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Comparison of Lethal and Nonlethal Mouse Models of Orientia tsutsugamushi Infection Reveals T-Cell Population-Associated Cytokine Signatures Correlated with Lethality and Protection. Trop Med Infect Dis 2021; 6:tropicalmed6030121. [PMID: 34287349 PMCID: PMC8293330 DOI: 10.3390/tropicalmed6030121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/25/2021] [Accepted: 06/30/2021] [Indexed: 11/19/2022] Open
Abstract
The antigenic diversity of Orientia tsutsugamushi as well as the interstrain difference(s) associated with virulence in mice impose the necessity to dissect the host immune response. In this study we compared the host response in lethal and non-lethal murine models of O. tsutsugamushi infection using the two strains, Karp (New Guinea) and Woods (Australia). The models included the lethal model: Karp intraperitoneal (IP) challenge; and the nonlethal models: Karp intradermal (ID), Woods IP, and Woods ID challenges. We monitored bacterial trafficking to the liver, lung, spleen, kidney, heart, and blood, and seroconversion during the 21-day challenge. Bacterial trafficking to all organs was observed in both the lethal and nonlethal models of infection, with significant increases in average bacterial loads observed in the livers and hearts of the lethal model. Multicolor flow cytometry was utilized to analyze the CD4+ and CD8+ T cell populations and their intracellular production of the cytokines IFNγ, TNF, and IL2 (single, double, and triple combinations) associated with both the lethal and nonlethal murine models of infection. The lethal model was defined by a cytokine signature of double- (IFNγ-IL2) and triple-producing (IL2-TNF-IFNγ) CD4+ T-cell populations; no multifunctional signature was identified in the CD8+ T-cell populations associated with the lethal model. In the nonlethal model, the cytokine signature was predominated by CD4+ and CD8+ T-cell populations associated with single (IL2) and/or double (IL2-TNF) populations of producers. The cytokine signatures associated with our lethal model will become depletion targets in future experiments; those signatures associated with our nonlethal model are hypothesized to be related to the protective nature of the nonlethal challenges.
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Mi Z, Feng ZC, Li C, Yang X, Ma MT, Rong PF. Salmonella-Mediated Cancer Therapy: An Innovative Therapeutic Strategy. J Cancer 2019; 10:4765-4776. [PMID: 31598148 PMCID: PMC6775532 DOI: 10.7150/jca.32650] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 07/06/2019] [Indexed: 12/31/2022] Open
Abstract
Bacterial-mediated cancer therapy (BMCT) has become a hot topic in the area of antitumor treatment. Salmonella has been recommended to specifically colonize and proliferate inside tumors and even inhibit tumor growth. Salmonella typhimurium (S. typhimurium) is one of the most promising mediators, which can be easily manipulated. S. typhimurium has been engineered and designed as cancer-targeting therapeutics, and can be improved by combining with other therapeutic methods, e.g. chemotherapy and radiotherapy, which regulate the tumor microenvironment synergistically. In view of all these strengths, the engineered attenuated strains have significant advantages for tumor diagnosis and treatment. This treatment has also been approved by the FDA for clinical trial. In this review, we summarized the recent progress and research in the field of Salmonella -mediated cancer therapy.
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Affiliation(s)
- Ze Mi
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Zhi-Chao Feng
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Cheng Li
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Xiao Yang
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Meng-Tian Ma
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Peng-Fei Rong
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
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3
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Wahid R, Kotloff KL, Levine MM, Sztein MB. Cell mediated immune responses elicited in volunteers following immunization with candidate live oral Salmonella enterica serovar Paratyphi A attenuated vaccine strain CVD 1902. Clin Immunol 2019; 201:61-69. [PMID: 30849494 DOI: 10.1016/j.clim.2019.03.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/22/2019] [Accepted: 03/03/2019] [Indexed: 01/01/2023]
Abstract
The incidence of Salmonella enterica serovar Paratyphi A (PA) infection is on the rise and no licensed vaccines are available. We evaluated cell mediated immune (CMI) responses elicited in volunteers following immunization with a single dose (109 or 1010 cfu) of a novel attenuated live oral PA-vaccine strain (CVD 1902). Results showed increases in PA-lipopolysaccharide-specific IgG- and/or IgA B-memory cells and production of IFN-γ, TNF-α, IL-10, IL-23 and RANTES following stimulation with PA-antigens by peripheral blood mononuclear cells obtained 28 days post immunization. Flow cytometry assays revealed that vaccine elicited PA-specific CD8+ and/or CD4+ T effector/memory cells were predominantly multifunctional concomitantly expressing CD107a and/or producing IFN-γ, TNF-α and/or IL-2. Similar proportions of these MF cells expressed, or not, the gut homing marker integrin α4β7. The results suggest that immunization with CVD 1902 elicits CMI responses against PA supporting its further evaluation as a potential vaccine candidate against paratyphoid A fever.
