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Jury B, Fleming C, Huston WM, Luu LDW. Molecular pathogenesis of Chlamydia trachomatis. Front Cell Infect Microbiol 2023; 13:1281823. [PMID: 37920447 PMCID: PMC10619736 DOI: 10.3389/fcimb.2023.1281823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 10/03/2023] [Indexed: 11/04/2023] Open
Abstract
Chlamydia trachomatis is a strict intracellular human pathogen. It is the main bacterial cause of sexually transmitted infections and the etiologic agent of trachoma, which is the leading cause of preventable blindness. Despite over 100 years since C. trachomatis was first identified, there is still no vaccine. However in recent years, the advancement of genetic manipulation approaches for C. trachomatis has increased our understanding of the molecular pathogenesis of C. trachomatis and progress towards a vaccine. In this mini-review, we aimed to outline the factors related to the developmental cycle phase and specific pathogenesis activity of C. trachomatis in order to focus priorities for future genetic approaches. We highlight the factors known to be critical for developmental cycle stages, gene expression regulatory factors, type III secretion system and their effectors, and individual virulence factors with known impacts.
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Affiliation(s)
- Brittany Jury
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Charlotte Fleming
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | | | - Laurence Don Wai Luu
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
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2
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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: 6] [Impact Index Per Article: 6.0] [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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3
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Huang Y, Wu H, Sun Y, Liu Y. Tryptophan residue of plasmid-encoded Pgp3 is important for Chlamydia muridarum to induce hydrosalpinx in mice. Front Microbiol 2023; 14:1216372. [PMID: 37497542 PMCID: PMC10367112 DOI: 10.3389/fmicb.2023.1216372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 06/12/2023] [Indexed: 07/28/2023] Open
Abstract
The crucial role of plasmid-encoded protein Pgp3 in Chlamydia pathogenesis has been demonstrated in various animal models. Previous studies have revealed that the Pgp3-deficient C. muridarum mutant fails to induce hydrosalpinx after vaginal inoculation in mice. Structural analysis of C. trachomatis Pgp3 trimer has indicated that Trp234 may play a critical role in trimeric crystal packing interactions and that Tyr197 is involved at predominant cation-binding sites. In this study, we constructed C. muridarum transformants harboring Pgp3, Trp234, or Tyr197 point mutations (Pgp3W234A and Pgp3Y197A). C3H/HeJ mice infected with Pgp3W234A mutant failed to induce severe hydrosalpinx in the oviduct tissue, which largely phenocopied the full-length Pgp3-deficient C. muridarum. The Pgp3Y197A variant induced an intermediate severity of pathology. The attenuated pathogenicity caused by the Pgp3W234A mutant may be due to its decreased survival in the lower genital tracts of mice, reduced ascension to the oviduct, and milder induction of inflammatory cell infiltration in the oviduct tissue. Thus, our results point to an important amino acid residue involved in Pgp3 virulence, providing a potential therapeutic target for chlamydial infection.
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Affiliation(s)
- Yumeng Huang
- Tianjin Medical University General Hospital, Tianjin, China
| | - Haoqing Wu
- Tianjin Medical University General Hospital, Tianjin, China
| | - Yina Sun
- National Health Commission (NHC) Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital, Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Yuanjun Liu
- Tianjin Medical University General Hospital, Tianjin, China
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Fisher DJ, Beare PA. Recent advances in genetic systems in obligate intracellular human-pathogenic bacteria. Front Cell Infect Microbiol 2023; 13:1202245. [PMID: 37404720 PMCID: PMC10315504 DOI: 10.3389/fcimb.2023.1202245] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 05/22/2023] [Indexed: 07/06/2023] Open
Abstract
The ability to genetically manipulate a pathogen is fundamental to discovering factors governing host-pathogen interactions at the molecular level and is critical for devising treatment and prevention strategies. While the genetic "toolbox" for many important bacterial pathogens is extensive, approaches for modifying obligate intracellular bacterial pathogens were classically limited due in part to the uniqueness of their obligatory lifestyles. Many researchers have confronted these challenges over the past two and a half decades leading to the development of multiple approaches to construct plasmid-bearing recombinant strains and chromosomal gene inactivation and deletion mutants, along with gene-silencing methods enabling the study of essential genes. This review will highlight seminal genetic achievements and recent developments (past 5 years) for Anaplasma spp., Rickettsia spp., Chlamydia spp., and Coxiella burnetii including progress being made for the still intractable Orientia tsutsugamushi. Alongside commentary of the strengths and weaknesses of the various approaches, future research directions will be discussed to include methods for C. burnetii that should have utility in the other obligate intracellular bacteria. Collectively, the future appears bright for unraveling the molecular pathogenic mechanisms of these significant pathogens.
