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Gaur R, Verma DK, Alam SI, Kamboj DV. Identification of MHC Class I bound peptides of Francisella tularensis Live Vaccine Strain using mass spectrometry. Eur J Pharm Sci 2021; 158:105651. [DOI: 10.1016/j.ejps.2020.105651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/30/2020] [Accepted: 11/18/2020] [Indexed: 11/29/2022]
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2
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Mathematical modelling of the role of mucosal vaccine on the within-host dynamics of Chlamydia trachomatis. J Theor Biol 2020; 497:110291. [PMID: 32315672 DOI: 10.1016/j.jtbi.2020.110291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 11/23/2022]
Abstract
A mathematical model of the within-host replicative dynamics of C. trachomatis infection and its interactions with the immune system, in the presence of a mucosal vaccine, is presented. Our aim is to estimate the requisite efficacy of an efficacious mucosal vaccine that could promote a stable disease-free state in vivo. Sensitivity analysis was used to quantify how variability in the model parameters influence the value of the disease threshold R0. This shows that the two most important factors to be considered for achieving a disease-free state state in vivo, based on their influence on R0, are the efficacy of the Chlamydia vaccine, and the rate at which the humoral immune response protects healthy epithelial cells from infection. Numerical simulations of the model show that a vaccine with a minimum efficacy of 86% may be required for the in vivo control of Chlamydia burden. Such effective but imperfect Chlamydia vaccine could confer long-term protective immunity to genital Chlamydia infections. Conditions under which lower vaccine efficacies may suffice are also explored.
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3
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Li Y, Wang C, Sun Z, Xiao J, Yan X, Chen Y, Yu J, Wu Y. Simultaneous Intramuscular And Intranasal Administration Of Chitosan Nanoparticles-Adjuvanted Chlamydia Vaccine Elicits Elevated Protective Responses In The Lung. Int J Nanomedicine 2019; 14:8179-8193. [PMID: 31632026 PMCID: PMC6790120 DOI: 10.2147/ijn.s218456] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/11/2019] [Indexed: 12/13/2022] Open
Abstract
Background Chlamydia psittaci is a zoonotic bacteria closely associated with psittacosis/ornithosis. Vaccination has been recognized as the best way to inhibit the spread of C. psittaci due to the majority ignored of infections. The optimal Chlamydia vaccine was obstructed by the defect of single immunization route and the lack of availability of nontoxic and valid adjuvants. Methods In this study, we developed a novel immunization strategy, simultaneous (SIM) intramuscular (IM) and intranasal (IN) administration of a C. psittaci antigens (Ags) adjuvanted with chitosan nanoparticles (CNPs). And SIM-CNPs-Ags were used to determine the different types of immune response and the protective role in vivo. Results CNPs-Ags with zeta-potential values of 13.12 mV and of 276.1 nm showed excellent stability and optimal size for crossing the mucosal barrier with high 71.7% encapsulation efficiency. SIM-CPN-Ags mediated stronger humoral and mucosal responses by producing meaningfully high levels of IgG and secretory IgA (sIgA) antibodies. The SIM route also led to Ags-specific T-cell responses and increased IFN-γ, IL-2, TNF-α and IL-17A in the splenocyte supernatants. Following respiratory infection with C. psittaci, we found that SIM immunization remarkably reduced bacterial load and the degree of inflammation in the infected lungs and made for a lower level of IFN-γ, TNF-α and IL-6. Furthermore, SIM vaccination with CNPs-Ags had obviously inhibited C. psittaci disseminating to various organs in vivo. Conclusion SIM immunization with CNPs-adjuvanted C. psittaci Ags may present a novel strategy for the development of a vaccine against the C. psittaci infection.
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Affiliation(s)
- Yumeng Li
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Chuan Wang
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Zhenjie Sun
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Jian Xiao
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Xiaoliang Yan
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Yuqing Chen
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Jian Yu
- Department of Experimental Zoology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Yimou Wu
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
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Nyari S, Booth R, Quigley BL, Waugh CA, Timms P. Therapeutic effect of a Chlamydia pecorum recombinant major outer membrane protein vaccine on ocular disease in koalas (Phascolarctos cinereus). PLoS One 2019; 14:e0210245. [PMID: 30615687 PMCID: PMC6322743 DOI: 10.1371/journal.pone.0210245] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 12/19/2018] [Indexed: 12/29/2022] Open
Abstract
Chlamydia pecorum is responsible for causing ocular infection and disease which can lead to blindness in koalas (Phascolarctos cinereus). Antibiotics are the current treatment for chlamydial infection and disease in koalas, however, they can be detrimental for the koala’s gastrointestinal tract microbiota and in severe cases, can lead to dysbiosis and death. In this study, we evaluated the therapeutic effects provided by a recombinant chlamydial major outer membrane protein (MOMP) vaccine on ocular disease in koalas. Koalas with ocular disease (unilateral or bilateral) were vaccinated and assessed for six weeks, evaluating any changes to the conjunctival tissue and discharge. Samples were collected pre- and post-vaccination to evaluate both humoral and cell-mediated immune responses. We further assessed the infecting C. pecorum genotype, host MHC class II alleles and presence of koala retrovirus type (KoRV-B). Our results clearly showed an improvement in the clinical ocular disease state of all seven koalas, post-vaccination. We observed increases in ocular mucosal IgA antibodies to whole C. pecorum elementary bodies, post-vaccination. We found that systemic cell-mediated immune responses to interferon-γ, interleukin-6 and interleukin-17A were not significantly predictive of ocular disease in koalas. Interestingly, one koala did not have as positive a clinical response (in one eye primarily) and this koala was infected with a C. pecorum genotype (E’) that was not used as part of the vaccine formula (MOMP genotypes A, F and G). The predominant MHC class II alleles identified were DAb*19, DAb*21 and DBb*05, with no two koalas identified with the same genetic sequence. Additionally, KoRV-B, which is associated with chlamydial disease outcome, was identified in two (29%) ocular diseased koalas, which still produced vaccine-induced immune responses and clinical ocular improvements post-vaccination. Our findings show promise for the use of a recombinant chlamydial MOMP vaccine for the therapeutic treatment of ocular disease in koalas.