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Affiliation(s)
- Rezwanul Wahid
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Karen L Kotloff
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Medicine, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Myron M Levine
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Medicine, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Marcelo B Sztein
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Medicine, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
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Tian Y, da Silva Antunes R, Sidney J, Lindestam Arlehamn CS, Grifoni A, Dhanda SK, Paul S, Peters B, Weiskopf D, Sette A. A Review on T Cell Epitopes Identified Using Prediction and Cell-Mediated Immune Models for Mycobacterium tuberculosis and Bordetella pertussis. Front Immunol 2018; 9:2778. [PMID: 30555469 PMCID: PMC6281829 DOI: 10.3389/fimmu.2018.02778] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 11/12/2018] [Indexed: 01/01/2023] Open
Abstract
In the present review, we summarize work from our as well as other groups related to the characterization of bacterial T cell epitopes, with a specific focus on two important pathogens, namely, Mycobacterium tuberculosis (Mtb), the bacterium that causes tuberculosis (TB), and Bordetella pertussis (BP), the bacterium that causes whooping cough. Both bacteria and their associated diseases are of large societal significance. Although vaccines exist for both pathogens, their efficacy is incomplete. It is widely thought that defects and/or alteration in T cell compartments are associated with limited vaccine effectiveness. As discussed below, a full genome-wide map was performed in the case of Mtb. For BP, our focus has thus far been on the antigens contained in the acellular vaccine; a full genome-wide screen is in the planning stage. Nevertheless, the sum-total of the results in the two different bacterial systems allows us to exemplify approaches and techniques that we believe are generally applicable to the mapping and characterization of human immune responses to bacterial pathogens. Finally, we add, as a disclaimer, that this review by design is focused on the work produced by our laboratory as an illustration of approaches to the study of T cell responses to Mtb and BP, and is not meant to be comprehensive, nor to detract from the excellent work performed by many other groups.
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Affiliation(s)
- Yuan Tian
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States
| | | | - John Sidney
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States
| | | | - Alba Grifoni
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Sandeep Kumar Dhanda
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Sinu Paul
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Bjoern Peters
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States.,Department of Medicine, University of California San Diego, La Jolla, CA, United States
| | - Daniela Weiskopf
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Alessandro Sette
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States.,Department of Medicine, University of California San Diego, La Jolla, CA, United States
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Pennington SH, Ferreira DM, Reiné J, Nyirenda TS, Thompson AL, Hancock CA, Wright AD, Gordon SB, Gordon MA. Longevity of duodenal and peripheral T-cell and humoral responses to live-attenuated Salmonella Typhi strain Ty21a. Vaccine 2018; 36:4725-4733. [PMID: 29958737 PMCID: PMC6041722 DOI: 10.1016/j.vaccine.2018.05.114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/08/2018] [Accepted: 05/31/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND We have previously demonstrated that polyfunctional Ty21a-responsive CD4+ and CD8+ T cells are generated at the duodenal mucosa 18 days following vaccination with live-attenuated S. Typhi (Ty21a). The longevity of cellular responses has been assessed in peripheral blood, but persistence of duodenal responses is unknown. METHODS We vaccinated eight healthy adults with Ty21a. Peripheral blood and duodenal samples were acquired after a median of 1.5 years (ranging from 1.1 to 3.7 years) following vaccination. Cellular responses were assessed in peripheral blood and at the duodenal mucosa by flow cytometry. Levels of IgG and IgA were also assessed in peripheral blood by enzyme-linked immunosorbent assay. RESULTS No T-cell responses were observed at the duodenal mucosa, but CD4+ T-cell responses to Ty21a and FliC were observed in peripheral blood. Peripheral anti-lipopolysaccharide IgG and IgA responses were also observed. Early immunoglobulin responses were not associated with the persistence of long-term cellular immune responses. CONCLUSIONS Early T-cell responses which we have previously observed at the duodenal mucosa 18 days following oral vaccination with Ty21a could not be detected at a median of 1.5 years. Peripheral responses were observed at this time. Immunoglobulin responses observed shortly after vaccination were not associated with cellular immune responses at 1.5 years, suggesting that the persistence of cellular immunity is not associated with the strength of the initial humoral response to vaccination.