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Affiliation(s)
- Derek J. Fisher
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, United States
| | - Paul A. Beare
- Rocky Mountain Laboratory, National Institute of Health, Hamilton, MT, United States
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5
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Cheong HC, Cheok YY, Chan YT, Tang TF, Sulaiman S, Looi CY, Gupta R, Arulanandam B, Chang LY, Wong WF. Chlamydia trachomatis plasmid-encoding Pgp3 protein induces secretion of distinct inflammatory signatures from HeLa cervical epithelial cells. BMC Microbiol 2023; 23:58. [PMID: 36870960 PMCID: PMC9985209 DOI: 10.1186/s12866-023-02802-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023] Open
Abstract
BACKGROUND Genital Chlamydia trachomatis infection is the most common bacterial sexual transmitted disease that causes severe complications including pelvic inflammatory disease, ectopic pregnancy, and infertility in females. The Pgp3 protein encoded by C. trachomatis plasmid has been speculated to be an important player in chlamydial pathogenesis. However, the precise function of this protein is unknown and thus remains to be thoroughly investigated. METHODS In this study, we synthesized Pgp3 protein for in vitro stimulation in the Hela cervical carcinoma cells. RESULTS AND CONCLUSION We showed that Pgp3 induced prominent expression of host inflammatory cytokine genes including interleukin-6 (IL-6), IL-8, tumor necrosis factor alpha-induced protein 3 (TNFAIP3), and chemokine C-X-C motif ligand 1 (CXCL1), implying a possible role of Pgp3 in modulating the inflammatory reaction in the host.
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Affiliation(s)
- Heng Choon Cheong
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Yi Ying Cheok
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Yee Teng Chan
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Ting Fang Tang
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Sofiah Sulaiman
- Department of Obstetrics and Gynecology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Chung Yeng Looi
- School of Biosciences, Faculty of Health and Medical Sciences, Taylor's University, 47500, Subang Jaya, Selangor, Malaysia
| | - Rishein Gupta
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA
| | - Bernard Arulanandam
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA.,Department of Immunology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Li-Yen Chang
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Won Fen Wong
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
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Whole Genome Sequencing of a Chlamydia trachomatis Strain Responsible for a Case of Rectal Lymphogranuloma Venereum in Italy. Curr Issues Mol Biol 2023; 45:1852-1859. [PMID: 36975489 PMCID: PMC10047300 DOI: 10.3390/cimb45030119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 02/25/2023] Open
Abstract
Lymphogranuloma venereum (LGV) is a systemic sexually transmitted infection caused by Chlamydia trachomatis serovars L1 to L3. The current LGV cases in Europe are mainly characterized by an anorectal syndrome, spreading within men who have sex with men (MSM). Whole-genome sequencing of LGV strains is crucial to the study of bacterial genomic variants and to improve strategies for contact tracing and prevention. In this study, we described the whole genome of a C. trachomatis strain (LGV/17) responsible for a case of rectal LGV. LGV/17 strain was isolated in 2017 in Bologna (North of Italy) from a HIV-positive MSM, presenting a symptomatic proctitis. After the propagation in LLC-MK2 cells, the strain underwent whole-genome sequencing by means of two platforms. Sequence type was determined using the tool MLST 2.0, whereas the genovariant was characterized by an ompA sequence evaluation. A phylogenetic tree was generated by comparing the LGV/17 sequence with a series of L2 genomes, downloaded from the NCBI website. LGV/17 belonged to sequence type ST44 and to the genovariant L2f. Nine ORFs encoding for polymorphic membrane proteins A-I and eight encoding for glycoproteins Pgp1-8 were detected in the chromosome and in the plasmid, respectively. LGV/17 was closely related to other L2f strains, even in the light of a not-negligible variability. The LGV/17 strain showed a genomic structure similar to reference sequences and was phylogenetically related to isolates from disparate parts of the world, indicative of the long-distance dynamics of transmission.