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Affiliation(s)
- Sharon Nyari
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Rosemary Booth
- Australia Zoo Wildlife Hospital, Beerwah, Queensland, Australia
| | - Bonnie L. Quigley
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Courtney A. Waugh
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Peter Timms
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
- * E-mail:
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5
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Lausen M, Christiansen G, Bouet Guldbæk Poulsen T, Birkelund S. Immunobiology of monocytes and macrophages during Chlamydia trachomatis infection. Microbes Infect 2018; 21:73-84. [PMID: 30528899 DOI: 10.1016/j.micinf.2018.10.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 02/03/2023]
Abstract
Infections caused by the intracellular bacterium Chlamydia trachomatis are a global health burden affecting more than 100 million people annually causing damaging long-lasting infections. In this review, we will present and discuss important aspects of the interaction between C. trachomatis and monocytes/macrophages.
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Affiliation(s)
- Mads Lausen
- Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 3b, 9220 Aalborg Ø, Denmark.
| | - Gunna Christiansen
- Department of Biomedicine, Aarhus University, Wilhelms Meyers Allé 4, 8000 Aarhus, Denmark
| | | | - Svend Birkelund
- Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 3b, 9220 Aalborg Ø, Denmark
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6
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Russi RC, Bourdin E, García MI, Veaute CMI. In silico prediction of T- and B-cell epitopes in PmpD: First step towards to the design of a Chlamydia trachomatis vaccine. Biomed J 2018; 41:109-117. [PMID: 29866599 PMCID: PMC6138762 DOI: 10.1016/j.bj.2018.04.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/30/2018] [Accepted: 04/25/2018] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Chlamydia trachomatis is the most common sexually transmitted bacterial infection globally. Currently, there are no vaccines available despite the efforts made to develop a protective one. Polymorphic membrane protein D (PmpD) is an attractive immunogen candidate as it is conserved among strains and it is target of neutralizing antibodies. However, its high molecular weight and its complex structure make it difficult to handle by recombinant DNA techniques. Our aim is to predict B-cell and T-cell epitopes of PmpD. METHOD A sequence (Genbank AAK69391.2) having 99-100% identity with various serovars of C. trachomatis was used for predictions. NetMHC and NetMHCII were used for T-cell epitope linked to MHC I or MHC II alleles prediction, respectively. BepiPred predicted linear B-cell epitopes. For three dimensional epitopes, PmpD was homology-modeled by Raptor X. Surface epitopes were predicted on its globular structure using DiscoTope. RESULTS NetMHC predicted 271 T-cell epitopes of 9-12aa with weak affinity, and 70 with strong affinity to MHC I molecules. NetMHCII predicted 2903 T-cell epitopes of 15aa with weak affinity, and 742 with strong affinity to MHC II molecules. Twenty four linear B-cell epitopes were predicted. Raptor X was able to model 91% of the three-dimensional structure whereas 57 residues of discontinuous epitopes were suggested by DiscoTope. Six regions containing B-cell and T-cell epitopes were identified by at least two predictors. CONCLUSIONS PmpD has potential B-cell and T-cell epitopes distributed throughout the sequence. Thus, several fragments were identified as valuable candidates for subunit vaccines against C. trachomatis.
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Affiliation(s)
- Romina Cecilia Russi
- Basic Immunology Laboratory, Faculty of Biochemistry and Biological Sciences, National University of the Littoral, Santa Fe, Argentina
| | - Elian Bourdin
- Independent professional, C1425BME, Buenos Aires, Argentina
| | - María Inés García
- Basic Immunology Laboratory, Faculty of Biochemistry and Biological Sciences, National University of the Littoral, Santa Fe, Argentina
| | - Carolina Melania I Veaute
- Basic Immunology Laboratory, Faculty of Biochemistry and Biological Sciences, National University of the Littoral, Santa Fe, Argentina.