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Affiliation(s)
- Shaun H Pennington
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, UK; Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Daniela M Ferreira
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Jesús Reiné
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Tonney S Nyirenda
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Queen Elizabeth Central Hospital, Malawi
| | - Ameeka L Thompson
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, UK; Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Carole A Hancock
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Angela D Wright
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK
| | - Stephen B Gordon
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Queen Elizabeth Central Hospital, Malawi
| | - Melita A Gordon
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Queen Elizabeth Central Hospital, Malawi.
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Hu J, Chen L, Yang W, Li B, Sun H, Wei S, He Y, Zhao Z, Yang S, Zou Q, Chen W, Guo H, Wu C. Systematic identification of immunodominant CD4+ T cell responses to HpaA in Helicobacter pylori infected individuals. Oncotarget 2018; 7:54380-54391. [PMID: 27509059 PMCID: PMC5342349 DOI: 10.18632/oncotarget.11092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 06/29/2016] [Indexed: 12/20/2022] Open
Abstract
In mice, antigen-specific CD4+ T cell response is indispensible for the protective immunity against Helicobacter pylori (H. pylori). It has been demonstrated that neuraminyllactose-binding hemagglutinin (HpaA) immunization protected mice from H. pylori infection in a CD4+ T cell dependent manner. However, much remains unclear concerning the human CD4+ T cell responses to HpaA. We conducted a systematic study here to explore the immunodominant, HpaA-specific CD4+ T cell responses in H. pylori infected individuals. We found that HpaA-specific CD4+ T cell responses varied remarkably in their magnitude and had broad epitope-specificity. Importantly, the main responses focused on two regions: HpaA76-105 and HpaA130-159. The HLA-DRB1*0901 restricted HpaA142-159 specific CD4+ T cell response was the most immunodominant response at a population level. The immunodominant epitope HpaA142-159 was naturally presented and highly conserved. We also demonstrated that it was not the broad peptide specificity, but the strength of HpaA specific CD4+ T cell responses associated with gastric diseases potentially caused by H. pylori infection. Such investigation will aid development of novel vaccines against H. pylori infection.
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Affiliation(s)
- Jian Hu
- Department of Gastroenterology, The Second Affiliated Hospital, Third Military Medical University, Chongqing, PR China.,Department of Intensive Care Unit, Chengdu Military General Hospital, Chengdu, PR China
| | - Li Chen
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China.,Department of Blood Transfusion, The Second Affiliated Hospital, Third Military Medical University, Chongqing, PR China
| | - Wuchen Yang
- Department of Gastroenterology, The Second Affiliated Hospital, Third Military Medical University, Chongqing, PR China.,Department of Hematology, The Second Affiliated Hospital, Third Military Medical University, Chongqing, PR China
| | - Bin Li
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Heqiang Sun
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Shanshan Wei
- Department of Gastroenterology, The Second Affiliated Hospital, Third Military Medical University, Chongqing, PR China
| | - Yafei He
- Department of Gastroenterology, The Second Affiliated Hospital, Third Military Medical University, Chongqing, PR China
| | - Zhuo Zhao
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Shiming Yang
- Department of Gastroenterology, The Second Affiliated Hospital, Third Military Medical University, Chongqing, PR China
| | - Quanming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Weisan Chen
- T Cell Laboratory, La Trobe Institute for Molecular Science, School of Molecular Science, La Trobe University, Bundoora, Victoria, Australia
| | - Hong Guo
- Department of Gastroenterology, The Second Affiliated Hospital, Third Military Medical University, Chongqing, PR China
| | - Chao Wu
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
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7
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Poston TB, Qu Y, Girardi J, O'Connell CM, Frazer LC, Russell AN, Wall M, Nagarajan UM, Darville T. A Chlamydia-Specific TCR-Transgenic Mouse Demonstrates Th1 Polyfunctionality with Enhanced Effector Function. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2017; 199:2845-2854. [PMID: 28855311 PMCID: PMC5770186 DOI: 10.4049/jimmunol.1700914] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/07/2017] [Indexed: 02/06/2023]
Abstract
Chlamydia is responsible for millions of new infections annually, and current efforts focus on understanding cellular immunity for targeted vaccine development. The Chlamydia-specific CD4 T cell response is characterized by the production of IFN-γ, and polyfunctional Th1 responses are associated with enhanced protection. A major limitation in studying these responses is the paucity of tools available for detection, quantification, and characterization of polyfunctional Ag-specific T cells. We addressed this problem by developing a TCR-transgenic (Tg) mouse with CD4 T cells that respond to a common Ag in Chlamydia muridarum and Chlamydia trachomatis Using an adoptive-transfer approach, we show that naive Tg CD4 T cells become activated, proliferate, migrate to the infected tissue, and acquire a polyfunctional Th1 phenotype in infected mice. Polyfunctional Tg Th1 effectors demonstrated enhanced IFN-γ production compared with polyclonal cells, protected immune-deficient mice against lethality, mediated bacterial clearance, and orchestrated an anamnestic response. Adoptive transfer of Chlamydia-specific CD4 TCR-Tg T cells with polyfunctional capacity offers a powerful approach for analysis of protective effector and memory responses against chlamydial infection and demonstrates that an effective monoclonal CD4 T cell response may successfully guide subunit vaccination strategies.
