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Russell FA, Trim L, Bryan E, Fisher MA, Leahy D, Harris JM, Hutmacher D, Dargaville TR, Beagley KW. Stability and antigenicity of Chlamydia muridarum major outer membrane protein antigen at body temperature. Vaccine 2024:S0264-410X(24)00674-1. [PMID: 38897891 DOI: 10.1016/j.vaccine.2024.06.015] [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: 02/19/2024] [Revised: 05/14/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024]
Abstract
Chlamydia is an obligate intracellular bacterial pathogen responsible for disease and infertility across multiple species. Currently vaccines are being studied to help reduce the prevalence of this disease. The main advantage of protein subunit vaccines is their high degree of safety although this is traded off with the requirement for multiple booster doses to achieve complete protection. Although in certain populations the booster dose can be difficult and costly to administer, development of delayed vaccine delivery techniques, such as a vaccine capsule, could be the solution to this problem. One of the main drawbacks in this technology is that the antigen must remain stable at body temperature (37 °C) until release is achieved. Here we elucidate the stability of a recombinant chlamydial major outer membrane protein (MOMP) antigen and assess its antigenic and immunogenic properties after subjecting the antigen to 37 °C for four to six weeks. Through in vitro and in vivo assessment we found that the aged chlamydial MOMP was able to produce equivalent humoral and cell-mediated immune responses when compared with the unaged vaccine. It was also found that vaccines formulated with the aged antigen conferred equivalent protection against a live infection challenge as the unaged antigen. Thus ageing chlamydial MOMP antigens at 37 °C for four to six weeks did not cause any significant structural or antigenic/immunogenic degradation and recombinant C. muridarum MOMP is suitable for use in a delayed vaccine delivery system.
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Affiliation(s)
- Freya A Russell
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland 4059, Australia; School of Biomedical Sciences and Centre for Immunology and Infection Control (CIIC), 300 Herston Road, QLD 4006, Australia.
| | - Logan Trim
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland 4059, Australia; School of Biomedical Sciences and Centre for Immunology and Infection Control (CIIC), 300 Herston Road, QLD 4006, Australia
| | - Emily Bryan
- School of Biomedical Sciences and Centre for Immunology and Infection Control (CIIC), 300 Herston Road, QLD 4006, Australia; Faculty of Medicine, University of Queensland Centre for Clinical Research, Herston 4006, Australia
| | - Mark A Fisher
- Queensland University of Technology, Faculty of Health, School of Biomedical Sciences, Centre for Genomics and Personalised Health, Cancer and Ageing Research Program, Translational Research Institute, Brisbane, Qld 4000, Australia
| | - Darren Leahy
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland 4059, Australia
| | - Jonathan M Harris
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland 4059, Australia
| | - Dietmar Hutmacher
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland 4059, Australia; School of Biomedical Sciences and Centre for Immunology and Infection Control (CIIC), 300 Herston Road, QLD 4006, Australia; Centre for Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Tim R Dargaville
- Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Kenneth W Beagley
- School of Biomedical Sciences and Centre for Immunology and Infection Control (CIIC), 300 Herston Road, QLD 4006, Australia
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2
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Chaiwattanarungruengpaisan S, Thongdee M, Arya N, Paungpin W, Sirimanapong W, Sariya L. Diversity and genetic characterization of Chlamydia isolated from Siamese crocodiles (Crocodylus siamensis). Acta Trop 2024; 253:107183. [PMID: 38479468 DOI: 10.1016/j.actatropica.2024.107183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/25/2024] [Accepted: 03/10/2024] [Indexed: 03/21/2024]
Abstract
Chlamydiosis, an infection caused by several Chlamydia species, has been reported in Nile, saltwater, and Siamese crocodiles. Despite its widespread reports in various countries, including Thailand, genetic information on Chlamydia species remains limited. This study presents a whole-genome-based characterization of Siamese crocodile-isolated Chlamydia. The results showed that Siamese crocodile Chlamydia contained a single circular chromosome with a size of 1.22-1.23 Mbp and a plasmid with a size of 7.7-8.0 kbp. A plasmid containing eight coding sequences (CDSs) was grouped in a β lineage. A chromosome sequence had approximately 1,018-1,031 CDSs. Chlamydial factors involving virulence were documented in terms of the presence of cytotoxins and several virulence factors in the chromosomes of Siamese crocodile Chlamydia. The analysis of antimicrobial resistance genes in the Chlamydia genome revealed that the most common resistance genes were associated with aminoglycosides, fluoroquinolones, macrolides, tetracyclines, and cephalosporins, with loose matching (identities between 21.12 % and 74.65 %). Phylogenetic analyses, encompassing the assessments of both whole proteome and nine taxonomic markers, revealed that Siamese crocodile Chlamydia was separated into three lineages (lineages I-III) with high bootstrapping statistic support. Interestingly, isolate 12-01 differed genetically from the others, suggesting that it is a new member of Chlamydia. The study findings indicate that Siamese crocodiles are susceptible hosts to Chlamydia, involving more than one species. This study is the first employing the highest number of whole-genome data on Siamese crocodile Chlamydia and provides better insights into pathogen genetics.
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Affiliation(s)
- Somjit Chaiwattanarungruengpaisan
- Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Metawee Thongdee
- Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Nlin Arya
- Department of Preclinic and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Weena Paungpin
- Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Wanna Sirimanapong
- Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Ladawan Sariya
- Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand.
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3
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Abstract
Type III secretion systems (T3SSs) are utilized by Gram-negative pathogens to enhance their pathogenesis. This secretion system is associated with the delivery of effectors through a needle-like structure from the bacterial cytosol directly into a target eukaryotic cell. These effector proteins then manipulate specific eukaryotic cell functions to benefit pathogen survival within the host. The obligate intracellular pathogens of the family Chlamydiaceae have a highly evolutionarily conserved nonflagellar T3SS that is an absolute requirement for their survival and propagation within the host with about one-seventh of the genome dedicated to genes associated with the T3SS apparatus, chaperones, and effectors. Chlamydiae also have a unique biphasic developmental cycle where the organism alternates between an infectious elementary body (EB) and replicative reticulate body (RB). T3SS structures have been visualized on both EBs and RBs. And there are effector proteins that function at each stage of the chlamydial developmental cycle, including entry and egress. This review will discuss the history of the discovery of chlamydial T3SS and the biochemical characterization of components of the T3SS apparatus and associated chaperones in the absence of chlamydial genetic tools. These data will be contextualized into how the T3SS apparatus functions throughout the chlamydial developmental cycle and the utility of heterologous/surrogate models to study chlamydial T3SS. Finally, there will be a targeted discussion on the history of chlamydial effectors and recent advances in the field.
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Affiliation(s)
- Elizabeth A. Rucks
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Durham Research Center II, Omaha, Nebraska, USA
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4
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Liu C, Mokashi NV, Darville T, Sun X, O’Connell CM, Hufnagel K, Waterboer T, Zheng X. A Machine Learning-Based Analytic Pipeline Applied to Clinical and Serum IgG Immunoproteome Data To Predict Chlamydia trachomatis Genital Tract Ascension and Incident Infection in Women. Microbiol Spectr 2023; 11:e0468922. [PMID: 37318345 PMCID: PMC10434056 DOI: 10.1128/spectrum.04689-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 06/01/2023] [Indexed: 06/16/2023] Open
Abstract
We developed a reusable and open-source machine learning (ML) pipeline that can provide an analytical framework for rigorous biomarker discovery. We implemented the ML pipeline to determine the predictive potential of clinical and immunoproteome antibody data for outcomes associated with Chlamydia trachomatis (Ct) infection collected from 222 cis-gender females with high Ct exposure. We compared the predictive performance of 4 ML algorithms (naive Bayes, random forest, extreme gradient boosting with linear booster [xgbLinear], and k-nearest neighbors [KNN]), screened from 215 ML methods, in combination with two different feature selection strategies, Boruta and recursive feature elimination. Recursive feature elimination performed better than Boruta in this study. In prediction of Ct ascending infection, naive Bayes yielded a slightly higher median value of are under the receiver operating characteristic curve (AUROC) 0.57 (95% confidence interval [CI], 0.54 to 0.59) than other methods and provided biological interpretability. For prediction of incident infection among women uninfected at enrollment, KNN performed slightly better than other algorithms, with a median AUROC of 0.61 (95% CI, 0.49 to 0.70). In contrast, xgbLinear and random forest had higher predictive performances, with median AUROC of 0.63 (95% CI, 0.58 to 0.67) and 0.62 (95% CI, 0.58 to 0.64), respectively, for women infected at enrollment. Our findings suggest that clinical factors and serum anti-Ct protein IgGs are inadequate biomarkers for ascension or incident Ct infection. Nevertheless, our analysis highlights the utility of a pipeline that searches for biomarkers and evaluates prediction performance and interpretability. IMPORTANCE Biomarker discovery to aid early diagnosis and treatment using machine learning (ML) approaches is a rapidly developing area in host-microbe studies. However, lack of reproducibility and interpretability of ML-driven biomarker analysis hinders selection of robust biomarkers that can be applied in clinical practice. We thus developed a rigorous ML analytical framework and provide recommendations for enhancing reproducibility of biomarkers. We emphasize the importance of robustness in selection of ML methods, evaluation of performance, and interpretability of biomarkers. Our ML pipeline is reusable and open-source and can be used not only to identify host-pathogen interaction biomarkers but also in microbiome studies and ecological and environmental microbiology research.
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Affiliation(s)
- Chuwen Liu
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Neha Vivek Mokashi
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Toni Darville
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Xuejun Sun
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Catherine M. O’Connell
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Katrin Hufnagel
- Infections and Cancer Epidemiology, German Cancer Research Center (Deutsches Krebsforschungszentrum), Heidelberg, Germany
| | - Tim Waterboer
- Infections and Cancer Epidemiology, German Cancer Research Center (Deutsches Krebsforschungszentrum), Heidelberg, Germany
| | - Xiaojing Zheng
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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5
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Turman BJ, Darville T, O'Connell CM. Plasmid-mediated virulence in Chlamydia. Front Cell Infect Microbiol 2023; 13:1251135. [PMID: 37662000 PMCID: PMC10469868 DOI: 10.3389/fcimb.2023.1251135] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 07/31/2023] [Indexed: 09/05/2023] Open
Abstract
Chlamydia trachomatis infection of ocular conjunctiva can lead to blindness, while infection of the female genital tract can lead to chronic pelvic pain, ectopic pregnancy, and/or infertility. Conjunctival and fallopian tube inflammation and the resulting disease sequelae are attributed to immune responses induced by chlamydial infection at these mucosal sites. The conserved chlamydial plasmid has been implicated in enhancing infection, via improved host cell entry and exit, and accelerating innate inflammatory responses that lead to tissue damage. The chlamydial plasmid encodes eight open reading frames, three of which have been associated with virulence: a secreted protein, Pgp3, and putative transcriptional regulators, Pgp4 and Pgp5. Although Pgp3 is an important plasmid-encoded virulence factor, recent studies suggest that chlamydial plasmid-mediated virulence extends beyond the expression of Pgp3. In this review, we discuss studies of genital, ocular, and gastrointestinal infection with C. trachomatis or C. muridarum that shed light on the role of the plasmid in disease development, and the potential for tissue and species-specific differences in plasmid-mediated pathogenesis. We also review evidence that plasmid-associated inflammation can be independent of bacterial burden. The functions of each of the plasmid-encoded proteins and potential molecular mechanisms for their role(s) in chlamydial virulence are discussed. Although the understanding of plasmid-associated virulence has expanded within the last decade, many questions related to how and to what extent the plasmid influences chlamydial infectivity and inflammation remain unknown, particularly with respect to human infections. Elucidating the answers to these questions could improve our understanding of how chlamydia augment infection and inflammation to cause disease.
