ty21a did not. No association between bactericidal activity and protection against typhoid after challenge was seen in either vaccine arm. Bactericidal activity after vaccination correlated significantly with delayed disease onset (p = 0.013), lower bacterial burden (p = 0.006), and decreased disease severity scores (p = 0.021). Depletion of antibodies directed against lipopolysaccharide significantly reduced bactericidal activity (p = 0.009). We conclude that antibodies induced after ingestion of oral live-attenuated typhoid vaccines or after challenge with wild-type S. Typhi exhibit bactericidal activity. This bactericidal activity is mediated by anti-O:LPS antibodies and significantly reduces clinical symptoms but does not provide sterile immunity. This directs future vaccine studies toward other antigens or mechanisms of protection against typhoid.
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Affiliation(s)
- Helene B Juel
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom.,Statens Serum Institut, Copenhagen, Denmark
| | - Helena B Thomaides-Brears
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Thomas C Darton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom.,Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Elizabeth Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Sonu Shrestha
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Rebecca Sie
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Andrew Eustace
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Ushma Galal
- Nuffield Department of Primary Care Health Sciences, Clinical Trials Unit, University of Oxford, Oxford, United Kingdom
| | - Prathiba Kurupati
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Tan T Van
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Nga T V Thieu
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,The Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Christoph J Blohmke
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
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58
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MacLennan CA, Msefula CL, Gondwe EN, Gilchrist JJ, Pensulo P, Mandala WL, Mwimaniwa G, Banda M, Kenny J, Wilson LK, Phiri A, MacLennan JM, Molyneux EM, Molyneux ME, Graham SM. Presentation of life-threatening invasive nontyphoidal Salmonella disease in Malawian children: A prospective observational study. PLoS Negl Trop Dis 2017; 11:e0006027. [PMID: 29216183 PMCID: PMC5745124 DOI: 10.1371/journal.pntd.0006027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 12/27/2017] [Accepted: 10/10/2017] [Indexed: 12/17/2022] Open
Abstract
Nontyphoidal Salmonellae commonly cause invasive disease in African children that is often fatal. The clinical diagnosis of these infections is hampered by the absence of a clear clinical syndrome. Drug resistance means that empirical antibiotic therapy is often ineffective and currently no vaccine is available. The study objective was to identify risk factors for mortality among children presenting to hospital with invasive Salmonella disease in Africa. We conducted a prospective study enrolling consecutive children with microbiologically-confirmed invasive Salmonella disease admitted to Queen Elizabeth Central Hospital, Blantyre, in 2006. Data on clinical presentation, co-morbidities and outcome were used to identify children at risk of inpatient mortality through logistic-regression modeling. Over one calendar year, 263 consecutive children presented with invasive Salmonella disease. Median age was 16 months (range 0-15 years) and 52/256 children (20%; 95%CI 15-25%) died. Nontyphoidal serovars caused 248/263 (94%) of cases. 211/259 (81%) of isolates were multi-drug resistant. 251/263 children presented with bacteremia, 6 with meningitis and 6 with both. Respiratory symptoms were present in 184/240 (77%; 95%CI 71-82%), 123/240 (51%; 95%CI 45-58%) had gastrointestinal symptoms and 101/240 (42%; 95%CI 36-49%) had an overlapping clinical syndrome. Presentation at <7 months (OR 10.0; 95%CI 2.8-35.1), dyspnea (OR 4.2; 95%CI 1.5-12.0) and HIV infection (OR 3.3; 95%CI 1.1-10.2) were independent risk factors for inpatient mortality. Invasive Salmonella disease in Malawi is characterized by high mortality and prevalence of multi-drug resistant isolates, along with non-specific presentation. Young infants, children with dyspnea and HIV-infected children bear a disproportionate burden of the Salmonella-associated mortality in Malawi. Strategies to improve prevention, diagnosis and management of invasive Salmonella disease should be targeted at these children.
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Affiliation(s)
- Calman A. MacLennan
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- School of Immunity and Infection, College of Medicine and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Chisomo L. Msefula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Department of Microbiology, College of Medicine, University of Malawi, Malawi
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Esther N. Gondwe
- School of Immunity and Infection, College of Medicine and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Department of Biochemistry, College of Medicine, University of Malawi, Malawi
| | - James J. Gilchrist
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Department of Paediatrics, University of Oxford, United Kingdom
- Wellcome Trust Centre for Human Genetics, University of Oxford, United Kingdom
| | - Paul Pensulo
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Wilson L. Mandala
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Department of Basic Medical Sciences, College of Medicine, University of Malawi, Blantyre, Malawi
- Academy of Medical Sciences, Malawi University of Science and Technology, Thyolo, Malawi
| | - Grace Mwimaniwa
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Meraby Banda
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Julia Kenny
- Department of Paediatrics, College of Medicine, University of Malawi, Malawi
- Infectious Diseases and Microbiology Unit, Institute of Child Health, University College London, London, United Kingdom
| | - Lorna K. Wilson
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Amos Phiri
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Jenny M. MacLennan
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Malcolm E. Molyneux
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Department of Medicine, College of Medicine, University of Malawi, Malawi
| | - Stephen M. Graham
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Department of Paediatrics, College of Medicine, University of Malawi, Malawi
- Centre for International Child Health, University of Melbourne and Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, Australia
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59
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Antigen Localization Influences the Magnitude and Kinetics of Endogenous Adaptive Immune Response to Recombinant Salmonella Vaccines. Infect Immun 2017; 85:IAI.00593-17. [PMID: 28893919 PMCID: PMC5695123 DOI: 10.1128/iai.00593-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 08/19/2017] [Indexed: 11/30/2022] Open
Abstract
The use of recombinant attenuated Salmonella vaccine (RASV) strains is a promising strategy for presenting heterologous antigens to the mammalian immune system to induce both cellular and humoral immune responses. However, studies on RASV development differ on where heterologous antigens are expressed and localized within the bacterium, and it is unclear how antigen localization modulates the immune response. Previously, we exploited the plasmid-encoded toxin (Pet) autotransporter system for accumulation of heterologous antigens in cell culture supernatant. In the present study, this Pet system was used to express early secretory antigen 6 (ESAT-6), an immunodominant and diagnostic antigen from Mycobacterium tuberculosis, in Salmonella enterica serovar Typhimurium strain SL3261. Three strains were generated, whereby ESAT-6 was expressed as a cytoplasmic (SL3261/cyto), surface-bound (SL3261/surf), or secreted (SL3261/sec) antigen. Using these RASVs, the relationship between antigen localization and immunogenicity in infected C57BL/6 mice was systematically examined. Using purified antigen and specific tetramers, we showed that mice infected with the SL3261/surf or SL3261/sec strain generated large numbers of Th1 CD4+ ESAT-6+ splenic T cells compared to those of mice infected with SL3261/cyto. While all mice showed ESAT-6-specific antibody responses when infected with SL3261/surf or SL3261/sec, peak total serum IgG antibody titers were reached more rapidly in mice that received SL3261/sec. Thus, how antigen is localized after production within bacteria has a more marked effect on the antibody response than on the CD4+ T cell response, which might influence the chosen strategy to localize recombinant antigen in RASVs.
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60
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Zhang Y, Dominguez-Medina C, Cumley NJ, Heath JN, Essex SJ, Bobat S, Schager A, Goodall M, Kracker S, Buckley CD, May RC, Kingsley RA, MacLennan CA, López-Macías C, Cunningham AF, Toellner KM. IgG1 Is Required for Optimal Protection after Immunization with the Purified Porin OmpD from Salmonella Typhimurium. THE JOURNAL OF IMMUNOLOGY 2017; 199:4103-4109. [PMID: 29127147 PMCID: PMC5713499 DOI: 10.4049/jimmunol.1700952] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/16/2017] [Indexed: 12/25/2022]
Abstract
In mice, the IgG subclass induced after Ag encounter can reflect the nature of the Ag. Th2 Ags such as alum-precipitated proteins and helminths induce IgG1, whereas Th1 Ags, such as Salmonella Typhimurium, predominantly induce IgG2a. The contribution of different IgG isotypes to protection against bacteria such as S. Typhimurium is unclear, although as IgG2a is induced by natural infection, it is assumed this isotype is important. Previously, we have shown that purified S. Typhimurium porins including outer membrane protein OmpD, which induce both IgG1 and IgG2a in mice, provide protection to S. Typhimurium infection via Ab. In this study we report the unexpected finding that mice lacking IgG1, but not IgG2a, are substantially less protected after porin immunization than wild-type controls. IgG1-deficient mice produce more porin-specific IgG2a, resulting in total IgG levels that are similar to wild-type mice. The decreased protection in IgG1-deficient mice correlates with less efficient bacterial opsonization and uptake by macrophages, and this reflects the low binding of outer membrane protein OmpD–specific IgG2a to the bacterial surface. Thus, the Th2-associated isotype IgG1 can play a role in protection against Th1-associated organisms such as S. Typhimurium. Therefore, individual IgG subclasses to a single Ag can provide different levels of protection and the IgG isotype induced may need to be a consideration when designing vaccines and immunization strategies.
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Affiliation(s)
- Yang Zhang
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Coral Dominguez-Medina
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Nicola J Cumley
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Jennifer N Heath
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Sarah J Essex
- School of Cancer Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Saeeda Bobat
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Anna Schager
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Margaret Goodall
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Sven Kracker
- Deutsches Rheuma-Forschungszentrum Berlin, Berlin 10117, Germany
| | - Christopher D Buckley
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Robin C May
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | | | - Calman A MacLennan
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Constantino López-Macías
- Medical Research Unit on Immunochemistry, Specialties Hospital, National Medical Centre Siglo XXI, Mexican Social Security Institute, 06720 México, DF, Mexico; and
| | - Adam F Cunningham
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom; .,Institute of Microbiology and Infection, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Kai-Michael Toellner
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom;
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61
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Antibodies Against Modified NS1 Wing Domain Peptide Protect Against Dengue Virus Infection. Sci Rep 2017; 7:6975. [PMID: 28765561 PMCID: PMC5539099 DOI: 10.1038/s41598-017-07308-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/26/2017] [Indexed: 01/10/2023] Open
Abstract
Dengue is the most common mosquito-transmitted viral infection for which an improved vaccine is still needed. Although nonstructural protein-1 (NS1) immunization can protect mice against dengue infection, molecular mimicry between NS1 and host proteins makes NS1-based vaccines challenging to develop. Based on the epitope recognized by the anti-NS1 monoclonal Ab (mAb) 33D2 which recognizes a conserved NS1 wing domain (NS1-WD) region but not host proteins, we synthesized a modified NS1-WD peptide to immunize mice. We found that both mAb 33D2 and modified NS1-WD peptide immune sera could induce complement-dependent lysis of dengue-infected but not un-infected cells in vitro. Furthermore, either active immunization with the modified NS1-WD peptide or passive transfer of mAb 33D2 efficiently protected mice against all serotypes of dengue virus infection. More importantly, dengue patients with more antibodies recognized the modified NS1-WD peptide had less severe disease. Thus, the modified NS1-WD peptide is a promising dengue vaccine candidate.
