1
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Depew CE, Rixon JA, McSorley SJ. Optimal generation of hepatic tissue-resident memory CD4 T cells requires IL-1 and IL-2. Proc Natl Acad Sci U S A 2023; 120:e2214699120. [PMID: 37040404 PMCID: PMC10120061 DOI: 10.1073/pnas.2214699120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 02/23/2023] [Indexed: 04/12/2023] Open
Abstract
Hepatic CD4 tissue-resident memory T cells (TRM) are required for robust protection against Salmonella infection; however, the generation of this T cell population is poorly understood. To interrogate the contribution of inflammation, we developed a simple Salmonella-specific T cell transfer system that allowed direct visualization of hepatic TRM formation. Salmonella-specific (SM1) T cell receptor (TCR) transgenic CD4 T cells were activated in vitro and adoptively transferred into C57BL/6 mice while hepatic inflammation was induced by acetaminophen overdose or L. monocytogenes infection. In both model systems, hepatic CD4 TRM formation was accentuated by local tissue responses. Liver inflammation also enhanced the suboptimal protection provided by a subunit Salmonella vaccine which typically induces circulating memory CD4 T cells. To further elucidate the mechanism of CD4 TRM formation in response to liver inflammation, various cytokines were examined by RNAseq, bone marrow chimeras, and in vivo neutralization. Surprisingly, IL-2 and IL-1 were found to enhance CD4 TRM formation. Thus, local inflammatory mediators enhance CD4 TRM populations and can boost the protective immunity provided by a suboptimal vaccine. This knowledge will be foundational for the development of a more effective vaccine against invasive nontyphoidal salmonellosis (iNTS).
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Affiliation(s)
- Claire E. Depew
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA95616
| | - Jordan A. Rixon
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA95616
| | - Stephen J. McSorley
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA95616
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2
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Optimal protection against Salmonella infection requires noncirculating memory. Proc Natl Acad Sci U S A 2018; 115:10416-10421. [PMID: 30254173 DOI: 10.1073/pnas.1808339115] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
While CD4 Th1 cells are required for resistance to intramacrophage infections, adoptive transfer of Th1 cells is insufficient to protect against Salmonella infection. Using an epitope-tagged vaccine strain of Salmonella, we found that effective protection correlated with expanded Salmonella-specific memory CD4 T cells in circulation and nonlymphoid tissues. However, naive mice that previously shared a blood supply with vaccinated partners lacked T cell memory with characteristics of tissue residence and did not acquire robust protective immunity. Using a YFP-IFN-γ reporter system, we identified Th1 cells in the liver of immunized mice that displayed markers of tissue residence, including P2X7, ARTC2, LFA-1, and CD101. Adoptive transfer of liver memory cells after ARTC2 blockade increased protection against highly virulent bacteria. Taken together, these data demonstrate that noncirculating memory Th1 cells are a vital component of immunity to Salmonella infection and should be the focus of vaccine strategies.
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3
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Issac JM, Mohamed YA, Bashir GH, Al-Sbiei A, Conca W, Khan TA, Iqbal A, Riemekasten G, Bieber K, Ludwig RJ, Cabral-Marques O, Fernandez-Cabezudo MJ, Al-Ramadi BK. Induction of Hypergammaglobulinemia and Autoantibodies by Salmonella Infection in MyD88-Deficient Mice. Front Immunol 2018; 9:1384. [PMID: 29973931 PMCID: PMC6019449 DOI: 10.3389/fimmu.2018.01384] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 06/04/2018] [Indexed: 12/14/2022] Open
Abstract
Growing evidence indicates a link between persistent infections and the development of autoimmune diseases. For instance, the inability to control Salmonella infection due to defective toll-like receptor (TLR)/myeloid differentiation primary response 88 (MyD88) signaling has linked the development of persistent infections to a breakdown in B cell tolerance. However, the extent of immune dysregulation in the absence of TLR-MyD88 signaling remains poorly characterized. Here, we show that MyD88−/− mice are unable to eliminate attenuated Salmonella enterica serovar Typhimurium, even when challenged with a low-dose inoculum (200 CFUs/mouse), developing a persistent and progressive infection when compared to wild-type (MyD88+/+) animals. The splenic niche of MyD88−/− mice revealed increased counts of activated, Sca-1-positive, myeloid subpopulations highly expressing BAFF during persistent Salmonella infection. Likewise, the T cell compartment of Salmonella-infected MyD88−/− mice showed increased levels of CD4+ and CD8+ T cells expressing Sca-1 and CD25 and producing elevated amounts of IL-4, IL-10, and IL-21 in response to CD3/CD28 stimulation. This was associated with increased Tfh cell differentiation and the presence of CD4+ T cells co-expressing IFN-γ/IL-4 and IFN-γ/IL-10. Noteworthy, infected MyD88−/− mice had enhanced serum titers of both anti-Salmonella antibodies as well as autoantibodies directed against double-stranded DNA, thyroglobulin, and IgG rheumatoid factor, positive nuclear staining with HEp-2 cells, and immune complex deposition in the kidneys of MyD88−/− mice infected with live but not heat-killed Salmonella. Infection with other microorganisms (Acinetobacter baumanii, Streptococcus agalactiae, or Escherichia coli) was unable to trigger the autoimmune phenomenon. Our findings suggest that dysregulation of the immune response in the absence of MyD88 is pathogen-dependent and highlight potentially important genotype–environmental factor correlations.