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Affiliation(s)
- Taylor B Poston
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; and
| | - Yanyan Qu
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224
| | - Jenna Girardi
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; and
| | - Catherine M O'Connell
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; and
| | - Lauren C Frazer
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; and
| | - Ali N Russell
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; and
| | - McKensie Wall
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; and
| | - Uma M Nagarajan
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; and
| | - Toni Darville
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; and
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8
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Guo SH, Wang HF, Nian ZG, Wang YD, Zeng QY, Zhang G. Immunization with alkyl hydroperoxide reductase subunit C reduces Fusobacterium nucleatum load in the intestinal tract. Sci Rep 2017; 7:10566. [PMID: 28874771 PMCID: PMC5585165 DOI: 10.1038/s41598-017-11127-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 08/18/2017] [Indexed: 12/19/2022] Open
Abstract
Fusobacterium nucleatum (Fn) is an important tumour-associated bacterium in colorectal cancer (CRC). The antioxidant protein alkyl hydroperoxide reductase subunit C (AhpC) can induce strong antibacterial immune response during various pathogen infections. Our study aimed to evaluate the efficacy of Fn-AhpC as a candidate vaccine. In this work, by western blot analysis, we showed that Fn-AhpC recombinant protein could be recognized specifically by antibodies present in the sera of CRC patients; using the mouse Fn-infection model, we observed that systemic prophylactic immunization with AhpC/alum conferred significant protection against infection in 77.3% of mice. In addition, we measured the anti-AhpC antibody level in the sera of CRC patients and found that there was no obvious increase of anti-AhpC antibodies in the early-stage CRC group. Furthermore, we treated Fn with the sera from both immunized mice and CRC patients and found that sera with high anti-AhpC antibodies titre could inhibit Fn growth. In conclusion, our findings support the use of AhpC as a potential vaccine candidate against inhabitation or infection of Fn in the intestinal tract, which could provide a practical strategy for the prevention of CRC associated with Fn infection.
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Affiliation(s)
- Song-He Guo
- Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Hai-Fang Wang
- Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhi-Gang Nian
- Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yi-Dan Wang
- Department of School of Life Science, Sun Yat-sen University, Guangzhou, China
| | - Qiu-Yao Zeng
- Department of Clinical Laboratory Medicine, Sun Yat-sen University cancer center, Guangzhou, China, Guangzhou, China
| | - Ge Zhang
- Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China.
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9
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Ahmad TA, Eweida AE, El-Sayed LH. T-cell epitope mapping for the design of powerful vaccines. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.vacrep.2016.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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10
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Karunakaran KP, Yu H, Jiang X, Chan Q, Goldberg MF, Jenkins MK, Foster LJ, Brunham RC. Identification of MHC-Bound Peptides from Dendritic Cells Infected with Salmonella enterica Strain SL1344: Implications for a Nontyphoidal Salmonella Vaccine. J Proteome Res 2016; 16:298-306. [PMID: 27802388 DOI: 10.1021/acs.jproteome.6b00926] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Worldwide Salmonella enterica infections result in substantial morbidity and mortality and are the major cause of infant bacteremia in Sub-Saharan Africa. Diseases caused by Salmonella are treatable with antibiotics, but successful antibiotic treatment has become difficult due to antimicrobial resistance and collateral effects on the microbiome. An effective vaccine together with public health efforts may be a better strategy to control these infections. Protective immunity against Salmonella depends primarily on CD4 T-cell-mediated immune responses; therefore, identifying relevant T-cell antigens is necessary for Salmonella vaccine development. We previously used a dendritic-cell-based immunoproteomics approach in our laboratory to identify T-cell antigens. The testing of these antigens as vaccine candidates against Chlamydia infection in mice yielded positive results. We applied this technology in the present study by infecting murine bone-marrow-derived dendritic cells from C57BL/6 mice with Salmonella enterica strain SL1344, followed by immunoaffinity isolation of MHC class I and II molecules and elution of bound peptides. The sequences of the peptides were identified using tandem mass spectrometry. We identified 87 MHC class-II- and 23 MHC class-I-binding Salmonella-derived peptides. Four of the 12 highest scoring class-II-binding Salmonella peptides stimulated IFN-γ production by CD4+ T cells from the spleens of mice with persistent Salmonella infection. We conclude that antigens identified by MHC immunoproteomics will be useful for Salmonella immunobiology studies and are potential Salmonella vaccine candidates. Data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the data set identifier PXD004451.
