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Yang S, Zeng J, Yu J, Sun R, Tuo Y, Bai H. Insights into Chlamydia Development and Host Cells Response. Microorganisms 2024; 12:1302. [PMID: 39065071 PMCID: PMC11279054 DOI: 10.3390/microorganisms12071302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/15/2024] [Accepted: 06/23/2024] [Indexed: 07/28/2024] Open
Abstract
Chlamydia infections commonly afflict both humans and animals, resulting in significant morbidity and imposing a substantial socioeconomic burden worldwide. As an obligate intracellular pathogen, Chlamydia interacts with other cell organelles to obtain necessary nutrients and establishes an intracellular niche for the development of a biphasic intracellular cycle. Eventually, the host cells undergo lysis or extrusion, releasing infectious elementary bodies and facilitating the spread of infection. This review provides insights into Chlamydia development and host cell responses, summarizing the latest research on the biphasic developmental cycle, nutrient acquisition, intracellular metabolism, host cell fates following Chlamydia invasion, prevalent diseases associated with Chlamydia infection, treatment options, and vaccine prevention strategies. A comprehensive understanding of these mechanisms will contribute to a deeper comprehension of the intricate equilibrium between Chlamydia within host cells and the progression of human disease.
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Affiliation(s)
| | | | | | | | | | - Hong Bai
- Tianjin Key Laboratory of Cellular and Molecular Immunology (The Educational Ministry of China), Tianjin Institute of Immunology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China; (S.Y.); (J.Z.); (J.Y.); (R.S.); (Y.T.)
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Scharbaai-Vázquez R, J. López Font F, A. Zayas Rodríguez F. Persistence in Chlamydia. Infect Dis (Lond) 2022. [DOI: 10.5772/intechopen.109299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Chlamydia spp. are important causes of acute and persistent/chronic infections. All Chlamydia spp. display a unique biphasic developmental cycle alternating between an infectious elementary body (EB) and a replicative form, the reticulate body (RB), followed by the multiplication of RBs by binary fission and progressive differentiation back into EBs. During its intracellular life, Chlamydia employs multiple mechanisms to ensure its persistence inside the host. These include evasion of diverse innate immune responses, modulation of host cell structure and endocytosis, inhibition of apoptosis, activation of pro-signaling pathways, and conversion to enlarged, non-replicative but viable “aberrant bodies” (ABs). Early research described several systems for Chlamydial persistence with a significant number of variables that make a direct comparison of results difficult. Now, emerging tools for genetic manipulations in Chlamydia and advances in global microarray, transcriptomics, and proteomics have opened new and exciting opportunities to understand the persistent state of Chlamydia and link the immune and molecular events of persistence with the pathogenesis of recurrent and chronic Chlamydial infections. This chapter reviews our current understanding and advances in the molecular biology of Chlamydia persistence.
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Sixt BS. Host cell death during infection with Chlamydia: a double-edged sword. FEMS Microbiol Rev 2021; 45:5902849. [PMID: 32897321 PMCID: PMC7794043 DOI: 10.1093/femsre/fuaa043] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022] Open
Abstract
The phylum Chlamydiae constitutes a group of obligate intracellular bacteria that infect a remarkably diverse range of host species. Some representatives are significant pathogens of clinical or veterinary importance. For instance, Chlamydia trachomatis is the leading infectious cause of blindness and the most common bacterial agent of sexually transmitted diseases. Chlamydiae are exceptionally dependent on their eukaryotic host cells as a consequence of their developmental biology. At the same time, host cell death is an integral part of the chlamydial infection cycle. It is therefore not surprising that the bacteria have evolved exquisite and versatile strategies to modulate host cell survival and death programs to their advantage. The recent introduction of tools for genetic modification of Chlamydia spp., in combination with our increasing awareness of the complexity of regulated cell death in eukaryotic cells, and in particular of its connections to cell-intrinsic immunity, has revived the interest in this virulence trait. However, recent advances also challenged long-standing assumptions and highlighted major knowledge gaps. This review summarizes current knowledge in the field and discusses possible directions for future research, which could lead us to a deeper understanding of Chlamydia's virulence strategies and may even inspire novel therapeutic approaches.
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Affiliation(s)
- Barbara S Sixt
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
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Chen H, Wen Y, Li Z. Clear Victory for Chlamydia: The Subversion of Host Innate Immunity. Front Microbiol 2019; 10:1412. [PMID: 31333596 PMCID: PMC6619438 DOI: 10.3389/fmicb.2019.01412] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 06/05/2019] [Indexed: 12/14/2022] Open
Abstract
As obligate intracellular bacterial pathogens, members of the Chlamydia genera are the pivotal triggers for a wide range of infections, which can lead to blinding trachoma, pelvic inflammation, and respiratory diseases. Because of their restricted parasitism inside eukaryotic cells, the pathogens have to develop multiple strategies for adaptation with the hostile intracellular environment—intrinsically present in all host cells—to survive. The strategies that are brought into play at different stages of chlamydial development mainly involve interfering with diverse innate immune responses, such as innate immune recognition, inflammation, apoptosis, autophagy, as well as the manipulation of innate immune cells to serve as potential niches for chlamydial replication. This review will focus on the innate immune responses against chlamydial infection, highlighting the underlying molecular mechanisms used by the Chlamydia spp. to counteract host innate immune defenses. Insights into these subtle pathogenic mechanisms not only provide a rationale for the augmentation of immune responses against chlamydial infection but also open avenues for further investigation of the molecular mechanisms driving the survival of these clinically important pathogens in host innate immunity.
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Affiliation(s)
- Hongliang Chen
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China.,Department of Clinical Microbiology Laboratory, Chenzhou No. 1 People's Hospital, Chenzhou, China
| | - Yating Wen
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Zhongyu Li
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
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Wolle MA, West SK. Ocular Chlamydia trachomatis infection: elimination with mass drug administration. Expert Rev Anti Infect Ther 2019; 17:189-200. [PMID: 30698042 DOI: 10.1080/14787210.2019.1577136] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Ocular Chlamydia trachomatis infection, the causative agent for trachoma, is responsible for 1.9 million cases of visual loss worldwide. Mass Drug Administration (MDA) with azithromycin to entire trachoma-endemic districts is part of the World Health Organization's public health strategy for trachoma elimination. Areas covered: Background on C. trachomatis and the epidemiology of trachoma are presented, followed by a review of the antibiotics for treatment and the need for a public health approach to trachoma elimination. The effectiveness of mass drug administration is presented, concluding with challenges to trachoma elimination in the future. Expert opinion: MDA using azithromycin is a key component of the public health strategy for trachoma elimination. With high coverage in children, there is good evidence that MDA drops the community pool of infection. There are challenges to trachoma elimination by the year 2020, and the drug donation program for country MDAs will be integral to ongoing efforts.