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Affiliation(s)
- Jincy M Issac
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Yassir A Mohamed
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Ghada Hassan Bashir
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Ashraf Al-Sbiei
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Walter Conca
- Department of Internal Medicine, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Taj A Khan
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Asif Iqbal
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | | | - Katja Bieber
- Lübeck Institute of Experimental Dermatology, University of Lübeck, Lübeck, Germany
| | - Ralf J Ludwig
- Lübeck Institute of Experimental Dermatology, University of Lübeck, Lübeck, Germany
| | | | - Maria J Fernandez-Cabezudo
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Basel K Al-Ramadi
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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4
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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: 24] [Impact Index Per Article: 4.0] [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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5
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Human genetic variation in VAC14 regulates Salmonella invasion and typhoid fever through modulation of cholesterol. Proc Natl Acad Sci U S A 2017; 114:E7746-E7755. [PMID: 28827342 DOI: 10.1073/pnas.1706070114] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Risk, severity, and outcome of infection depend on the interplay of pathogen virulence and host susceptibility. Systematic identification of genetic susceptibility to infection is being undertaken through genome-wide association studies, but how to expeditiously move from genetic differences to functional mechanisms is unclear. Here, we use genetic association of molecular, cellular, and human disease traits and experimental validation to demonstrate that genetic variation affects expression of VAC14, a phosphoinositide-regulating protein, to influence susceptibility to Salmonella enterica serovar Typhi (S Typhi) infection. Decreased VAC14 expression increased plasma membrane cholesterol, facilitating Salmonella docking and invasion. This increased susceptibility at the cellular level manifests as increased susceptibility to typhoid fever in a Vietnamese population. Furthermore, treating zebrafish with a cholesterol-lowering agent, ezetimibe, reduced susceptibility to S Typhi. Thus, coupling multiple genetic association studies with mechanistic dissection revealed how VAC14 regulates Salmonella invasion and typhoid fever susceptibility and may open doors to new prophylactic/therapeutic approaches.
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6
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Lee SJ, Benoun J, Sheridan BS, Fogassy Z, Pham O, Pham QM, Puddington L, McSorley SJ. Dual Immunization with SseB/Flagellin Provides Enhanced Protection against Salmonella Infection Mediated by Circulating Memory Cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2017; 199:1353-1361. [PMID: 28710253 PMCID: PMC5548602 DOI: 10.4049/jimmunol.1601357] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 06/19/2017] [Indexed: 01/09/2023]
Abstract
The development of a subunit Salmonella vaccine has been hindered by the absence of detailed information about antigenic targets of protective Salmonella-specific T and B cells. Recent studies have identified SseB as a modestly protective Ag in susceptible C57BL/6 mice, but the mechanism of protective immunity remains undefined. In this article, we report that simply combining Salmonella SseB with flagellin substantially enhances protective immunity, allowing immunized C57BL/6 mice to survive for up to 30 d following challenge with virulent bacteria. Surprisingly, the enhancing effect of flagellin did not require flagellin Ag targeting during secondary responses or recognition of flagellin by TLR5. Although coimmunization with flagellin did not affect SseB-specific Ab responses, it modestly boosted CD4 responses. In addition, protective immunity was effectively transferred in circulation to parabionts of immunized mice, demonstrating that tissue-resident memory is not required for vaccine-induced protection. Finally, protective immunity required host expression of IFN-γR but was independent of induced NO synthase expression. Taken together, these data indicate that Salmonella flagellin has unique adjuvant properties that improve SseB-mediated protective immunity provided by circulating memory.
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Affiliation(s)
- Seung-Joo Lee
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
| | - Joseph Benoun
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
| | - Brian S Sheridan
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030
| | - Zachary Fogassy
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
| | - Oanh Pham
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
| | - Quynh-Mai Pham
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030
| | - Lynn Puddington
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030
| | - Stephen J McSorley
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616;
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
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7
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Steele AD, Hay Burgess DC, Diaz Z, Carey ME, Zaidi AKM. Challenges and Opportunities for Typhoid Fever Control: A Call for Coordinated Action. Clin Infect Dis 2016; 62 Suppl 1:S4-8. [PMID: 26933019 PMCID: PMC4772836 DOI: 10.1093/cid/civ976] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The burden of enteric fever caused by Salmonella enterica serovars Typhi and Paratyphi is substantial and has high impact in toddlers and young children. This burden is relatively well documented in Asia, and this supplement provides new data on the substantial burden in several sub-Saharan African countries. Challenges in standardized surveillance and imperfect diagnostic tools have resulted in patchy local disease data, which are not well acknowledged or integrated into local country evidence and health awareness for decision making. There is a need to strengthen diagnostics for the generation of burden data in country. Furthermore, the guidelines and training for treatment of enteric fever cases in Africa are sorely needed to help mitigate the inappropriate use of antimicrobial treatment. Classic water safety and access to sanitation development remain powerful tools for the control of typhoid fever, yet the huge economic costs and long timelines are unlikely to provide a short- to middle-term solution. Emerging threats, including multidrug resistance and increasing urbanization in regions such as sub-Saharan Africa, warrant focused attention to shorter-term interventions including immunization, and must include vaccine strategies with the new typhoid conjugate vaccines.