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7
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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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8
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Yu H, Karunakaran KP, Jiang X, Brunham RC. Subunit vaccines for the prevention of mucosal infection with Chlamydia trachomatis. Expert Rev Vaccines 2016; 15:977-88. [PMID: 26938202 DOI: 10.1586/14760584.2016.1161510] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chlamydia trachomatis is the most common preventable cause of tubal infertility in women. In high-income countries, despite public health control efforts, C. trachomatis case rates continue to rise. Most medium and low-income countries lack any Chlamydia control program; therefore, a vaccine is essential for the control of Chlamydia infections. A rationally designed Chlamydia vaccine requires understanding of the immunological correlates of protective immunity, pathological responses to this mucosal pathogen, identification of optimal vaccine antigens and selection of suitable adjuvant delivery systems that engender protective immunity. Fortunately, Chlamydia vaccinology is facilitated by genomic knowledge and by murine models that reproduce many of the features of human C. trachomatis infection. This article reviews recent progress in these areas with a focus on subunit vaccine development.
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Affiliation(s)
- Hong Yu
- a Vaccine Research Laboratory , University of British Columbia Centre for Disease Control , Vancouver , British Columbia , Canada
| | - Karuna P Karunakaran
- a Vaccine Research Laboratory , University of British Columbia Centre for Disease Control , Vancouver , British Columbia , Canada
| | - Xiaozhou Jiang
- a Vaccine Research Laboratory , University of British Columbia Centre for Disease Control , Vancouver , British Columbia , Canada
| | - Robert C Brunham
- a Vaccine Research Laboratory , University of British Columbia Centre for Disease Control , Vancouver , British Columbia , Canada
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9
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Nunes A, Gomes JP, Karunakaran KP, Brunham RC. Bioinformatic Analysis of Chlamydia trachomatis Polymorphic Membrane Proteins PmpE, PmpF, PmpG and PmpH as Potential Vaccine Antigens. PLoS One 2015; 10:e0131695. [PMID: 26131720 PMCID: PMC4488443 DOI: 10.1371/journal.pone.0131695] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/05/2015] [Indexed: 12/31/2022] Open
Abstract
Chlamydia trachomatis is the most important infectious cause of infertility in women with important implications in public health and for which a vaccine is urgently needed. Recent immunoproteomic vaccine studies found that four polymorphic membrane proteins (PmpE, PmpF, PmpG and PmpH) are immunodominant, recognized by various MHC class II haplotypes and protective in mouse models. In the present study, we aimed to evaluate genetic and protein features of Pmps (focusing on the N-terminal 600 amino acids where MHC class II epitopes were mapped) in order to understand antigen variation that may emerge following vaccine induced immune selection. We used several bioinformatics platforms to study: i) Pmps' phylogeny and genetic polymorphism; ii) the location and distribution of protein features (GGA(I, L)/FxxN motifs and cysteine residues) that may impact pathogen-host interactions and protein conformation; and iii) the existence of phase variation mechanisms that may impact Pmps' expression. We used a well-characterized collection of 53 fully-sequenced strains that represent the C. trachomatis serovars associated with the three disease groups: ocular (N=8), epithelial-genital (N=25) and lymphogranuloma venereum (LGV) (N=20). We observed that PmpF and PmpE are highly polymorphic between LGV and epithelial-genital strains, and also within populations of the latter. We also found heterogeneous representation among strains for GGA(I, L)/FxxN motifs and cysteine residues, suggesting possible alterations in adhesion properties, tissue specificity and immunogenicity. PmpG and, to a lesser extent, PmpH revealed low polymorphism and high conservation of protein features among the genital strains (including the LGV group). Uniquely among the four Pmps, pmpG has regulatory sequences suggestive of phase variation. In aggregate, the results suggest that PmpG may be the lead vaccine candidate because of sequence conservation but may need to be paired with another protective antigen (like PmpH) in order to prevent immune selection of phase variants.
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Affiliation(s)
- Alexandra Nunes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - João P. Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Karuna P. Karunakaran
- Vaccine Research Laboratory, University of British Columbia Centre for Disease Control, Vancouver, Canada
| | - Robert C. Brunham
- Vaccine Research Laboratory, University of British Columbia Centre for Disease Control, Vancouver, Canada
- * E-mail:
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10
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Knittler MR, Sachse K. Chlamydia psittaci: update on an underestimated zoonotic agent. Pathog Dis 2014; 73:1-15. [PMID: 25853998 DOI: 10.1093/femspd/ftu007] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2014] [Indexed: 12/16/2022] Open
Abstract
Chlamydia (C.) psittaci is an economically relevant pathogen in poultry and pet birds, where it causes psittacosis/ornithosis, and also a human pathogen causing atypical pneumonia after zoonotic transmission. Despite its well-documented prevalence, the agent has received less attention by researchers than other Chlamydia spp. in the last decades. In the present paper, we review recently published data on C. psittaci infection and attempt to single out characteristic features distinguishing it from related chlamydial agents. It is remarkable that C. psittaci is particularly efficient in disseminating in the host organism causing systemic disease, which occasionally can take a fulminant course. At the cellular level, the pathogen's broad host cell spectrum (from epithelial cells to macrophages), its rapid entry and fast replication, proficient use of intracellular transport routes to mitochondria and the Golgi apparatus, the pronounced physical association of chlamydial inclusions with energy-providing cell compartments, as well as the subversive regulation of host cell survival during productive and persistent states facilitate the characteristic efficient growth and successful host-to-host spread of C. psittaci. At the molecular level, the pathogen was shown to upregulate essential chlamydial genes when facing the host immune response. We hypothesize that this capacity, in concert with expression of specific effectors of the type III secretion system and efficient suppression of selected host defense signals, contributes to successful establishment of the infection in the host. Concerning the immunology of host-pathogen interactions, C. psittaci has been shown to distinguish itself by coping more efficiently than other chlamydiae with pro-inflammatory mediators during early host response, which can, to some extent, explain the effective evasion and adaptation strategies of this bacterium. We conclude that thorough analysis of the large number of whole-genome sequences already available will be essential to identify genetic markers of the species-specific features and trigger more in-depth studies in cellular and animal models to address such vital topics as treatment and vaccination.