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Affiliation(s)
- Meraf A Wolle
- a Dana Center for Preventive Ophthalmology , Johns Hopkins Medical Institutions , Baltimore , MD , USA
| | - Sheila K West
- a Dana Center for Preventive Ophthalmology , Johns Hopkins Medical Institutions , Baltimore , MD , USA
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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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Lu J, Zhu L, Zhang L, Jiang J, Xie F, Huang Q, Li X, Yi C. Abnormal Expression of TRAIL Receptors in Decidual Tissue of Chlamydia trachomatis-Infected Rats During Early Pregnancy Loss. Reprod Sci 2016; 24:1041-1052. [PMID: 27852922 DOI: 10.1177/1933719116676393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chlamydia trachomatis is the scientific name of pathogenic bacteria causing infection that has been linked to spontaneous abortion. In this study, the expression pattern of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL; a cytokine related to cell apoptosis) and its receptors was monitored in the decidua of C trachomatis-infected pregnant rats during early gestation to investigate the potential role of this molecular system in C trachomatis-induced spontaneous abortion. The data showed that C trachomatis infection significantly altered the messenger RNA (mRNA) expression of the receptors; death receptor (DR) 4 and DR5 increased, but decoy receptor (DcR) 1 and DcR2 decreased. Consistent with mRNA data, immunohistochemical staining of TRAIL and its receptors indicated that both DR4 and DR5 protein levels were elevated in infected tissues, primarily, decidual cells, decidual vessel wall, and uterine glands, whereas DcR1 and DcR2 showed lower levels compared to the noninfected group. Although receptor expression was altered, there was no difference detected in TRAIL expression. The observed altered expression of TRAIL receptors in C trachomatis-infected rats compared to noninfected rats during the embryo implantation phase suggests a possible mechanism for spontaneous abortion due to apoptosis and therefore failed embryo implantation. In addition, the observed increase in caspase-3 levels in infected cells further supports this finding. Taken together, the data presented in this study suggests C trachomatis infection altered the expression of TRAIL receptors, thus representing a general mechanism for C trachomatis-induced spontaneous abortion in C trachomatis-infected rats during early pregnancy loss.
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Affiliation(s)
- Jinzhi Lu
- 1 Department of Laboratory Medicine, The First Affiliated Hospital of Yangtze University, Jingzhou, Hubei, People's Republic of China
| | - Liya Zhu
- 2 Department of Obstetrics and Gynecology, The First Affiliated Hospital of Yangtze University, Jingzhou, Hubei, People's Republic of China
| | - Lei Zhang
- 2 Department of Obstetrics and Gynecology, The First Affiliated Hospital of Yangtze University, Jingzhou, Hubei, People's Republic of China
| | - Jinpeng Jiang
- 2 Department of Obstetrics and Gynecology, The First Affiliated Hospital of Yangtze University, Jingzhou, Hubei, People's Republic of China
| | - Fang Xie
- 2 Department of Obstetrics and Gynecology, The First Affiliated Hospital of Yangtze University, Jingzhou, Hubei, People's Republic of China
| | - Qing Huang
- 2 Department of Obstetrics and Gynecology, The First Affiliated Hospital of Yangtze University, Jingzhou, Hubei, People's Republic of China
| | - Xiaolan Li
- 3 Department of Obstetrics and Gynecology, Yichang second People's Hospital, Yichang, Hubei, People's Republic of China
| | - Cunjian Yi
- 2 Department of Obstetrics and Gynecology, The First Affiliated Hospital of Yangtze University, Jingzhou, Hubei, People's Republic of China
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Boiko EV, Pozniak AL, Maltsev DS, Suetov AA, Nuralova IV. High frequency of latent Chlamydia trachomatis infection in patients with rhegmatogenous retinal detachment. Int J Ophthalmol 2016; 9:863-8. [PMID: 27366689 DOI: 10.18240/ijo.2016.06.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 08/18/2015] [Indexed: 11/23/2022] Open
Abstract
AIM To determine the frequency of detection of ocular and extraocular Chlamydia trachomatis (CT) infection in non-high myopes with rhegmatogenous retinal detachment (RRD). METHODS This was a single-center, nonrandomized, prospective, case-control study. One hundred and four patients were divided into a study group with RRD (n=63) and a control group with traumatic retinal detachment (n=41). Samples of subretinal fluid (SFR), conjunctival, urethral/cervical swabs, and blood were collected. The frequency of detection of CT infection in SRF samples was determined by polymerase chain reaction (PCR), direct fluorescence assay (DFA) and cell culture, whereas that in conjunctival swabs was determined by PCR and DFA, and those in urethral/cervical swabs and blood were determined by DFA. Yates Chi-square test (with Bonferroni correction) and two-tailed Student's t-test were used for statistical analysis. RESULTS SRF CT infection was detected more frequently in the study group (50.8%-71.4%) than in the control group (9.8%-12.2%) by all the methods used (P<0.01). The frequency of detection of conjunctival CT infection by DFA was higher in the RRD patients compared with the controls (81.0% vs 24.4%, P=0.004). The PCR detected conjunctival CT infection more often in the study group than in the controls (46.0% vs 9.8%, P=0.007). The DFA detected CT in blood specimens almost as frequently as in urogenital specimens, for the RRD patients (61.2% vs 63.5%) and the controls (7.3% vs 9.8%). CONCLUSION CT infection is detected with high frequency in non-high myopes with RRD.
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Affiliation(s)
- Ernest V Boiko
- St. Petersburg Branch of the Academician S. Fyodorov IRTC "Eye Microsurgery", St. Petersburg 192283, Russia; Department of Ophthalmology, Military Medical Academy, St. Petersburg 194044, Russia
| | - Alexei L Pozniak
- St. Petersburg Branch of the Academician S. Fyodorov IRTC "Eye Microsurgery", St. Petersburg 192283, Russia
| | - Dmitrii S Maltsev
- St. Petersburg Branch of the Academician S. Fyodorov IRTC "Eye Microsurgery", St. Petersburg 192283, Russia
| | - Alexei A Suetov
- St. Petersburg Branch of the Academician S. Fyodorov IRTC "Eye Microsurgery", St. Petersburg 192283, Russia
| | - Irina V Nuralova
- St. Petersburg Branch of the Academician S. Fyodorov IRTC "Eye Microsurgery", St. Petersburg 192283, Russia
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Genital Chlamydia trachomatis: understanding the roles of innate and adaptive immunity in vaccine research. Clin Microbiol Rev 2016; 27:346-70. [PMID: 24696438 DOI: 10.1128/cmr.00105-13] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Chlamydia trachomatis is the leading cause of bacterial sexually transmitted disease worldwide, and despite significant advances in chlamydial research, a prophylactic vaccine has yet to be developed. This Gram-negative obligate intracellular bacterium, which often causes asymptomatic infection, may cause pelvic inflammatory disease (PID), ectopic pregnancies, scarring of the fallopian tubes, miscarriage, and infertility when left untreated. In the genital tract, Chlamydia trachomatis infects primarily epithelial cells and requires Th1 immunity for optimal clearance. This review first focuses on the immune cells important in a chlamydial infection. Second, we summarize the research and challenges associated with developing a chlamydial vaccine that elicits a protective Th1-mediated immune response without inducing adverse immunopathologies.