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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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Karanovic U, Lei L, Martens CA, Barbian K, McClarty G, Caldwell HD, Yang C. TargeTron inactivation of plasmid-regulated Chlamydia trachomatis CT084 results in a nonlytic phenotype. Pathog Dis 2023; 81:ftad026. [PMID: 37804183 PMCID: PMC10589100 DOI: 10.1093/femspd/ftad026] [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: 06/26/2023] [Revised: 09/07/2023] [Accepted: 10/05/2023] [Indexed: 10/09/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that causes blinding trachoma and sexually transmitted disease. The chlamydial plasmid is a critical virulence factor in the pathogenesis of these diseases. Plasmid gene protein 4 (Pgp4) plays a major role in chlamydial virulence by regulating the expression of both chromosomal genes and Pgp3. Despite the importance of Pgp4 in mediating lytic exit from host cells the pathogenic mechanism by which it functions is unknown. CT084 is a highly conserved chromosomal gene with homology to phospholipase D. We showed CT084 expression is regulated by Pgp4 and expressed late in the chlamydial developmental cycle. To investigate the function of CT084 in chlamydial lytic exit from infected cells, we made a CT084 null strain (ct084::bla) by using Targetron. The ct084::bla strain grew normally in vitro compared to wild-type strain; however, the strain did not lyse infected cells and produced significantly less and smaller plaques. Collectively, our finding shows Pgp4-regulated CT084-mediated chlamydia lytic exit from infected host cells.
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Affiliation(s)
- Una Karanovic
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland, 208952, United States
| | - Lei Lei
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland, 208952, United States
| | - Craig A Martens
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, 59840, United States
| | - Kent Barbian
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, 59840, United States
| | - Grant McClarty
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Harlan D Caldwell
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland, 208952, United States
| | - Chunfu Yang
- School of Public Health and Emergency Management, Southern University of Science and Technology, Shenzhen 518055, China
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Fields KA, Bodero MD, Scanlon KR, Jewett TJ, Wolf K. A Minimal Replicon Enables Efficacious, Species-Specific Gene Deletion in Chlamydia and Extension of Gene Knockout Studies to the Animal Model of Infection Using Chlamydia muridarum. Infect Immun 2022; 90:e0045322. [PMID: 36350146 PMCID: PMC9753632 DOI: 10.1128/iai.00453-22] [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: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 11/11/2022] Open
Abstract
The genus Chlamydia consists of diverse, obligate intracellular bacteria that infect various animals, including humans. Although chlamydial species share many aspects of the typical intracellular lifestyle, such as the biphasic developmental cycle and the preference for invasion of epithelial cells, each chlamydial strain also employs sophisticated species-specific strategies that contribute to an extraordinary diversity in organ and/or tissue tropism and disease manifestation. In order to discover and understand the mechanisms underlying how these pathogens infect particular hosts and cause specific diseases, it is imperative to develop a mutagenesis approach that would be applicable to every chlamydial species. We present functional evidence that the region between Chlamydia trachomatis and Chlamydia muridarum pgp6 and pgp7, containing four 22-bp tandem repeats that are present in all chlamydial endogenous plasmids, represents the plasmid origin of replication. Furthermore, by introducing species-specific ori regions into an engineered 5.45-kb pUC19-based plasmid, we generated vectors that can be successfully transformed into and propagated under selective pressure by C. trachomatis serovars L2 and D, as well as C. muridarum. Conversely, these vectors were rapidly lost upon removal of the selective antibiotic. This conditionally replicating system was used to generate a tarP deletion mutant by fluorescence-reported allelic exchange mutagenesis in both C. trachomatis serovar D and C. muridarum. The strains were analyzed using in vitro invasion and fitness assays. The virulence of the C. muridarum strains was then assessed in a murine infection model. Our approach represents a novel and efficient strategy for targeted genetic manipulation in Chlamydia beyond C. trachomatis L2. This advance will support comparative studies of species-specific infection biology and enable studies in a well-established murine model of chlamydial pathogenesis.
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Affiliation(s)
- Kenneth A. Fields
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Maria D. Bodero
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Kaylyn R. Scanlon
- Division of Immunity and Pathogenesis, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Travis J. Jewett
- Division of Immunity and Pathogenesis, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Katerina Wolf
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
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Rigamonti S, Floriano AM, Scaltriti E, Longbottom D, Livingstone M, Comandatore F, Pongolini S, Capucci L, Mandola ML, Bazzucchi M, Prati P, Vicari N. Comparative analysis of two genomes of Chlamydia pecorum isolates from an Alpine chamois and a water buffalo. BMC Genomics 2022; 23:645. [PMID: 36088280 PMCID: PMC9464383 DOI: 10.1186/s12864-022-08860-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 08/18/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
To date, whole genome sequencing has been performed mainly for isolates of Chlamydia trachomatis, C. pneumoniae, C. psittaci and C. abortus, but only a few isolates of C. pecorum have been entirely sequenced and this makes it difficult to understand its diversity and population structure. In this study the genome of two C. pecorum strains isolated from the lung of an Alpine chamois affected with pneumonia (isolate PV7855) and the brain of a water buffalo affected with meningoencephalomyelitis (isolate PV6959), were completely sequenced with MiSeq system (Illumina) and analyzed in their most polymorphic regions.