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62
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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: 16] [Impact Index Per Article: 2.0] [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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Erova TE, Kirtley ML, Fitts EC, Ponnusamy D, Baze WB, Andersson JA, Cong Y, Tiner BL, Sha J, Chopra AK. Protective Immunity Elicited by Oral Immunization of Mice with Salmonella enterica Serovar Typhimurium Braun Lipoprotein (Lpp) and Acetyltransferase (MsbB) Mutants. Front Cell Infect Microbiol 2016; 6:148. [PMID: 27891321 PMCID: PMC5103298 DOI: 10.3389/fcimb.2016.00148] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 10/27/2016] [Indexed: 12/12/2022] Open
Abstract
We evaluated the extent of attenuation and immunogenicity of the ΔlppAB and ΔlppAB ΔmsbB mutants of Salmonella enterica serovar Typhimurium when delivered to mice by the oral route. These mutants were deleted either for the Braun lipoprotein genes (lppA and lppB) or in combination with the msbB gene, which encodes an acetyltransferase required for lipid A modification of lipopolysaccharide. Both the mutants were attenuated (100% animal survival) and triggered robust innate and adaptive immune responses. Comparable levels of IgG and its isotypes were produced in mice infected with wild-type (WT) S. typhimurium or its aforementioned mutant strains. The ΔlppAB ΔmsbB mutant-immunized animals resulted in the production of higher levels of fecal IgA and serum cytokines during later stages of vaccination (adaptive response). A significant production of interleukin-6 from T-cells was also noted in the ΔlppAB ΔmsbB mutant-immunized mice when compared to that of the ΔlppAB mutant. On the other hand, IL-17A production was significantly more in the serum of ΔlppAB mutant-immunized mice (innate response) with a stronger splenic T-cell proliferative and tumor-necrosis factor-α production. Based on 2-dimensional gel analysis, alterations in the levels of several proteins were observed in both the mutant strains when compared to that in WT S. typhimurium and could be associated with the higher immunogenicity of the mutants. Finally, both ΔlppAB and ΔlppAB ΔmsbB mutants provided complete protection to immunized mice against a lethal oral challenge dose of WT S. typhimurium. Thus, these mutants may serve as excellent vaccine candidates and also provide a platform for delivering heterologous antigens.
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Affiliation(s)
- Tatiana E Erova
- Department of Microbiology and Immunology, University of Texas Medical Branch Galveston, TX, USA
| | - Michelle L Kirtley
- Department of Microbiology and Immunology, University of Texas Medical Branch Galveston, TX, USA
| | - Eric C Fitts
- Department of Microbiology and Immunology, University of Texas Medical Branch Galveston, TX, USA
| | - Duraisamy Ponnusamy
- Department of Microbiology and Immunology, University of Texas Medical Branch Galveston, TX, USA
| | - Wallace B Baze
- Department of Veterinary Sciences, University of Texas M. D. Anderson Cancer Center Bastrop, TX, USA
| | - Jourdan A Andersson
- Department of Microbiology and Immunology, University of Texas Medical Branch Galveston, TX, USA
| | - Yingzi Cong
- Department of Microbiology and Immunology, University of Texas Medical BranchGalveston, TX, USA; Institute for Human Infections and Immunity, University of Texas Medical BranchGalveston, TX, USA; Sealy Center for Vaccine Development and World Health Organisation Collaborating Center for Vaccine Research, University of Texas Medical BranchGalveston, TX, USA; Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical BranchGalveston, TX, USA
| | - Bethany L Tiner
- Department of Microbiology and Immunology, University of Texas Medical Branch Galveston, TX, USA
| | - Jian Sha
- Department of Microbiology and Immunology, University of Texas Medical BranchGalveston, TX, USA; Institute for Human Infections and Immunity, University of Texas Medical BranchGalveston, TX, USA
| | - Ashok K Chopra
- Department of Microbiology and Immunology, University of Texas Medical BranchGalveston, TX, USA; Institute for Human Infections and Immunity, University of Texas Medical BranchGalveston, TX, USA; Sealy Center for Vaccine Development and World Health Organisation Collaborating Center for Vaccine Research, University of Texas Medical BranchGalveston, TX, USA; Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical BranchGalveston, TX, USA
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Isolation, Identification, and Antibiotic Susceptibility Testing of Salmonella from Slaughtered Bovines and Ovines in Addis Ababa Abattoir Enterprise, Ethiopia: A Cross-Sectional Study. INTERNATIONAL JOURNAL OF BACTERIOLOGY 2016; 2016:3714785. [PMID: 27660816 PMCID: PMC5021890 DOI: 10.1155/2016/3714785] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/12/2016] [Accepted: 07/25/2016] [Indexed: 11/25/2022]
Abstract
Salmonellae are ubiquitous, found in animals, humans, and the environment, a condition which facilitates transmission and cross contamination. Salmonella enterica serotypes exert huge health and economic impacts due to their virulence or carriage of antibiotic resistance traits. To address this significant issues with regard to public health, availability of adequate information on the prevalence and antibiotic resistance patterns of Salmonella, and establishment of adequate measures to control contamination and infection are needed. A cross-sectional study was conducted to assess the level of Salmonella infection in slaughtered bovines and ovines at Addis Ababa abattoir. Samples were collected randomly and processed for identification and antimicrobial susceptibility testing of Salmonella spp. From 280 animals examined, 13 (4.64%) (8 bovines and 5 ovines) were positive, with most samples (12/13, 92%) comprising Salmonella Dublin. Very high level of resistance to some antibiotics used in human medicine was detected. Most isolates were susceptible to gentamycin and amikacin. Nine (69%) of all isolates were resistant to multiple antibiotics. Serotyping revealed 12 of 13 isolates to be of the Dublin serotype with 9,12:g,p:- antigenic formula. This study emphasizes the importance of improving the evisceration practice during slaughtering and restricting the use of antibiotics in farm animals.
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Carreño JM, Perez-Shibayama C, Gil-Cruz C, Printz A, Pastelin R, Isibasi A, Chariatte D, Tanoue Y, Lopez-Macias C, Gander B, Ludewig B. PLGA-microencapsulation protects Salmonella typhi outer membrane proteins from acidic degradation and increases their mucosal immunogenicity. Vaccine 2016; 34:4263-4269. [PMID: 27372155 DOI: 10.1016/j.vaccine.2016.05.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 04/15/2016] [Accepted: 05/13/2016] [Indexed: 11/28/2022]
Abstract
Salmonella (S.) enterica infections are an important global health problem with more than 20 million individuals suffering from enteric fever annually and more than 200,000 lethal cases per year. Although enteric fever can be treated appropriately with antibiotics, an increasing number of antibiotic resistant Salmonella strains is detected. While two vaccines against typhoid fever are currently on the market, their availability in subtropical endemic areas is limited because these products need to be kept in uninterrupted cold chains. Hence, the development of a thermally stable vaccine that induces mucosal immune responses would greatly improve human health in endemic areas. Here, we have combined the high structural stability of Salmonella typhi outer membrane proteins (porins) with their microencapsulation into poly(lactic-co-glycolic acid) (PLGA) to generate an orally applicable vaccine. Encapsulated porins were protected from acidic degradation and exhibited enhanced immunogenicity following oral administration. In particular, the vaccine elicited strong S. typhi-specific B cell responses in Peyer's patches and mesenteric lymph nodes. In sum, PLGA microencapsulation substantially improved the efficacy of oral vaccination against S. typhi.
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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
| | - Andrea Printz
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Rodolfo Pastelin
- Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Mexico D.F., Mexico
| | - Armando Isibasi
- Medical Research Unit on Immunochemistry (UIMIQ), Specialties Hospital, National Medical Centre "Siglo XXI", Mexican Social Security Institute (IMSS), Mexico City, Mexico
| | - Dominic Chariatte
- Institute of Pharmaceutical Sciences, ETH Zürich, Zürich, Switzerland
| | - Yutaka Tanoue
- Takeda Pharmaceutical Company, CMC Center, Osaka, Japan
| | - Constantino Lopez-Macias
- Medical Research Unit on Immunochemistry (UIMIQ), Specialties Hospital, National Medical Centre "Siglo XXI", Mexican Social Security Institute (IMSS), Mexico City, Mexico.
| | - Bruno Gander
- Institute of Pharmaceutical Sciences, ETH Zürich, Zürich, Switzerland
| | - Burkhard Ludewig
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland.
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66
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Mastroeni P, Rossi O. Immunology, epidemiology and mathematical modelling towards a better understanding of invasive non-typhoidal Salmonella disease and rational vaccination approaches. Expert Rev Vaccines 2016; 15:1545-1555. [PMID: 27171941 DOI: 10.1080/14760584.2016.1189330] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Invasive non-typhoidal Salmonella (iNTS) infections cause a high burden of lethal sepsis in young children and HIV patients, often associated with malaria, anaemia, malnutrition and sickle-cell disease. Vaccines against iNTS are urgently needed but none are licensed yet. Areas covered: This review illustrates how immunology, epidemiology and within-host pathogen behaviour affect invasive Salmonella infections and highlights how this knowledge can assist the improvement and choice of vaccines. Expert Commentary: Control of iNTS disease requires approaches that reduce transmission and improve diagnosis and treatment. These are often difficult to implement due to the fragile ecology and economies in endemic countries. Vaccines will be key tools in the fight against iNTS disease. To optimise vaccine design, we need to better define protective antigens and mechanisms of resistance to disease in susceptible populations even in those individuals where innate immunity may be impaired by widespread comorbidities.