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10
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Fischer A, Rudel T. Subversion of Cell-Autonomous Host Defense by Chlamydia Infection. Curr Top Microbiol Immunol 2016; 412:81-106. [PMID: 27169422 DOI: 10.1007/82_2016_13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Obligate intracellular bacteria entirely depend on the metabolites of their host cell for survival and generation of progeny. Due to their lifestyle inside a eukaryotic cell and the lack of any extracellular niche, they have to perfectly adapt to compartmentalized intracellular environment of the host cell and counteract the numerous defense strategies intrinsically present in all eukaryotic cells. This so-called cell-autonomous defense is present in all cell types encountering Chlamydia infection and is in addition closely linked to the cellular innate immune defense of the mammalian host. Cell type and chlamydial species-restricted mechanisms point a long-term evolutionary adaptation that builds the basis of the currently observed host and cell-type tropism among different Chlamydia species. This review will summarize the current knowledge on the strategies pathogenic Chlamydia species have developed to subvert and overcome the multiple mechanisms by which eukaryotic cells defend themselves against intracellular pathogens.
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Affiliation(s)
- Annette Fischer
- Department of Microbiology and Biocenter, University of Würzburg, Am Hubland, 97074, Wuerzburg, Germany
| | - Thomas Rudel
- Department of Microbiology and Biocenter, University of Würzburg, Am Hubland, 97074, Wuerzburg, Germany.
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Herweg JA, Rudel T. Interaction of Chlamydiae with human macrophages. FEBS J 2015; 283:608-18. [PMID: 26613554 DOI: 10.1111/febs.13609] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 11/13/2015] [Accepted: 11/24/2015] [Indexed: 11/28/2022]
Abstract
The phylum Chlamydiae contains several members that are well-known human pathogens, like Chlamydia trachomatis and C. pneumoniae. Establishing a chronic bacterial infection requires the active evasion of the host immune response. A major arm of the innate immune defence is constituted by macrophages, which fight infections by removing bacteria and triggering an adaptive immune response. However, some pathogenic Chlamydia infect and survive in macrophages at least for a certain period of time. Therefore, macrophages can serve as vehicles for the dissemination of bacterial infections from the primary infection site via the urogenital or respiratory tract to distant sites in the body. The capacity to infect macrophages seems to depend on the chlamydial strain and the source of macrophages. In vitro infections of macrophages with C. trachomatis, C. psittaci and C. pneumoniae reveal low efficiency of infection and progeny formation, as well as failure to develop mature inclusions. In contrast, the emerging pathogen, Simkania negevensis, actively replicates in macrophages. Here we summarize the current knowledge of the intracellular and molecular key mechanisms of C. trachomatis, C. pneumoniae and S. negevensis infections in human macrophages.
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Affiliation(s)
- Jo-Ana Herweg
- Biocenter, Department of Microbiology, University of Würzburg, Germany
| | - Thomas Rudel
- Biocenter, Department of Microbiology, University of Würzburg, Germany
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Alvarez-Navarro C, Cragnolini JJ, Dos Santos HG, Barnea E, Admon A, Morreale A, López de Castro JA. Novel HLA-B27-restricted epitopes from Chlamydia trachomatis generated upon endogenous processing of bacterial proteins suggest a role of molecular mimicry in reactive arthritis. J Biol Chem 2013; 288:25810-25825. [PMID: 23867464 DOI: 10.1074/jbc.m113.493247] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Reactive arthritis (ReA) is an HLA-B27-associated spondyloarthropathy that is triggered by diverse bacteria, including Chlamydia trachomatis, a frequent intracellular parasite. HLA-B27-restricted T-cell responses are elicited against this bacterium in ReA patients, but their pathogenetic significance, autoimmune potential, and relevant epitopes are unknown. High resolution and sensitivity mass spectrometry was used to identify HLA-B27 ligands endogenously processed and presented by HLA-B27 from three chlamydial proteins for which T-cell epitopes were predicted. Fusion protein constructs of ClpC, Na(+)-translocating NADH-quinone reductase subunit A, and DNA primase were expressed in HLA-B27(+) cells, and their HLA-B27-bound peptidomes were searched for endogenous bacterial ligands. A non-predicted peptide, distinct from the predicted T-cell epitope, was identified from ClpC. A peptide recognized by T-cells in vitro, NQRA(330-338), was detected from the reductase subunit. This is the second HLA-B27-restricted T-cell epitope from C. trachomatis with relevance in ReA demonstrated to be processed and presented in live cells. A novel peptide from the DNA primase, DNAP(211-223), was also found. This was a larger variant of a known epitope and was highly homologous to a self-derived natural ligand of HLA-B27. All three bacterial peptides showed high homology with human sequences containing the binding motif of HLA-B27. Molecular dynamics simulations further showed a striking conformational similarity between DNAP(211-223) and its homologous and much more flexible human-derived HLA-B27 ligand. The results suggest that molecular mimicry between HLA-B27-restricted bacterial and self-derived epitopes is frequent and may play a role in ReA.
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Affiliation(s)
- Carlos Alvarez-Navarro
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and
| | - Juan J Cragnolini
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and
| | - Helena G Dos Santos
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and
| | - Eilon Barnea
- the Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Arie Admon
- the Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Antonio Morreale
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and
| | - José A López de Castro
- From the Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma, Madrid, Spain and.
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Al-Zeer MA, Al-Younes HM, Lauster D, Abu Lubad M, Meyer TF. Autophagy restricts Chlamydia trachomatis growth in human macrophages via IFNG-inducible guanylate binding proteins. Autophagy 2012; 9:50-62. [PMID: 23086406 DOI: 10.4161/auto.22482] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Interferon γ (IFNG) is a key host response regulator of intracellular pathogen replication, including that of Chlamydia spp The antichlamydial functions of IFNG manifest in a strictly host, cell-type and chlamydial strain dependent manner. It has been recently shown that the IFNG-inducible family of immunity-related GTPases (IRG) proteins plays a key role in the defense against nonhost adapted chlamydia strains in murine epithelial cells. In humans, IFN-inducible guanylate binding proteins (hGBPs) have been shown to potentiate the antichlamydial effect of IFNG; however, how hGBPs regulate this property of IFNG is unknown. In this study, we identified hGBP1/2 as important resistance factors against C. trachomatis infection in IFNG-stimulated human macrophages. Exogenous IFNG reduced chlamydial infectivity by 50 percent in wild-type cells, whereas shRNA hGBP1/2 knockdown macrophages fully supported chlamydial growth in the presence of exogenous IFNG. hGBP1/2 were recruited to bacterial inclusions in human macrophages upon stimulation with IFNG, which triggered rerouting of the typically nonfusogenic bacterial inclusions for lysosomal degradation. Inhibition of lysosomal activity and autophagy impaired the IFNG-mediated elimination of inclusions. Thus, hGBP1/2 are critical effectors of antichlamydial IFNG responses in human macrophages. Through their capacity to remodel classically nonfusogenic chlamydial inclusions and stimulate fusion with autophagosomes, hGBP1/2 disable a major chlamydial virulence mechanism and contribute to IFNG-mediated pathogen clearance.