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Affiliation(s)
- Breanna J. Turman
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, United States
| | - Toni Darville
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, United States
- Department of Pediatrics, University of North Carolina, Chapel Hill, NC, United States
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6
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Clemente TM, Angara RK, Gilk SD. Establishing the intracellular niche of obligate intracellular vacuolar pathogens. Front Cell Infect Microbiol 2023; 13:1206037. [PMID: 37645379 PMCID: PMC10461009 DOI: 10.3389/fcimb.2023.1206037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023] Open
Abstract
Obligate intracellular pathogens occupy one of two niches - free in the host cell cytoplasm or confined in a membrane-bound vacuole. Pathogens occupying membrane-bound vacuoles are sequestered from the innate immune system and have an extra layer of protection from antimicrobial drugs. However, this lifestyle presents several challenges. First, the bacteria must obtain membrane or membrane components to support vacuole expansion and provide space for the increasing bacteria numbers during the log phase of replication. Second, the vacuole microenvironment must be suitable for the unique metabolic needs of the pathogen. Third, as most obligate intracellular bacterial pathogens have undergone genomic reduction and are not capable of full metabolic independence, the bacteria must have mechanisms to obtain essential nutrients and resources from the host cell. Finally, because they are separated from the host cell by the vacuole membrane, the bacteria must possess mechanisms to manipulate the host cell, typically through a specialized secretion system which crosses the vacuole membrane. While there are common themes, each bacterial pathogen utilizes unique approach to establishing and maintaining their intracellular niches. In this review, we focus on the vacuole-bound intracellular niches of Anaplasma phagocytophilum, Ehrlichia chaffeensis, Chlamydia trachomatis, and Coxiella burnetii.
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Affiliation(s)
| | | | - Stacey D. Gilk
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
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7
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Huang W, Hu S, Zhu Y, Liu S, Zhou X, Fang Y, Lu Y, Wang R. Metagenomic surveillance and comparative genomic analysis of Chlamydia psittaci in patients with pneumonia. Front Microbiol 2023; 14:1157888. [PMID: 37323913 PMCID: PMC10265514 DOI: 10.3389/fmicb.2023.1157888] [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: 02/03/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023] Open
Abstract
Chlamydia psittaci, a strictly intracellular bacterium, is an underestimated etiologic agent leading to infections in a broad range of animals and mild illness or pneumonia in humans. In this study, the metagenomes of bronchoalveolar lavage fluids from the patients with pneumonia were sequenced and highly abundant C. psittaci was found. The target-enriched metagenomic reads were recruited to reconstruct draft genomes with more than 99% completeness. Two C. psittaci strains from novel sequence types were detected and these were closely related to the animal-borne isolates derived from the lineages of ST43 and ST28, indicating the zoonotic transmissions of C. psittaci would benefit its prevalence worldwide. Comparative genomic analysis combined with public isolate genomes revealed that the pan-genome of C. psittaci possessed a more stable gene repertoire than those of other extracellular bacteria, with ~90% of the genes per genome being conserved core genes. Furthermore, the evidence for significantly positive selection was identified in 20 virulence-associated gene products, particularly bacterial membrane-embedded proteins and type three secretion machines, which may play important roles in the pathogen-host interactions. This survey uncovered novel strains of C. psittaci causing pneumonia and the evolutionary analysis characterized prominent gene candidates involved in bacterial adaptation to immune pressures. The metagenomic approach is of significance to the surveillance of difficult-to-culture intracellular pathogens and the research into molecular epidemiology and evolutionary biology of C. psittaci.
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Affiliation(s)
- Weifeng Huang
- Department of Intensive Care Medicine, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shuqin Hu
- Department of Critical Care Medicine, Shanghai General Hospital of Nanjing Medical University, Shanghai, China
| | - Yongzhe Zhu
- Department of Microbiology, Navy Medical University, Shanghai, China
| | - Shijia Liu
- Department of Pulmonary Disease, PLA 905 Hospital, Shanghai, China
| | - Xingya Zhou
- Genoxor Medical Science and Technology Inc., Shanghai, China
| | - Yuan Fang
- Genoxor Medical Science and Technology Inc., Shanghai, China
| | - Yihan Lu
- Department of Epidemiology, Ministry of Education Key Laboratory of Public Health Safety, School of Public Health, Fudan University, Shanghai, China
- Shanghai Institute of Infectious Disease and Biosecurity, Shanghai, China
| | - Ruilan Wang
- Department of Critical Care Medicine, Shanghai General Hospital of Nanjing Medical University, Shanghai, China
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8
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Virulence Protein Pgp3 Is Insufficient To Mediate Plasmid-Dependent Infectivity of Chlamydia trachomatis. Infect Immun 2023; 91:e0039222. [PMID: 36722979 PMCID: PMC9933628 DOI: 10.1128/iai.00392-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Chlamydia trachomatis is the most common cause of infectious blindness and sexually transmitted bacterial infection globally. C. trachomatis contains a conserved chlamydial plasmid with eight coding sequences. Plasmid-cured Chlamydia strains are attenuated and display reduced infectivity in cell culture and in vivo genital infection of female mice. Mutants that do not express the plasmid-encoded proteins Pgp3, a secreted protein with unknown function, or Pgp4, a putative regulator of pgp3 and other chromosomal loci, display an infectivity defect similar to plasmid-deficient strains. Our objective was to determine the combined and individual contributions of Pgp3 and Pgp4 to this phenotype. Deletion of pgp3 and pgp4 resulted in an infectivity defect detected by competition assay in cell culture and in mice. The pgp3 locus was placed under the control of an anhydrotetracycline-inducible promoter to examine the individual contributions of Pgp3 and Pgp4 to infectivity. Expression of pgp3 was induced 100- to 1,000-fold after anhydrotetracycline administration, regardless of the presence or absence of pgp4. However, secreted Pgp3 was not detected when pgp4 was deleted, confirming a role for Pgp4 in Pgp3 secretion. We discovered that expression of pgp3 or pgp4 alone was insufficient to restore normal infectivity, which required expression of both Pgp3 and Pgp4. These results suggest Pgp3 and Pgp4 are both required for infectivity during C. trachomatis infection. Future studies are required to determine the mechanism by which Pgp3 and Pgp4 influence chlamydial infectivity as well as the potential roles of Pgp4-regulated loci.
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9
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Intracellular lifestyle of Chlamydia trachomatis and host-pathogen interactions. Nat Rev Microbiol 2023:10.1038/s41579-023-00860-y. [PMID: 36788308 DOI: 10.1038/s41579-023-00860-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2023] [Indexed: 02/16/2023]
Abstract
In recent years, substantial progress has been made in the understanding of the intracellular lifestyle of Chlamydia trachomatis and how the bacteria establish themselves in the human host. As an obligate intracellular pathogenic bacterium with a strongly reduced coding capacity, C. trachomatis depends on the provision of nutrients from the host cell. In this Review, we summarize the current understanding of how C. trachomatis establishes its intracellular replication niche, how its metabolism functions in the host cell, how it can defend itself against the cell autonomous and innate immune response and how it overcomes adverse situations through the transition to a persistent state. In particular, we focus on those processes for which a mechanistic understanding has been achieved.
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10
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Li X, Zuo Z, Wang Y, Hegemann JH, He C. Polymorphic Membrane Protein 17G of Chlamydia psittaci Mediated the Binding and Invasion of Bacteria to Host Cells by Interacting and Activating EGFR of the Host. Front Immunol 2022; 12:818487. [PMID: 35173712 PMCID: PMC8841347 DOI: 10.3389/fimmu.2021.818487] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/24/2021] [Indexed: 01/06/2023] Open
Abstract
Chlamydia psittaci (C. psittaci) is an obligate intracellular, gram-negative bacterium, and mainly causes systemic disease in psittacine birds, domestic poultry, and wild fowl. The pathogen is threating to human beings due to closely contacted to employees in poultry industry. The polymorphic membrane proteins (Pmps) enriched in C. psittaci includes six subtypes (A, B/C, D, E/F, G/I and H). Compared to that of the 1 pmpG gene in Chlamydia trachomatis (C. trachomatis), the diverse pmpG gene-coding proteins of C. psittaci remain elusive. In the present study, polymorphic membrane protein 17G (Pmp17G) of C. psittaci mediated adhesion to different host cells. More importantly, expression of Pmp17G in C. trachomatis upregulated infections to host cells. Afterwards, crosstalk between Pmp17G and EGFR was screened and identified by MALDI-MS and Co-IP. Subsequently, EGFR overexpression in CHO-K1 cells and EGFR knockout in HeLa 229 cells were assessed to determine whether Pmp17G directly correlated with EGFR during Chlamydial adhesion. Finally, the EGFR phosphorylation was recognized by Grb2, triggering chlamydial invasion. Based on above evidence, Pmp17G possesses adhesive property that serves as an adhesin and activate intracellular bacterial internalization by recognizing EGFR during C. psittaci infection
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Affiliation(s)
- Xiaohui Li
- Key Lab of Animal Epidemiology and Zoonoses of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Zonghui Zuo
- Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin, China
- Department of Biology, Institute for Functional Microbial Genomics, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Yihui Wang
- Key Lab of Animal Epidemiology and Zoonoses of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Johannes H. Hegemann
- Department of Biology, Institute for Functional Microbial Genomics, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Cheng He
- Key Lab of Animal Epidemiology and Zoonoses of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China
- *Correspondence: Cheng He,
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11
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Liu C, Hufnagel K, O'Connell CM, Goonetilleke N, Mokashi N, Waterboer T, Tollison TS, Peng X, Wiesenfeld HC, Hillier SL, Zheng X, Darville T. Reduced Endometrial Ascension and Enhanced Reinfection Associated with IgG Antibodies to Specific Chlamydia trachomatis Proteins in Women at Risk for Chlamydia. J Infect Dis 2021; 225:846-855. [PMID: 34610131 DOI: 10.1093/infdis/jiab496] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/28/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Previous research revealed antibodies targeting Chlamydia trachomatis (CT) elementary bodies was not associated with reduced endometrial or incident infection in CT-exposed women. However, data on the role of CT protein-specific antibodies in protection are limited. METHODS A whole-proteome CT array screening serum pools from CT-exposed women identified 121 immunoprevalent proteins. Individual sera were probed using a focused array. IgG antibody frequencies and endometrial or incident infection relationships were examined using Wilcoxon Rank sum test. The impact of breadth and magnitude of protein-specific IgGs on ascension and incident infection were examined using multivariable stepwise logistic regression. Complementary RNA-sequencing quantified CT gene transcripts in cervical swabs from infected women. RESULTS IgG to Pgp3 and CT005 were associated with reduced endometrial infection; anti-CT443, -CT486 and -CT123 were associated with increased incident infection. Increased breadth of protein recognition did not however predict protection from endometrial or incident infection. mRNAs for immunoprevalent CT proteins were highly abundant in the cervix. CONCLUSIONS Protein-specific CT antibodies are not sufficient to protect against ascending or incident infection but broad recognition of CT proteins by IgG correlates with cervical CT gene transcript abundance, suggesting CT protein abundance correlates with immunogenicity and signifies their potential as vaccine candidates.