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Affiliation(s)
- A Duncan Steele
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Deborah C Hay Burgess
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Zoey Diaz
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Megan E Carey
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Anita K M Zaidi
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
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8
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Salmonella Infection Enhances Erythropoietin Production by the Kidney and Liver, Which Correlates with Elevated Bacterial Burdens. Infect Immun 2016; 84:2833-41. [PMID: 27456828 PMCID: PMC5038055 DOI: 10.1128/iai.00337-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/18/2016] [Indexed: 02/06/2023] Open
Abstract
Salmonella infection profoundly affects host erythroid development, but the mechanisms responsible for this effect remain poorly understood. We monitored the impact of Salmonella infection on erythroid development and found that systemic infection induced anemia, splenomegaly, elevated erythropoietin (EPO) levels, and extramedullary erythropoiesis in a process independent of Salmonella pathogenicity island 2 (SPI2) or flagellin. The circulating EPO level was also constitutively higher in mice lacking the expression of signal-regulatory protein α (SIRPα). The expression level of EPO mRNA was elevated in the kidney and liver but not increased in the spleens of infected mice despite the presence of extramedullary erythropoiesis in this tissue. In contrast to data from a previous report, mice lacking EPO receptor (EPOR) expression on nonerythroid cells (EPOR rescued) had bacterial loads similar to those of wild-type mice following Salmonella infection. Indeed, treatment to reduce splenic erythroblasts and mature red blood cells correlated with elevated bacterial burdens, implying that extramedullary erythropoiesis benefits the host. Together, these findings emphasize the profound effect of Salmonella infection on erythroid development and suggest that the modulation of erythroid development has both positive and negative consequences for host immunity.
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9
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Di Niro R, Lee SJ, Vander Heiden JA, Elsner RA, Trivedi N, Bannock JM, Gupta NT, Kleinstein SH, Vigneault F, Gilbert TJ, Meffre E, McSorley SJ, Shlomchik MJ. Salmonella Infection Drives Promiscuous B Cell Activation Followed by Extrafollicular Affinity Maturation. Immunity 2015; 43:120-31. [PMID: 26187411 PMCID: PMC4523395 DOI: 10.1016/j.immuni.2015.06.013] [Citation(s) in RCA: 159] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 03/25/2015] [Accepted: 06/16/2015] [Indexed: 12/25/2022]
Abstract
The B cell response to Salmonella typhimurium (STm) occurs massively at extrafollicular sites, without notable germinal centers (GCs). Little is known in terms of its specificity. To expand the knowledge of antigen targets, we screened plasmablast (PB)-derived monoclonal antibodies (mAbs) for Salmonella specificity, using ELISA, flow cytometry, and antigen microarray. Only a small fraction (0.5%-2%) of the response appeared to be Salmonella-specific. Yet, infection of mice with limited B cell receptor (BCR) repertoires impaired the response, suggesting that BCR specificity was important. We showed, using laser microdissection, that somatic hypermutation (SHM) occurred efficiently at extrafollicular sites leading to affinity maturation that in turn led to detectable STm Ag-binding. These results suggest a revised vision of how clonal selection and affinity maturation operate in response to Salmonella. Clonal selection initially is promiscuous, activating cells with virtually undetectable affinity, yet SHM and selection occur during the extrafollicular response yielding higher affinity, detectable antibodies.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- B-Lymphocytes/immunology
- Clonal Selection, Antigen-Mediated/genetics
- Clonal Selection, Antigen-Mediated/immunology
- Germinal Center/immunology
- Immunoglobulin G/biosynthesis
- Immunoglobulin G/immunology
- Lymphocyte Activation/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/immunology
- Salmonella Infections/immunology
- Salmonella Infections/microbiology
- Salmonella typhimurium/immunology
- Somatic Hypermutation, Immunoglobulin/genetics
- Somatic Hypermutation, Immunoglobulin/immunology
- Spleen/cytology
- Spleen/immunology
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Affiliation(s)
- Roberto Di Niro
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Laboratory Medicine and Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Seung-Joo Lee
- Center for Comparative Medicine, University of California, Davis, CA 95616, USA
| | - Jason A Vander Heiden
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA
| | - Rebecca A Elsner
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Nikita Trivedi
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Jason M Bannock
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Namita T Gupta
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA
| | - Steven H Kleinstein
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA; Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Pathology, Yale University School of Medicine, New Haven, CT 06520, USA
| | | | | | - Eric Meffre
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Stephen J McSorley
- Center for Comparative Medicine, University of California, Davis, CA 95616, USA
| | - Mark J Shlomchik
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Laboratory Medicine and Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA.