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Affiliation(s)
- Munir A Al-Zeer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
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Macdonald SHF, Woodward E, Coleman MM, Dorris ER, Nadarajan P, Chew WM, McLaughlin AM, Keane J. Networked T cell death following macrophage infection by Mycobacterium tuberculosis. PLoS One 2012; 7:e38488. [PMID: 22675566 PMCID: PMC3366923 DOI: 10.1371/journal.pone.0038488] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 05/06/2012] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Depletion of T cells following infection by Mycobacterium tuberculosis (Mtb) impairs disease resolution, and interferes with clinical test performance that relies on cell-mediated immunity. A number of mechanisms contribute to this T cell suppression, such as activation-induced death and trafficking of T cells out of the peripheral circulation and into the diseased lungs. The extent to which Mtb infection of human macrophages affects T cell viability however, is not well characterised. METHODOLOGY/PRINCIPAL FINDINGS We found that lymphopenia (<1.5 × 10(9) cells/l) was prevalent among culture-positive tuberculosis patients, and lymphocyte counts significantly improved post-therapy. We previously reported that Mtb-infected human macrophages resulted in death of infected and uninfected bystander macrophages. In the current study, we sought to examine the influence of infected human alveolar macrophages on T cells. We infected primary human alveolar macrophages (the primary host cell for Mtb) or PMA-differentiated THP-1 cells with Mtb H37Ra, then prepared cell-free supernatants. The supernatants of Mtb-infected macrophages caused dose-dependent, caspase-dependent, T cell apoptosis. This toxic effect of infected macrophage secreted factors did not require TNF-α or Fas. The supernatant cytotoxic signal(s) were heat-labile and greater than 50 kDa in molecular size. Although ESAT-6 was toxic to T cells, other Mtb-secreted factors tested did not influence T cell viability; nor did macrophage-free Mtb bacilli or broth from Mtb cultures. Furthermore, supernatants from Mycobacterium bovis Bacille de Calmette et Guerin (BCG)- infected macrophages also elicited T cell death suggesting that ESAT-6 itself, although cytotoxic, was not the principal mediator of T cell death in our system. CONCLUSIONS Mtb-Infected macrophages secrete heat-labile factors that are toxic to T cells, and may contribute to the immunosuppression seen in tuberculosis as well as interfere with microbial eradication in the granuloma.
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Affiliation(s)
- Stephen H-F Macdonald
- Department of Clinical Medicine, Trinity Institute of Molecular Medicine, St James's Hospital, Dublin, Ireland.
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15
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Brucella abortus induces apoptosis of human T lymphocytes. Microbes Infect 2012; 14:639-50. [PMID: 22387699 DOI: 10.1016/j.micinf.2012.02.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/16/2012] [Accepted: 02/15/2012] [Indexed: 01/18/2023]
Abstract
Immune evasion is essential for Brucella abortus to survive in the face of robust adaptive CD4+ T cell response. We have previously demonstrated that B. abortus can indirectly inhibit CD4+ T cells by down-regulating MHC-II expression and antigen presentation on macrophages. However, whether B. abortus is able to directly interfere with T lymphocytes is not known. We report here that B. abortus induces apoptosis of human T lymphocytes, even though invasion of T lymphocytes was low and non-replicative. The ability of heat-killed B. abortus to reproduce the same phenomenon suggested that there was a bacterial structural component involved. We demonstrated that a prototypical B. abortus outer membrane lipoprotein (l-Omp19), but not its unlipidated form, induced T lymphocyte apoptosis. Moreover, a synthetic lipohexapeptide that mimics the structure of the protein lipid moiety also induced an increase in T lymphocyte cell death, indicating that the structural component implicated in the phenomenon could be any B. abortus lipoprotein. B. abortus-induced T lymphocyte apoptosis was dependent on the secretion of TNF-α since pre-incubation of T lymphocytes with anti-TNF-α mAb inhibited the apoptosis of the cells. Overall, these results represent a new mechanism whereby B. abortus by directly inhibiting T cell-mediated responses may evade adaptive immune responses.
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Abstract
Apoptosis is a natural process where cells that are no longer required can be eliminated in a highly regulated, controlled manner. Apoptosis is important in maintaining the mammalian immune system and plays a significant role in immune response, positive and negative T cell selection, and cytotoxic death of target cells. When the apoptotic pathways are impaired or are not tightly regulated, autoimmune diseases, inflammatory diseases, viral and bacterial infections and cancers ensue. An imbalance in the anti-apoptotic and pro-apoptotic factors has been implicated in these diseases. Moreover, current therapies directed towards these diseases focus on the modulation of the apoptotic death pathways to regulate the immune response. In this review, we will focus on the process of T cell activation and apoptosis in autoimmune reactions, in response to tumor progression as well as in response to bacterial and viral infections.
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Affiliation(s)
- Anuradha K Murali
- Departments of Surgery, Medical University of South Carolina, Charleston, SC 29425
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Azenabor AA, Cintrón-Cuevas J, Schmitt H, Bumah V. Chlamydia trachomatis induces anti-inflammatory effect in human macrophages by attenuation of immune mediators in Jurkat T-cells. Immunobiology 2011; 216:1248-55. [PMID: 21802168 DOI: 10.1016/j.imbio.2011.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 07/03/2011] [Indexed: 11/30/2022]
Abstract
The chronic course of Chlamydia trachomatis infection is subtle with no obvious unusual inflammatory change. The reason for this is not clear. The data reported here explain how macrophage usual inflammatory response switches to anti-inflammatory response during C. trachomatis infection of mixed culture of macrophages and Jurkat T-cells. We assessed the establishment of productive infection in individual or mixed cell culture models, determined the status of C. trachomatis in the cells by monitoring HSP-60:MOMP or the proportions of the estimated IFUs that shed HSP-60 or MOMP. Also, the specific time-course expression of IL-12, IL-10 and IFN-γ or IL-12R, IL-10R, and IFN-γ-R during infection of cell models was assessed. Finally, the early events in cytokine elaboration in circumstances of varying intracellular Ca²⁺ levels were determined. There was evidence of productive infection in all individual and mixed cell culture models. The shedding of HSP-60 was highest in THP-1/Jurkat mixed cell culture model. The proportions of IFU that shed HSP-60 was heightened in infected THP-1/Jurkat mixed culture model, while the proportion of IFU that shed MOMP was higher in infected macrophage/Jurkat mixed culture and infected macrophages only. There was profound early elaboration of IL-10, varying significantly from IL-12 and IFN-γ in all infected individual or mixed cell culture models except in the case of Jurkat; where all cytokine elaboration was downregulated. The receptor to IL-10 was upregulated in infected macrophage/Jurkat cells and THP-1/Jurkat cells compared with other models in which IL-12 and IFN-γ receptors were more expressed. There was no observed significant change in cytokine in any model following the impairment of intracellular Ca²⁺ except in the case of macrophage/Jurkat cell model in which IL-12 and IL-10 were upregulated in 1h or 3 h, respectively. The implication of these findings is that C. trachomatis mediates a switch from inflammatory to anti-inflammatory function in macrophages due to downregulation of the regulatory cytokine, IFN-γ in Jurkat cells, culminating in C. trachomatis chronic course.