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Affiliation(s)
- Michael R Knittler
- Institute of Immunology, Friedrich-Loeffler-Institut, Isle of Riems, 07743 Jena, Germany
| | - Konrad Sachse
- Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut, 07743 Jena, Germany
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11
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Zhu Y, Jiang J, Said-Sadier N, Boxx G, Champion C, Tetlow A, Kickhoefer VA, Rome LH, Ojcius DM, Kelly KA. Activation of the NLRP3 inflammasome by vault nanoparticles expressing a chlamydial epitope. Vaccine 2014; 33:298-306. [PMID: 25448112 DOI: 10.1016/j.vaccine.2014.11.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 11/04/2014] [Accepted: 11/15/2014] [Indexed: 11/28/2022]
Abstract
The full potential of vaccines relies on development of effective delivery systems and adjuvants and is critical for development of successful vaccine candidates. We have shown that recombinant vaults engineered to encapsulate microbial epitopes are highly stable structures and are an ideal vaccine vehicle for epitope delivery which does not require the inclusion of an adjuvant. We studied the ability of vaults which were engineered for use as a vaccine containing an immunogenic epitope of Chlamydia trachomatis, polymorphic membrane protein G (PmpG), to be internalized into human monocytes and behave as a "natural adjuvant". We here show that incubation of monocytes with the PmpG-1-vaults activates caspase-1 and stimulates IL-1β secretion through a process requiring the NLRP3 inflammasome and that cathepsin B and Syk are involved in the inflammasome activation. We also observed that the PmpG-1-vaults are internalized through a pathway that is transiently acidic and leads to destabilization of lysosomes. In addition, immunization of mice with PmpG-1-vaults induced PmpG-1 responsive CD4(+) cells upon re-stimulation with PmpG peptide in vitro, suggesting that vault vaccines can be engineered for specific adaptive immune responses. We conclude that PmpG-1-vault vaccines can stimulate NLRP3 inflammasomes and induce PmpG-specific T cell responses.
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Affiliation(s)
- Ye Zhu
- Department of Molecular Cell Biology, and Health Sciences Research Institute, University of California, Merced, CA 95343, USA
| | - Janina Jiang
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA
| | - Najwane Said-Sadier
- Department of Molecular Cell Biology, and Health Sciences Research Institute, University of California, Merced, CA 95343, USA
| | - Gale Boxx
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA
| | - Cheryl Champion
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA
| | - Ashley Tetlow
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA
| | - Valerie A Kickhoefer
- Department of Biological Chemistry, University of California, Los Angeles, CA 90095, USA
| | - Leonard H Rome
- Department of Biological Chemistry, University of California, Los Angeles, CA 90095, USA
| | - David M Ojcius
- Department of Molecular Cell Biology, and Health Sciences Research Institute, University of California, Merced, CA 95343, USA.
| | - Kathleen A Kelly
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA.
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12
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Davies DH, Chun S, Hermanson G, Tucker JA, Jain A, Nakajima R, Pablo J, Felgner PL, Liang X. T cell antigen discovery using soluble vaccinia proteome reveals recognition of antigens with both virion and nonvirion association. THE JOURNAL OF IMMUNOLOGY 2014; 193:1812-27. [PMID: 25024392 DOI: 10.4049/jimmunol.1400663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Vaccinia virus (VACV) is a useful model system for understanding the immune response to a complex pathogen. Proteome-wide Ab profiling studies reveal the humoral response to be strongly biased toward virion-associated Ags, and several membrane proteins induce Ab-mediated protection against VACV challenge in mice. Some studies have indicated that the CD4 response is also skewed toward proteins with virion association, whereas the CD8 response is more biased toward proteins with early expression. In this study, we have leveraged a VACV strain Western Reserve (VACV-WR) plasmid expression library, produced previously for proteome microarrays for Ab profiling, to make a solubilized full VACV-WR proteome for T cell Ag profiling. Splenocytes from VACV-WR-infected mice were assayed without prior expansion against the soluble proteome in assays for Th1 and Th2 signature cytokines. The response to infection was polarized toward a Th1 response, with the distribution of reactive T cell Ags comprising both early and late VACV proteins. Interestingly, the proportions of different functional subsets were similar to that present in the whole proteome. In contrast, the targets of Abs from the same mice were enriched for membrane and other virion components, as described previously. We conclude that a "nonbiasing" approach to T cell Ag discovery reveals a T cell Ag profile in VACV that is broader and less skewed to virion association than the Ab profile. The T cell Ag mapping method developed in the present study should be applicable to other organisms where expressible "ORFeome" libraries are also available, and it is readily scalable for larger pathogens.