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Affiliation(s)
- Pietro Mastroeni
- a Department of Veterinary Medicine , University of Cambridge , Cambridge , United Kingdom
| | - Omar Rossi
- a Department of Veterinary Medicine , University of Cambridge , Cambridge , United Kingdom
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67
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Goh YS, Necchi F, O’Shaughnessy CM, Micoli F, Gavini M, Young SP, Msefula CL, Gondwe EN, Mandala WL, Gordon MA, Saul AJ, MacLennan CA. Bactericidal Immunity to Salmonella in Africans and Mechanisms Causing Its Failure in HIV Infection. PLoS Negl Trop Dis 2016; 10:e0004604. [PMID: 27057743 PMCID: PMC4825999 DOI: 10.1371/journal.pntd.0004604] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 03/12/2016] [Indexed: 12/17/2022] Open
Abstract
Background Nontyphoidal strains of Salmonella are a leading cause of death among HIV-infected Africans. Antibody-induced complement-mediated killing protects healthy Africans against Salmonella, but increased levels of anti-lipopolysaccharide (LPS) antibodies in some HIV-infected African adults block this killing. The objective was to understand how these high levels of anti-LPS antibodies interfere with the killing of Salmonella. Methodology/Principal Findings Sera and affinity-purified antibodies from African HIV-infected adults that failed to kill invasive S. Typhimurium D23580 were compared to sera from HIV-uninfected and HIV-infected subjects with bactericidal activity. The failure of sera from certain HIV-infected subjects to kill Salmonella was found to be due to an inherent inhibitory effect of anti-LPS antibodies. This inhibition was concentration-dependent and strongly associated with IgA and IgG2 anti-LPS antibodies (p<0.0001 for both). IgG anti-LPS antibodies, from sera of HIV-infected individuals that inhibit killing at high concentration, induced killing when diluted. Conversely, IgG, from sera of HIV-uninfected adults that induce killing, inhibited killing when concentrated. IgM anti-LPS antibodies from all subjects also induced Salmonella killing. Finally, the inhibitory effect of high concentrations of anti-LPS antibodies is seen with IgM as well as IgG and IgA. No correlation was found between affinity or avidity, or complement deposition or consumption, and inhibition of killing. Conclusion/Significance IgG and IgM classes of anti-S. Typhimurium LPS antibodies from HIV-infected and HIV-uninfected individuals are bactericidal, while at very high concentrations, anti-LPS antibodies of all classes inhibit in vitro killing of Salmonella. This could be due to a variety of mechanisms relating to the poor ability of IgA and IgG2 to activate complement, and deposition of complement at sites where it cannot insert in the bacterial membrane. Vaccine trials are required to understand the significance of lack of in vitro killing by anti-LPS antibodies from a minority of HIV-infected individuals with impaired immune homeostasis. Bacteremia caused by nontyphoidal Salmonellae are a major health burden in Africa. While antibody-induced complement-mediated killing protects healthy Africans against Salmonella, increased levels of anti-LPS antibodies in some HIV-infected Africans block this killing. Little is known about the mechanism of the interference of killing by these antibodies. Here, we compared sera and affinity-purified antibodies from African HIV-infected adults that are unable to kill invasive S. Typhimurium D23580, with sera from HIV-uninfected and HIV-infected subjects with bactericidal activity. We found that the blocking effect of anti-LPS antibodies is a factor of antibody concentration, rather than antibody structure or specificity. While all three isotypes (IgG, IgA and IgM) can inhibit killing of Salmonella at grossly high concentrations, the IgG and IgM isotypes of the anti-LPS antibodies have in vitro bactericidal activity against invasive African S. Typhimurium. Inhibition of killing did not associate with antibody affinity or avidity, or complement deposition or consumption. It is possible that a LPS-based vaccine would induce antibodies at bactericidal rather than inhibitory concentrations in HIV-uninfected individuals. In HIV-infected individuals, it is uncertain whether vaccination will induce a protective response or a dysregulated excess of anti-LPS antibodies that impairs serum killing of Salmonella.
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Affiliation(s)
- Yun Shan Goh
- Singapore Immunology Network, Agency for Science, Technology and Research, Biopolis, Singapore
| | - Francesca Necchi
- Sclavo Behring Vaccines Institute for Global Health, a GlaxoSmith Kline Company, Siena, Italy
| | - Colette M. O’Shaughnessy
- School of Immunity and Infection, College of Medicine and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Francesca Micoli
- Sclavo Behring Vaccines Institute for Global Health, a GlaxoSmith Kline Company, Siena, Italy
| | | | - Stephen P. Young
- Centre for Translational Inflammation Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Chisomo L. Msefula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Department of Pathology, Division of Microbiology, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Esther N. Gondwe
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Department of Basic Medical Sciences, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Wilson L. Mandala
- Centre for Translational Inflammation Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Melita A. Gordon
- Department of Gastroenterology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Allan J. Saul
- Sclavo Behring Vaccines Institute for Global Health, a GlaxoSmith Kline Company, Siena, Italy
| | - Calman A. MacLennan
- School of Immunity and Infection, College of Medicine and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
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Aribam SD, Harada T, Elsheimer-Matulova M, Iwata T, Kanehira K, Hikono H, Matsui H, Ogawa Y, Shimoji Y, Eguchi M. Specific Monoclonal Antibody Overcomes the Salmonella enterica Serovar Typhimurium's Adaptive Mechanisms of Intramacrophage Survival and Replication. PLoS One 2016; 11:e0151352. [PMID: 26986057 PMCID: PMC4795626 DOI: 10.1371/journal.pone.0151352] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/26/2016] [Indexed: 12/31/2022] Open
Abstract
Salmonella-specific antibodies play an important role in host immunity; however, the mechanisms of Salmonella clearance by pathogen-specific antibodies remain to be completely elucidated since previous studies on antibody-mediated protection have yielded inconsistent results. These inconsistencies are at least partially attributable to the use of polyclonal antibodies against Salmonella antigens. Here, we developed a new monoclonal antibody (mAb)-449 and identified its related immunogen that protected BALB/c mice from infection with Salmonella enterica serovar Typhimurium. In addition, these data indicate that the mAb-449 immunogen is likely a major protective antigen. Using in vitro infection studies, we also analyzed the mechanism by which mAb-449 conferred host protection. Notably, macrophages infected with mAb-449-treated S. Typhimurium showed enhanced pathogen uptake compared to counterparts infected with control IgG-treated bacteria. Moreover, these macrophages produced elevated levels of pro-inflammatory cytokine TNFα and nitric oxide, indicating that mAb-449 enhanced macrophage activation. Finally, the number of intracellular bacteria in mAb-449-activated macrophages decreased considerably, while the opposite was found in IgG-treated controls. Based on these findings, we suggest that, although S. Typhimurium has the potential to survive and replicate within macrophages, host production of a specific antibody can effectively mediate macrophage activation for clearance of intracellular bacteria.
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Affiliation(s)
- Swarmistha Devi Aribam
- National Institute of Animal Health, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305–0856, Japan
| | - Tomoyuki Harada
- National Institute of Animal Health, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305–0856, Japan
| | | | - Taketoshi Iwata
- National Institute of Animal Health, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305–0856, Japan
| | - Katsushi Kanehira
- National Institute of Animal Health, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305–0856, Japan
| | - Hirokazu Hikono
- National Institute of Animal Health, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305–0856, Japan
| | - Hidenori Matsui
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108–8641, Japan
| | - Yohsuke Ogawa
- National Institute of Animal Health, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305–0856, Japan
| | - Yoshihiro Shimoji
- National Institute of Animal Health, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305–0856, Japan
| | - Masahiro Eguchi
- National Institute of Animal Health, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305–0856, Japan
- * E-mail:
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69
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Intestinal Inflammation Leads to a Long-lasting Increase in Resistance to Systemic Salmonellosis that Requires Macrophages But Not B or T Lymphocytes at the Time of Pathogen Challenge. Inflamm Bowel Dis 2015; 21. [PMID: 26222341 PMCID: PMC4654659 DOI: 10.1097/mib.0000000000000544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Intestinal inflammation is associated with systemic translocation of commensal antigens and the consequent activation of B and T lymphocytes. The long-term consequences of such immune activation are not completely understood. METHODS C57BL/6 mice were subjected to 2 courses of treatment with dextran sulfate sodium (DSS) to induce colitis. Two to 7 weeks after the DSS treatment, the mice were infected intraperitoneally with Salmonella enterica serovar Typhimurium. The outcome of infection was evaluated based on survival and tissue pathogen burden. RESULTS Mice that had recovered from DSS colitis displayed a significant increase in resistance to S. Typhimurium infection as indicated by improved survival and decreased tissue pathogen numbers. The colitis-induced increase in resistance to systemic salmonellosis lasted for as long as 7 weeks after discontinuing DSS and was dependent on T lymphocytes but not on B cells. Interestingly, depletion of CD4 and CD8 T cells just before the Salmonella infection did not alter the colitis-induced increase in resistance. Mice that had recovered from colitis had evidence of persistent activation of resident peritoneal macrophages and enhanced Salmonella-induced neutrophil recruitment to the peritoneum. Macrophage depletion with clodronate liposomes abrogated the colitis-induced increase in resistance to Salmonella. CONCLUSIONS Taken together, our results indicate that DSS colitis leads to a long-lasting increase in resistance to Salmonella infection that is initiated in a T cell-dependent manner but is ultimately mediated independently of B and T cells as a result of persistent changes in innate immune cell function.
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Abstract
Salmonella enterica is a leading cause of community-acquired bloodstream infection in Africa. The contribution of typhoidal and nontyphoidal Salmonella serovars to invasive disease varies considerably in place and time, even within the same country. Nonetheless, many African countries are now thought to experience typhoid fever incidence >100 per 100,000 per year with approximately 1% of patients dying. Invasive nontyphoidal Salmonella (iNTS) disease was estimated to cause 3.4 million illnesses and 681 316 deaths in 2010, with the most disease in Africa. Antimicrobial drug resistance is a growing problem in S. enterica that threatens to further compromise patient outcomes. Reservoirs for nontyphoidal Salmonella and the predominant routes of transmission for typhoidal and nontyphoidal Salmonella are not well understood in Africa, hampering the design of evidence-based, non-vaccine- and vaccine-based prevention measures. It is difficult to distinguish clinically invasive Salmonella disease from febrile illnesses caused by other pathogens. Blood cultures are the mainstay of laboratory diagnosis, but lack sensitivity due to the low magnitude of bacteremia, do not produce results at point of care, and are not widely available in Africa. Serologic approaches to diagnosis remain inaccurate, and nucleic acid amplification tests are also compromised by low concentrations of bacteria. High-throughput whole-genome sequencing, together with a range of novel analytic pipelines, has provided new insights into the complex pattern of epidemiology, pathogenesis, and host adaptation. Concerted efforts are therefore needed to apply these new tools in the context of high-quality field surveillance to improve diagnosis, patient management, control, and prevention of invasive Salmonella infections in Africa.
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Affiliation(s)
- John A. Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Robert S. Heyderman
- Division of Infection and Immunity, Faculty of Medical Sciences, University College London, United Kingdom
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre
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71
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Crump JA, Sjölund-Karlsson M, Gordon MA, Parry CM. Epidemiology, Clinical Presentation, Laboratory Diagnosis, Antimicrobial Resistance, and Antimicrobial Management of Invasive Salmonella Infections. Clin Microbiol Rev 2015; 28:901-37. [PMID: 26180063 PMCID: PMC4503790 DOI: 10.1128/cmr.00002-15] [Citation(s) in RCA: 705] [Impact Index Per Article: 70.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Salmonella enterica infections are common causes of bloodstream infection in low-resource areas, where they may be difficult to distinguish from other febrile illnesses and may be associated with a high case fatality ratio. Microbiologic culture of blood or bone marrow remains the mainstay of laboratory diagnosis. Antimicrobial resistance has emerged in Salmonella enterica, initially to the traditional first-line drugs chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole. Decreased fluoroquinolone susceptibility and then fluoroquinolone resistance have developed in association with chromosomal mutations in the quinolone resistance-determining region of genes encoding DNA gyrase and topoisomerase IV and also by plasmid-mediated resistance mechanisms. Resistance to extended-spectrum cephalosporins has occurred more often in nontyphoidal than in typhoidal Salmonella strains. Azithromycin is effective for the management of uncomplicated typhoid fever and may serve as an alternative oral drug in areas where fluoroquinolone resistance is common. In 2013, CLSI lowered the ciprofloxacin susceptibility breakpoints to account for accumulating clinical, microbiologic, and pharmacokinetic-pharmacodynamic data suggesting that revision was needed for contemporary invasive Salmonella infections. Newly established CLSI guidelines for azithromycin and Salmonella enterica serovar Typhi were published in CLSI document M100 in 2015.