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Affiliation(s)
- Chuwen Liu
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Katrin Hufnagel
- Division of Infections and Cancer Epidemiology, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany
| | - Catherine M O'Connell
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Nilu Goonetilleke
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Neha Mokashi
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Tim Waterboer
- Division of Infections and Cancer Epidemiology, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany
| | - Tammy S Tollison
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Xinxia Peng
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, North Carolina, USA.,Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina, USA
| | - Harold C Wiesenfeld
- Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Pittsburgh School of Medicine, The Magee-Womens Research Institute, Pittsburgh, Pennsylvania, USA
| | - Sharon L Hillier
- Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Pittsburgh School of Medicine, The Magee-Womens Research Institute, Pittsburgh, Pennsylvania, USA
| | - Xiaojing Zheng
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Toni Darville
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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12
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Murray SM, McKay PF. Chlamydia trachomatis: Cell biology, immunology and vaccination. Vaccine 2021; 39:2965-2975. [PMID: 33771390 DOI: 10.1016/j.vaccine.2021.03.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 02/06/2023]
Abstract
Chlamydia trachomatis is the causative agent of a highly prevalent sexually transmitted bacterial disease and is associated with a number of severe disease complications. Current therapy options are successful at treating disease, but patients are left without protective immunity and do not benefit the majority asymptomatic patients who do not seek treatment. As such, there is a clear need for a broad acting, protective vaccine that can prevent transmission and protect against symptomatic disease presentation. There are three key elements that underlie successful vaccine development: 1) Chlamydia biology and immune-evasion adaptations, 2) the correlates of protection that prevent disease in natural and experimental infection, 3) reflection upon the evidence provided by previous vaccine attempts. In this review, we give an overview of the unique intra-cellular biology of C. trachomatis and give insight into the dynamic combination of adaptations that allow Chlamydia to subvert host immunity and survive within the cell. We explore the current understanding of chlamydial immunity in animal models and in humans and characterise the key immune correlates of protection against infection. We discuss in detail the specific immune interactions involved in protection, with relevance placed on the CD4+ T lymphocyte and B lymphocyte responses that are key to pathogen clearance. Finally, we provide a timeline of C. trachomatis vaccine research to date and evaluate the successes and failures in development so far. With insight from these three key elements of research, we suggest potential solutions for chlamydial vaccine development and promising avenues for further exploration.
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Affiliation(s)
- Sam M Murray
- Department of Infectious Diseases, Imperial College London, Norfolk Place, London W2 1PG, UK.
| | - Paul F McKay
- Department of Infectious Diseases, Imperial College London, Norfolk Place, London W2 1PG, UK.
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Pagliarani S, Johnston SD, Beagley KW, Dief H, Palmieri C. The occurrence and pathology of chlamydiosis in the male reproductive tract of non-human mammals: A review. Theriogenology 2020; 154:152-160. [PMID: 32622195 DOI: 10.1016/j.theriogenology.2020.05.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 11/19/2022]
Abstract
Organisms belonging to the Family Chlamydiaceae are responsible for a broad range of diseases in humans, livestock, companion animals and non-domestic species. Infection of the reproductive organs can cause a range of syndromes of which sub- and infertility are the most frequently observed clinical manifestations. While the gross and histological lesions associated with the isolation of Chlamydiaceae from the non-human female reproductive tract are well documented, little attention has been given to the pathological effects of this infection in the male genital system. As such, the occurrence and importance of Chlamydia-associated disease in male non-human mammalian species is less well documented. In order to improve our understanding of the significance of chlamydiosis in domestic, laboratory and wild animals, this review provides an up-to-date summary of Chlamydia-associated male reproductive pathology, whether that infection occurs naturally or experimentally. Although most lesions in males are described as incidental and of minor significance, results of recent studies suggest that infection with Chlamydiaceae can adversely impact male fertility and/or be instrumental in disease transmission. Although in humans, bulls and mice Chlamydia infection has been associated with morphological and functional abnormalities of the spermatozoa, this review will focus on the gross and histological findings linked to the colonisation of the genital system by this pathogen. Advances in our understanding of male reproductive chlamydiosis are necessary for diagnostic and therapeutic strategies, as well as epidemiological and conservation studies.
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Affiliation(s)
- Sara Pagliarani
- School of Veterinary Science, The University of Queensland, Gatton, 4343, Australia; School of Agriculture and Food Sciences, The University of Queensland, Gatton, 4343, Australia.
| | - Stephen D Johnston
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, 4343, Australia
| | - Kenneth W Beagley
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, 4001, Australia
| | - Hamdy Dief
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, 4343, Australia
| | - Chiara Palmieri
- School of Veterinary Science, The University of Queensland, Gatton, 4343, Australia
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14
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Chiarelli TJ, Grieshaber NA, Grieshaber SS. Live-Cell Forward Genetic Approach to Identify and Isolate Developmental Mutants in Chlamydia trachomatis. J Vis Exp 2020. [PMID: 32597859 DOI: 10.3791/61365] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The intracellular bacterial pathogen Chlamydia trachomatis undergoes a developmental cycle consisting of two morphologically discrete developmental forms. The non-replicative elementary body (EB) initiates infection of the host. Once inside, the EB differentiates into the reticulate body (RB). The RB then undergoes multiple rounds of replication, before differentiating back to the infectious EB form. This cycle is essential for chlamydial survival as failure to switch between cell types prevents either host invasion or replication. Limitations in genetic techniques due to the obligate intracellular nature of Chlamydia have hampered identification of the molecular mechanisms involved in the cell-type development. We designed a novel dual promoter-reporter plasmid system that, in conjunction with live-cell microscopy, allows for the visualization of cell type switching in real time. To identify genes involved in the regulation of cell-type development, the live-cell promoter-reporter system was leveraged for the development of a forward genetic approach by combining chemical mutagenesis of the dual reporter strain, imaging and tracking of Chlamydia with altered developmental kinetics, followed by clonal isolation of mutants. This forward genetic workflow is a flexible tool that can be modified for directed interrogation into a wide range of genetic pathways.
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15
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Caven L, Carabeo RA. Pathogenic Puppetry: Manipulation of the Host Actin Cytoskeleton by Chlamydia trachomatis. Int J Mol Sci 2019; 21:ijms21010090. [PMID: 31877733 PMCID: PMC6981773 DOI: 10.3390/ijms21010090] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/18/2019] [Accepted: 12/19/2019] [Indexed: 12/25/2022] Open
Abstract
The actin cytoskeleton is crucially important to maintenance of the cellular structure, cell motility, and endocytosis. Accordingly, bacterial pathogens often co-opt the actin-restructuring machinery of host cells to access or create a favorable environment for their own replication. The obligate intracellular organism Chlamydia trachomatis and related species exemplify this dynamic: by inducing actin polymerization at the site of pathogen-host attachment, Chlamydiae induce their own uptake by the typically non-phagocytic epithelium they infect. The interaction of chlamydial adhesins with host surface receptors has been implicated in this effect, as has the activity of the chlamydial effector TarP (translocated actin recruitment protein). Following invasion, C. trachomatis dynamically assembles and maintains an actin-rich cage around the pathogen’s membrane-bound replicative niche, known as the chlamydial inclusion. Through further induction of actin polymerization and modulation of the actin-crosslinking protein myosin II, C. trachomatis promotes egress from the host via extrusion of the inclusion. In this review, we present the experimental findings that can inform our understanding of actin-dependent chlamydial pathogenesis, discuss lingering questions, and identify potential avenues of future study.
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Affiliation(s)
- Liam Caven
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA;
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - Rey A. Carabeo
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-5900, USA
- Correspondence: ; Tel.: +1-402-836-9778
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Gitsels A, Sanders N, Vanrompay D. Chlamydial Infection From Outside to Inside. Front Microbiol 2019; 10:2329. [PMID: 31649655 PMCID: PMC6795091 DOI: 10.3389/fmicb.2019.02329] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 09/24/2019] [Indexed: 12/16/2022] Open
Abstract
Chlamydia are obligate intracellular bacteria, characterized by a unique biphasic developmental cycle. Specific interactions with the host cell are crucial for the bacteria’s survival and amplification because of the reduced chlamydial genome. At the start of infection, pathogen-host interactions are set in place in order for Chlamydia to enter the host cell and reach the nutrient-rich peri-Golgi region. Once intracellular localization is established, interactions with organelles and pathways of the host cell enable the necessary hijacking of host-derived nutrients. Detailed information on the aforementioned processes will increase our understanding on the intracellular pathogenesis of chlamydiae and hence might lead to new strategies to battle chlamydial infection. This review summarizes how chlamydiae generate their intracellular niche in the host cell, acquire host-derived nutrients in order to enable their growth and finally exit the host cell in order to infect new cells. Moreover, the evolution in the development of molecular genetic tools, necessary for studying the chlamydial infection biology in more depth, is discussed in great detail.