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Affiliation(s)
- D Huw Davies
- Division of Infectious Diseases, School of Medicine, University of California, Irvine, Irvine, CA 92697; Antigen Discovery, Inc., Irvine, CA 92618; and
| | - Sookhee Chun
- Division of Infectious Diseases, School of Medicine, University of California, Irvine, Irvine, CA 92697
| | | | - Jo Anne Tucker
- Division of Hematology and Oncology, School of Medicine, University of California, Irvine, Irvine, CA 92697
| | - Aarti Jain
- Division of Infectious Diseases, School of Medicine, University of California, Irvine, Irvine, CA 92697
| | - Rie Nakajima
- Division of Infectious Diseases, School of Medicine, University of California, Irvine, Irvine, CA 92697
| | - Jozelyn Pablo
- Division of Infectious Diseases, School of Medicine, University of California, Irvine, Irvine, CA 92697; Antigen Discovery, Inc., Irvine, CA 92618; and
| | - Philip L Felgner
- Division of Infectious Diseases, School of Medicine, University of California, Irvine, Irvine, CA 92697
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13
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Mabey DCW, Hu V, Bailey RL, Burton MJ, Holland MJ. Towards a safe and effective chlamydial vaccine: lessons from the eye. Vaccine 2014; 32:1572-8. [PMID: 24606636 PMCID: PMC3991328 DOI: 10.1016/j.vaccine.2013.10.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 09/24/2013] [Accepted: 10/03/2013] [Indexed: 02/06/2023]
Abstract
As well as being the most common bacterial sexually transmitted infection, Chlamydia trachomatis (Ct) is the leading infectious cause of blindness. The pathogenesis of ocular chlamydial infection (trachoma) is similar to that of genital infection. In the 1960s the efficacy of Ct vaccines against ocular infection was evaluated in major field trials in Saudi Arabia, Taiwan, The Gambia, India and Ethiopia. These trials showed that it was possible to induce short term immunity to ocular infection, and to reduce the incidence of inflammatory trachoma, by parenteral immunisation with killed or live whole organism vaccines. In one study, it was also shown that the incidence of scarring sequelae was reduced in vaccinated children. Detailed studies in non-human primates conducted at this time suggested that vaccination could lead to more severe inflammatory disease on subsequent challenge. Since that time there have been many studies on the immunological correlates of protective immunity and immunopathology in ocular Ct infection in humans and non-human primates, and on host genetic polymorphisms associated with protection from adverse sequelae. These have provided important information to guide the development and evaluation of a human Ct vaccine.
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Affiliation(s)
- David C W Mabey
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, United Kingdom.
| | - Victor Hu
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, United Kingdom
| | - Robin L Bailey
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, United Kingdom
| | - Matthew J Burton
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, United Kingdom
| | - Martin J Holland
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, United Kingdom
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Dixit S, Singh SR, Yilma AN, Agee RD, Taha M, Dennis VA. Poly(lactic acid)-poly(ethylene glycol) nanoparticles provide sustained delivery of a Chlamydia trachomatis recombinant MOMP peptide and potentiate systemic adaptive immune responses in mice. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2014; 10:1311-21. [PMID: 24602605 DOI: 10.1016/j.nano.2014.02.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 02/04/2014] [Accepted: 02/21/2014] [Indexed: 12/22/2022]
Abstract
UNLABELLED PLA-PEG [poly(lactic acid)-poly (ethylene glycol)], a biodegradable copolymer, is underexploited for vaccine delivery although it exhibits enhanced biocompatibility and slow release immune-potentiating properties. We document here successful encapsulation of M278, a Chlamydia trachomatis MOMP (major outer-membrane protein) peptide, within PLA-PEG nanoparticles by size (~73-100nm), zeta potential (-16 mV), smooth morphology, encapsulation efficiency (~60%), slow release pattern, and non-toxicity to macrophages. Immunization of mice with encapsulated M278 elicited higher M278-specific T-cell cytokines [Th1 (IFN-γ, IL-2), Th17 (IL-17)] and antibodies [Th1 (IgG2a), Th2 (IgG1, IgG2b)] compared to bare M278. Encapsulated-M278 mouse serum inhibited Chlamydia infectivity of macrophages, with a concomitant transcriptional down-regulation of MOMP, its cognate TLR2 and CD80 co-stimulatory molecule. Collectively, encapsulated M278 potentiated crucial adaptive immune responses, which are required by a vaccine candidate for protective immunity against Chlamydia. Our data highlight PLA-PEG's potential for vaccines, which resides in its slow release and potentiating effects to bolster immune responses. FROM THE CLINICAL EDITOR This study highlights the potential of a PLA-PEG-based nanoparticle formulation containing a major outer membrane protein of chlamydia trachomatis in inducing a sustained enhanced immune response, paving the way to the development of a vaccination strategy against this infection.