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Affiliation(s)
- John A Crump
- Centre for International Health, University of Otago, Dunedin, Otago, New Zealand Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Maria Sjölund-Karlsson
- Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Melita A Gordon
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Christopher M Parry
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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72
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Gilchrist JJ, MacLennan CA, Hill AVS. Genetic susceptibility to invasive Salmonella disease. Nat Rev Immunol 2015; 15:452-63. [PMID: 26109132 DOI: 10.1038/nri3858] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Invasive Salmonella disease, in the form of enteric fever and invasive non-typhoidal Salmonella (iNTS) disease, causes substantial morbidity and mortality in children and adults in the developing world. The study of genetic variations in humans and mice that influence susceptibility of the host to Salmonella infection provides important insights into immunity to Salmonella. In this Review, we discuss data that have helped to elucidate the host genetic determinants of human enteric fever and iNTS disease, alongside data from the mouse model of Salmonella infection. Considered together, these studies provide a detailed picture of the immunobiology of human invasive Salmonella disease.
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Affiliation(s)
- James J Gilchrist
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford OX3 7BN, UK
| | - Calman A MacLennan
- 1] Jenner Institute, Nuffield Department of Medicine, Old Road Campus Research Building, Roosevelt Drive, University of Oxford, Oxford, OX3 7DQ, UK. [2] Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Adrian V S Hill
- 1] Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford OX3 7BN, UK. [2] Jenner Institute, Nuffield Department of Medicine, Old Road Campus Research Building, Roosevelt Drive, University of Oxford, Oxford, OX3 7DQ, UK
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Abstract
Salmonella are gram-negative bacilli within the family Enterobacteriaceae. They are the cause of significant morbidity and mortality worldwide. Animals (pets) are an important reservoir for nontyphoidal Salmonella, whereas humans are the only natural host and reservoir for Salmonella Typhi. Salmonella infections are a major cause of gastroenteritis worldwide. They account for an estimated 2.8 billion cases of diarrheal disease each year. The transmission of Salmonella is frequently associated with the consumption of contaminated water and food of animal origin, and it is facilitated by conditions of poor hygiene. Nontyphoidal Salmonella infections have a worldwide distribution, whereas most typhoidal Salmonella infections in the United States are acquired abroad. In the United States, Salmonella is a common agent for food-borne–associated infections. Several outbreaks have been identified and are most commonly associated with agricultural products. Nontyphoidal Salmonella infection is usually characterized by a self-limited gastroenteritis in immunocompetent hosts in industrialized countries, but it may also cause invasive disease in vulnerable individuals (eg, children less than 1 year of age, immunocompromised). Antibiotic treatment is not recommended for treatment of mild to moderate gastroenteritis by nontyphoidal Salmonella in immunocompetent adults or children more than 1 year of age. Antibiotic treatment is recommended for nontyphoidal Salmonella infections in infants less than 3 months of age, because they are at higher risk for bacteremia and extraintestinal complications. Typhoid (enteric) fever and its potential complications have a significant impact on children, especially those who live in developing countries. Antibiotic treatment of typhoid fever has become challenging because of the emergence of Salmonella Typhi strains that are resistant to classically used first-line agents: ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol. The choice of antibiotics for the management of typhoid fever should be guided by the local resistance pattern. Recommendations include using an extended spectrum cephalosporin, azithromycin, or a fluoroquinolone. Fecal carriage of Salmonella is an important factor in the spread of the organism to healthy individuals. The most important measures to prevent the spread and outbreaks of Salmonella infections and typhoid fever are adequate sanitation protocols for food processing and handling as well as hand hygiene. In the United States, 2 vaccines are commercially available against Salmonella Typhi. The WHO recommends the use of these vaccines in endemic areas and for outbreak control.
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Monoclonal Antibodies of a Diverse Isotype Induced by an O-Antigen Glycoconjugate Vaccine Mediate In Vitro and In Vivo Killing of African Invasive Nontyphoidal Salmonella. Infect Immun 2015; 83:3722-31. [PMID: 26169269 PMCID: PMC4534659 DOI: 10.1128/iai.00547-15] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 06/30/2015] [Indexed: 12/15/2022] Open
Abstract
Nontyphoidal Salmonella (NTS), particularly Salmonella enterica serovars Typhimurium and Enteritidis, is responsible for a major global burden of invasive disease with high associated case-fatality rates. We recently reported the development of a candidate O-antigen–CRM197 glycoconjugate vaccine against S. Typhimurium. Here, using a panel of mouse monoclonal antibodies generated by the vaccine, we examined the relative efficiency of different antibody isotypes specific for the O:4 antigen of S. Typhimurium to effect in vitro and in vivo killing of the invasive African S. Typhimurium strain D23580. All O:4-specific antibody isotypes could mediate cell-free killing and phagocytosis of S. Typhimurium by mouse blood cells. Opsonization of Salmonella with O:4-specific IgA, IgG1, IgG2a, and IgG2b, but not IgM, resulted in cell-dependent bacterial killing. At high concentrations, O:4-specific antibodies inhibited both cell-free complement-mediated and cell-dependent opsonophagocytic killing of S. Typhimurium in vitro. Using passive immunization in mice, the O:4-specific antibodies provided in vivo functional activity by decreasing the bacterial load in the blood and tissues, with IgG2a and IgG2b being the most effective isotypes. In conclusion, an O-antigen–CRM197 glycoconjugate vaccine can induce O-antigen-specific antibodies of different isotypes that exert in vitro and in vivo killing of S. Typhimurium.
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Kariuki S, Gordon MA, Feasey N, Parry CM. Antimicrobial resistance and management of invasive Salmonella disease. Vaccine 2015; 33 Suppl 3:C21-9. [PMID: 25912288 PMCID: PMC4469558 DOI: 10.1016/j.vaccine.2015.03.102] [Citation(s) in RCA: 177] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 01/08/2023]
Abstract
Invasive Salmonella infections (typhoidal and non-typhoidal) cause a huge burden of illness estimated at nearly 3.4 million cases and over 600,000 deaths annually especially in resource-limited settings. Invasive non-typhoidal Salmonella (iNTS) infections are particularly important in immunosuppressed populations especially in sub-Saharan Africa, causing a mortality of 20-30% in vulnerable children below 5 years of age. In these settings, where routine surveillance for antimicrobial resistance is rare or non-existent, reports of 50-75% multidrug resistance (MDR) in NTS are common, including strains of NTS also resistant to flouroquinolones and 3rd generation cephalosporins. Typhoid (enteric) fever caused by Salmonella Typhi and Salmonella Paratyphi A remains a major public health problem in many parts of Asia and Africa. Currently over a third of isolates in many endemic areas are MDR, and diminished susceptibility or resistance to fluoroquinolones, the drugs of choice for MDR cases over the last decade is an increasing problem. The situation is particularly worrying in resource-limited settings where the few remaining effective antimicrobials are either unavailable or altogether too expensive to be afforded by either the general public or by public health services. Although the prudent use of effective antimicrobials, improved hygiene and sanitation and the discovery of new antimicrobial agents may offer hope for the management of invasive salmonella infections, it is essential to consider other interventions including the wider use of WHO recommended typhoid vaccines and the acceleration of trials for novel iNTS vaccines. The main objective of this review is to describe existing data on the prevalence and epidemiology of antimicrobial resistant invasive Salmonella infections and how this affects the management of these infections, especially in endemic developing countries.
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Affiliation(s)
- Samuel Kariuki
- Centre for Microbiology Research, Kenya Medical Research Institute, PO Box 43640-00100, Nairobi, Kenya; The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom.
| | - Melita A Gordon
- Institute for Infection and Global Health, University of Liverpool, United Kingdom; Malawi Liverpool Wellcome Trust Clinical Research Programme, United Kingdom
| | - Nicholas Feasey
- Malawi Liverpool Wellcome Trust Clinical Research Programme, United Kingdom; Liverpool School of Tropical Medicine, United Kingdom
| | - Christopher M Parry
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 5HT, United Kingdom; School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
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Yang J, Barrila J, Roland KL, Kilbourne J, Ott CM, Forsyth RJ, Nickerson CA. Characterization of the Invasive, Multidrug Resistant Non-typhoidal Salmonella Strain D23580 in a Murine Model of Infection. PLoS Negl Trop Dis 2015; 9:e0003839. [PMID: 26091096 PMCID: PMC4474555 DOI: 10.1371/journal.pntd.0003839] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 05/18/2015] [Indexed: 01/09/2023] Open
Abstract
A distinct pathovar of Salmonella enterica serovar Typhimurium, ST313, has emerged in sub-Saharan Africa as a major cause of fatal bacteremia in young children and HIV-infected adults. D23580, a multidrug resistant clinical isolate of ST313, was previously shown to have undergone genome reduction in a manner that resembles that of the more human-restricted pathogen, Salmonella enterica serovar Typhi. It has since been shown through tissue distribution studies that D23580 is able to establish an invasive infection in chickens. However, it remains unclear whether ST313 can cause lethal disease in a non-human host following a natural course of infection. Herein we report that D23580 causes lethal and invasive disease in a murine model of infection following peroral challenge. The LD50 of D23580 in female BALB/c mice was 4.7 x 105 CFU. Tissue distribution studies performed 3 and 5 days post-infection confirmed that D23580 was able to more rapidly colonize the spleen, mesenteric lymph nodes and gall bladder in mice when compared to the well-characterized S. Typhimurium strain SL1344. D23580 exhibited enhanced resistance to acid stress relative to SL1344, which may lend towards increased capability to survive passage through the gastrointestinal tract as well as during its intracellular lifecycle. Interestingly, D23580 also displayed higher swimming motility relative to SL1344, S. Typhi strain Ty2, and the ST313 strain A130. Biochemical tests revealed that D23580 shares many similar metabolic features with SL1344, with several notable differences in the Voges-Proskauer and catalase tests, as well alterations in melibiose, and inositol utilization. These results represent the first full duration infection study using an ST313 strain following the entire natural course of disease progression, and serve as a benchmark for ongoing and future studies into the pathogenesis of D23580. A deadly form of non-typhoidal Salmonella has emerged as a major cause of invasive disease in sub-Saharan Africa. Initial genomic profiling of this novel Salmonella sequence type, ST313, indicated that although it is technically classified as S. Typhimurium (a serovar characterized by a broad host range), it may be evolving towards becoming a more human-specific, ‘typhoid-like’ pathogen. However, it was recently demonstrated that ST313 strains were indeed able to establish an invasive and damaging infection in chickens. Despite these important findings, it remains unclear whether ST313 is able to cause lethal disease in a non-human host, since no study has yet followed the entire natural course of disease progression. As such, there are no data available concerning the median lethal dose (LD50) of any ST313 strain. This is an important metric, as the LD50 value will serve as a benchmark for mechanistic studies focused on understanding the relationship between virulence and the phenotypic and molecular genetic attributes associated with ST313 infections. Here we report that D23580 causes lethal disease in BALB/c mice and determined the LD50 following peroral challenge. Phenotypic characterization revealed distinct differences in tissue distribution, acid stress resistance, and biochemical utilization between D23580 and the ‘classic’ Typhimurium strain SL1344.