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Affiliation(s)
- Arlieke Gitsels
- Laboratory for Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Niek Sanders
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Daisy Vanrompay
- Laboratory for Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Bugalhão JN, Mota LJ. The multiple functions of the numerous Chlamydia trachomatis secreted proteins: the tip of the iceberg. MICROBIAL CELL 2019; 6:414-449. [PMID: 31528632 PMCID: PMC6717882 DOI: 10.15698/mic2019.09.691] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Chlamydia trachomatis serovars are obligate intracellular bacterial pathogens mainly causing ocular and urogenital infections that affect millions of people worldwide and which can lead to blindness or sterility. They reside and multiply intracellularly within a membrane-bound vacuolar compartment, known as inclusion, and are characterized by a developmental cycle involving two morphologically and physiologically distinct chlamydial forms. Completion of the developmental cycle involves the secretion of > 70 C. trachomatis proteins that function in the host cell cytoplasm and nucleus, in the inclusion membrane and lumen, and in the extracellular milieu. These proteins can, for example, interfere with the host cell cytoskeleton, vesicular and non-vesicular transport, metabolism, and immune signalling. Generally, this promotes C. trachomatis invasion into, and escape from, host cells, the acquisition of nutrients by the chlamydiae, and evasion of cell-autonomous, humoral and cellular innate immunity. Here, we present an in-depth review on the current knowledge and outstanding questions about these C. trachomatis secreted proteins.
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Affiliation(s)
- Joana N Bugalhão
- UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Luís Jaime Mota
- UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
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18
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Christensen S, McMahon RM, Martin JL, Huston WM. Life inside and out: making and breaking protein disulfide bonds in Chlamydia. Crit Rev Microbiol 2019; 45:33-50. [PMID: 30663449 DOI: 10.1080/1040841x.2018.1538933] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Disulphide bonds are widely used among all domains of life to provide structural stability to proteins and to regulate enzyme activity. Chlamydia spp. are obligate intracellular bacteria that are especially dependent on the formation and degradation of protein disulphide bonds. Members of the genus Chlamydia have a unique biphasic developmental cycle alternating between two distinct cell types; the extracellular infectious elementary body (EB) and the intracellular replicating reticulate body. The proteins in the envelope of the EB are heavily cross-linked with disulphides and this is known to be critical for this infectious phase. In this review, we provide a comprehensive summary of what is known about the redox state of chlamydial envelope proteins throughout the developmental cycle. We focus especially on the factors responsible for degradation and formation of disulphide bonds in Chlamydia and how this system compares with redox regulation in other organisms. Focussing on the unique biology of Chlamydia enables us to provide important insights into how specialized suites of disulphide bond (Dsb) proteins cater for specific bacterial environments and lifecycles.
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Affiliation(s)
- Signe Christensen
- a Division of Chemistry and Structural Biology , Institute for Molecular Bioscience, University of Queensland , St. Lucia , QLD , Australia.,b Griffith Institute for Drug Discovery, Griffith University , Nathan , QLD , Australia
| | - Róisín M McMahon
- b Griffith Institute for Drug Discovery, Griffith University , Nathan , QLD , Australia
| | - Jennifer L Martin
- b Griffith Institute for Drug Discovery, Griffith University , Nathan , QLD , Australia
| | - Wilhelmina M Huston
- c School of Life Sciences , University of Technology Sydney , Ultimo , NSW , Australia
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19
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Park JS, Helble JD, Lazarus JE, Yang G, Blondel CJ, Doench JG, Starnbach MN, Waldor MK. A FACS-Based Genome-wide CRISPR Screen Reveals a Requirement for COPI in Chlamydia trachomatis Invasion. iScience 2018; 11:71-84. [PMID: 30590252 PMCID: PMC6308251 DOI: 10.1016/j.isci.2018.12.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 09/20/2018] [Accepted: 12/10/2018] [Indexed: 12/26/2022] Open
Abstract
The invasion of Chlamydia trachomatis, an obligate intracellular bacterium, into epithelial cells is driven by a complex interplay of host and bacterial factors. To comprehensively define the host genes required for pathogen invasion, we undertook a fluorescence-activated cell sorting (FACS)-based CRISPR screen in human cells. A genome-wide loss-of-function library was infected with fluorescent C. trachomatis and then sorted to enrich for invasion-deficient mutants. The screen identified heparan sulfate, a known pathogen receptor, as well as coatomer complex I (COPI). We found that COPI, through a previously unappreciated role, promotes heparan sulfate cell surface presentation, thereby facilitating C. trachomatis attachment. The heparan sulfate defect does not fully account for the resistance of COPI mutants. COPI also promotes the activity of the pathogen's type III secretion system. Together, our findings establish the requirement for COPI in C. trachomatis invasion and the utility of FACS-based CRISPR screening for the elucidation of host factors required for pathogen invasion. FACS-based CRISPR screen to identify host factors required for C. trachomatis invasion Candidate genes comprise heparan sulfate biosynthesis, actin remodeling, and COPI COPI regulates heparan sulfate cell surface presentation and C. trachomatis attachment COPI is also required for efficient C. trachomatis T3SS translocation
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Affiliation(s)
- Joseph S Park
- Howard Hughes Medical Institute, Boston, MA 02215, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA; Boston University School of Medicine, Boston, MA 02120, USA
| | - Jennifer D Helble
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Jacob E Lazarus
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA; Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Guanhua Yang
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA
| | - Carlos J Blondel
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA
| | - John G Doench
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Michael N Starnbach
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Matthew K Waldor
- Howard Hughes Medical Institute, Boston, MA 02215, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Division of Infectious Diseases, Brigham & Women's Hospital, Boston 02115, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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20
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Mackern-Oberti JP, Motrich RD, Damiani MT, Saka HA, Quintero CA, Sánchez LR, Moreno-Sosa T, Olivera C, Cuffini C, Rivero VE. Male genital tract immune response against Chlamydia trachomatis infection. Reproduction 2018; 154:R99-R110. [PMID: 28878094 DOI: 10.1530/rep-16-0561] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 07/01/2017] [Accepted: 07/11/2017] [Indexed: 01/01/2023]
Abstract
Chlamydia trachomatis is the most commonly reported agent of sexually transmitted bacterial infections worldwide. This pathogen frequently leads to persistent, long-term, subclinical infections, which in turn may cause severe pathology in susceptible hosts. This is in part due to the strategies that Chlamydia trachomatis uses to survive within epithelial cells and to evade the host immune response, such as subverting intracellular trafficking, interfering signaling pathways and preventing apoptosis. Innate immune receptors such as toll-like receptors expressed on epithelial and immune cells in the genital tract mediate the recognition of chlamydial molecular patterns. After bacterial recognition, a subset of pro-inflammatory cytokines and chemokines are continuously released by epithelial cells. The innate immune response is followed by the initiation of the adaptive response against Chlamydia trachomatis, which in turn may result in T helper 1-mediated protection or in T helper 2-mediated immunopathology. Understanding the molecular mechanisms developed by Chlamydia trachomatis to avoid killing and host immune response would be crucial for designing new therapeutic approaches and developing protective vaccines. In this review, we focus on chlamydial survival strategies and the elicited immune responses in male genital tract infections.
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Affiliation(s)
- Juan Pablo Mackern-Oberti
- Instituto de Medicina y Biología Experimental de Cuyo. IMBECU-CONICETMendoza, Argentina .,Instituto de Fisiología. Facultad de Ciencias MédicasUniversidad Nacional de Cuyo, Mendoza, Argentina
| | - Rubén Darío Motrich
- Centro de Investigaciones en Bioquímica Clínica e Inmunología CIBICI-CONICETDepartamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Maria Teresa Damiani
- Instituto de Histología y Embriología de Mendoza. IHEM-CONICETFacultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Héctor Alex Saka
- Centro de Investigaciones en Bioquímica Clínica e Inmunología CIBICI-CONICETDepartamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | | | - Leonardo Rodolfo Sánchez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología CIBICI-CONICETDepartamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Tamara Moreno-Sosa
- Instituto de Medicina y Biología Experimental de Cuyo. IMBECU-CONICETMendoza, Argentina
| | - Carolina Olivera
- Centro de Investigaciones en Bioquímica Clínica e Inmunología CIBICI-CONICETDepartamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Cecilia Cuffini
- Instituto de Virología Dr. J. M. VanellaFacultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Virginia Elena Rivero
- Centro de Investigaciones en Bioquímica Clínica e Inmunología CIBICI-CONICETDepartamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Abstract
Both actin and microtubules are major cytoskeletal elements in eukaryotic cells that participate in many cellular processes, including cell division and motility, vesicle and organelle movement, and the maintenance of cell shape. Inside its host cell, the human pathogen Chlamydia trachomatis manipulates the cytoskeleton to promote its survival and enhance its pathogenicity. In particular, Chlamydia induces the drastic rearrangement of both actin and microtubules, which is vital for its entry, inclusion structure and development, and host cell exit. As significant progress in Chlamydia genetics has greatly enhanced our understanding of how this pathogen co-opts the host cytoskeleton, we will discuss the machinery used by Chlamydia to coordinate the reorganization of actin and microtubules.
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Affiliation(s)
- Jordan Wesolowski
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Fabienne Paumet
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
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22
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O'Meara CP, Armitage CW, Andrew DW, Kollipara A, Lycke NY, Potter AA, Gerdts V, Petrovsky N, Beagley KW. Multistage vaccines containing outer membrane, type III secretion system and inclusion membrane proteins protects against a Chlamydia genital tract infection and pathology. Vaccine 2017; 35:3883-3888. [PMID: 28602608 DOI: 10.1016/j.vaccine.2017.05.063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 05/20/2017] [Accepted: 05/23/2017] [Indexed: 01/07/2023]
Abstract
Pathogens with a complex lifecycles can effectively evade host immunity in part due to each developmental stage expressing unique sets of antigens. Multisubunit vaccines incorporating signature antigens reflecting distinct developmental stages (multistage vaccines) have proven effective against viral, bacterial and parasitic infection at preventing pathogen evasion of host immunity. Chlamydia trachomatis is characterized by a biphasic extra/intracellular developmental cycle and an acute/persistent (latent) metabolic state; hence a multistage vaccine may prevent immune evasion and enhance clearance. Here we tested the efficacy of a multistage vaccine containing outer membrane (MOMP and PmpG), type three secretion system (T3SS) (CdsF and TC0873) and inclusion membrane proteins (IncA and TC0500) in mice against an intravaginal challenge with Chlamydia muridarum. Comparison of single (eg. MOMP) and double antigen vaccines (eg. MOMP and PmpG), largely targeting the extracellular stage, elicited significant yet comparable protection against vaginal shedding when compared to unimmunized control mice. Utilization of different adjuvants (ISCOMATRIX - IMX, PCEP/polyI:C/IDR1002 - VIDO, CTA1-DD and ADVAX) and numerous immunization routes (subcutaneous - SQ and intranasal - IN) further enhanced protection against infection. However, a multistage vaccine elicited significantly greater protection against vaginal shedding and upper genital tract pathology than vaccines targeting only extra- or intracellular stages. This indicates that protection elicited by a vaccine targeting extracellular chlamydial antigens could be improved by including chlamydial antigen expressed during intracellular phase.