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Affiliation(s)
- Karuna P Karunakaran
- Vaccine Research Laboratory, University of British Columbia Centre for Disease Control , Vancouver, British Columbia V5Z 4R4, Canada
| | - Hong Yu
- Vaccine Research Laboratory, University of British Columbia Centre for Disease Control , Vancouver, British Columbia V5Z 4R4, Canada
| | - Xiaozhou Jiang
- Vaccine Research Laboratory, University of British Columbia Centre for Disease Control , Vancouver, British Columbia V5Z 4R4, Canada
| | - Queenie Chan
- Department of Biochemistry and Molecular Biology, Centre for High-Throughput Biology, University of British Columbia , Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael F Goldberg
- Center for Immunology, Department of Microbiology and Immunology, University of Minnesota Medical School , Minneapolis, Minnesota 55455, United States
| | - Marc K Jenkins
- Center for Immunology, Department of Microbiology and Immunology, University of Minnesota Medical School , Minneapolis, Minnesota 55455, United States
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology, Centre for High-Throughput Biology, University of British Columbia , Vancouver, British Columbia V6T 1Z3, Canada
| | - Robert C Brunham
- Vaccine Research Laboratory, University of British Columbia Centre for Disease Control , Vancouver, British Columbia V5Z 4R4, Canada
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11
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Cross-reactive multifunctional CD4+ T cell responses against Salmonella enterica serovars Typhi, Paratyphi A and Paratyphi B in humans following immunization with live oral typhoid vaccine Ty21a. Clin Immunol 2016; 173:87-95. [PMID: 27634430 DOI: 10.1016/j.clim.2016.09.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 08/25/2016] [Accepted: 09/09/2016] [Indexed: 12/11/2022]
Abstract
The live oral typhoid vaccine Ty21a elicits predominantly CD8+, as well as CD4+ T cells mediated immune responses. Clinical field studies showed that Ty21a is moderately effective against S. Typhi and S. Paratyphi B, but not S. Paratyphi A infections. In this study we describe the in depth characterization of S. Typhi, S. Paratyphi A and S. Paratyphi B cross-reactive CD4+ T cell responses elicited following immunization with Ty21a. PBMC samples were collected from 16 healthy volunteers before and 42/84days after Ty21a immunization and stimulated ex-vivo with Salmonella-infected targets. Multiparametric flow cytometry was used to detect the vaccine elicited Salmonella-specific responses in T effector/memory (TEM) and CD45RA+ T effector/memory (TEMRA) CD4+ cell subsets, by measuring CD4+ multifunctional (MF) cells that concomitantly produced IFN-γ, TNF-α, IL-2, MIP-1β, IL-17A and/or expressed CD107a. Post-vaccination increases in S. Typhi-specific MF cells were observed in CD4+ TEM and TEMRA subsets which predominantly produced IFN-γ and/or TNF-α, while IL-2 was produced by a smaller cell subset. A small proportion of those MF cells also produced MIP-1β, IL-17A and expressed CD107a (a marker associated with cytotoxicity). Approximately one third of these specific MF cells have the potential to migrate to the gut mucosa, as evidenced by co-expression of the gut-homing molecule integrin α4β7. In contrast to our previous observations with CD8+ T cells, MF CD4+ T cell responses to the different Salmonella serovars evaluated were similar in magnitude and characteristics. We conclude that although induction of cross-reactive CD4+ MF effector T cells suggest a possible role in Salmonella-immunity, these responses are unlikely to provide an immunological basis for the observed efficacy of Ty21a against S. Typhi and S. Paratyphi B, but not to S. Paratyphi A.