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10
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Laughlin RC, Mickum M, Rowin K, Adams LG, Alaniz RC. Altered host immune responses to membrane vesicles from Salmonella and Gram-negative pathogens. Vaccine 2015; 33:5012-9. [PMID: 26001432 DOI: 10.1016/j.vaccine.2015.05.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 05/05/2015] [Accepted: 05/09/2015] [Indexed: 02/08/2023]
Abstract
Membrane vesicles (MVs), discrete nano-structures produced from the outer membrane of Gram-negative bacteria such as Salmonella enterica Typhimurium (S. Typhimurium), strongly activate dendritic cells (DCs), contain major antigens (Ags) recognized by Salmonella-specific B-cells and CD4+ T-cells, and provide protection against S. Typhimurium challenge in a mouse model. With this in mind, we hypothesized that alterations to the gene expression profile of bacteria will be reflected in the immunologic response to MVs. To test this, we assessed the ability of MVs from wild-type (WT) S. Typhimurium or a strain with a phenotype mimicking the intracellular-phase of S. Typhimurium (PhoP(c)) to activate dendritic cells and initiate a strong inflammatory response. MVs, isolated from wild-type and PhoP(c)S. Typhimurium (WTMVs and PhoPcMVs, respectively) had pro-inflammatory properties consistent with the parental bacterial strains: PhoPcMVs were less stimulatory for DC activation in vitro and were impaired for subsequent inflammatory responses compared to WTMVs. Interestingly, the reduced pro-inflammatory properties of PhoPcMVs did not completely rely on signals through TLR4, the receptor for LPS. Nonetheless, both WTMVs and PhoPcMVs contained abundant immunogenic antigens capable of being recognized by memory-immune CD4+ T-cells from mice previously infected with S. Typhimurium. Furthermore, we analyzed a suite of pathogenic Gram-negative bacteria and their purified MVs for their ability to activate DCs and stimulate inflammation in a manner consistent with the known inflammatory properties of the parental strains, as shown for S. Typhimurium. Finally, analysis of the potential vaccine utility of S. Typhimurium MVs revealed their capacity to encapsulate an exogenous model antigen and stimulate antigen-specific CD4+ and CD8+ T-cell responses. Taken together, our results demonstrate the dependence of bacterial cell gene expression for MV immunogenicity and subsequent in vitro immunologic response, as well as their potential utility as a vaccine platform.
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Affiliation(s)
- Richard C Laughlin
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Megan Mickum
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX 77843, USA
| | - Kristina Rowin
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX 77843, USA
| | - L Garry Adams
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Robert C Alaniz
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX 77843, USA.
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11
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Reynolds CJ, Jones C, Blohmke CJ, Darton TC, Goudet A, Sergeant R, Maillere B, Pollard AJ, Altmann DM, Boyton RJ. The serodominant secreted effector protein of Salmonella, SseB, is a strong CD4 antigen containing an immunodominant epitope presented by diverse HLA class II alleles. Immunology 2014; 143:438-46. [PMID: 24891088 PMCID: PMC4212957 DOI: 10.1111/imm.12327] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/03/2014] [Accepted: 05/19/2014] [Indexed: 12/25/2022] Open
Abstract
Detailed characterization of the protective T-cell response in salmonellosis is a pressing unmet need in light of the global burden of human Salmonella infections and the likely contribution of CD4 T cells to immunity against this intracellular infection. In previous studies screening patient sera against antigen arrays, SseB was noteworthy as a serodominant target of adaptive immunity, inducing significantly raised antibody responses in HIV-seronegative compared with seropositive patients. SseB is a secreted protein, part of the Espa superfamily, localized to the bacterial surface and forming part of the translocon of the type III secretion system (T3SS) encoded by Salmonella pathogenicity island 2. We demonstrate here that SseB is also a target of CD4 T-cell immunity, generating a substantial response after experimental infection in human volunteers, with around 0·1% of the peripheral repertoire responding to it. HLA-DR/peptide binding studies indicate that this protein encompasses a number of peptides with ability to bind to several different HLA-DR alleles. Of these, peptide 11 (p11) was shown in priming of both HLA-DR1 and HLA-DR4 transgenic mice to contain an immunodominant CD4 epitope. Analysis of responses in human donors showed immunity focused on p11 and another epitope in peptide 2. The high frequency of SseB-reactive CD4 T cells and the broad applicability to diverse HLA genotypes coupled with previous observations of serodominance and protective vaccination in mouse challenge experiments, make SseB a plausible candidate for next-generation Salmonella vaccines.