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Affiliation(s)
- Anthony A Azenabor
- Department of Health Sciences, University of Wisconsin, Milwaukee, WI 53211, USA.
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18
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Abstract
Pathogenicity of Chlamydia and Chlamydia-related bacteria could be partially mediated by an enhanced activation of the innate immune response. The study of this host pathogen interaction has proved challenging due to the restricted in vitro growth of these strict intracellular bacteria and the lack of genetic tools to manipulate their genomes. Despite these difficulties, the interactions of Chlamydiales with the innate immune cells and their effectors have been studied thoroughly. This review aims to point out the role of pattern recognition receptors and signal molecules (cytokines, reactive oxygen species) of the innate immune response in the pathogenesis of chlamydial infection. Besides inducing clearance of the bacteria, some of these effectors may be used by the Chlamydia to establish chronic infections or to spread. Thus, the induced innate immune response seems to be variable depending on the species and/or the serovar, making the pattern more complex. It remains crucial to determine the common players of the innate immune response in order to help define new treatment strategies and to develop effective vaccines. The excellent growth in phagocytic cells of some Chlamydia-related organisms such as Waddlia chondrophila supports their use as model organisms to study conserved features important for interactions between the innate immunity and Chlamydia.
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Affiliation(s)
- Brigida Rusconi
- Institute of Microbiology, University of Lausanne and University Hospital Center, Lausanne, Switzerland
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19
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Cochrane M, Armitage CW, O’Meara CP, Beagley KW. Towards a Chlamydia trachomatis vaccine: how close are we? Future Microbiol 2010; 5:1833-56. [DOI: 10.2217/fmb.10.148] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chlamydia trachomatis is the leading cause of bacterial sexually transmitted infections and preventable blindness worldwide. The incidence of chlamydial sexually transmitted infections has increased rapidly and current antibiotic therapy has failed as an intervention strategy. The most accepted strategy for protection and/or control of chlamydial infections is a vaccine that induces both local neutralizing antibodies to prevent infections by the extracellular elementary bodies and a cell-mediated immune response to target the intracellular infection. This article will discuss the challenges in vaccine design for the prevention of chlamydial urogenital infection and/or disease, including selection of target antigens, discussion of effective delivery systems, immunization routes and adjuvants for induction of protective immunity at the targeted mucosal surface whilst minimizing severe inflammatory disease sequelae.
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Affiliation(s)
- Melanie Cochrane
- Institute of Health & Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland, Australia
| | - Charles W Armitage
- Institute of Health & Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland, Australia
| | - Connor P O’Meara
- Institute of Health & Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland, Australia
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20
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Huang SJ, Zenclussen AC, Chen CP, Basar M, Yang H, Arcuri F, Li M, Kocamaz E, Buchwalder L, Rahman M, Kayisli U, Schatz F, Toti P, Lockwood CJ. The implication of aberrant GM-CSF expression in decidual cells in the pathogenesis of preeclampsia. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:2472-82. [PMID: 20829438 DOI: 10.2353/ajpath.2010.091247] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Preeclampsia is characterized by an exaggerated systemic inflammatory state as well as shallow placentation. In the decidual implantation site, preeclampsia is accompanied by an excessive number of both macrophages and dendritic cells as well as their recruiting chemokines, which have been implicated in the impairment of endovascular trophoblast invasion. Granulocyte-macrophage colony-stimulating factor is known to regulate the differentiation of both macrophages and dendritic cells, prompting both in vivo and in vitro evaluation of granulocyte-macrophage colony-stimulating factor expression in human decidua as well as in a mouse model of preeclampsia. This study revealed increased granulocyte-macrophage colony-stimulating factor expression levels in preeclamptic decidua. Moreover, both tumor necrosis factor-α and interleukin-1 β, cytokines that are implicated in the genesis of preeclampsia, markedly up-regulated granulocyte-macrophage colony-stimulating factor production in cultured first-trimester human decidual cells. The conditioned media of these cultures promoted the differentiation of both macrophages and dendritic cells from a monocyte precursor. Evaluation of a murine model of preeclampsia revealed that the decidua of affected animals displayed higher levels of immunoreactive granulocyte-macrophage colony-stimulating factor as well as increased numbers of both macrophages and dendritic cells when compared to control animals. Because granulocyte-macrophage colony-stimulating factor is a potent inducer of differentiation and activation of both macrophages and dendritic cells, these findings suggest that this factor plays a crucial role in the pathogenesis of preeclampsia.
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Affiliation(s)
- S Joseph Huang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, 333 Cedar Street, P.O. Box 208063, New Haven, CT 06520-8063, USA.
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21
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Linhares IM, Witkin SS. Immunopathogenic consequences of Chlamydia trachomatis 60 kDa heat shock protein expression in the female reproductive tract. Cell Stress Chaperones 2010; 15:467-73. [PMID: 20182835 PMCID: PMC3006632 DOI: 10.1007/s12192-010-0171-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 01/19/2010] [Accepted: 01/21/2010] [Indexed: 01/26/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that infects chiefly urogenital and ocular epithelial cells. In some infected women the microorganism migrates to the upper reproductive tract resulting in a chronic, but asymptomatic, infection. The immune response to this infection, production of interferon-gamma and pro-inflammatory cytokines, results in interruption of chlamydial intracellular replication. However, the Chlamydia remains viable and enters into a persistent state. In this form, most chlamydial genes are inactive. An exception is the gene coding for the 60 kDa heat shock protein (hsp60), which is synthesized in increased amounts and is released into the extracellular milieu. The chronic release of chlamydial hsp60 induces a local pro-inflammatory immune response in fallopian tube epithelia and results in scar formation and tubal occlusion. In addition, long-term exposure of the maternal immune system to the chlamydial hsp60 eventually results in the release of tolerance and generation of an immune response that recognizes regions of the chlamydial hsp60 that are also present in the human hsp60. Production of cross-reacting antibodies and cell-mediated immunity to the human hsp60 is detrimental to subsequent pregnancy outcome and may also possibly increase susceptibility to atherosclerosis, autoimmune disorders, or malignancies.