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Affiliation(s)
- Jiseon Yang
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Jennifer Barrila
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Kenneth L. Roland
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Jacquelyn Kilbourne
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - C. Mark Ott
- Biomedical Research and Environmental Sciences Division, NASA Johnson Space Center, Houston, Texas, United States of America
| | - Rebecca J. Forsyth
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Cheryl A. Nickerson
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- * E-mail:
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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: 0.8] [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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Dickinson GS, Akkoyunlu M, Bram RJ, Alugupalli KR. BAFF receptor and TACI in B-1b cell maintenance and antibacterial responses. Ann N Y Acad Sci 2015; 1362:57-67. [PMID: 25962322 DOI: 10.1111/nyas.12772] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although evidence of the protective immunity conferred by B-1b cells (CD19(+) B220(+) IgM(hi) Mac1(+) CD5(-)) has been established, the mechanisms governing the maintenance and activation of B-1b cells following pathogen encounter remain unclear. B cell-activating factor (BAFF) and a proliferation-inducing ligand (APRIL) mediate their function in mature B cells through the BAFF receptor (BAFFR) and transmembrane activator and CAML interactor (TACI). BAFFR-deficient mice have lower numbers of B-1b cells, and this reduction is directly proportional to BAFFR levels. The generation of B-1b cells is also dependent on the strength of B cell receptor (BCR) signaling. Mice with impaired BCR signaling, such as X-linked immunodeficient (xid) mice, have B-1b cell deficiency, indicating that both BCR- and BAFFR-mediated signaling are critical for B-1b cell homeostasis. Borrelia hermsii induces expansion and persistence of B-1b cells in xid mice, and these B-1b cells provide a heightened protective response. Toll-like receptor (TLR)-mediated stimulation of xid B cells results in a significant increase in TACI expression and restoration of TACI-mediated functions. The activation of TLR signaling by B. hermsii and BCR/TLR costimulation-mediated upregulation of BAFFR and TACI on B-1b cells suggests that B-1b cell maintenance and function following bacterial exposure may depend on BAFFR- and TACI-mediated signaling. In fact, the loss of both BAFFR and TACI results in a greater impairment in anti-B. hermsii responses compared to deficiency of BAFFR or TACI alone.
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Affiliation(s)
- Gregory S Dickinson
- Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Mustafa Akkoyunlu
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland
| | - Richard J Bram
- Department of Pediatrics and Adolescent Medicine, College of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Kishore R Alugupalli
- Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
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Onsare RS, Micoli F, Lanzilao L, Alfini R, Okoro CK, Muigai AW, Revathi G, Saul A, Kariuki S, MacLennan CA, Rondini S. Relationship between antibody susceptibility and lipopolysaccharide O-antigen characteristics of invasive and gastrointestinal nontyphoidal Salmonellae isolates from Kenya. PLoS Negl Trop Dis 2015; 9:e0003573. [PMID: 25739091 PMCID: PMC4352093 DOI: 10.1371/journal.pntd.0003573] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 01/28/2015] [Indexed: 01/01/2023] Open
Abstract
Background Nontyphoidal Salmonellae (NTS) cause a large burden of invasive and gastrointestinal disease among young children in sub-Saharan Africa. No vaccine is currently available. Previous reports indicate the importance of the O-antigen of Salmonella lipopolysaccharide for virulence and resistance to antibody-mediated killing. We hypothesised that isolates with more O-antigen have increased resistance to antibody-mediated killing and are more likely to be invasive than gastrointestinal. Methodology/Principal Findings We studied 192 NTS isolates (114 Typhimurium, 78 Enteritidis) from blood and stools, mostly from paediatric admissions in Kenya 2000–2011. Isolates were tested for susceptibility to antibody-mediated killing, using whole adult serum. O-antigen structural characteristics, including O-acetylation and glucosylation, were investigated. Overall, isolates were susceptible to antibody-mediated killing, but S. Enteritidis were less susceptible and expressed more O-antigen than Typhimurium (p<0.0001 for both comparisons). For S. Typhimurium, but not Enteritidis, O-antigen expression correlated with reduced sensitivity to killing (r = 0.29, 95% CI = 0.10-0.45, p = 0.002). Both serovars expressed O-antigen populations ranging 21–33 kDa average molecular weight. O-antigen from most Typhimurium were O-acetylated on rhamnose and abequose residues, while Enteritidis O-antigen had low or no O-acetylation. Both Typhimurium and Enteritidis O-antigen were approximately 20%–50% glucosylated. Amount of S. Typhimurium O-antigen and O-antigen glucosylation level were inversely related. There was no clear association between clinical presentation and antibody susceptibility, O-antigen level or other O-antigen features. Conclusion/Significance Kenyan S. Typhimurium and Enteritidis clinical isolates are susceptible to antibody-mediated killing, with degree of susceptibility varying with level of O-antigen for S. Typhimurium. This supports the development of an antibody-inducing vaccine against NTS for Africa. No clear differences were found in the phenotype of isolates from blood and stool, suggesting that the same isolates can cause invasive disease and gastroenteritis. Genome studies are required to understand whether invasive and gastrointestinal isolates differ at the genotypic level. Nontyphoidal Salmonellae (NTS) are an emerging major cause of invasive bacterial disease in African children aged less than 5 years and immunocompromised adults, with an estimated case fatality rate of 20–25%. NTS also cause diarrhoea, a killer of about 1.5 million young children annually, mainly in low- and middle-income countries. No vaccine against NTS is available, but improved understanding of the Salmonella bacteria that cause disease in Africa would help the development of new vaccines. The authors characterized a collection of 192 Kenyan NTS strains (114 S. Typhimurium and 78 S. Enteritidis) from blood and stool specimens. All strains could be killed to differing extents by antibodies present in the blood of healthy HIV-uninfected African adults, supporting the development of a vaccine that will induce protective antibodies when given to African children. Differences in killing by antibody were partly related to the amount of O-antigen on the bacterial surface. There were no clear distinction between stains causing invasive disease and diarrhoea, suggesting that the same strains may be capable of causing both forms of disease. Clarification of this will require genomic analysis.
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Affiliation(s)
- Robert S. Onsare
- Centre for Microbiology Research (CMR), Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
- Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Francesca Micoli
- Novartis Vaccines Institute for Global Health (NVGH), Siena, Italy
| | - Luisa Lanzilao
- Novartis Vaccines Institute for Global Health (NVGH), Siena, Italy
| | - Renzo Alfini
- Novartis Vaccines Institute for Global Health (NVGH), Siena, Italy
| | - Chinyere K. Okoro
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Anne W. Muigai
- Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Gunturu Revathi
- Division of Microbiology, Department of Pathology, Aga Khan University Hospital, Nairobi, Kenya
| | - Allan Saul
- Novartis Vaccines Institute for Global Health (NVGH), Siena, Italy
| | - Samuel Kariuki
- Centre for Microbiology Research (CMR), Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | | | - Simona Rondini
- Novartis Vaccines Institute for Global Health (NVGH), Siena, Italy
- * E-mail:
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Kintz E, Davies MR, Hammarlöf DL, Canals R, Hinton JCD, van der Woude MW. A BTP1 prophage gene present in invasive non-typhoidal Salmonella determines composition and length of the O-antigen of the lipopolysaccharide. Mol Microbiol 2015; 96:263-75. [PMID: 25586744 PMCID: PMC4413052 DOI: 10.1111/mmi.12933] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2015] [Indexed: 12/20/2022]
Abstract
Salmonella Typhimurium isolate D23580 represents a recently identified ST313 lineage of invasive non-typhoidal Salmonellae (iNTS). One of the differences between this lineage and other non-iNTS S. Typhimurium isolates is the presence of prophage BTP1. This prophage encodes a gtrC gene, implicated in O-antigen modification. GtrCBTP1 is essential for maintaining O-antigen length in isolate D23580, since a gtrBTP1 mutant yields a short O-antigen. This phenotype can be complemented by gtrCBTP1 or very closely related gtrC genes. The short O-antigen of the gtrBTP1 mutant was also compensated by deletion of the BTP1 phage tailspike gene in the D23580 chromosome. This tailspike protein has a putative endorhamnosidase domain and thus may mediate O-antigen cleavage. Expression of the gtrCBTP1 gene is, in contrast to expression of many other gtr operons, not subject to phase variation and transcriptional analysis suggests that gtrC is produced under a variety of conditions. Additionally, GtrCBTP1 expression is necessary and sufficient to provide protection against BTP1 phage infection of an otherwise susceptible strain. These data are consistent with a model in which GtrCBTP1 mediates modification of the BTP1 phage O-antigen receptor in lysogenic D23580, and thereby prevents superinfection by itself and other phage that uses the same O-antigen co-receptor.
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Affiliation(s)
- Erica Kintz
- Centre for Immunology and Infection, Hull York Medical School and the Department of Biology, University of York, York, UK
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Chetanbhai MF, Eshwara KV, Vinay P, Chiranjay M. Nontyphoidal salmonellosis and multiple ring enhancing lesions in the brain of an HIV infected adult: a diagnostic dilemma. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2015. [DOI: 10.1016/s2222-1808(14)60642-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Carden S, Okoro C, Dougan G, Monack D. Non-typhoidal Salmonella Typhimurium ST313 isolates that cause bacteremia in humans stimulate less inflammasome activation than ST19 isolates associated with gastroenteritis. Pathog Dis 2014; 73:ftu023. [PMID: 25808600 PMCID: PMC4399442 DOI: 10.1093/femspd/ftu023] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2014] [Indexed: 02/07/2023] Open
Abstract
Salmonella is an enteric pathogen that causes a range of diseases in humans. Non-typhoidal Salmonella (NTS) serovars such as Salmonella enterica serovar Typhimurium generally cause a self-limiting gastroenteritis whereas typhoidal serovars cause a systemic disease, typhoid fever. However, S. Typhimurium isolates within the multi-locus sequence type ST313 have emerged in sub-Saharan Africa as a major cause of bacteremia in humans. The S. Typhimurium ST313 lineage is phylogenetically distinct from classical S. Typhimurium lineages, such as ST19, that cause zoonotic gastroenteritis worldwide. Previous studies have shown that the ST313 lineage has undergone genome degradation when compared to the ST19 lineage, similar to that observed for typhoidal serovars. Currently, little is known about phenotypic differences between ST313 isolates and other NTS isolates. We find that representative ST313 isolates invade non-phagocytic cells less efficiently than the classical ST19 isolates that are more commonly associated with gastroenteritis. In addition, ST313 isolates induce less Caspase-1-dependent macrophage death and IL-1β release than ST19 isolates. ST313 isolates also express relatively lower levels of mRNA of the genes encoding the SPI-1 effector sopE2 and the flagellin, fliC, providing possible explanations for the decrease in invasion and inflammasome activation. The ST313 isolates have invasion and inflammatory phenotypes that are intermediate; more invasive and inflammatory than Salmonella enterica serovar Typhi and less than ST19 isolates associated with gastroenteritis. This suggests that both phenotypically and at the genomic level ST313 isolates are evolving signatures that facilitate a systemic lifestyle in humans.