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Affiliation(s)
- Catherine J Reynolds
- Section of Infectious Diseases and Immunity, Department of Medicine, Imperial College, Hammersmith Hospital, London, UK
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12
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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: 1.8] [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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Dunstan SJ, Hue NT, Han B, Li Z, Tram TTB, Sim KS, Parry CM, Chinh NT, Vinh H, Lan NPH, Thieu NTV, Vinh PV, Koirala S, Dongol S, Arjyal A, Karkey A, Shilpakar O, Dolecek C, Foo JN, Phuong LT, Lanh MN, Do T, Aung T, Hon DN, Teo YY, Hibberd ML, Anders KL, Okada Y, Raychaudhuri S, Simmons CP, Baker S, de Bakker PIW, Basnyat B, Hien TT, Farrar JJ, Khor CC. Variation at HLA-DRB1 is associated with resistance to enteric fever. Nat Genet 2014; 46:1333-6. [PMID: 25383971 PMCID: PMC5099079 DOI: 10.1038/ng.3143] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 10/15/2014] [Indexed: 12/18/2022]
Abstract
Enteric fever affects more than 25 million people annually and results from systemic infection with Salmonella enterica serovar Typhi or Paratyphi pathovars A, B or C(1). We conducted a genome-wide association study of 432 individuals with blood culture-confirmed enteric fever and 2,011 controls from Vietnam. We observed strong association at rs7765379 (odds ratio (OR) for the minor allele = 0.18, P = 4.5 × 10(-10)), a marker mapping to the HLA class II region, in proximity to HLA-DQB1 and HLA-DRB1. We replicated this association in 595 enteric fever cases and 386 controls from Nepal and also in a second independent collection of 151 cases and 668 controls from Vietnam. Imputation-based fine-mapping across the extended MHC region showed that the classical HLA-DRB1*04:05 allele (OR = 0.14, P = 2.60 × 10(-11)) could entirely explain the association at rs7765379, thus implicating HLA-DRB1 as a major contributor to resistance against enteric fever, presumably through antigen presentation.
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Affiliation(s)
- Sarah J Dunstan
- 1] Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. [2] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, UK. [3] Nossal Institute of Global Health, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Nguyen Thi Hue
- 1] Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. [2] Faculty of Biology, University of Science, Vietnam National University, Ho Chi Minh City, Vietnam
| | - Buhm Han
- 1] Asan Institute for Life Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea. [2] Department of Medicine, Division of Genetics, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. [3] Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts, USA. [4] Partners Center for Personalized Genetic Medicine, Boston, Massachusetts, USA
| | - Zheng Li
- Genome Institute of Singapore, Singapore
| | - Trinh Thi Bich Tram
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | - Christopher M Parry
- 1] Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. [2] Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Ha Vinh
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | - Nga Tran Vu Thieu
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Phat Voong Vinh
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Samir Koirala
- Oxford University Clinical Research Unit-Nepal, Patan Academy of Health Sciences, Patan Hospital, Patan, Nepal
| | - Sabina Dongol
- Oxford University Clinical Research Unit-Nepal, Patan Academy of Health Sciences, Patan Hospital, Patan, Nepal
| | - Amit Arjyal
- Oxford University Clinical Research Unit-Nepal, Patan Academy of Health Sciences, Patan Hospital, Patan, Nepal
| | - Abhilasha Karkey
- Oxford University Clinical Research Unit-Nepal, Patan Academy of Health Sciences, Patan Hospital, Patan, Nepal
| | - Olita Shilpakar
- Oxford University Clinical Research Unit-Nepal, Patan Academy of Health Sciences, Patan Hospital, Patan, Nepal
| | - Christiane Dolecek
- 1] Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. [2] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, UK
| | | | | | | | - Tan Do
- Vietnam National Institute of Ophthalmology, Hanoi, Vietnam
| | - Tin Aung
- Singapore Eye Research Institute, Singapore
| | - Do Nu Hon
- Vietnam National Institute of Ophthalmology, Hanoi, Vietnam
| | - Yik Ying Teo
- 1] Department of Statistics and Applied Probability, National University of Singapore, Singapore. [2] Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Martin L Hibberd
- 1] Genome Institute of Singapore, Singapore. [2] London School of Tropical Medicine and Hygiene, London, UK
| | - Katherine L Anders
- 1] Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. [2] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, UK
| | - Yukinori Okada
- 1] Department of Human Genetics and Disease Diversity, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. [2] Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Soumya Raychaudhuri
- 1] Department of Medicine, Division of Genetics, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. [2] Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts, USA. [3] Partners Center for Personalized Genetic Medicine, Boston, Massachusetts, USA. [4] Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, Massachusetts, USA. [5] Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
| | - Cameron P Simmons
- 1] Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. [2] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, UK. [3] Department of Microbiology and Immunology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Stephen Baker
- 1] Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. [2] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, UK. [3] London School of Tropical Medicine and Hygiene, London, UK