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Affiliation(s)
- Iara Moreno Linhares
- Division of Immunology and Infectious Diseases, Department of Obstetrics and Gynecology, Weill Cornell Medical College, 525 East 68th Street, P.O. Box 35, New York, NY 10065 USA
- Department of Gynecology, University of Sao Paulo Medical School and Hospital das Clinicas, Sao Paulo, Brazil
| | - Steven S. Witkin
- Division of Immunology and Infectious Diseases, Department of Obstetrics and Gynecology, Weill Cornell Medical College, 525 East 68th Street, P.O. Box 35, New York, NY 10065 USA
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22
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Sessa R, Di Pietro M, Schiavoni G, Macone A, Maras B, Fontana M, Zagaglia C, Nicoletti M, Del Piano M, Morrone S. Chlamydia pneumoniae induces T cell apoptosis through glutathione redox imbalance and secretion of TNF-alpha. Int J Immunopathol Pharmacol 2009; 22:659-68. [PMID: 19822082 DOI: 10.1177/039463200902200311] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Chlamydia pneumoniae persistent infection has been implicated in the pathogenesis of several chronic inflammatory diseases including atherosclerosis, and we hypothesized that modulation of the apoptosis of macrophages and/or T cells by C. pneumoniae infection may contribute to the development of such diseases. We therefore evaluated apoptosis, cytokine response, and redox status in human primary T cells and macrophages infected with C. pneumoniae. In addition, co-cultures of T cells and macrophages infected with C. pneumoniae were also carried out. Apoptosis, and levels of glutathione (GSH), glutathione disulfide (GSSG), and tumour necrosis factor (TNF)-alpha were measured by flow cytometry, high performance liquid chromatography and enzyme-linked immunosorbent assay. C. pneumoniae induced apoptosis in T cells as well as in co-cultures of T cells and infected macrophages by marked decrease in GSH/GSSG ratio and increased production of TNF-alpha, respectively. The results demonstrate that interaction of C. pneumoniae with T cells and/or macrophages characterized by interference with redox status, and secretion of tumour necrosis factor-alpha culminates in the induction of T cell apoptosis and survival of infected macrophages. In conclusion, the inappropriate T cell response against C. pneumoniae and survival of infected macrophages could explain the persistence of this intracellular obligate pathogen in the host-organism; it may contribute to the development of chronic inflammatory diseases, although further studies are needed to clarify such a complex mechanism.
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Affiliation(s)
- R Sessa
- Department of Public Health Sciences, Sapienza University, Rome, Italy
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23
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Grotenbreg GM, Roan NR, Guillen E, Meijers R, Wang JH, Bell GW, Starnbach MN, Ploegh HL. Discovery of CD8+ T cell epitopes in Chlamydia trachomatis infection through use of caged class I MHC tetramers. Proc Natl Acad Sci U S A 2008; 105:3831-6. [PMID: 18245382 PMCID: PMC2268777 DOI: 10.1073/pnas.0711504105] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Indexed: 11/18/2022] Open
Abstract
Class I MHC tetramers allow direct phenotypic identification of CD8(+) T cell populations, but their production remains laborious. A peptide exchange strategy that employs class I MHC products loaded with conditional ligands (caged MHC molecules) provides a fast and straightforward method to obtain diverse arrays of class I MHC tetramers and facilitates CD8(+) T cell epitope discovery. Here, we describe the development of photocleavable analogs of the FAPGNYPAL (SV9) epitope that bind H-2K(b) and H-2D(b) with full retention of their structural and functional integrity. We ranked all possible H-2K(b) octameric and H-2D(b) nonameric epitopes that span the genome of Chlamydia trachomatis and prepared MHC tetramers from approximately 2,000 of the highest scoring peptides by replacement of the SV9 analog with the peptide of choice. The resulting 2,000-member class I MHC tetramer array allowed the discovery of two variants of an epitope derived from polymorphic membrane protein I (PmpI) and an assessment of the kinetics of emergence and the effector function of the corresponding CD8(+) T cells.
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Affiliation(s)
| | | | - Eduardo Guillen
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02139
| | - Rob Meijers
- Medicine
- Laboratory of Immunology, Department of Medical Oncology, Dana–Farber Cancer Institute, Boston, MA 02115
| | - Jia-huai Wang
- Pediatrics, and
- Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115; and
- Laboratory of Immunology, Department of Medical Oncology, Dana–Farber Cancer Institute, Boston, MA 02115
| | - George W. Bell
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02139
| | | | - Hidde L. Ploegh
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02139
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24
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Abstract
Infection with the bacterium Chlamydia trachomatis can lead to a variety of diseases, including ectopic pregnancy, infertility and blindness. Exposure of the host to C. trachomatis stimulates multiple innate and adaptive immune effectors that can contribute towards controlling bacterial replication. However, these effectors are often insufficient to resolve the infection and prevent re-infection, and the continued presence of C. trachomatis within the host may induce immune effectors to chronically produce inflammatory cytokines. This may eventually lead to the tissue pathologies associated with the infection. Reducing the incidence and sequelae of infection will ultimately require the development of a C. trachomatis vaccine that can stimulate sterilizing immunity while avoiding immune-mediated pathology.
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Affiliation(s)
- Nadia R Roan
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
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25
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Krausse-Opatz B, Busmann A, Tammen H, Menzel C, Möhring T, Le Yondre N, Schmidt C, Schulz-Knappe P, Zeidler H, Selle H, Köhler L. Peptidomic analysis of human peripheral monocytes persistently infected by Chlamydia trachomatis. Med Microbiol Immunol 2007; 196:103-14. [PMID: 17206452 DOI: 10.1007/s00430-006-0033-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Indexed: 10/23/2022]
Abstract
Peptidomic analysis using Differential Peptide Display (DPD) of human peripheral blood mononuclear cells (PBMC) mock-infected or persistently infected by Chlamydia trachomatis (CT) revealed 10 peptides, expressed upon CT infection. Analysis of these 10 candidates by tandem mass spectrometry enabled the determination of seven candidates as fragments from the precursors (I) ferritin heavy chain subunit, (II) HLA class II histocompatibility antigen, (III) vimentin, (IV) indoleamine 2,3-dioxygenase, (V and VI) pre-B cell enhancing factor (PBEF), and (VII) Interleukin-8 (CXCL8). The identified candidates proved the presence of anti-bacterial and immunologically active monocytic proteins after CT infection.