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12
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Pigny F, Lassus A, Terrettaz J, Tranquart F, Corthésy B, Bioley G. Intranasal Vaccination WithSalmonella-Derived Serodominant Secreted Effector Protein B Associated With Gas-Filled Microbubbles Partially Protects Against Gut Infection in Mice. J Infect Dis 2016; 214:438-46. [DOI: 10.1093/infdis/jiw162] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 04/18/2016] [Indexed: 12/13/2022] Open
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Nelson RW, Beisang D, Tubo NJ, Dileepan T, Wiesner DL, Nielsen K, Wüthrich M, Klein BS, Kotov DI, Spanier JA, Fife BT, Moon JJ, Jenkins MK. T cell receptor cross-reactivity between similar foreign and self peptides influences naive cell population size and autoimmunity. Immunity 2015; 42:95-107. [PMID: 25601203 DOI: 10.1016/j.immuni.2014.12.022] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 10/25/2014] [Accepted: 12/22/2014] [Indexed: 01/06/2023]
Abstract
T cell receptor (TCR) cross-reactivity between major histocompatibility complex II (MHCII)-binding self and foreign peptides could influence the naive CD4(+) T cell repertoire and autoimmunity. We found that nonamer peptides that bind to the same MHCII molecule only need to share five amino acids to cross-react on the same TCR. This property was biologically relevant because systemic expression of a self peptide reduced the size of a naive cell population specific for a related foreign peptide by deletion of cells with cross-reactive TCRs. Reciprocally, an incompletely deleted naive T cell population specific for a tissue-restricted self peptide could be triggered by related microbial peptides to cause autoimmunity. Thus, TCR cross-reactivity between similar self and foreign peptides can reduce the size of certain foreign peptide-specific T cell populations and might allow T cell populations specific for tissue-restricted self peptides to cause autoimmunity after infection.
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14
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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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15
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Musson JA, Reynolds CJ, Rinchai D, Nithichanon A, Khaenam P, Favry E, Spink N, Chu KKY, De Soyza A, Bancroft GJ, Lertmemongkolchai G, Maillere B, Boyton RJ, Altmann DM, Robinson JH. CD4+ T cell epitopes of FliC conserved between strains of Burkholderia: implications for vaccines against melioidosis and cepacia complex in cystic fibrosis. THE JOURNAL OF IMMUNOLOGY 2014; 193:6041-9. [PMID: 25392525 DOI: 10.4049/jimmunol.1402273] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis characterized by pneumonia and fatal septicemia and prevalent in Southeast Asia. Related Burkholderia species are strong risk factors of mortality in cystic fibrosis (CF). The B. pseudomallei flagellar protein FliC is strongly seroreactive and vaccination protects challenged mice. We assessed B. pseudomallei FliC peptide binding affinity to multiple HLA class II alleles and then assessed CD4 T cell immunity in HLA class II transgenic mice and in seropositive individuals in Thailand. T cell hybridomas were generated to investigate cross-reactivity between B. pseudomallei and the related Burkholderia species associated with Cepacia Complex CF. B. pseudomallei FliC contained several peptide sequences with ability to bind multiple HLA class II alleles. Several peptides were shown to encompass strong CD4 T cell epitopes in B. pseudomallei-exposed individuals and in HLA transgenic mice. In particular, the p38 epitope is robustly recognized by CD4 T cells of seropositive donors across diverse HLA haplotypes. T cell hybridomas against an immunogenic B. pseudomallei FliC epitope also cross-reacted with orthologous FliC sequences from Burkholderia multivorans and Burkholderia cenocepacia, important pathogens in CF. Epitopes within FliC were accessible for processing and presentation from live or heat-killed bacteria, demonstrating that flagellin enters the HLA class II Ag presentation pathway during infection of macrophages with B. cenocepacia. Collectively, the data support the possibility of incorporating FliC T cell epitopes into vaccination programs targeting both at-risk individuals in B. pseudomallei endemic regions as well as CF patients.