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Affiliation(s)
- Connor P O'Meara
- Institute of Health and Biomedical Innovation (IHBI) and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia; Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Baden-Wüttemburg, Germany
| | - Charles W Armitage
- Institute of Health and Biomedical Innovation (IHBI) and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Dean W Andrew
- Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Avinash Kollipara
- Institute of Health and Biomedical Innovation (IHBI) and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Nils Y Lycke
- Mucosal Immunobiology and Vaccine Centre, University of Gothenburg, Sweden
| | - Andrew A Potter
- Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, Canada
| | - Volker Gerdts
- Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, Canada
| | - Nikolai Petrovsky
- Vaxine Pty Ltd, Adelaide, Australia; Department of Endocrinology, Flinders Medical Centre/Flinders University, Adelaide, Australia
| | - Kenneth W Beagley
- Institute of Health and Biomedical Innovation (IHBI) and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
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23
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Hadad R, Marks E, Kalbina I, Schön K, Unemo M, Lycke N, Strid Å, Andersson S. Protection against genital tract Chlamydia trachomatis infection following intranasal immunization with a novel recombinant MOMP VS2/4 antigen. APMIS 2017; 124:1078-1086. [PMID: 27859689 DOI: 10.1111/apm.12605] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 08/18/2016] [Indexed: 12/01/2022]
Abstract
The asymptomatic nature of most Chlamydia trachomatis infections and the lack of appropriate effects by current prevention and management call for vaccine development. We evaluated a recombinant subunit vaccine candidate based on the major outer membrane protein variable segments 2 and 4 (MOMP VS2/4). To achieve maximal immunogenicity and ease of production and purification, MOMP VS2/4 was constructed by using highly immunogenic sequences of MOMP only, thereby minimizing the presence of hydrophobic regions, and spacing the immunogenic epitopes with a flexible amino acid sequence. A purification tag was also added. The MOMP VS2/4 was given intranasally, with or without intravaginal boost, with cholera toxin (CT) adjuvant to C57BL/6 mice, which were screened for immunogenicity and protection against a live challenge infection with C. trachomatis serovar D. Bacterial shedding, cell-mediated responses, and antibody responses were monitored. Immunized mice exhibited significantly less bacterial shedding and were better protected against infertility as compared to unimmunized control mice. Immunizations stimulated both systemic and local specific antibody (IgG1, IgG2c, and IgA) responses, and primed T cells that produced interferon-γ and interleukins 13 and 17 upon challenge with recall antigen. Thus, MOMP VS2/4, in combination with CT adjuvant, stimulated Th1, Th2, and Th17 effector cells, and generated protective immunity associated with less pathology. We regard MOMP VS2/4 as a promising candidate for further development into a mucosal chlamydial vaccine.
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Affiliation(s)
- Ronza Hadad
- Örebro Life Science Center, School of Science and Technology, Örebro University, Örebro, Sweden.,Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Ellen Marks
- Department of Medical Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden
| | - Irina Kalbina
- Örebro Life Science Center, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Karin Schön
- Department of Medical Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden
| | - Magnus Unemo
- Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Nils Lycke
- Department of Medical Microbiology and Immunology, University of Gothenburg, Gothenburg, Sweden
| | - Åke Strid
- Örebro Life Science Center, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Sören Andersson
- Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
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24
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Galaine J, Kellermann G, Guillaume Y, Boidot R, Picard E, Loyon R, Queiroz L, Boullerot L, Beziaud L, Jary M, Mansi L, André C, Lethier L, Ségal-Bendirdjian E, Borg C, Godet Y, Adotévi O. Heparan Sulfate Proteoglycans Promote Telomerase Internalization and MHC Class II Presentation on Dendritic Cells. THE JOURNAL OF IMMUNOLOGY 2016; 197:1597-608. [DOI: 10.4049/jimmunol.1502633] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 06/01/2016] [Indexed: 01/18/2023]
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25
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Abstract
Glycosaminoglycans (GAGs) are complex linear polysaccharides expressed in intracellular compartments, at the cell surface, and in the extracellular environment where they interact with various molecules to regulate many cellular processes implicated in health and disease. Subversion of GAGs is a pathogenic strategy shared by a wide variety of microbial pathogens, including viruses, bacteria, parasites, and fungi. Pathogens use GAGs at virtually every major portals of entry to promote their attachment and invasion of host cells, movement from one cell to another, and to protect themselves from immune attack. Pathogens co-opt fundamental activities of GAGs to accomplish these tasks. This ingenious strategy to subvert essential activities of GAGs likely prevented host organisms from deleting or inactivating these mechanisms during their evolution. The goal of this review is to provide a mechanistic overview of our current understanding of how microbes subvert GAGs at major steps of pathogenesis, using select GAG-pathogen interactions as representative examples.
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Affiliation(s)
- Rafael S Aquino
- Division of Respiratory Diseases and 2Division of Newborn Medicine, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Pyong Woo Park
- Division of Respiratory Diseases Children's Hospital, Harvard Medical School, Boston, MA 02115, USA and Division of Newborn Medicine, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA,
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Poston TB, Darville T. Chlamydia trachomatis: Protective Adaptive Responses and Prospects for a Vaccine. Curr Top Microbiol Immunol 2016; 412:217-237. [PMID: 27033698 DOI: 10.1007/82_2016_6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Chlamydia trachomatis is the most common cause of sexually transmitted bacterial infection globally. These infections translate to a significant public health burden, particularly women's healthcare costs due to serious disease sequelae such as pelvic inflammatory disease (PID), tubal factor infertility, chronic pelvic pain, and ectopic pregnancy. There is no evidence that natural immunity can provide complete, long-term protection necessary to prevent chronic pathology, making human vaccine development critical. Vaccine design will require careful consideration of protective versus pathological host-response mechanisms in concert with elucidation of optimal antigens and adjuvants. Evidence suggests that a Th1 response, facilitated by IFN-γ-producing CD4 T cells, will be instrumental in generating long-term, sterilizing immunity. Although the role of antibodies is not completely understood, they have exhibited a protective effect by enhancing chlamydial clearance. Future work will require investigation of broadly neutralizing antibodies and antibody-augmented cellular immunity to successfully design a vaccine that potently elicits both arms of the immune response. Sterilizing immunity is the ultimate goal. However, vaccine-induced partial immunity that prevents upper genital tract infection and inflammation would be cost-effective compared to current screening and treatment strategies. In this chapter, we examine evidence from animal and human studies demonstrating protective adaptive immune responses to Chlamydia and discuss future challenges and prospects for vaccine development.
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Affiliation(s)
- Taylor B Poston
- Department of Pediatrics, University of North Carolina, Chapel Hill, NC, USA
| | - Toni Darville
- Department of Pediatrics, University of North Carolina, Chapel Hill, NC, USA.
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Gracey E, Baglaenko Y, Prayitno N, Van Rooijen N, Akram A, Lin A, Chiu B, Inman RD. Pulmonary Chlamydia muridarum challenge activates lung interstitial macrophages which correlate with IFN-γ production and infection control in mice. Eur J Immunol 2015; 45:3417-30. [PMID: 26344246 DOI: 10.1002/eji.201545874] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 07/23/2015] [Accepted: 09/01/2015] [Indexed: 11/09/2022]
Abstract
Protective immunity to the pathogen Chlamydia is dependent on a robust IFN-γ response generated by innate and adaptive lymphocytes. Here we assess the role of the macrophage in orchestrating a protective response in vivo to the murine pathogen, Chlamydia muridarum. During acute pulmonary and peritoneal infection, resident macrophages in both sites are infected with C. muridarum and adopt an inflammatory phenotype. In the lung, this activation is restricted to interstitial macrophages, which harbor higher levels of C. muridarum 16sRNA than alveolar macrophages. We examined innate and adaptive lymphocyte activation in the peritoneal cavity with macrophage depletion and with adoptive transfer of infected macrophages. These experiments demonstrate macrophage activation correlates with a protective IFN-γ response and effective control of C. muridarum. These studies suggest that a quantitative or qualitative alteration in macrophages may play a key role in the development of Chlamydia-associated diseases.
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Affiliation(s)
- Eric Gracey
- Department of Immunology, University of Toronto, Canada.,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | - Yuriy Baglaenko
- Department of Immunology, University of Toronto, Canada.,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | | | - Nico Van Rooijen
- Vrije Universiteit, Vrije Universiteit Medical Center, Department of Molecular Cell Biology, Amsterdam, The Netherlands
| | - Ali Akram
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | - Aifeng Lin
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | - Basil Chiu
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | - Robert D Inman
- Department of Immunology, University of Toronto, Canada.,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
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28
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Karunakaran K, Subbarayal P, Vollmuth N, Rudel T. Chlamydia-infected cells shed Gp96 to prevent chlamydial re-infection. Mol Microbiol 2015; 98:694-711. [PMID: 26235316 DOI: 10.1111/mmi.13151] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2015] [Indexed: 12/29/2022]
Abstract
Chlamydia trachomatis is an obligate intracellular human pathogen with a biphasic developmental life cycle. The infectious elementary bodies (EBs) enter a host cell where they transform into reticulate bodies (RBs) that use cellular metabolites to multiply. Re-infection of an infected cell during the replicative phase of chlamydial development may prevent formation of infectious EBs, interrupting the infectious cycle. Here, we report that Glucose Regulated Protein 96 (Gp96), a chaperone for cell surface receptors, binds to and facilitates adherence and entry of C. trachomatis. Gp96 expression was increased early in infection in a MAP kinase-dependent way, thereby increasing chlamydial adherence and invasion. Gp96 co-precipitated with Protein Disulphide Isomerase (PDI), known to be involved in chlamydial host cell entry. During the replicative phase, Gp96 was depleted from infected cells and shed into the supernatant by activation of metalloproteinase TACE (ADAM17). Loss of Gp96 also reduced the activity of PDI on the cell surface. Reduced surface display of Gp96 prevented chlamydial re-infection in a TACE-dependent manner in cell lines but also in primary cells derived from human fimbriae, the natural site of chlamydial infection. Our data suggest a role of infection-induced Gp96 shedding in the protection of the chlamydial replicative niche.
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Affiliation(s)
- Karthika Karunakaran
- Department of Microbiology, Biocenter, University of Wuerzburg, Am Hubland, Wuerzburg, D-97074, Germany
| | - Prema Subbarayal
- Department of Microbiology, Biocenter, University of Wuerzburg, Am Hubland, Wuerzburg, D-97074, Germany
| | - Nadine Vollmuth
- Department of Microbiology, Biocenter, University of Wuerzburg, Am Hubland, Wuerzburg, D-97074, Germany
| | - Thomas Rudel
- Department of Microbiology, Biocenter, University of Wuerzburg, Am Hubland, Wuerzburg, D-97074, Germany
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29
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Quintero CA, Tudela JG, Damiani MT. Rho GTPases as pathogen targets: Focus on curable sexually transmitted infections. Small GTPases 2015; 6:108-18. [PMID: 26023809 DOI: 10.4161/21541248.2014.991233] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Pathogens have evolved highly specialized mechanisms to infect hosts. Several microorganisms modulate the eukaryotic cell surface to facilitate their engulfment. Once internalized, they hijack the molecular machinery of the infected cell for their own benefit. At different stages of phagocytosis, particularly during invasion, certain pathogens manipulate pathways governed by small GTPases. In this review, we focus on the role of Rho proteins on curable, sexually transmitted infections caused by Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Treponema pallidum. Despite the high, worldwide frequencies of these sexually-transmitted diseases, very little is known about the strategies developed by these microorganisms to usurp key eukaryotic proteins that control intracellular signaling and actin dynamics. Improved knowledge of these molecular mechanisms will contribute to the elucidation of how these clinically important pathogens manipulate intracellular processes and parasitize their hosts.