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Affiliation(s)
- Sarah Carden
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Chinyere Okoro
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Denise Monack
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
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83
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MacLennan CA. Antibodies and protection against invasive salmonella disease. Front Immunol 2014; 5:635. [PMID: 25566248 PMCID: PMC4273658 DOI: 10.3389/fimmu.2014.00635] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 11/27/2014] [Indexed: 11/29/2022] Open
Affiliation(s)
- Calman A MacLennan
- Novartis Vaccines Institute for Global Health , Siena , Italy ; School of Immunity and Infection, College of Medicine and Dental Sciences, University of Birmingham , Birmingham , UK
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Lam LH, Monack DM. Intraspecies competition for niches in the distal gut dictate transmission during persistent Salmonella infection. PLoS Pathog 2014; 10:e1004527. [PMID: 25474319 PMCID: PMC4256465 DOI: 10.1371/journal.ppat.1004527] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 10/16/2014] [Indexed: 12/31/2022] Open
Abstract
In order to be transmitted, a pathogen must first successfully colonize and multiply within a host. Ecological principles can be applied to study host-pathogen interactions to predict transmission dynamics. Little is known about the population biology of Salmonella during persistent infection. To define Salmonella enterica serovar Typhimurium population structure in this context, 129SvJ mice were oral gavaged with a mixture of eight wild-type isogenic tagged Salmonella (WITS) strains. Distinct subpopulations arose within intestinal and systemic tissues after 35 days, and clonal expansion of the cecal and colonic subpopulation was responsible for increases in Salmonella fecal shedding. A co-infection system utilizing differentially marked isogenic strains was developed in which each mouse received one strain orally and the other systemically by intraperitoneal (IP) injection. Co-infections demonstrated that the intestinal subpopulation exerted intraspecies priority effects by excluding systemic S. Typhimurium from colonizing an extracellular niche within the cecum and colon. Importantly, the systemic strain was excluded from these distal gut sites and was not transmitted to naïve hosts. In addition, S. Typhimurium required hydrogenase, an enzyme that mediates acquisition of hydrogen from the gut microbiota, during the first week of infection to exert priority effects in the gut. Thus, early inhibitory priority effects are facilitated by the acquisition of nutrients, which allow S. Typhimurium to successfully compete for a nutritional niche in the distal gut. We also show that intraspecies colonization resistance is maintained by Salmonella Pathogenicity Islands SPI1 and SPI2 during persistent distal gut infection. Thus, important virulence effectors not only modulate interactions with host cells, but are crucial for Salmonella colonization of an extracellular intestinal niche and thereby also shape intraspecies dynamics. We conclude that priority effects and intraspecies competition for colonization niches in the distal gut control Salmonella population assembly and transmission.
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Affiliation(s)
- Lilian H. Lam
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Denise M. Monack
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
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85
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Nanton MR, Lee SJ, Atif SM, Nuccio SP, Taylor JJ, Bäumler AJ, Way SS, McSorley SJ. Direct visualization of endogenous Salmonella-specific B cells reveals a marked delay in clonal expansion and germinal center development. Eur J Immunol 2014; 45:428-41. [PMID: 25346524 DOI: 10.1002/eji.201444540] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 09/30/2014] [Accepted: 10/21/2014] [Indexed: 11/11/2022]
Abstract
CD4(+) T cells and B cells are both essential for acquired immunity to Salmonella infection. It is well established that Salmonella inhibit host CD4(+) T-cell responses, but a corresponding inhibitory effect on B cells is less well defined. Here, we utilize an Ag tetramer and pull-down enrichment strategy to directly visualize OVA-specific B cells in mice, as they respond to infection with Salmonella-OVA. Surprisingly, OVA-specific B-cell expansion and germinal center formation was not detected until bacteria were cleared from the host. Furthermore, Salmonella infection also actively inhibited both B- and T-cell responses to the same coinjected Ag but this did not require the presence of iNOS. The Salmonella Pathogenicity Island 2 (SPI2) locus has been shown to be responsible for inhibition of Salmonella-specific CD4(+) T-cell responses, and an examination of SPI2-deficient bacteria demonstrated a recovery in B-cell expansion in infected mice. Together, these data suggest that Salmonella can simultaneously inhibit host B- and T-cell responses using SPI2-dependent mechanisms.
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Affiliation(s)
- Minelva R Nanton
- Center for Comparative Medicine, Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA; Microbiology, Immunology, and Cancer Biology Graduate Program, University of Minnesota Medical School-Twin Cities, Minneapolis, MN, USA
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86
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Cunningham AF, Flores-Langarica A, Bobat S, Dominguez Medina CC, Cook CNL, Ross EA, Lopez-Macias C, Henderson IR. B1b cells recognize protective antigens after natural infection and vaccination. Front Immunol 2014; 5:535. [PMID: 25400633 PMCID: PMC4215630 DOI: 10.3389/fimmu.2014.00535] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 10/10/2014] [Indexed: 12/18/2022] Open
Abstract
There are multiple, distinct B-cell populations in human beings and other animals such as mice. In the latter species, there is a well-characterized subset of B-cells known as B1 cells, which are enriched in peripheral sites such as the peritoneal cavity but are rare in the blood. B1 cells can be further subdivided into B1a and B1b subsets. There may be additional B1 subsets, though it is unclear if these are distinct populations or stages in the developmental process to become mature B1a and B1b cells. A limitation in understanding B1 subsets is the relative paucity of specific surface markers. In contrast to mice, the existence of B1 cells in human beings is controversial and more studies are needed to investigate the nature of these enigmatic cells. Examples of B1b antigens include pneumococcal polysaccharide and the Vi antigen from Salmonella Typhi, both used routinely as vaccines in human beings and experimental antigens such as haptenated-Ficoll. In addition to inducing classical T-dependent responses some proteins are B1b antigens and can induce T-independent (TI) immunity, examples include factor H binding protein from Borrelia hermsii and porins from Salmonella. Therefore, B1b antigens can be proteinaceous or non-proteinaceous, induce TI responses, memory, and immunity, they exist in a diverse range of pathogenic bacteria, and a single species can contain multiple B1b antigens. An unexpected benefit to studying B1b cells is that they appear to have a propensity to recognize protective antigens in bacteria. This suggests that studying B1b cells may be rewarding for vaccine design as immunoprophylactic and immunotherapeutic interventions become more important due to the decreasing efficacy of small molecule antimicrobials.
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Affiliation(s)
- Adam F Cunningham
- MRC Centre for Immune Regulation, Institute for Microbiology and Infection, School of Immunity and Infection, Institute for Biomedical Research, Medical School, University of Birmingham , Birmingham , UK
| | - Adriana Flores-Langarica
- MRC Centre for Immune Regulation, Institute for Microbiology and Infection, School of Immunity and Infection, Institute for Biomedical Research, Medical School, University of Birmingham , Birmingham , UK
| | - Saeeda Bobat
- MRC Centre for Immune Regulation, Institute for Microbiology and Infection, School of Immunity and Infection, Institute for Biomedical Research, Medical School, University of Birmingham , Birmingham , UK
| | - Carmen C Dominguez Medina
- MRC Centre for Immune Regulation, Institute for Microbiology and Infection, School of Immunity and Infection, Institute for Biomedical Research, Medical School, University of Birmingham , Birmingham , UK
| | - Charlotte N L Cook
- MRC Centre for Immune Regulation, Institute for Microbiology and Infection, School of Immunity and Infection, Institute for Biomedical Research, Medical School, University of Birmingham , Birmingham , UK
| | - Ewan A Ross
- MRC Centre for Immune Regulation, Institute for Microbiology and Infection, School of Immunity and Infection, Institute for Biomedical Research, Medical School, University of Birmingham , Birmingham , UK
| | - Constantino Lopez-Macias
- Medical Research Unit on Immunochemistry, National Medical Centre "Siglo XXI", Specialties Hospital, Mexican Institute for Social Security (IMSS) , Mexico City , Mexico
| | - Ian R Henderson
- MRC Centre for Immune Regulation, Institute for Microbiology and Infection, School of Immunity and Infection, Institute for Biomedical Research, Medical School, University of Birmingham , Birmingham , UK
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87
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Huson MAM, Grobusch MP, van der Poll T. The effect of HIV infection on the host response to bacterial sepsis. THE LANCET. INFECTIOUS DISEASES 2014; 15:95-108. [PMID: 25459220 DOI: 10.1016/s1473-3099(14)70917-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Bacterial sepsis is an important cause of morbidity and mortality in patients with HIV. HIV causes increased susceptibility to invasive infections and affects sepsis pathogenesis caused by pre-existing activation and exhaustion of the immune system. We review the effect of HIV on different components of immune responses implicated in bacterial sepsis, and possible mechanisms underlying the increased risk of invasive bacterial infections. We focus on pattern recognition receptors and innate cellular responses, cytokines, lymphocytes, coagulation, and the complement system. A combination of factors causes increased susceptibility to infection and can contribute to a disturbed immune response during a septic event in patients with HIV. HIV-induced perturbations of the immune system depend on stage of infection and are only in part restored by combination antiretroviral therapy. Immunomodulatory treatments currently under development for sepsis might be particularly beneficial to patients with HIV co-infection because many pathogenic mechanisms in HIV and sepsis overlap.