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Affiliation(s)
- Saurabh Dixit
- Center for NanoBiotechnology Research (CNBR), Alabama State University, Montgomery, AL, USA
| | - Shree R Singh
- Center for NanoBiotechnology Research (CNBR), Alabama State University, Montgomery, AL, USA
| | - Abebayehu N Yilma
- Center for NanoBiotechnology Research (CNBR), Alabama State University, Montgomery, AL, USA; Global Institue of Public Health, New York University, New York, NY, USA
| | - Ronald D Agee
- Center for NanoBiotechnology Research (CNBR), Alabama State University, Montgomery, AL, USA; College of Podiatric Medicine, Western University of Health Sciences, Pomona, CA, USA
| | - Murtada Taha
- Center for NanoBiotechnology Research (CNBR), Alabama State University, Montgomery, AL, USA; Department of Natural Sciences, Albany State University, Albany, GA, USA
| | - Vida A Dennis
- Center for NanoBiotechnology Research (CNBR), Alabama State University, Montgomery, AL, USA.
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Chlamydia trachomatis-infected epithelial cells and fibroblasts retain the ability to express surface-presented major histocompatibility complex class I molecules. Infect Immun 2013; 82:993-1006. [PMID: 24343651 DOI: 10.1128/iai.01473-13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The obligate intracellular bacterial pathogen Chlamydia trachomatis is the causative agent of a variety of infectious diseases such as trachoma and sexually transmitted diseases. In infected target cells, C. trachomatis replicates within parasitophorous vacuoles and expresses the protease-like activity factor CPAF. Previous studies have suggested that CPAF degrades the host transcription factors RFX5 and NF-κB p65, which are involved in the regulation of constitutive and inducible expression of major histocompatibility complex class I (MHC I). It was speculated that Chlamydia suppresses the surface presentation of MHC I in order to evade an effective immune response. Nevertheless, a recent study suggested that RFX5 and NF-κB p65 may not serve as target substrates for CPAF-mediated degradation, raising concerns about the proposed MHC I subversion by Chlamydia. Hence, we investigated the direct influence of Chlamydia on MHC I expression and surface presentation in infected host cells. By using nine different human cells and cell lines infected with C. trachomatis (serovar D or LGV2), we demonstrate that chlamydial infection does not interfere with expression, maturation, transport, and surface presentation of MHC I, suggesting functional antigen processing in bacterium-infected cells. Our findings provide novel insights into the interaction of chlamydiae with their host cells and should be taken into consideration for the design of future therapies and vaccines.
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Jaiswal V, Chauhan RS, Rout C. Common antigens prediction in bacterial bioweapons: a perspective for vaccine design. INFECTION GENETICS AND EVOLUTION 2013; 21:315-9. [PMID: 24300889 DOI: 10.1016/j.meegid.2013.11.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 11/10/2013] [Accepted: 11/11/2013] [Indexed: 01/22/2023]
Abstract
Bioweapons (BWs) are a serious threat to mankind and the lack of efficient vaccines against bacterial bioweapons (BBWs) further worsens the situation in face of BW attack. Experts believe that difficulties in detection and ease in dissemination of deadly pathogens make BW a better option for attack compared to nuclear weapons. Molecular biology techniques facilitate the use of genetically modified BBWs thus creating uncertainty on which bacteria will be used for BW attack. In the present work, available resources such as proteomic sequences of BBWs, protective antigenic proteins (PAPs) reported in Protegen database and VaxiJen dataset, and immunogenic epitopes in immune epitope database (IEDB) were used to predict potential broad-specific vaccine candidates against BBWs. Comparison of proteomes sequences of BBWs and their analyses using in-house PERL scripts identified 44 conserved proteins and many of them were known to be immunogenic. Comparison of conserved proteins against PAPs identified six either as PAPs or their homologues with a potential of providing protection against multiple pathogens. Similarly, mapping of conserved proteins against experimentally known IEDB epitopes identified six epitopes which had exact epitope match in four proteins including three from earlier predicted six PAPs. These epitopes were also reported to provide protection against several pathogens. In the backdrop of conserved heat shock GroEL protein from Salmonella enterica providing protection against five diverse bacterial pathogens involved in different diseases, and synthetic proteins produced by combination of epitopes from Mycobacterium tuberculosis and 4 viruses providing protection against both bacterium and viruses, the identified putative immunogenic conserved proteins and immune-protective epitopes can further be explored for their potential as broad-specific vaccine candidates against BBWs.
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Affiliation(s)
- Varun Jaiswal
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh 173234, India.
| | - Rajinder S Chauhan
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh 173234, India.
| | - Chittaranjan Rout
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh 173234, India.
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Hafner LM, Wilson DP, Timms P. Development status and future prospects for a vaccine against Chlamydia trachomatis infection. Vaccine 2013; 32:1563-71. [PMID: 23973245 DOI: 10.1016/j.vaccine.2013.08.020] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 07/04/2013] [Accepted: 08/11/2013] [Indexed: 01/08/2023]
Abstract
Chlamydia trachomatis continues to be the most commonly reported sexually transmitted bacterial infection in many countries with more than 100 million new cases estimated annually. These acute infections translate into significant downstream health care costs, particularly for women, where complications can include pelvic inflammatory disease and other disease sequelae such as tubal factor infertility. Despite years of research, the immunological mechanisms responsible for protective immunity versus immunopathology are still not well understood, although it is widely accepted that T cell driven IFN-g and Th17 responses are critical for clearing infection. While antibodies are able to neutralize infections in vitro, alone they are not protective, indicating that any successful vaccine will need to elicit both arms of the immune response. In recent years, there has been an expansion in the number and types of antigens that have been evaluated as vaccines, and combined with the new array of mucosal adjuvants, this aspect of chlamydial vaccinology is showing promise. Most recently, the opportunities to develop successful vaccines have been given a significant boost with the development of a genetic transformation system for Chlamydia, as well as the identification of the key role of the chlamydial plasmid in virulence. While still remaining a major challenge, the development of a successful C. trachomatis vaccine is starting to look more likely.