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Affiliation(s)
- Cristián A Quintero
- a Laboratory of Phagocytosis and Intracellular Trafficking; IHEM-CONICET; School of Medicine; University of Cuyo ; Mendoza , Argentina
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Kebbi-Beghdadi C, Domröse A, Becker E, Cisse OH, Hegemann JH, Greub G. OmpA family proteins and Pmp-like autotransporter: new adhesins of Waddlia chondrophila. Pathog Dis 2015; 73:ftv035. [PMID: 25986220 DOI: 10.1093/femspd/ftv035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2015] [Indexed: 11/12/2022] Open
Abstract
Waddlia chondrophila is a obligate intracellular bacterium belonging to the Chlamydiales order, a clade that also includes the well-known classical Chlamydia responsible for a number of severe human and animal diseases. Waddlia is an emerging pathogen associated with adverse pregnancy outcomes in humans and abortion in ruminants. Adhesion to the host cell is an essential prerequisite for survival of every strict intracellular bacteria and, in classical Chlamydia, this step is partially mediated by polymorphic outer membrane proteins (Pmps), a family of highly diverse autotransporters that represent about 15% of the bacterial coding capacity. Waddlia chondrophila genome however only encodes one putative Pmp-like protein. Using a proteomic approach, we identified several bacterial proteins potentially implicated in the adhesion process and we characterized their expression during the replication cycle of the bacteria. In addition, we demonstrated that the Waddlia Pmp-like autotransporter as well as OmpA2 and OmpA3, two members of the extended Waddlia OmpA protein family, exhibit adhesive properties on epithelial cells. We hypothesize that the large diversity of the OmpA protein family is linked to the wide host range of these bacteria that are able to enter and multiply in various host cells ranging from protozoa to mammalian and fish cells.
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Affiliation(s)
- Carole Kebbi-Beghdadi
- Center for Research on Intracellular Bacteria (CRIB), Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland
| | - Andreas Domröse
- Institut für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Elisabeth Becker
- Institut für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Ousmane H Cisse
- Center for Research on Intracellular Bacteria (CRIB), Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland
| | - Johannes H Hegemann
- Institut für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Gilbert Greub
- Center for Research on Intracellular Bacteria (CRIB), Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland
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In vitro passage selects for Chlamydia muridarum with enhanced infectivity in cultured cells but attenuated pathogenicity in mouse upper genital tract. Infect Immun 2015; 83:1881-92. [PMID: 25712926 DOI: 10.1128/iai.03158-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/13/2015] [Indexed: 12/30/2022] Open
Abstract
Although modern Chlamydia muridarum has been passaged for decades, there are no reports on the consequences of serial passage with strong selection pressure on its fitness. In order to explore the potential for Pasteurian selection to induce genomic and phenotypic perturbations to C. muridarum, a starter population was passaged in cultured cells for 28 generations without standard infection assistance. The resultant population, designated CMG28, displays markedly reduced in vitro dependence on centrifugation for infection and low incidence and severity of upper genital tract pathology following intravaginal inoculation into mice compared to the parental C. muridarum population, CMG0. Deep sequencing of CMG0 and CMG28 revealed novel protein variants in the hypothetical genes TC0237 (Q117E) and TC0668 (G322R). In vitro attachment assays of isogenic plaque clone pairs with mutations in either TC0237 and TC0668 or only TC0237 reveal that TC0237(Q117E) is solely responsible for enhanced adherence to host cells. Paradoxically, double mutants, but not TC0237(Q117E) single mutants, display severely attenuated in vivo pathogenicity. These findings implicate TC0237 and TC0668 as novel genetic factors involved in chlamydial attachment and pathogenicity, respectively, and show that serial passage under selection pressure remains an effective tool for studying Chlamydia pathogenicity.
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32
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Redgrove KA, McLaughlin EA. The Role of the Immune Response in Chlamydia trachomatis Infection of the Male Genital Tract: A Double-Edged Sword. Front Immunol 2014; 5:534. [PMID: 25386180 PMCID: PMC4209867 DOI: 10.3389/fimmu.2014.00534] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 10/09/2014] [Indexed: 01/16/2023] Open
Abstract
Chlamydia trachomatis (CT) is the most prevalent bacterial sexually transmitted infection in the world, with more than 100 million cases reported annually. While there have been extensive studies into the adverse effects that CT infection has on the female genital tract, and on the subsequent ability of these women to conceive, studies into the consequences on male fertility have been limited and controversial. This is in part due to the asymptomatic nature of the infection, where it is estimated that 50% of men with Chlamydia fail to show any symptoms. It is accepted, however, that acute and/or persistent CT infection is the causative agent for conditions such as urethritis, epididymitis, epididymo-orchitis, and potentially prostatitis. As with most infections, the immune system plays a fundamental role in the body’s attempts to eradicate the infection. The first and most important immune response to Chlamydia infection is a local one, whereby immune cells such as leukocytes are recruited to the site of infections, and subsequently secrete pro-inflammatory cytokines and chemokines such as interferon gamma. Immune cells also work to initiate and potentiate chronic inflammation through the production of reactive oxygen species (ROS), and the release of molecules with degradative properties including defensins, elastase, collagenase, cathespins, and lysozyme. This long-term inflammation can lead to cell proliferation (a possible precursor to cancer), tissue remodeling, and scarring, as well as being linked to the onset of autoimmune responses in genetically disposed individuals. This review will focus on the ability of the immune system to recognize and clear acute and persistent chlamydial infections in the male genital tract, and on the paradoxical damage that chronic inflammation resulting from the infection can cause on the reproductive health of the individual.
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Affiliation(s)
- Kate A Redgrove
- Priority Research Centre in Reproductive Biology and Chemical Biology, University of Newcastle , Callaghan, NSW , Australia ; School of Environmental and Life Science, University of Newcastle , Callaghan, NSW , Australia
| | - Eileen A McLaughlin
- Priority Research Centre in Reproductive Biology and Chemical Biology, University of Newcastle , Callaghan, NSW , Australia ; School of Environmental and Life Science, University of Newcastle , Callaghan, NSW , Australia
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33
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Fan W, Zhang Q. Bilateral inflammation of the paraurethral glands around the external urethral orifice due to Chlamydia trachomatis in a male. Int J Dermatol 2014; 52:1567-8. [PMID: 24261726 DOI: 10.1111/j.1365-4632.2011.05160.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wenge Fan
- Department of Dermatology First People's Hospital of Changshu City Changshu Hospital Affiliated to Soochow University Changshu Jiangsu Province ChinaDepartment of Dermatology Traditional Chinese Medical Hospital of Changshu City Changshu Jiangsu Province China
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34
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Becker E, Hegemann JH. All subtypes of the Pmp adhesin family are implicated in chlamydial virulence and show species-specific function. Microbiologyopen 2014; 3:544-56. [PMID: 24985494 PMCID: PMC4287181 DOI: 10.1002/mbo3.186] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/30/2014] [Accepted: 05/15/2014] [Indexed: 01/27/2023] Open
Abstract
The bacterial pathogens Chlamydia trachomatis and C. pneumoniae are obligate intracellular parasites, cause a number of serious diseases, and can infect various cell types in humans. Chlamydial infections are probably initiated by binding of the bacterial outer membrane protein OmcB to host cell glycosaminoglycans (GAGs). Here, we show that all nine members of the polymorphic membrane protein (Pmp) family of C. trachomatis mediate adhesion to human epithelial and endothelial cells. Importantly, exposure of infectious particles to soluble recombinant Pmps blocks subsequent infection, thus implicating an important function of the entire protein family in the infection process. Analogous experiments with pairs of recombinant Pmps or a combination of Pmp and OmcB revealed that all Pmps probably act in an adhesion pathway that is distinct from the OmcB-GAG pathway. Finally, we provide evidence that the Pmps of C. trachomatis and C. pneumoniae exhibit species and tissue specificity. These findings argue for the involvement of C. trachomatis Pmps in the initial phase of infection and suggest that they may interact with a receptor other than the epidermal growth factor receptor recently identified for their counterparts in C. pneumoniae.
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Affiliation(s)
- Elisabeth Becker
- Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany
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35
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Mehlitz A, Rudel T. Modulation of host signaling and cellular responses by Chlamydia. Cell Commun Signal 2013; 11:90. [PMID: 24267514 PMCID: PMC4222901 DOI: 10.1186/1478-811x-11-90] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 11/19/2013] [Indexed: 01/24/2023] Open
Abstract
Modulation of host cell signaling and cellular functions is key to intracellular survival of pathogenic bacteria. Intracellular growth has several advantages e.g. escape from the humoral immune response and access to a stable nutrient rich environment. Growth in such a preferred niche comes at the price of an ongoing competition between the bacteria and the host as well as other microbes that compete for the very same host resources. This requires specialization and constant evolution of dedicated systems for adhesion, invasion and accommodation. Interestingly, obligate intracellular bacteria of the order Chlamydiales have evolved an impressive degree of control over several important host cell functions. In this review we summarize how Chlamydia controls its host cell with a special focus on signal transduction and cellular modulation.
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Affiliation(s)
- Adrian Mehlitz
- University of Wuerzburg, Biocenter, Department of Microbiology, Am Hubland, D-97074, Wuerzburg, Germany.