| | - Paul I W de Bakker
- 1] Department of Medical Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, the Netherlands. [2] Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Buddha Basnyat
- Oxford University Clinical Research Unit-Nepal, Patan Academy of Health Sciences, Patan Hospital, Patan, Nepal
| | - Tran Tinh Hien
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Jeremy J Farrar
- 1] Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. [2] Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, UK
| | - Chiea Chuen Khor
- 1] Genome Institute of Singapore, Singapore. [2] Singapore Eye Research Institute, Singapore. [3] Saw Swee Hock School of Public Health, National University of Singapore, Singapore. [4] Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. [5] Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Porta A, Morello S, Granata I, Iannone R, Maresca B. Insertion of a 59 amino acid peptide in Salmonella Typhimurium membrane results in loss of virulence in mice. FEBS J 2014; 281:5043-53. [PMID: 25208333 DOI: 10.1111/febs.13042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/03/2014] [Accepted: 09/05/2014] [Indexed: 12/26/2022]
Abstract
We demonstrated previously that expression of a single trans-membrane region of the Δ(12) -desaturase gene of Synechocystis sp. PCC 6803 in Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) altered the membrane physical state of this pathogen, induced a significant change in the pattern of mRNA transcription of major heat shock genes, and inhibited pathogen growth inside murine macrophages. In this study, we demonstrate that injection of the modified Salmonella strain [Stm(pBAD200)] into C57Bl6j mice is safe. Survival of mice was associated with bacterial clearance, an increased number of splenic leukocytes, and high levels of interleukin-12, interferon γ and tumor necrosis factor α in spleens as well as in sera. Furthermore, Stm(pBAD200)-injected mice developed a Salmonella-specific antibody and Th1-like responses. Mice challenged with Stm(pBAD200) are protected from systemic infection with Salmonella wild-type. Similarly, mice infected with Stm(pBAD200) by the oral route survived when challenged with an oral lethal dose of Salmonella wild-type. The avirulent Stm(pBAD200) phenotype is associated with a remarkable change in the expression of the hilC, hilD, hilA, invF and phoP genes, among others, whose products are required for invasion and replication of Salmonella inside phagocytic cells. These data demonstrate the use of trans-membrane peptides to generate attenuated strains, providing a potential novel strategy to develop vaccines for both animal and human use.
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Affiliation(s)
- Amalia Porta
- Department of Pharmacy, University of Salerno, Fisciano, Italy
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Coward C, Restif O, Dybowski R, Grant AJ, Maskell DJ, Mastroeni P. The effects of vaccination and immunity on bacterial infection dynamics in vivo. PLoS Pathog 2014; 10:e1004359. [PMID: 25233077 PMCID: PMC4169467 DOI: 10.1371/journal.ppat.1004359] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 07/25/2014] [Indexed: 01/31/2023] Open
Abstract
Salmonella enterica infections are a significant global health issue, and development of vaccines against these bacteria requires an improved understanding of how vaccination affects the growth and spread of the bacteria within the host. We have combined in vivo tracking of molecularly tagged bacterial subpopulations with mathematical modelling to gain a novel insight into how different classes of vaccines and branches of the immune response protect against secondary Salmonella enterica infections of the mouse. We have found that a live Salmonella vaccine significantly reduced bacteraemia during a secondary challenge and restrained inter-organ spread of the bacteria in the systemic organs. Further, fitting mechanistic models to the data indicated that live vaccine immunisation enhanced both the bacterial killing in the very early stages of the infection and bacteriostatic control over the first day post-challenge. T-cell immunity induced by this vaccine is not necessary for the enhanced bacteriostasis but is required for subsequent bactericidal clearance of Salmonella in the blood and tissues. Conversely, a non-living vaccine while able to enhance initial blood clearance and killing of virulent secondary challenge bacteria, was unable to alter the subsequent bacterial growth rate in the systemic organs, did not prevent the resurgence of extensive bacteraemia and failed to control the spread of the bacteria in the body. The bacterium Salmonella enterica causes gastroenteritis and the severe systemic diseases typhoid, paratyphoid fever and non-typhoidal septicaemia (NTS). Treatment of systemic disease with antibiotics is becoming increasingly difficult due to the acquisition of resistance. Licensed vaccines are available for the prevention of typhoid, but not paratyphoid fever or NTS. Vaccines can be either living (attenuated strains) or non-living (e.g. inactivated whole cells or surface polysaccharides) and these different classes potentially activate different components of the host immune system. Improvements in vaccine design require a better understanding of how different vaccine types differ in their ability to control a subsequent infection. We have improved a previously developed experimental system and mathematical model to investigate how these different vaccine types act. We show that the inactivated vaccine can only control bacterial numbers by a transient increase in bactericidal activity whereas the living vaccine is superior as it can induce an immune response that rapidly kills, then restrains the growth and spread of infecting bacteria.