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Affiliation(s)
- Louise M Hafner
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - David P Wilson
- The Kirby Institute, University of New South Wales, Sydney, Australia
| | - Peter Timms
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
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Gomez G, Adams LG, Rice-Ficht A, Ficht TA. Host-Brucella interactions and the Brucella genome as tools for subunit antigen discovery and immunization against brucellosis. Front Cell Infect Microbiol 2013; 3:17. [PMID: 23720712 PMCID: PMC3655278 DOI: 10.3389/fcimb.2013.00017] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 04/26/2013] [Indexed: 01/18/2023] Open
Abstract
Vaccination is the most important approach to counteract infectious diseases. Thus, the development of new and improved vaccines for existing, emerging, and re-emerging diseases is an area of great interest to the scientific community and general public. Traditional approaches to subunit antigen discovery and vaccine development lack consideration for the critical aspects of public safety and activation of relevant protective host immunity. The availability of genomic sequences for pathogenic Brucella spp. and their hosts have led to development of systems-wide analytical tools that have provided a better understanding of host and pathogen physiology while also beginning to unravel the intricacies at the host-pathogen interface. Advances in pathogen biology, host immunology, and host-agent interactions have the potential to serve as a platform for the design and implementation of better-targeted antigen discovery approaches. With emphasis on Brucella spp., we probe the biological aspects of host and pathogen that merit consideration in the targeted design of subunit antigen discovery and vaccine development.
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Affiliation(s)
- Gabriel Gomez
- Department of Veterinary Pathobiology, Texas A&M University College Station, TX 77843, USA.
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Cambridge CD, Singh SR, Waffo AB, Fairley SJ, Dennis VA. Formulation, characterization, and expression of a recombinant MOMP Chlamydia trachomatis DNA vaccine encapsulated in chitosan nanoparticles. Int J Nanomedicine 2013; 8:1759-71. [PMID: 23690681 PMCID: PMC3656902 DOI: 10.2147/ijn.s42723] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Chlamydia trachomatis is a bacterial sexually transmitted infection affecting millions of people worldwide. Previous vaccination attempts have employed the recombinant major outer membrane protein (MOMP) of C. trachomatis nonetheless, with limited success, perhaps, due to stability, degradation, and delivery issues. In this study we cloned C. trachomatis recombinant MOMP DNA (DMOMP) and encapsulated it in chitosan nanoparticles (DMCNP) using the complex coacervation technique. Physiochemical characterizations of DMCNP included transmission and scanning electron microcopy, Fourier transform infrared and ultraviolet-visible spectroscopy, and zeta potential. Encapsulated DMOMP was 167–250 nm, with a uniform spherical shape and homogenous morphology, and an encapsulation efficiency > 90%. A slow release pattern of encapsulated DMOMP, especially in acidic solution, was observed over 7 days. The zeta potential of DMCNP was ~8.80 mV, which indicated that it was highly stable. Toxicity studies of DMCNP (25–400 μg/mL) to Cos-7 cells using the MTT assay revealed minimal toxicity over 24–72 hours with >90% viable cells. Ultra-violet visible (UV-vis) spectra indicated encapsulated DMOMP protection by chitosan, whereas agarose gel electrophoresis verified its protection from enzymatic degradation. Expression of MOMP protein in DMCNP-transfected Cos-7 cells was demonstrated via Western blotting and immunofluorescence microscopy. Significantly, intramuscular injection of BALB/c mice with DMCNP confirmed the delivery of encapsulated DMOMP, and expression of the MOMP gene transcript in thigh muscles and spleens. Our data show that encapsulation of DMOMP in biodegradable chitosan nanoparticles imparts stability and protection from enzymatic digestion, and enhances delivery and expression of DMOMP in vitro and in mice. Further investigations of the nanoencapsulated DMCNP vaccine formulation against C. trachomatis in mice are warranted.