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Affiliation(s)
- Birgit Krausse-Opatz
- Division of Rheumatology, Department of Internal Medicine, Hannover Medical School, Hannover, Germany.
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26
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Inman RD. Mechanisms of disease: infection and spondyloarthritis. ACTA ACUST UNITED AC 2006; 2:163-9. [PMID: 16932676 DOI: 10.1038/ncprheum0118] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Accepted: 11/22/2005] [Indexed: 01/20/2023]
Abstract
There is compelling evidence that some infections can initiate a chronic nonseptic arthritis. This has proved to be an important area of investigation into gene-environment interactions, particularly since HLA-B27 confers increased susceptibility to reactive arthritis. This research has investigated the microbiology of these events, and the strategies used by pathogens to induce chronic joint inflammation. Insights into the HLA-orchestrated immune response in this context have also shed light on the impact of HLA-B27 on immunity, which might provide insights into the mechanism of other HLA-B27-associated diseases. Despite the genetic link to reactive arthritis, there is no proven relationship between ankylosing spondylitis and an inciting infection. In general, most trials have found antibiotics to be ineffective in modifying the course of spondyloarthritis.
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Affiliation(s)
- Robert D Inman
- Arthritis Center of Excellence, University Health Network, University of Toronto, Toronto, ON, Canada.
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Chander H, Majumdar S, Sapru S, Rishi P. 55 kDa outer-membrane protein from short-chain fatty acids exposed Salmonella enterica serovar Typhi induces apoptosis in macrophages. Antonie van Leeuwenhoek 2006; 89:317-23. [PMID: 16779627 DOI: 10.1007/s10482-005-9033-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/21/2005] [Indexed: 11/24/2022]
Abstract
Various pathogens including Salmonella species are known to induce apoptosis in host cell types during their infection processes. However, the bacterial components capable of inducing apoptosis have not been fully understood. It is now known that in vivo expression of virulence determinants differ from the expression under in vitro conditions. Therefore, in the present study, attempts were made to evaluate the apoptotic potential of outer-membrane protein (OMP) from short-chain fatty acids (SCFA) exposed Salmonella enterica serovar Typhi. Short-chain fatty acids exposure is one of the in vivo stresses encountered by the pathogen in the intestine. Therefore, to simulate the in vivo condition, S. enterica serovar Typhi was grown in the presence of SCFA and its OMP profile was analyzed. The apoptotic potential of 55 kDa protein expressed with enhanced intensity under the SCFA stress was evaluated. Murine peritoneal macrophages interacted with 55 kDa protein showed DNA fragmentation, changes in fluorescence and exposure of phosphatidylserine on their outer leaflets. Levels of nitrite and citrulline were found to be increased in the supernatant of macrophages after interacting them with 55 kDa protein. However, the enzymatic activity of superoxide dismutase was found to be decreased as compared to that of the control (uninteracted) macrophages. These observations indicate that increased levels of nitrite and decreased levels of superoxide dismutase may be one of the mechanisms to induce apoptosis in macrophages by SCFA induced 55 kDa OMP. These findings may help us better understand the pathophysiology of the disease during the host pathogen interactions.
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Affiliation(s)
- Harish Chander
- Department of Microbiology, Panjab University, Chandigarh, India
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28
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Miyairi I, Byrne GI. Chlamydia and programmed cell death. Curr Opin Microbiol 2006; 9:102-8. [PMID: 16406838 DOI: 10.1016/j.mib.2005.12.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Accepted: 12/16/2005] [Indexed: 11/18/2022]
Abstract
Discordant views regarding host cell death induction by Chlamydia are likely owing to the different methods used for evaluation of apoptosis. Apoptotic and non-apoptotic death owing to both caspase-dependent and -independent activation of the Bax protein occur late in the productive growth cycle. Evidence also suggests that Chlamydia inhibits apoptosis during productive growth as part of its intracellular survival strategy. This is in part owing to proteolytic degradation of the BH3-only family of pro-apoptotic proteins in the mitochondrial pathway. Chlamydia also inhibits apoptosis during persistent growth or in phagocytes, but induces apoptosis in T cells, which suggests that apoptosis has an immunomodulatory role in chlamydial infections. The contribution of apoptosis in disease pathogenesis remains a focus for future research.
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Affiliation(s)
- Isao Miyairi
- Department of Molecular Sciences, University of Tennessee Health Science Center, 858 Madison Ave, Memphis, TN 38163, USA
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29
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Kaehler J, Haar A, Schaps KP, Gaede A, Carstensen M, Schalwat I, Koester R, Laufs R, Meinertz T, Terres W. A randomized trial in patients undergoing percutaneous coronary angioplasty: roxithromycin does not reduce clinical restenosis but angioplasty increases antibody concentrations against Chlamydia pneumoniae. Am Heart J 2005; 150:987-93. [PMID: 16290983 DOI: 10.1016/j.ahj.2005.01.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2004] [Accepted: 01/15/2005] [Indexed: 11/24/2022]
Abstract
BACKGROUND Elevated antibodies against Chlamydia pneumoniae have been associated with coronary artery disease. In patients undergoing percutaneous coronary angioplasty, we therefore investigated the effect of roxithromycin on symptomatic restenosis and determined antichlamydial antibodies as well as inflammatory and immunological parameters. METHODS A total of 327 patients undergoing coronary angioplasty were randomized to roxithromycin or placebo and followed-up for 1 year. Antibodies were determined by microimmunofluorescence and enzyme-linked immunosorbent assay; C-reactive protein, interleukin-10, tumor necrosis factor-alpha (TNF-alpha), and eotaxin were determined by enzyme-linked immunosorbent assay. RESULTS Although the frequency of restenosis was not affected by roxithromycin (25 restenoses vs 32 in the control group), antichlamydial antibodies increased during follow-up (anti-CP IgG +12 +/- 2%, P < .001). Concentrations of TNF-alpha and eotaxin increased as well (TNF-alpha +9 +/- 1% and eotaxin +10 +/- 2%) and correlated with antichlamydial antibody concentrations (TNF-alpha, r = 0.23, P = .02; eotaxin, r = 0.32, P = .002). CONCLUSIONS Treatment with roxithromycin was not associated with a reduction of symptomatic restenoses. During follow-up, a marked increase in antichlamydial antibodies, TNF-alpha, and eotaxin was observed, suggesting that angioplasty-induced plaque rupture induces a specific immunological response without activation of inflammatory mechanisms as represented by C-reactive protein. Whether this mechanism occurs in all plaque ruptures remains to be determined.
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Affiliation(s)
- Jan Kaehler
- Department of Cardiology, University Hospital, Hamburg, Germany.