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Affiliation(s)
- Chris Coward
- University of Cambridge, Department of Veterinary Medicine, Cambridge, United Kingdom
| | - Olivier Restif
- University of Cambridge, Department of Veterinary Medicine, Cambridge, United Kingdom
| | - Richard Dybowski
- University of Cambridge, Department of Veterinary Medicine, Cambridge, United Kingdom
| | - Andrew J Grant
- University of Cambridge, Department of Veterinary Medicine, Cambridge, United Kingdom
| | - Duncan J Maskell
- University of Cambridge, Department of Veterinary Medicine, Cambridge, United Kingdom
| | - Pietro Mastroeni
- University of Cambridge, Department of Veterinary Medicine, Cambridge, United Kingdom
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McSorley SJ. The Role of Non-Cognate T Cell Stimulation during Intracellular Bacterial Infection. Front Immunol 2014; 5:319. [PMID: 25071779 PMCID: PMC4089505 DOI: 10.3389/fimmu.2014.00319] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 06/24/2014] [Indexed: 01/29/2023] Open
Abstract
Intra-macrophage bacterial infections cause significant morbidity and mortality in both the developed and developing world. Protective host immune responses to these infections initially requires the activation and expansion of pathogen-specific CD4 Th1 cells within lymphoid tissues and subsequent relocation of these effector cells to sites of infection. After entering infected tissues, the elicitation of Th1 bactericidal activity can be triggered by cognate or non-cognate signals that are delivered by locally infected antigen-presenting cells and innate cells. However, the contribution of non-cognate stimulation to the resolution of bacterial infection remains poorly understood, especially in the context of a Th1 response. Here, we review the current data on Th1 cell activation and expansion in mouse models of Salmonella and Chlamydia infection and discuss the potential role of non-cognate Th1 cell stimulation in these disease models. Greater understanding of this pathway of T cell activation may lead to the design of therapeutics or vaccines to combat intra-macrophage pathogens.
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Affiliation(s)
- Stephen J McSorley
- Department of Anatomy, Physiology and Cell Biology, Center for Comparative Medicine, School of Veterinary Medicine, University of California Davis , Davis, CA , USA
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Haloarchaeal gas vesicle nanoparticles displaying Salmonella SopB antigen reduce bacterial burden when administered with live attenuated bacteria. Vaccine 2014; 32:4543-4549. [PMID: 24950351 DOI: 10.1016/j.vaccine.2014.06.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 04/25/2014] [Accepted: 06/06/2014] [Indexed: 11/20/2022]
Abstract
Innovative vaccines against typhoid and other Salmonella diseases that are safe, effective, and inexpensive are urgently needed. In order to address this need, buoyant, self-adjuvating gas vesicle nanoparticles (GVNPs) from the halophilic archaeon Halobacterium sp. NRC-1 were bioengineered to display the highly conserved Salmonella enterica antigen SopB, a secreted inosine phosphate effector protein injected by pathogenic bacteria during infection into the host cell. Two highly conserved sopB gene segments near the 3'-coding region, named sopB4 and B5, were each fused to the gvpC gene, and resulting GVNPs were purified by centrifugally accelerated flotation. Display of SopB4 and B5 antigenic epitopes on GVNPs was established by Western blotting analysis using antisera raised against short synthetic peptides of SopB. Immunostimulatory activities of the SopB4 and B5 nanoparticles were tested by intraperitoneal administration of recombinant GVNPs to BALB/c mice which had been immunized with S. enterica serovar Typhimurium 14028 ΔpmrG-HM-D (DV-STM-07), a live attenuated vaccine strain. Proinflammatory cytokines IFN-γ, IL-2, and IL-9 were significantly induced in mice boosted with SopB5-GVNPs, consistent with a robust Th1 response. After challenge with virulent S. enterica serovar Typhimurium 14028, bacterial burden was found to be diminished in spleen of mice boosted with SopB4-GVNPs and absent or significantly diminished in liver, mesenteric lymph node, and spleen of mice boosted with SopB5-GVNPs, indicating that the C-terminal portions of SopB displayed on GVNPs elicit a protective response to Salmonella infection in mice. SopB antigen-GVNPs were found to be stable at elevated temperatures for extended periods without refrigeration in Halobacterium cells. The results all together show that bioengineered GVNPs are likely to represent a valuable platform for the development of improved vaccines against Salmonella diseases.