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Affiliation(s)
- Chino D Cambridge
- Center for NanoBiotechnology Research (CNBR), Alabama State University, Montgomery, AL, USA
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Childs TS, Webley WC. In vitro assessment of halobacterial gas vesicles as a Chlamydia vaccine display and delivery system. Vaccine 2012; 30:5942-8. [DOI: 10.1016/j.vaccine.2012.07.038] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 06/06/2012] [Accepted: 07/18/2012] [Indexed: 12/30/2022]
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Proteomic identification of immunodominant chlamydial antigens in a mouse model. J Proteomics 2012; 77:176-86. [PMID: 22959960 DOI: 10.1016/j.jprot.2012.08.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 08/04/2012] [Accepted: 08/23/2012] [Indexed: 11/20/2022]
Abstract
Chlamydia trachomatis is the most common bacterial sexually transmitted pathogen in the world. To identify new vaccine candidates a protein microarray was constructed by expressing the open reading frames (ORFs) from Chlamydia mouse pneumonitis (MoPn). C57BL/6, C3H/HeN and BALB/c mice were immunized either intranasally or intravaginally with live MoPn elementary bodies (EB). Two additional groups were immunized by the intramuscular plus subcutaneous routes with UV-treated EB, using CpG and Montanide as adjuvants to favor a Th1 response, or Alum, to elicit a Th2 response. Serum samples collected from the three strains of mice were tested in the microarray. The array included the expression of 909 proteins from the 921 ORFs of the MoPn genome and plasmid. A total of 530 ORFs were recognized by at least one serum sample. Of these, 36 reacted with sera from the three strains of mice immunized with live EB. These antigens included proteins that were previously described as immunogenic such as MOMP and HSP60. In addition, we uncovered new immunogens, including 11 hypothetical proteins. In summary, we have identified new immunodominant chlamydial proteins that can be tested for their ability to induce protection in animal models and subsequently in humans.
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Gondek DC, Olive AJ, Stary G, Starnbach MN. CD4+ T cells are necessary and sufficient to confer protection against Chlamydia trachomatis infection in the murine upper genital tract. THE JOURNAL OF IMMUNOLOGY 2012; 189:2441-9. [PMID: 22855710 DOI: 10.4049/jimmunol.1103032] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Chlamydia trachomatis infection is the most common bacterial sexually transmitted disease in the United States. Chlamydia infections that ascend to the upper genital tract can persist, trigger inflammation, and result in serious sequelae such as infertility. However, mouse models in which the vaginal vault is inoculated with C. trachomatis do not recapitulate the course of human disease. These intravaginal infections of the mouse do not ascend efficiently to the upper genital tract, do not cause persistent infection, do not induce significant inflammation, and do not induce significant CD4⁺ T cell infiltration. In this article, we describe a noninvasive transcervical infection model in which we bypass the cervix and directly inoculate C. trachomatis into the uterus. We show that direct C. trachomatis infection of the murine upper genital tract stimulates a robust Chlamydia-specific CD4⁺ T cell response that is both necessary and sufficient to clear infection and provide protection against reinfection.
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Affiliation(s)
- David C Gondek
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Entrican G, Wheelhouse N, Wattegedera SR, Longbottom D. New challenges for vaccination to prevent chlamydial abortion in sheep. Comp Immunol Microbiol Infect Dis 2011; 35:271-6. [PMID: 22209689 DOI: 10.1016/j.cimid.2011.12.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 12/05/2011] [Accepted: 12/06/2011] [Indexed: 10/14/2022]
Abstract
Ovine enzootic abortion (OEA) is caused by the obligate intracellular Gram-negative bacterium Chlamydia abortus. OEA remains a common cause of infectious abortion in many sheep-rearing countries despite the existence of commercially available vaccines that protect against the disease. There are a number of confounding factors that influence the uptake and use of these vaccines, which includes an inability to discriminate between infected and vaccinated animals (DIVA) using conventional serological diagnostic techniques. This suggests that the immunity elicited by current vaccines is similar to that observed in convalescent, immune sheep that have experienced OEA. The existence of these vaccines provides an opportunity to understand how protection against OEA is elicited and also to understand why vaccines can occasionally appear to fail, as has been reported recently for OEA. Interferon-gamma (IFN-γ), the cytokine that classically defines Th1-type adaptive immunity, is a strong correlate of protection against OEA in sheep and has been shown to inhibit the growth of C. abortus in vitro. Humoral immunity to C. abortus is observed in both vaccinated and naturally infected sheep, but antibody responses tend to be used more as diagnostic markers than targets for strategic vaccine design. A future successful DIVA vaccine against OEA should aim to elicit the immunological correlate of protection (IFN-γ) concomitantly with an antibody profile that is distinct from that of the natural infection. Such an approach requires careful selection of protective components of C. abortus combined with an effective delivery system that elicits IFN-γ-producing CD4+ve memory T cells.
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Affiliation(s)
- Gary Entrican
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ Scotland, United Kingdom.
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Abstract
PURPOSE OF REVIEW The aim is to review recent findings on immunity and vaccine development to Chlamydia trachomatis. RECENT FINDINGS There is increasing knowledge on the interactions between C. trachomatis and infected host cells. During genital infection the organism avoids generating protective immunity but immune responses to a number of chlamydial proteins have been associated with reproductive tract pathology. Various vaccine and adjuvant preparations have been tried experimentally. Information generated by proteomics and complex studies of serological and T-lymphocyte immune responses points to novel vaccine candidates. SUMMARY C. trachomatis, an obligate intracellular bacterium, is the commonest sexually transmitted infection worldwide and is associated with reproductive pathology. To develop rational vaccines it is necessary to understand the complex lifecycle of the organism, the host immune response to infection and how these relate to disease. Infection does not prevent re-infection and antibiotic treatment prevents antibody production at a population level. It remains unclear what type of immune response would be sufficient to prevent infection and/or re-infection. Although the prevalence and demographics of infection and the severity of disease associations suggest that it would be desirable, there is no vaccine currently available. A number of studies have identified novel vaccine candidates.
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