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30
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Abstract
PURPOSE OF REVIEW The hallmark of ankylosing spondylitis is acute and chronic spinal inflammation initiating in the sacroiliac joints, often coupled with enthesitis, presenting as chronic inflammation at the sites of ligamentous and tendinous insertions into bone. Peripheral joint synovitis can be a prominent feature as well. Reactive arthritis is a sterile synovitis arising after an extra-articular infection of enteric or urogenital tracts. HLA-B27 has been known for about the past 30 years to be associated with ankylosing spondylitis and reactive arthritis, but the pathogenesis of ankylosing spondylitis and reactive arthritis is still not well defined. Although the clinical manifestations of ankylosing spondylitis and reactive arthritis may differ, this update discusses the two diseases together and focuses on recent evidence in both. RECENT FINDINGS With respect to HLA-B27 several recent studies address arthritogenic peptides, molecular mimicry, and aberrant forms of B27. Several candidate genes in addition to B27 have been implicated in recent genetic studies. With respect to bacterial infection, recent findings in bacterial antigenicity, host response through interactions of antigen-presenting cells, T cells, and cytokines are providing new understanding of host-pathogen interactions and the pathogenesis of arthritis. Endogenous host factors such as proteoglycans may play a role as autoantigens and contribute to chronic inflammation on that basis. SUMMARY Recent advances provide additional new insights into distinct pathogenetic mechanisms in AS and ReA that arise from a complex interplay between genetic factors including HLA-B27 and environmental factors.
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Affiliation(s)
- Tae-Hwan Kim
- The Hospital for Rheumatic Diseases, Hanyang University, Seoul, Korea
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31
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Abstract
Chlamydial persistence is a reversible state generated during conditions deleterious to growth. In persistence, Chlamydia trachomatis remains viable but atypical, with an enlarged, aberrant form and quiescent metabolism. It favours chronic chlamydiosis, leading to serious sequelae. Although the mechanism of persistence formation is still unknown, more reliable molecular approaches tend to confirm that its occurs in vivo, even lasting 3 years. One approach consists of identifying unprocessed rRNA found only in viable Chlamydia, when infection is not apparent. Another approach, referring to the fact that immunity is type-specific, consists of showing by genotyping that multiple recurrences are due to the same genovar. At the molecular level, persistence is characterized by increased expression of ct755, one of the three heat shock protein (hsp60)-coding genes. In addition, chromosomal replication occurs continuously, and cell division is blocked possibly due to the repression of genes such as ftsW and amiA. At the immunological level, persistence reveals the failure of host-defence mechanisms because of reduced or suppressed pro-inflammatory or cytotoxic responses.
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Affiliation(s)
- Philomène Mpiga
- Département de microbiologie clinique, Centre hospitalier de l'Université de Montréal, Hôtel-Dieu, 3840 rue St-Urbain, Montréal, Québec H2W 1T8, Canada
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32
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Brunham RC, Rey-Ladino J. Immunology of Chlamydia infection: implications for a Chlamydia trachomatis vaccine. Nat Rev Immunol 2005; 5:149-61. [PMID: 15688042 DOI: 10.1038/nri1551] [Citation(s) in RCA: 441] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Sexually transmitted Chlamydia trachomatis infections are a serious public-health problem. With more than 90 million new cases occurring annually, C. trachomatis is the most common cause of bacterial sexually transmitted disease worldwide. Recent progress in elucidating the immunobiology of Chlamydia muridarum infection of mice has helped to guide the interpretation of immunological findings in studies of human C. trachomatis infection and has led to the development of a common model of immunity. In this review, we describe our current understanding of the immune response to infection with Chlamydia spp. and how this information is improving the prospects for development of a vaccine against infection with C. trachomatis.
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Affiliation(s)
- Robert C Brunham
- University of British Columbia Centre for Disease Control, Vancouver, British Columbia V5Z 4R4, Canada.
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Yélamos J, Buendía AJ, Ortega N, Monreal Y, Gallego MC, Sánchez J, Ramírez P, Parrilla P, Caro MR, Aparicio P, Salinas J. Genetic and pharmacological inhibition of poly(ADP-ribose) polymerase-1 interferes in the chlamydial life cycle. Biochem Biophys Res Commun 2004; 324:840-8. [PMID: 15474504 DOI: 10.1016/j.bbrc.2004.09.135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Indexed: 11/30/2022]
Abstract
Chlamydiaceae are intracellular bacteria responsible for a variety of infections, ranging from asymptomatic to very severe, in humans and animals. We have investigated the role of poly(ADP-ribose) polymerase-1 (PARP-1) in Chlamydophila abortus infection using PARP-1-/- and their littermates PARP-1+/+ mice. Infection was resolved more efficiently by PARP-1-/- than PARP-1+/+ mice. However, the inflammatory response was similar in both strains, suggesting a potential role for PARP-1 in the cross-talk between this microorganism and the host cells. PARP-1-/- fibroblasts showed a 10-fold lower rate of chlamydiae production than PARP-1+/+. Moreover, a strong inhibition of bacterial production was also observed after pharmacological inhibition of PARP-1 activity in McCoy cells. Likewise, PARP-1 inhibition induced a higher level of cell death of infected cells, interfering in this way with the normal bacterial cell cycle. Overall, we identify PARP-1 as a new molecule involved in chlamydial developmental cycle, although the intrinsic mechanisms deserve further studies.
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Affiliation(s)
- José Yélamos
- Department of Biochemistry, Molecular Biology B and Immunology, University of Murcia, Murcia, Spain.
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Abstract
PURPOSE OF REVIEW Chlamydia-induced arthritis is the most frequent form of reactive arthritis in Western countries. This article gives an overview of the recent findings with respect to diagnosis, pathogenesis, and therapy of the disease. RECENT FINDINGS Recent advances in the modification and standardization of polymerase chain reaction techniques give promise to identify Chlamydia more frequently from joint samples. Based on the sequenced chlamydial genome, considerable progress has been achieved in the understanding of the Chlamydia-host cell interaction, indicating that persistence is an alternate state of the bacteria used by Chlamydia to escape the immune system of the host rather than a general stress response. Furthermore, Chlamydia has the ability to reprogram the host cell by chlamydial effector proteins, which are transported from the inclusion into the host cell cytoplasm. The role of HLA-B27 is discussed in view of the pathogenesis of the disease. HLA-B27 should be considered a risk factor for chronic and/or axial disease rather than a true susceptibility factor for the development of Chlamydia-induced arthritis. No progress has been made in terms of causative therapy aiming at eradication of the bacteria. Tumor necrosis factor-alpha blocking agents may represent a new option in cases that are refractory to therapy. SUMMARY Molecular biology not only has improved the ability to detect Chlamydia in the joint for diagnostic purposes but also has extended the current understanding of the pathogenesis of the disease. In contrast to this progress, causative therapy of Chlamydia-induced arthritis is still an unfulfilled need.
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Affiliation(s)
- Henning Zeidler
- Division of Rheumatology, Department of Medicine, Medical School Hannover, Hannover, Germany.
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