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Affiliation(s)
- Julie A Musson
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear NE2 4HH, United Kingdom
| | - Catherine J Reynolds
- Section of Infectious Diseases and Immunity, Department of Medicine, Imperial College, London W12 0NN, United Kingdom
| | - Darawan Rinchai
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Arnone Nithichanon
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Prasong Khaenam
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Emmanuel Favry
- Commiseriat à l'Energie Atomique, Insititut de Biologie et de Technologies de Saclay, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), 91191 Gif Sur Yvette, France; and
| | - Natasha Spink
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Karen K Y Chu
- Section of Infectious Diseases and Immunity, Department of Medicine, Imperial College, London W12 0NN, United Kingdom
| | - Anthony De Soyza
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear NE2 4HH, United Kingdom
| | - Gregory J Bancroft
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Ganjana Lertmemongkolchai
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Bernard Maillere
- Commiseriat à l'Energie Atomique, Insititut de Biologie et de Technologies de Saclay, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), 91191 Gif Sur Yvette, France; and
| | - Rosemary J Boyton
- Section of Infectious Diseases and Immunity, Department of Medicine, Imperial College, London W12 0NN, United Kingdom
| | - Daniel M Altmann
- Section of Infectious Diseases and Immunity, Department of Medicine, Imperial College, London W12 0NN, United Kingdom
| | - John H Robinson
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear NE2 4HH, United Kingdom;
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16
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Chang WW, Lee CH. Salmonella as an innovative therapeutic antitumor agent. Int J Mol Sci 2014; 15:14546-54. [PMID: 25196596 PMCID: PMC4159867 DOI: 10.3390/ijms150814546] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 07/28/2014] [Accepted: 08/18/2014] [Indexed: 12/12/2022] Open
Abstract
Lack of specificity of the therapeutic agent is a primary limitation in the treatment of a tumor. The use of preferentially replicating bacteria as therapeutic agents is an innovative approach to tumor treatment. This is based on the observation that certain obligate or facultative anaerobic bacteria are capable of multiplying selectively in tumors and inhibiting their growth. Bacteria have been employed as antitumor agents that are capable of preferentially amplifying within tumors and inhibiting their growth. Moreover, bacteria-derived factors have an immune-stimulation effect. Therefore, bacteria are able to transfer therapeutic genes into the tumor cells using their infective ability. Herein, we introduce the application of bacteria for tumor therapy and focus on Salmonella, which have been widely used for tumor therapy. Salmonella have mainly been applied as gene-delivery vectors, antitumor immune activators and tumor cell death inducers. This study will not only evaluate the therapeutic efficacy of Salmonella for the treatment of tumor but will also elucidate the mechanisms underlying the antitumor activities mediated by Salmonella, which involve host immune responses and cellular molecular responses.
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Affiliation(s)
- Wen-Wei Chang
- Department of Biomedical Sciences, College of Medical Science and Technology, Chung Shan Medical University, Taichung 402, Taiwan.
| | - Che-Hsin Lee
- Department of Microbiology, School of Medicine, China Medical University, Taichung 404, Taiwan.
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17
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Bumann D. Identification of Protective Antigens for Vaccination against Systemic Salmonellosis. Front Immunol 2014; 5:381. [PMID: 25157252 PMCID: PMC4127814 DOI: 10.3389/fimmu.2014.00381] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 07/25/2014] [Indexed: 12/21/2022] Open
Abstract
There is an urgent medical need for improved vaccines with broad serovar coverage and high efficacy against systemic salmonellosis. Subunit vaccines offer excellent safety profiles but require identification of protective antigens, which remains a challenging task. Here, I review crucial properties of Salmonella antigens that might help to narrow down the number of potential candidates from more than 4000 proteins encoded in Salmonella genomes, to a more manageable number of 50–200 most promising antigens. I also discuss complementary approaches for antigen identification and potential limitations of current pre-clinical vaccine testing.
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Affiliation(s)
- Dirk Bumann
- Focal Area Infection Biology, Biozentrum, University of Basel , Basel , Switzerland
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18
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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: 2.9] [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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Xiong X, Qi Y, Jiao J, Gong W, Duan C, Wen B. Exploratory study on Th1 epitope-induced protective immunity against Coxiella burnetii infection. PLoS One 2014; 9:e87206. [PMID: 24498044 PMCID: PMC3907486 DOI: 10.1371/journal.pone.0087206] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 12/21/2013] [Indexed: 11/18/2022] Open
Abstract
Coxiella burnetii is a Gram-negative bacterium that causes Q fever in humans. In the present study, 131 candidate peptides were selected from the major immunodominant proteins (MIPs) of C. burnetii due to their high-affinity binding capacity for the MHC class II molecule H2 I-Ab based on bioinformatic analyses. Twenty-two of the candidate peptides with distinct MIP epitopes were well recognized by the IFN-γ recall responses of CD4+ T cells from mice immunized with parental proteins in an ELISPOT assay. In addition, 7 of the 22 peptides could efficiently induce CD4+ T cells from mice immunized with C. burnetii to rapidly proliferate and significantly increase IFN-γ production. Significantly higher levels of IL-2, IL-12p70, IFN-γ, and TNF-α were also detected in serum from mice immunized with a pool of the 7 peptides. Immunization with the pool of 7 peptides, but not the individual peptides, conferred a significant protection against C. burnetii infection in mice, suggesting that these Th1 peptides could work together to efficiently activate CD4+ T cells to produce the Th1-type immune response against C. burnetii infection. These observations could contribute to the rational design of molecular vaccines for Q fever.