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36
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Jeffrey BM, Suchland RJ, Eriksen SG, Sandoz KM, Rockey DD. Genomic and phenotypic characterization of in vitro-generated Chlamydia trachomatis recombinants. BMC Microbiol 2013; 13:142. [PMID: 23786423 PMCID: PMC3703283 DOI: 10.1186/1471-2180-13-142] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 05/24/2013] [Indexed: 11/10/2022] Open
Abstract
Background Pre-genomic and post-genomic studies demonstrate that chlamydiae actively recombine in vitro and in vivo, although the molecular and cellular biology of this process is not well understood. In this study, we determined the genome sequence of twelve Chlamydia trachomatis recombinants that were generated in vitro under antibiotic selection. These strains were used to explore the process of recombination in Chlamydia spp., including analysis of candidate recombination hotspots, and to correlate known C. trachomatis in vitro phenotypes with parental phenotypes and genotypes. Results Each of the 190 examined recombination events was the product of homologous recombination, and no candidate targeting motifs were identified at recombination sites. There was a single deletion event in one recombinant progeny that resulted in the removal of 17.1 kilobases between two rRNA operons. There was no evidence for preference for any specific region of the chromosome for recombination, and analyses of a total of over 200 individual recombination events do not provide any support for recombination hotspots in vitro. Two measurable phenotypes were analyzed in these studies. First, the efficiency of attachment to host cells in the absence of centrifugation was examined, and this property segregated to regions of the chromosome that carry the polymorphic membrane protein (Pmp) genes. Second, the formation of secondary inclusions within cells varied among recombinant progeny, but this did not cleanly segregate to specific regions of the chromosome. Conclusions These experiments examined the process of recombination in C. trachomatis and identified tools that can be used to associate phenotype with genotype in recombinant progeny. There were no data supporting the hypothesis that particular nucleotide sequences are preferentially used for recombination in vitro. Selected phenotypes can be segregated by analysis of recombination, and this technology may be useful in preliminary analysis of the relationship of genetic variation to phenotypic variation in the chlamydiae.
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Affiliation(s)
- Brendan M Jeffrey
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, OR, USA
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37
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Bastidas RJ, Elwell CA, Engel JN, Valdivia RH. Chlamydial intracellular survival strategies. Cold Spring Harb Perspect Med 2013; 3:a010256. [PMID: 23637308 DOI: 10.1101/cshperspect.a010256] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen and the causative agent of blinding trachoma. Although Chlamydia is protected from humoral immune responses by residing within remodeled intracellular vacuoles, it still must contend with multilayered intracellular innate immune defenses deployed by its host while scavenging for nutrients. Here we provide an overview of Chlamydia biology and highlight recent findings detailing how this vacuole-bound pathogen manipulates host-cellular functions to invade host cells and maintain a replicative niche.
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Affiliation(s)
- Robert J Bastidas
- Department of Molecular Genetics and Microbiology, Center for Microbial Pathogenesis, Duke University Medical Center, Durham, NC 27710, USA
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38
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O’Meara CP, Armitage CW, Harvie MCG, Timms P, Lycke NY, Beagley KW. Immunization with a MOMP-based vaccine protects mice against a pulmonary Chlamydia challenge and identifies a disconnection between infection and pathology. PLoS One 2013; 8:e61962. [PMID: 23613984 PMCID: PMC3628704 DOI: 10.1371/journal.pone.0061962] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 03/16/2013] [Indexed: 12/31/2022] Open
Abstract
Chlamydia pneumoniae is responsible for up to 20% of community acquired pneumonia and can exacerbate chronic inflammatory diseases. As the majority of infections are either mild or asymptomatic, a vaccine is recognized to have the greatest potential to reduce infection and disease prevalence. Using the C. muridarum mouse model of infection, we immunized animals via the intranasal (IN), sublingual (SL) or transcutaneous (TC) routes, with recombinant chlamydial major outer membrane protein (MOMP) combined with adjuvants CTA1-DD or a combination of cholera toxin/CpG-oligodeoxynucleotide (CT/CpG). Vaccinated animals were challenged IN with C. muridarum and protection against infection and pathology was assessed. SL and TC immunization with MOMP and CT/CpG was the most protective, significantly reducing chlamydial burden in the lungs and preventing weight loss, which was similar to the protection induced by a previous live infection. Unlike a previous infection however, these vaccinations also provided almost complete protection against fibrotic scarring in the lungs. Protection against infection was associated with antigen-specific production of IFNγ, TNFα and IL-17 by splenocytes, however, protection against both infection and pathology required the induction of a similar pro-inflammatory response in the respiratory tract draining lymph nodes. Interestingly, we also identified two contrasting vaccinations capable of preventing infection or pathology individually. Animals IN immunized with MOMP and either adjuvant were protected from infection, but not the pathology. Conversely, animals TC immunized with MOMP and CTA1-DD were protected from pathology, even though the chlamydial burden in this group was equivalent to the unimmunized controls. This suggests that the development of pathology following an IN infection of vaccinated animals was independent of bacterial load and may have been driven instead by the adaptive immune response generated following immunization. This identifies a disconnection between the control of infection and the development of pathology, which may influence the design of future vaccines.
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Affiliation(s)
- Connor P. O’Meara
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Charles W. Armitage
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Marina C. G. Harvie
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Peter Timms
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Nils Y. Lycke
- Mucosal Immunobiology and Vaccine Centre (MIVAC), University of Göteborg, Göteborg, Götaland, Sweden
| | - Kenneth W. Beagley
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), Brisbane, Queensland, Australia
- * E-mail:
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39
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Kim JH, Chan C, Elwell C, Singer MS, Dierks T, Lemjabbar-Alaoui H, Rosen SD, Engel JN. Endosulfatases SULF1 and SULF2 limit Chlamydia muridarum infection. Cell Microbiol 2013; 15:1560-71. [PMID: 23480519 DOI: 10.1111/cmi.12133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 03/04/2013] [Accepted: 03/04/2013] [Indexed: 12/30/2022]
Abstract
The first step in attachment of Chlamydia to host cells is thought to involve reversible binding to host heparan sulfate proteoglycans (HSPGs), polymers of variably sulfated repeating disaccharide units coupled to diverse protein backbones. However, the key determinants of HSPG structure that are involved in Chlamydia binding are incompletely defined. A previous genome-wide Drosophila RNAi screen suggested that the level of HSPG 6-O sulfation rather than the identity of the proteoglycan backbone maybe a critical determinant for binding. Here, we tested in mammalian cells whether SULF1 or SULF2, human endosulfatases, which remove 6-O sulfates from HSPGs, modulate Chlamydia infection. Ectopic expression of SULF1 or SULF2 in HeLa cells, which decreases cell surface HSPG sulfation, diminished C. muridarum binding and decreased vacuole formation. ShRNA depletion of endogenous SULF2 in a cell line that primarily expresses SULF2 augmented binding and increased vacuole formation. C. muridarum infection of diverse cell lines resulted indownregulation of SULF2 mRNA. In a murine model of acute pneumonia, mice genetically deficient in both endosulfatases or in SULF2 alone demonstrated increased susceptibility to C. muridarum lung infection. Collectively, these studies demonstrate that the level of HSPG 6-O sulfation is a critical determinant of C. muridarum infection in vivo and that 6-O endosulfatases are previously unappreciated modulators of microbial pathogenesis.
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Affiliation(s)
- J H Kim
- Department of Medicine, University of California San Francisco, San Francisco, California, USA
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40
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Beeckman DS, De Puysseleyr L, De Puysseleyr K, Vanrompay D. Chlamydial biology and its associated virulence blockers. Crit Rev Microbiol 2012; 40:313-28. [PMID: 23134414 DOI: 10.3109/1040841x.2012.726210] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Chlamydiales are obligate intracellular parasites of eukaryotic cells. They can be distinguished from other Gram-negative bacteria through their characteristic developmental cycle, in addition to special biochemical and physical adaptations to subvert the eukaryotic host cell. The host spectrum includes humans and other mammals, fish, birds, reptiles, insects and even amoeba, causing a plethora of diseases. The first part of this review focuses on the specific chlamydial infection biology and metabolism. As resistance to classical antibiotics is emerging among Chlamydiae as well, the second part elaborates on specific compounds and tools to block chlamydial virulence traits, such as adhesion and internalization, Type III secretion and modulation of gene expression.
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Affiliation(s)
- Delphine S Beeckman
- Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University , Coupure Links 653, B-9000 Ghent , Belgium
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Attachment of Chlamydia trachomatis L2 to host cells requires sulfation. Proc Natl Acad Sci U S A 2012; 109:10059-64. [PMID: 22675117 DOI: 10.1073/pnas.1120244109] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Chlamydia trachomatis is a pathogen responsible for a prevalent sexually transmitted disease. It is also the most common cause of infectious blindness in the developing world. We performed a loss-of-function genetic screen in human haploid cells to identify host factors important in C. trachomatis L2 infection. We identified and confirmed B3GAT3, B4GALT7, and SLC35B2, which encode glucuronosyltransferase I, galactosyltransferase I, and the 3'-phosphoadenosine 5'-phosphosulfate transporter 1, respectively, as important in facilitating Chlamydia infection. Knockout of any of these three genes inhibits Chlamydia attachment. In complementation studies, we found that the introduction of functional copies of these three genes into the null clones restored full susceptibility to Chlamydia infection. The degree of attachment of Chlamydia strongly correlates with the level of sulfation of the host cell, not simply with the amount of heparan sulfate. Thus, other, as-yet unidentified sulfated macromolecules must contribute to infection. These results demonstrate the utility of screens in haploid cells to study interactions of human cells with bacteria. Furthermore, the human null clones generated can be used to investigate the role of heparan sulfate and sulfation in other settings not limited to infectious disease.
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Lazarev VN, Borisenko GG, Shkarupeta MM, Demina IA, Serebryakova MV, Galyamina MA, Levitskiy SA, Govorun VM. The role of intracellular glutathione in the progression of Chlamydia trachomatis infection. Free Radic Biol Med 2010; 49:1947-55. [PMID: 20888409 DOI: 10.1016/j.freeradbiomed.2010.09.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 08/17/2010] [Accepted: 09/23/2010] [Indexed: 12/17/2022]
Abstract
The productive internalization in the host cell of Chlamydia trachomatis elementary bodies and their infectivity depends on the degree of reduction of disulfide bonds in the outer envelope of the elementary body. We have hypothesized that the reducing agent may be intracellular glutathione (GSH). Three approaches were used to modulate the intracellular GSH concentration: (1) treatment of cells with buthionine sulfoximine, which causes irreversible inhibition of GSH biosynthesis; (2) hydrogen peroxide-induced oxidation of GSH by intracellular glutathione peroxidases; and (3) treatment of cells with N-acetyl-l-cysteine (NAC), a precursor of glutathione. In the first two cases, we observed a four- to sixfold inhibition of C. trachomatis infection, whereas in NAC-treated cells we detected an increase in the size of chlamydial inclusions. Using a proteomics approach, we showed that the inhibition of chlamydial infection does not combine with alterations in protein expression patterns after cell treatment. These results suggest that GSH plays a key role in the reduction of disulfide bonds in the C. trachomatis outer envelope at an initial stage of the infection.