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Advancing the management and control of typhoid fever: A review of the historical role of human challenge studies. J Infect 2014; 68:405-18. [DOI: 10.1016/j.jinf.2014.01.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 01/15/2014] [Accepted: 01/19/2014] [Indexed: 01/31/2023]
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Regulatory T-cell vaccination independent of auto-antigen. Exp Mol Med 2014; 46:e82. [PMID: 24626168 PMCID: PMC3972794 DOI: 10.1038/emm.2014.4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 12/06/2013] [Indexed: 12/21/2022] Open
Abstract
To date, efforts to treat autoimmune diseases have primarily focused on the disease symptoms rather than on the cause of the disease. In large part, this is attributed to not knowing the responsible auto-antigens (auto-Ags) for driving the self-reactivity coupled with the poor success of treating autoimmune diseases using oral tolerance methods. Nonetheless, if tolerogenic approaches or methods that stimulate regulatory T (Treg) cells can be devised, these could subdue autoimmune diseases. To forward such efforts, our approach with colonization factor antigen I (CFA/I) fimbriae is to establish bystander immunity to ultimately drive the development of auto-Ag-specific Treg cells. Using an attenuated Salmonella vaccine expressing CFA/I fimbriae, fimbriae-specific Treg cells were induced without compromising the vaccine's capacity to protect against travelers' diarrhea or salmonellosis. By adapting the vaccine's anti-inflammatory properties, it was found that it could also dampen experimental inflammatory diseases resembling multiple sclerosis (MS) and rheumatoid arthritis. Because of this bystander effect, disease-specific Treg cells are eventually induced to resolve disease. Interestingly, this same vaccine could elicit the required Treg cell subset for each disease. For MS-like disease, conventional CD25+ Treg cells are stimulated, but for arthritis CD39+ Treg cells are induced instead. This review article will examine the potential of treating autoimmune diseases without having previous knowledge of the auto-Ag using an innocuous antigen to stimulate Treg cells via the production of transforming growth factor-β and interleukin-10.
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Abstract
PURPOSE OF REVIEW Infection caused by ingestion of human-restricted Salmonella enterica serovars Typhi and Paratyphi predominantly affects the most impoverished sections of society. In this review, we describe recent advances made in estimating the burden of illness and the important role improved diagnostic tests may have in controlling infection and report the development of a new human challenge model of typhoid infection. RECENT FINDINGS Typhoid continues to be a major cause of morbidity, particularly in children and young adults in south east Asia, although accurate assessments are still hindered by the lack of reliable surveillance data. Recent reports of high rates of infection in Africa and the dominance of paratyphoid in several geographic areas are of particular concern. Diagnosis of enteric fever remains frustrated by the nonspecific clinical presentation of cases and the lack of test sensitivity. Methods to improve diagnostic accuracy are hindered by the incomplete understanding of immunobiological mechanisms of infection and lack of a suitable animal infection model. SUMMARY Enteric fever is a major global problem, the burden of which has only partially been recognized. Control strategies utilizing cheap accurate diagnostics and effective vaccines are urgently required, and their development should be accelerated by the use of a human challenge model.
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Ault A, Tennant SM, Gorres JP, Eckhaus M, Sandler NG, Roque A, Livio S, Bao S, Foulds KE, Kao SF, Roederer M, Schmidlein P, Boyd MA, Pasetti MF, Douek DC, Estes JD, Nabel GJ, Levine MM, Rao SS. Safety and tolerability of a live oral Salmonella typhimurium vaccine candidate in SIV-infected nonhuman primates. Vaccine 2013; 31:5879-88. [PMID: 24099872 DOI: 10.1016/j.vaccine.2013.09.041] [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: 04/17/2013] [Revised: 09/10/2013] [Accepted: 09/23/2013] [Indexed: 12/13/2022]
Abstract
Nontyphoidal Salmonella (NTS) serovars are a common cause of acute food-borne gastroenteritis worldwide and can cause invasive systemic disease in young infants, the elderly, and immunocompromised hosts, accompanied by high case fatality. Vaccination against invasive NTS disease is warranted where the disease incidence and mortality are high and multidrug resistance is prevalent, as in sub-Saharan Africa. Live-attenuated vaccines that mimic natural infection constitute one strategy to elicit protection. However, they must particularly be shown to be adequately attenuated for consideration of immunocompromised subjects. Accordingly, we examined the safety and tolerability of an oral live attenuated Salmonella typhimurium vaccine candidate, CVD 1921, in an established chronic simian immunodeficiency virus (SIV)-infected rhesus macaque model. We evaluated clinical parameters, histopathology, and measured differences in mucosal permeability to wild-type and vaccine strains. Compared to the wild-type S. typhimurium strain I77 in both SIV-infected and SIV-uninfected nonhuman primate hosts, this live-attenuated vaccine shows reduced shedding and systemic spread, exhibits limited pathological disease manifestations in the digestive tract, and induces low levels of cellular infiltration in tissues. Furthermore, wild-type S. typhimurium induces increased intestinal epithelial damage and permeability, with infiltration of neutrophils and macrophages in both SIV-infected and SIV-uninfected nonhuman primates compared to the vaccine strain. Based on shedding, systemic spread, and histopathology, the live-attenuated S. typhimurium strain CVD 1921 appears to be safe and well-tolerated in the nonhuman primate model, including chronically SIV-infected rhesus macaques.
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Affiliation(s)
- Alida Ault
- Laboratory Animal Medicine, Vaccine Research Center, NIAID, NIH, Bethesda, MD 20892, United States
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