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Affiliation(s)
- Xiaolu Xiong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- * E-mail: (XX); (BW)
| | - Yong Qi
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jun Jiao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Wenping Gong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Changsong Duan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Bohai Wen
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- * E-mail: (XX); (BW)
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20
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Barat S, Willer Y, Rizos K, Claudi B, Mazé A, Schemmer AK, Kirchhoff D, Schmidt A, Burton N, Bumann D. Immunity to intracellular Salmonella depends on surface-associated antigens. PLoS Pathog 2012; 8:e1002966. [PMID: 23093937 PMCID: PMC3475680 DOI: 10.1371/journal.ppat.1002966] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 08/14/2012] [Indexed: 01/05/2023] Open
Abstract
Invasive Salmonella infection is an important health problem that is worsening because of rising antimicrobial resistance and changing Salmonella serovar spectrum. Novel vaccines with broad serovar coverage are needed, but suitable protective antigens remain largely unknown. Here, we tested 37 broadly conserved Salmonella antigens in a mouse typhoid fever model, and identified antigen candidates that conferred partial protection against lethal disease. Antigen properties such as high in vivo abundance or immunodominance in convalescent individuals were not required for protectivity, but all promising antigen candidates were associated with the Salmonella surface. Surprisingly, this was not due to superior immunogenicity of surface antigens compared to internal antigens as had been suggested by previous studies and novel findings for CD4 T cell responses to model antigens. Confocal microscopy of infected tissues revealed that many live Salmonella resided alone in infected host macrophages with no damaged Salmonella releasing internal antigens in their vicinity. In the absence of accessible internal antigens, detection of these infected cells might require CD4 T cell recognition of Salmonella surface-associated antigens that could be processed and presented even from intact Salmonella. In conclusion, our findings might pave the way for development of an efficacious Salmonella vaccine with broad serovar coverage, and suggest a similar crucial role of surface antigens for immunity to both extracellular and intracellular pathogens. Salmonella infections cause extensive morbidity and mortality worldwide. A vaccine that prevents systemic Salmonella infections is urgently needed but suitable antigens remain largely unknown. In this study we identified several antigen candidates that mediated protective immunity to Salmonella in a mouse typhoid fever model. Interestingly, all these antigens were associated with the Salmonella surface. This suggested that similar antigen properties might be relevant for CD4 T cell dependent immunity to intracellular pathogens like Salmonella, as for antibody-dependent immunity to extracellular pathogens. Detailed analysis revealed that Salmonella surface antigens were not generally more immunogenic compared to internal antigens. However, internal antigens were inaccessible for CD4 T cell recognition of a substantial number of infected host cells that contained exclusively live intact Salmonella. Together, these results might pave the way for development of an efficacious Salmonella vaccine, and provide a basis to facilitate antigen identification for Salmonella and possibly other intracellular pathogens.
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Affiliation(s)
- Somedutta Barat
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Yvonne Willer
- Junior Group “Mucosal Infections”, Hannover Medical School, Hannover, Germany
| | - Konstantin Rizos
- Department of Molecular Biology, Max-Planck-Institute for Infection Biology, Berlin, Germany
| | - Beatrice Claudi
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Alain Mazé
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Anne K. Schemmer
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Dennis Kirchhoff
- Immunomodulation Group, Deutsches Rheuma-Forschungszentrum Berlin, Berlin, Germany
| | - Alexander Schmidt
- Proteomics Core Facility, Biozentrum, University of Basel, Basel, Switzerland
| | - Neil Burton
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Dirk Bumann
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
- Junior Group “Mucosal Infections”, Hannover Medical School, Hannover, Germany
- Department of Molecular Biology, Max-Planck-Institute for Infection Biology, Berlin, Germany
- * E-mail:
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