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Infectivity acts as in vivo selection for maintenance of the chlamydial cryptic plasmid. Infect Immun 2010; 79:98-107. [PMID: 20974819 DOI: 10.1128/iai.01105-10] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Chlamydia trachomatis contains a conserved ∼7.5-kb plasmid. Loss of the plasmid results in reduced glycogen accumulation, failure to activate TLR2, and reduced infectivity. We hypothesized that reduced infectivity functions as a means of selection for plasmid maintenance. We directly examined the biological significance of the reduced infectivity associated with plasmid deficiency by determining the relative fitness of plasmid-deficient CM972 versus that of wild-type C. muridarum Nigg in mixed inocula in vitro and in vivo. C. muridarum Nigg rapidly out-competed its plasmid-cured derivative CM972 in vitro but was not competitive with CM3.1, a derivative of CM972 that has reverted to a normal infectivity phenotype. C. muridarum Nigg also effectively competed with CM972 during lower and upper genital tract infection in the mouse, demonstrating that strong selective pressure for plasmid maintenance occurs during infection. The severity of oviduct inflammation and dilatation resulting from these mixed infections correlated directly with the amount of C. muridarum Nigg in the initial inoculum, confirming the role of the plasmid in virulence. Genetic characterization of CM972 and CM3.1 revealed no additional mutations (other than loss of the plasmid) to account for the reduced infectivity of CM972 and detected a single base substitution in TC_0236 in CM3.1 that may be responsible for its restored infectivity. These data demonstrate that a chlamydial strain that differs genetically from its wild-type parent only with respect to the lack of the chlamydial plasmid is unable to compete in vitro and in vivo, likely explaining the rarity of plasmid-deficient isolates in nature.
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Dunn JD, Valdivia RH. Uncivil engineers: Chlamydia, Salmonella and Shigella alter cytoskeleton architecture to invade epithelial cells. Future Microbiol 2010; 5:1219-32. [DOI: 10.2217/fmb.10.77] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The obligate intracellular bacterial pathogen Chlamydia trachomatis is a major cause of blindness and sexually transmitted diseases. Like the enteric pathogens Salmonella and Shigella, Chlamydia injects effector proteins into epithelial cells to initiate extensive remodeling of the actin cytoskeleton at the bacterial attachment site, which culminates in the engulfment of the bacterium by plasma membrane extensions. Numerous Salmonella and Shigella effectors promote this remodeling by activating Rho GTPases and tyrosine kinase signaling cascades and by directly manipulating actin dynamics. Recent studies indicate that similar host-cell alterations occur during Chlamydia invasion, but few effectors are known. The identification of additional Chlamydia effectors and the elucidation of their modes of function are critical steps towards an understanding of how this clinically important pathogen breaches epithelial surfaces and causes infection.
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Affiliation(s)
- Joe Dan Dunn
- Department of Molecular Genetics & Microbiology & Center for Microbial Pathogenesis Duke University Medical Center, 272 Jones Building, Box 3580, Durham, NC 27710, USA
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Phylogenetic analysis of Chlamydia trachomatis Tarp and correlation with clinical phenotype. Infect Immun 2010; 78:3678-88. [PMID: 20605986 DOI: 10.1128/iai.00515-10] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chlamydia trachomatis is the leading cause of infectious blindness worldwide and is the most commonly reported pathogen causing sexually transmitted infections. Tarp (translocated actin recruiting phosphoprotein), a type III secreted effector that mediates actin nucleation, is central to C. trachomatis infection. The phylogenetic analysis of tarP from reference strains as well as ocular, genital, and lymphogranuloma venereum (LGV) clinical isolates demonstrated an evolutionary relationship with disease phenotype, with LGV and ocular isolates branched into clades that were separate from the urogenital isolates. The sequence analysis of Tarp indicated a high degree of variability and identified trends within clinical groupings. Tarps from LGV strains contained the highest number of tyrosine-rich repeat regions (up to nine) and the fewest (two) predicted actin binding domains. The converse was noted for Tarp proteins from ocular isolates that contained up to four actin binding domains and as few as one tyrosine-rich repeat region. The results suggest that Tarp is among the few known genes to play a role in C. trachomatis adaptations to specific niches within the host.
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Carey AJ, Timms P, Rawlinson G, Brumm J, Nilsson K, Harris JM, Beagley KW. ORIGINAL ARTICLE: A Multi-Subunit Chlamydial Vaccine Induces Antibody and Cell-Mediated Immunity in Immunized Koalas (Phascolarctos cinereus): Comparison of Three Different Adjuvants. Am J Reprod Immunol 2010; 63:161-72. [DOI: 10.1111/j.1600-0897.2009.00776.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Hickey DK, Aldwell FE, Beagley KW. Transcutaneous immunization with a novel lipid-based adjuvant protects against Chlamydia genital and respiratory infections. Vaccine 2009; 27:6217-25. [PMID: 19698810 DOI: 10.1016/j.vaccine.2009.08.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 07/29/2009] [Accepted: 08/02/2009] [Indexed: 12/30/2022]
Abstract
Mucosal adjuvants are important to overcome the state of immune tolerance normally associated with mucosal delivery and to enhance adaptive immunity to often-weakly immunogenic subunit vaccine antigens. Unfortunately, adverse side effects of many experimental adjuvants limit the number of adjuvants approved for vaccination. Lipid C is a novel, non-toxic, lipid oral vaccine-delivery formulation, developed originally for oral delivery of the live Mycobacterium bovis Bacille Calmette-Guerin (BCG) vaccine. In the present study, murine models of chlamydial respiratory and genital tract infections were used to determine whether transcutaneous immunization (TCI) with Lipid C-incorporated protein antigens could elicit protective immunity at the genital and respiratory mucosae. BALB/c mice were immunized transcutaneously with Lipid C containing the chlamydial major outer membrane protein (MOMP), with and without addition of cholera toxin and CpG-ODN 1826 (CT/CpG). Both vaccine combinations induced mixed cell-mediated and mucosal antibody immune responses. Immunization with Lipid C-incorporated MOMP (Lipid C/MOMP), either alone or with CT/CpG resulted in partial protection following live challenge with Chlamydia muridarum as evidenced by a significant reduction in recoverable Chlamydia from both the genital secretions and lung tissue. Protection induced by immunization with Lipid C/MOMP alone was not further enhanced by the addition of CT/CpG. These results highlight the potential of Lipid C as a novel mucosal adjuvant capable of targeting multiple mucosal surfaces following TCI. Protection at both the respiratory and genital mucosae was achieved without the requirement for potentially toxic adjuvants, suggesting that Lipid C may provide a safe effective mucosal adjuvant for human vaccination.
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Affiliation(s)
- Danica K Hickey
- School of Biomedical Sciences, The University of Newcastle, Newcastle, Australia and Hunter Medical Research Institute, Newcastle, Australia
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Abstract
Chlamydia sp. are responsible for a wide range of diseases of significant clinical and public health importance. In this review, we highlight how recent cellular and functional genomic approaches have significantly increased our knowledge of the pathogenic mechanisms used by these genetically intractable bacteria. As the extensive repertoire of chlamydial proteins that are translocated into the mammalian host is identified and characterized, a molecular understanding of how Chlamydiae co-opt host cellular functions and block innate immune pathways is beginning to emerge.
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Affiliation(s)
- Jordan L Cocchiaro
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
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Attachment and entry of Chlamydia have distinct requirements for host protein disulfide isomerase. PLoS Pathog 2009; 5:e1000357. [PMID: 19343202 PMCID: PMC2655716 DOI: 10.1371/journal.ppat.1000357] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Accepted: 02/28/2009] [Indexed: 11/19/2022] Open
Abstract
Chlamydia is an obligate intracellular pathogen that causes a wide range of diseases in humans. Attachment and entry are key processes in infectivity and subsequent pathogenesis of Chlamydia, yet the mechanisms governing these interactions are unknown. It was recently shown that a cell line, CHO6, that is resistant to attachment, and thus infectivity, of multiple Chlamydia species has a defect in protein disulfide isomerase (PDI) N–terminal signal sequence processing. Ectopic expression of PDI in CHO6 cells led to restoration of Chlamydia attachment and infectivity; however, the mechanism leading to this recovery was not ascertained. To advance our understanding of the role of PDI in Chlamydia infection, we used RNA interference to establish that cellular PDI is essential for bacterial attachment to cells, making PDI the only host protein identified as necessary for attachment of multiple species of Chlamydia. Genetic complementation and PDI-specific inhibitors were used to determine that cell surface PDI enzymatic activity is required for bacterial entry into cells, but enzymatic function was not required for bacterial attachment. We further determined that it is a PDI-mediated reduction at the cell surface that triggers bacterial uptake. While PDI is necessary for Chlamydia attachment to cells, the bacteria do not appear to utilize plasma membrane–associated PDI as a receptor, suggesting that Chlamydia binds a cell surface protein that requires structural association with PDI. Our findings demonstrate that PDI has two essential and independent roles in the process of chlamydial infectivity: it is structurally required for chlamydial attachment, and the thiol-mediated oxido-reductive function of PDI is necessary for entry. Chlamydia is a large burden on global health. It is the most common cause of infectious blindness, and the CDC (Centers for Disease Control and Prevention) estimates that in the United States alone there are more than 2 million people with sexually transmitted Chlamydia infections. Chlamydia is an obligate intracellular bacteria; thus, attachment and subsequent invasion of cells are key steps in Chlamydia pathogenesis. While strides have been made in understanding the molecular mechanism of Chlamydia infection, fundamental aspects of this process still remain elusive. We have identified a host protein, protein disulfide isomerase (PDI), that is essential for Chlamydia attachment as well as for entry into cells. Cell-surface PDI-mediated disulfide reduction is required for Chlamydia entry into cells, whereas bacterial attachment is independent of PDI enzymatic activity. Although PDI is necessary for Chlamydia attachment, the bacteria apparently does not bind directly to cell-associated PDI, suggesting that Chlamydia attaches to a host protein(s) associated with PDI. This study advances our understanding of Chlamydia pathogenesis by the characterization of a host factor essential for independent stages of bacterial attachment and entry.
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Shimazaki K, Chan AM, Moniz RJ, Wadehra M, Nagy A, Coulam CP, Mareninov S, Lepin EM, Wu AM, Kelly KA, Braun J, Gordon LK. Blockade of epithelial membrane protein 2 (EMP2) abrogates infection of Chlamydia muridarum murine genital infection model. ACTA ACUST UNITED AC 2009; 55:240-9. [PMID: 19159428 DOI: 10.1111/j.1574-695x.2008.00525.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New methods are needed to eradicate or prevent Chlamydia trachomatis infections. Blockade of epithelial membrane protein 2 (EMP2) by genetic silencing or neutralizing polyclonal antibody reduced chlamydial infectivity in vitro. This study tests the prediction that recombinant anti-EMP2 diabody could reduce early chlamydial infection of the genital tract in vivo. In a murine infection model, pretreatment with anti-EMP2 diabody, as compared with control diabody, significantly reduced bacterial load, tissue production of inflammatory cytokines, recruitment of polymorphonuclear leukocytes, and local tissue inflammation. These findings support EMP2 as a potential preventative and therapeutic target for genital chlamydial infection.
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Affiliation(s)
- Kaori Shimazaki
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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