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Affiliation(s)
- Michaëla A M Huson
- Division of Infectious Diseases, Centre of Experimental and Molecular Medicine, University of Amsterdam, Amsterdam, Netherlands.
| | - Martin P Grobusch
- Division of Infectious Diseases, Centre of Tropical Medicine and Travel Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Tom van der Poll
- Division of Infectious Diseases, Centre of Experimental and Molecular Medicine, University of Amsterdam, Amsterdam, Netherlands
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88
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Takem EN, Roca A, Cunnington A. The association between malaria and non-typhoid Salmonella bacteraemia in children in sub-Saharan Africa: a literature review. Malar J 2014; 13:400. [PMID: 25311375 PMCID: PMC4210537 DOI: 10.1186/1475-2875-13-400] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 10/06/2014] [Indexed: 11/21/2022] Open
Abstract
Plasmodium falciparum malaria and non-typhoid Salmonella (NTS) bacteraemia are both major causes of morbidity and mortality in children in sub-Saharan Africa. Co-infections are expected to occur because of their overlapping geographical distribution, but accumulating evidence indicates that malaria is a risk factor for NTS bacteraemia. A literature review was undertaken to provide an overview of the evidence available for this association, the epidemiology of malaria-NTS co-infection (including the highest risk groups), the underlying mechanisms, and the clinical consequences of this association, in children in sub-Saharan Africa. The burden of malaria-NTS co-infection is highest in young children (especially those less than three years old). Malaria is one of the risk factors for NTS bacteraemia in children, and the risk is higher with severe malaria, especially severe malarial anaemia. There is insufficient evidence to determine whether asymptomatic parasitaemia is a risk factor for NTS bacteraemia. Many mechanisms have been proposed to explain how malaria causes susceptibility to NTS, ranging from macrophage dysfunction to increased gut permeability, but the most consistent evidence is that malarial haemolysis creates conditions which favour bacterial growth, by increasing iron availability and by impairing neutrophil function. Few discriminatory clinical features have been described for those with malaria and NTS co-infection, except for a higher risk of anaemia compared to those with either infection alone. Children with malaria and NTS bacteraemia co-infection have higher case fatality rates compared to those with malaria alone, and similar to those with bacteraemia alone. Antimicrobial resistance is becoming widespread in invasive NTS serotypes, making empirical treatment problematic, and increasing the need for prevention measures. Observational studies indicate that interventions to reduce malaria transmission might also have a substantial impact on decreasing the incidence of NTS bacteraemia.
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89
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Effect of human immunodeficiency virus infection on plasma bactericidal activity against Salmonella enterica serovar Typhimurium. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:1437-42. [PMID: 25121777 DOI: 10.1128/cvi.00501-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Individuals with human immunodeficiency virus (HIV) infection have increased susceptibility to invasive disease caused by Salmonella enterica serovar Typhimurium. Studies from Africa have suggested that this susceptibility is related in part to the development of a high level of lipopolysaccharide (LPS)-specific IgG that is able to inhibit the killing of S. Typhimurium by bactericidal antibodies in healthy individuals. To explore this issue further, we examined the bactericidal activity against S. Typhimurium using serum and plasma samples from healthy controls and various clinical subgroups of HIV-infected adults in the United States. We found that the bactericidal activity in the samples from HIV-positive elite controllers was comparable to that from healthy individuals, whereas it was significantly reduced in HIV-positive viremic controllers and untreated chronic progressors. As demonstrated previously for healthy controls, the bactericidal activity of the plasma from the elite controllers was inhibited by preincubation with S. Typhimurium LPS, suggesting that it was mediated by anti-LPS antibodies. S. Typhimurium LPS-specific IgG was significantly reduced in all subgroups of HIV-infected individuals. Interestingly, and in contrast to the healthy controls, plasma from all HIV-positive subgroups inhibited in vitro killing of S. Typhimurium by plasma from a healthy individual. Our results, together with the findings from Africa, suggest that multiple mechanisms may be involved in the HIV-induced dysregulation of humoral immunity to S. Typhimurium.
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90
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Wells TJ, Whitters D, Sevastsyanovich YR, Heath JN, Pravin J, Goodall M, Browning DF, O'Shea MK, Cranston A, De Soyza A, Cunningham AF, MacLennan CA, Henderson IR, Stockley RA. Increased severity of respiratory infections associated with elevated anti-LPS IgG2 which inhibits serum bactericidal killing. ACTA ACUST UNITED AC 2014; 211:1893-904. [PMID: 25113975 PMCID: PMC4144740 DOI: 10.1084/jem.20132444] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An antibody directed against the O-antigen of Pseudomonas aeruginosa LPS can block complement-mediated bacterial killing and contributes to the severity of respiratory infection. Although specific antibody induced by pathogens or vaccines is a key component of protection against infectious threats, some viruses, such as dengue, induce antibody that enhances the development of infection. In contrast, antibody-dependent enhancement of bacterial infection is largely unrecognized. Here, we demonstrate that in a significant portion of patients with bronchiectasis and Pseudomonas aeruginosa lung infection, antibody can protect the bacterium from complement-mediated killing. Strains that resist antibody-induced, complement-mediated killing produce lipopolysaccharide containing O-antigen. The inhibition of antibody-mediated killing is caused by excess production of O-antigen–specific IgG2 antibodies. Depletion of IgG2 to O-antigen restores the ability of sera to kill strains with long-chain O-antigen. Patients with impaired serum-mediated killing of P. aeruginosa by IgG2 have poorer respiratory function than infected patients who do not produce inhibitory antibody. We suggest that excessive binding of IgG2 to O-antigen shields the bacterium from other antibodies that can induce complement-mediated killing of bacteria. As there is significant sharing of O-antigen structure between different Gram-negative bacteria, this IgG2-mediated impairment of killing may operate in other Gram-negative infections. These findings have marked implications for our understanding of protection generated by natural infection and for the design of vaccines, which should avoid inducing such blocking antibodies.
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Affiliation(s)
- Timothy J Wells
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK
| | - Deborah Whitters
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK Lung Investigation Unit, Queen Elizabeth Hospital, Birmingham B15 2TH, England, UK
| | - Yanina R Sevastsyanovich
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK
| | - Jennifer N Heath
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK
| | - John Pravin
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK
| | - Margaret Goodall
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK
| | - Douglas F Browning
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK
| | - Matthew K O'Shea
- The University of Oxford, The Jenner Institute, Oxford OX3 7DQ, England, UK
| | - Amy Cranston
- Sir William Leech Centre for Respiratory Research Newcastle upon Tyne Hospitals Trust, Newcastle NE7 7DN, England, UK
| | - Anthony De Soyza
- Institute of Cellular Medicine, Newcastle University and Adult Bronchiectasis service Freeman Hospital, Newcastle NE7 7DN, England, UK
| | - Adam F Cunningham
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK
| | - Calman A MacLennan
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK
| | - Ian R Henderson
- Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK Institute of Microbiology and Infection, School of Immunity and Infection, School Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, England, UK
| | - Robert A Stockley
- Lung Investigation Unit, Queen Elizabeth Hospital, Birmingham B15 2TH, England, UK
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91
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Geurtsen J, Fae KC, van den Dobbelsteen GPJM. Importance of (antibody-dependent) complement-mediated serum killing in protection against Bordetella pertussis. Expert Rev Vaccines 2014; 13:1229-40. [PMID: 25081731 DOI: 10.1586/14760584.2014.944901] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pertussis is a highly contagious respiratory disease that is caused by Bordetella pertussis. Despite being vaccine preventable, pertussis rates have been rising steadily over the last decades, even in areas with high vaccine uptake. Recently, experiments with infant baboons indicated that although vaccination with acellular pertussis vaccines prevented disease, no apparent effect was observed on infection and transmission. One explanation may be that current acellular pertussis vaccines do not induce high levels of opsonophagocytic and/or bactericidal activity, implying that engineering of vaccines that promote bacterial killing may improve efficacy. Here, we discuss the importance of complement-mediated killing in vaccine-induced protection against B. pertussis. We first examine how B. pertussis may have evolved different complement evasion strategies. Second, we explore the benefits of opsonophagocytic and/or bactericidal killing in vaccine-induced protection and discuss whether or not inclusion of new opsonophagocytic or bactericidal target antigens in pertussis vaccines may benefit efficacy.
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Affiliation(s)
- Jeroen Geurtsen
- Crucell Holland B.V, one of the Janssen Pharmaceutical Companies of Johnson & Johnson - Bacterial Vaccines Research and Development, PO Box 2048, Archimedesweg 4-6, 2333 CN Leiden, The Netherlands
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92
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Independent bottlenecks characterize colonization of systemic compartments and gut lymphoid tissue by salmonella. PLoS Pathog 2014; 10:e1004270. [PMID: 25079958 PMCID: PMC4117638 DOI: 10.1371/journal.ppat.1004270] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 06/10/2014] [Indexed: 02/04/2023] Open
Abstract
Vaccination represents an important instrument to control typhoid fever in humans and protects mice from lethal infection with mouse pathogenic serovars of Salmonella species. Mixed infections with tagged Salmonella can be used in combination with probabilistic models to describe the dynamics of the infection process. Here we used mixed oral infections with tagged Salmonella strains to identify bottlenecks in the infection process in naïve and vaccinated mice. We established a next generation sequencing based method to characterize the composition of tagged Salmonella strains which offers a fast and reliable method to characterise the composition of genome-tagged Salmonella strains. We show that initial colonization of Salmonella was distinguished by a non-Darwinian selection of few bacteria setting up the infection independently in gut associated lymphoid tissue and systemic compartments. Colonization of Peyer's patches fuels the sustained spread of bacteria into mesenteric lymph nodes via dendritic cells. In contrast, infection of liver and spleen originated from an independent pool of bacteria. Vaccination only moderately reduced invasion of Peyer's patches but potently uncoupled bacterial populations present in different systemic compartments. Our data indicate that vaccination differentially skews the capacity of Salmonella to colonize systemic and gut immune compartments and provide a framework for the further dissection of infection dynamics.
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93
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Nyirenda TS, Gilchrist JJ, Feasey NA, Glennie SJ, Bar-Zeev N, Gordon MA, MacLennan CA, Mandala WL, Heyderman RS. Sequential acquisition of T cells and antibodies to nontyphoidal Salmonella in Malawian children. J Infect Dis 2014; 210:56-64. [PMID: 24443544 PMCID: PMC4054899 DOI: 10.1093/infdis/jiu045] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 01/10/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Salmonella Typhimurium (STm) remain a prominent cause of bacteremia in sub-Saharan Africa. Complement-fixing antibodies to STm develop by 2 years of age. We hypothesized that STm-specific CD4⁺ T cells develop alongside this process. METHODS Eighty healthy Malawian children aged 0-60 months were recruited. STm-specific CD4⁺ T cells producing interferon γ, tumor necrosis factor α, and interleukin 2 were quantified using intracellular cytokine staining. Antibodies to STm were measured by serum bactericidal activity (SBA) assay, and anti-STm immunoglobulin G antibodies by enzyme-linked immunosorbent assay. RESULTS Between 2006 and 2011, STm bacteremias were detected in 449 children <5 years old. STm-specific CD4⁺ T cells were acquired in infancy, peaked at 14 months, and then declined. STm-specific SBA was detectable in newborns, declined in the first 8 months, and then increased to a peak at age 35 months. Acquisition of SBA correlated with acquisition of anti-STm-lipopolysaccharide (LPS) immunoglobulin G (r = 0.329 [95% confidence interval, .552-.062]; P = .01) but not anti-STm-outer membrane protein or anti-STm-flagellar protein (FliC). CONCLUSIONS Acquisition of STm-specific CD4⁺ T cells in early childhood is consistent with early exposure to STm or cross-reactive protein antigens priming this T-cell development. STm-specific CD4⁺ T cells seem insufficient to protect against invasive nontyphoidal Salmonella disease, but sequential acquisition of SBA to STm LPS is associated with a decline in its incidence.
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Affiliation(s)
| | | | - Nicholas A. Feasey
- Malawi Liverpool Wellcome Trust Clinical Research Programme
- Liverpool School of Tropical Medicine
| | | | - Naor Bar-Zeev
- Malawi Liverpool Wellcome Trust Clinical Research Programme
| | - Melita A. Gordon
- Institute of Infection and Global Health, University of Liverpool
| | - Calman A. MacLennan
- Medical Research Council Centre for Immune Regulation, Institute of Biomedical Research, College of Medicine and Dental Sciences, University of Birmingham, United Kingdom
- Novartis Vaccines Institute for Global Health, Siena, Italy
| | - Wilson L. Mandala
- Biochemistry Section, Basic Medical Sciences Department, University of Malawi College of Medicine, Blantyre
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94
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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: 162] [Impact Index Per Article: 14.7] [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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95
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Perez-Shibayama C, Gil-Cruz C, Pastelin-Palacios R, Cervantes-Barragan L, Hisaki E, Chai Q, Onder L, Scandella E, Regen T, Waisman A, Isibasi A, Lopez-Macias C, Ludewig B. IFN-γ-producing CD4+ T cells promote generation of protective germinal center-derived IgM+ B cell memory against Salmonella Typhi. THE JOURNAL OF IMMUNOLOGY 2014; 192:5192-200. [PMID: 24778443 DOI: 10.4049/jimmunol.1302526] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Abs play a significant role in protection against the intracellular bacterium Salmonella Typhi. In this article, we investigated how long-term protective IgM responses can be elicited by a S. Typhi outer-membrane protein C- and F-based subunit vaccine (porins). We found that repeated Ag exposure promoted a CD4(+) T cell-dependent germinal center reaction that generated mutated IgM-producing B cells and was accompanied by a strong expansion of IFN-γ-secreting T follicular helper cells. Genetic ablation of individual cytokine receptors revealed that both IFN-γ and IL-17 are required for optimal germinal center reactions and production of porin-specific memory IgM(+) B cells. However, more profound reduction of porin-specific IgM B cell responses in the absence of IFN-γR signaling indicated that this cytokine plays a dominant role. Importantly, mutated IgM mAbs against porins exhibited bactericidal capacity and efficiently augmented S. Typhi clearance. In conclusion, repeated vaccination with S. Typhi porins programs type I T follicular helper cell responses that contribute to the diversification of B cell memory and promote the generation of protective IgM Abs.
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Affiliation(s)
- Christian Perez-Shibayama
- Institute of Immunobiology, Kantonal Hospital St. Gallen, CH-9007 St. Gallen, Switzerland; Medical Research Unit on Immunochemistry, Specialties Hospital, National Medical Centre "Siglo XXI," Mexican Social Security Institute, Mexico City, C.P. 06020 Mexico
| | - Cristina Gil-Cruz
- Institute of Immunobiology, Kantonal Hospital St. Gallen, CH-9007 St. Gallen, Switzerland; Medical Research Unit on Immunochemistry, Specialties Hospital, National Medical Centre "Siglo XXI," Mexican Social Security Institute, Mexico City, C.P. 06020 Mexico
| | | | - Luisa Cervantes-Barragan
- Institute of Immunobiology, Kantonal Hospital St. Gallen, CH-9007 St. Gallen, Switzerland; Department of Pathology, Washington University School of Medicine, St. Louis, MO 63130; Department of Immunology, Washington University School of Medicine, St. Louis, MO 63130; and
| | - Emiliano Hisaki
- Medical Research Unit on Immunochemistry, Specialties Hospital, National Medical Centre "Siglo XXI," Mexican Social Security Institute, Mexico City, C.P. 06020 Mexico
| | - Qian Chai
- Institute of Immunobiology, Kantonal Hospital St. Gallen, CH-9007 St. Gallen, Switzerland
| | - Lucas Onder
- Institute of Immunobiology, Kantonal Hospital St. Gallen, CH-9007 St. Gallen, Switzerland
| | - Elke Scandella
- Institute of Immunobiology, Kantonal Hospital St. Gallen, CH-9007 St. Gallen, Switzerland
| | - Tommy Regen
- Institute for Molecular Medicine, University of Mainz, D-55131 Mainz, Germany
| | - Ari Waisman
- Institute for Molecular Medicine, University of Mainz, D-55131 Mainz, Germany
| | - Armando Isibasi
- Medical Research Unit on Immunochemistry, Specialties Hospital, National Medical Centre "Siglo XXI," Mexican Social Security Institute, Mexico City, C.P. 06020 Mexico
| | - Constantino Lopez-Macias
- Medical Research Unit on Immunochemistry, Specialties Hospital, National Medical Centre "Siglo XXI," Mexican Social Security Institute, Mexico City, C.P. 06020 Mexico
| | - Burkhard Ludewig
- Institute of Immunobiology, Kantonal Hospital St. Gallen, CH-9007 St. Gallen, Switzerland;
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96
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Vaccination with a single CD4 T cell peptide epitope from a Salmonella type III-secreted effector protein provides protection against lethal infection. Infect Immun 2014; 82:2424-33. [PMID: 24686055 DOI: 10.1128/iai.00052-14] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Salmonella infections affect millions worldwide and remain a significant cause of morbidity and mortality. It is known from mouse studies that CD4 T cells are essential mediators of immunity against Salmonella infection, yet it is not clear whether targeting CD4 T cell responses directly with peptide vaccines against Salmonella can be effective in combating infection. Additionally, it is not known whether T cell responses elicited against Salmonella secreted effector proteins can provide protective immunity against infection. In this study, we investigated both of these possibilities using prime-boost immunization of susceptible mice with a single CD4 T cell peptide epitope from Salmonella secreted effector protein I (SseI), a component of the Salmonella type III secretion system. This immunization conferred significant protection against lethal oral infection, equivalent to that conferred by whole heat-killed Salmonella bacteria. Surprisingly, a well-characterized T cell epitope from the flagellar protein FliC afforded no protection compared to immunization with an irrelevant control peptide. The protective response appeared to be most associated with polyfunctional CD4 T cells raised against the SseI peptide, since no antibodies were produced against any of the peptides and very little CD8 T cell response was observed. Overall, this study demonstrates that eliciting CD4 T cell responses against components of the Salmonella type III secretion system can contribute to protection against infection and should be considered in the design of future Salmonella subunit vaccines.
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97
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Siggins MK, O'Shaughnessy CM, Pravin J, Cunningham AF, Henderson IR, Drayson MT, MacLennan CA. Differential timing of antibody-mediated phagocytosis and cell-free killing of invasive African Salmonella allows immune evasion. Eur J Immunol 2014; 44:1093-8. [PMID: 24375424 DOI: 10.1002/eji.201343529] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Revised: 10/17/2013] [Accepted: 12/19/2013] [Indexed: 11/07/2022]
Abstract
Nontyphoidal Salmonellae commonly cause fatal bacteraemia in African children lacking anti-Salmonella antibodies. These are facultative intracellular bacteria capable of cell-free and intracellular survival within macrophages. To better understand the relationship between extracellular and intracellular infection in blood and general mechanisms of Ab-related protection against Salmonella, we used human blood and sera to measure kinetics of Ab and complement deposition, serum-mediated bactericidal killing and phagocytosis of invasive African Salmonella enterica serovar Typhimurium D23580. Binding of antibodies peaked by 30 s, but C3 deposition lagged behind, peaking after 2-4 min. C5b-9 deposition was undetectable until between 2 and 6 min and peaked after 10 min, after which time an increase in serum-mediated killing occurred. In contrast, intracellular, opsonized Salmonellae were readily detectable within 5 min. By 10 min, around half of monocytes and most neutrophils contained bacteria. The same kinetics of serum-mediated killing and phagocytosis were observed with S. enterica Typhimurium laboratory strain SL1344, and the S. enterica Enteritidis African invasive isolate D24954 and laboratory strain PT4. The differential kinetics between cell-free killing and phagocytosis of invasive nontyphoidal Salmonella allows these bacteria to escape the blood and establish intracellular infection before they are killed by the membrane attack complex.
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Affiliation(s)
- Matthew K Siggins
- 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; Novartis Vaccines Institute for Global Health, Siena, Italy
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98
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Strugnell RA, Scott TA, Wang N, Yang C, Peres N, Bedoui S, Kupz A. Salmonella vaccines: lessons from the mouse model or bad teaching? Curr Opin Microbiol 2014; 17:99-105. [PMID: 24440968 DOI: 10.1016/j.mib.2013.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 12/15/2013] [Accepted: 12/16/2013] [Indexed: 10/25/2022]
Abstract
Salmonella enterica subsp. enterica includes several very important human serovars including Typhi, Paratyphi, Typhimurium and Enteritidis. These bacteria cause a significant global burden of disease, typically classified into enteric fever, gastroenteritis and, more recently, invasive non-typhoidal salmonellosis (iNTS). Vaccines have been developed for one of these serovars, S. Typhi and the recent increase in iNTS cases has resulted in a push to develop new vaccines that will inhibit disease by S. Typhimurium and S. Enteritidis, the most common iNTS S. enterica serovars. The development of new human vaccines has been informed by studies in the murine model of typhoid fever based on S. Typhimurium infections of very 'sensitive' (Nramp-1(S)) mice, which has some obvious deficiencies, not the least that antibodies protect humans against S. Typhi infection but are only weakly protective in 'sensitive' mice infected with S. Typhimurium. S. Typhimurium also lacks Vi, the target of protective antibodies in typhoid fever. Notwithstanding these deficiencies, the murine model has identified a very complex series of innate and adaptive immune responses to infection that might be exploited to develop new vaccines. Equally, advances in understanding the pathogenesis of infection, through pathogenomics and more sophisticated animal models will likely contribute to the development of novel immunogens.
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Affiliation(s)
- Richard A Strugnell
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC 3010, Australia.
| | - Timothy A Scott
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Nancy Wang
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Chenying Yang
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Newton Peres
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Sammy Bedoui
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Andreas Kupz
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC 3010, Australia
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99
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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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100
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MacLennan CA, Levine MM. Invasive nontyphoidal Salmonella disease in Africa: current status. Expert Rev Anti Infect Ther 2013; 11:443-6. [PMID: 23627848 DOI: 10.1586/eri.13.27] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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