Results
The genome length and GC content of the two isolates were found to be consistent with other C. pecorum isolates and the gene content of polymorphic membrane proteins and plasticity zone was found to be very similar. Some differences were observed in the phospholipase genes for both isolates and in the number of genes in the plasticity zone, such as the presence of some hypothetical proteins in PV6959, not present in any other genomes analyzed in this study. Interestingly, PV6959 possesses an extra pmp and has an incomplete tryptophan biosynthesis operon. Plasmids were detected in both isolates.
Conclusions
Genome sequencing of the two C. pecorum strains did not reveal differences in length and GC content despite the origin from different animal species with different clinical disease. In the plasticity zone, the differences in the genes pattern might be related to the onset of specific symptoms or infection of specific hosts. The absence of a tryptophan biosynthesis pathway in PV6959 may suggest a strict relationship between C. pecorum and its host.
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Pereira IS, Pais SV, Borges V, Borrego MJ, Gomes JP, Mota LJ. The Type III Secretion Effector CteG Mediates Host Cell Lytic Exit of Chlamydia trachomatis. Front Cell Infect Microbiol 2022; 12:902210. [PMID: 35903198 PMCID: PMC9318579 DOI: 10.3389/fcimb.2022.902210] [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: 03/22/2022] [Accepted: 05/25/2022] [Indexed: 11/17/2022] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium causing ocular and urogenital infections in humans that are a significant burden worldwide. The completion of its characteristic infectious cycle relies on the manipulation of several host cell processes by numerous chlamydial type III secretion effector proteins. We previously identified the C. trachomatis CteG effector and showed it localizes at the host cell plasma membrane at late stages of infection. Here, we showed that, from 48 h post-infection, mammalian cells infected by wild-type C. trachomatis contained more infectious chlamydiae in the culture supernatant than cells infected by a CteG-deficient strain. This phenotype was CteG-dependent as it could be complemented in cells infected by the CteG-deficient strain carrying a plasmid encoding CteG. Furthermore, we detected a CteG-dependent defect on host cell cytotoxicity, indicating that CteG mediates chlamydial lytic exit. Previous studies showed that Pgp4, a global regulator of transcription encoded in the C. trachomatis virulence plasmid, also mediates chlamydial lytic exit. However, by using C. trachomatis strains encoding or lacking Pgp4, we showed that production and localization of CteG are not regulated by Pgp4. A C. trachomatis strain lacking both CteG and Pgp4 was as defective in promoting host cell cytotoxicity as mutant strains lacking only CteG or Pgp4. Furthermore, CteG overproduction in a plasmid suppressed the host cell cytotoxic defect of CteG- and Pgp4-deficient chlamydiae. Overall, we revealed the first chlamydial type III secretion effector involved in host cell lytic exit. Our data indicates that CteG and Pgp4 participate in a single cascade of events, but involving multiple layers of regulation, leading to lysis of host cells and release of the infectious chlamydiae.
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Affiliation(s)
- Inês Serrano Pereira
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Sara Vilela Pais
- UCIBIO – Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Vítor Borges
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge (INSA), Lisbon, Portugal
| | - Maria José Borrego
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge (INSA), Lisbon, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge (INSA), Lisbon, Portugal
| | - Luís Jaime Mota
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- *Correspondence: Luís Jaime Mota,
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12
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Triboulet S, N’Gadjaga MD, Niragire B, Köstlbacher S, Horn M, Aimanianda V, Subtil A. CT295 Is Chlamydia trachomatis’ Phosphoglucomutase and a Type 3 Secretion Substrate. Front Cell Infect Microbiol 2022; 12:866729. [PMID: 35795184 PMCID: PMC9251005 DOI: 10.3389/fcimb.2022.866729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/24/2022] [Indexed: 11/13/2022] Open
Abstract
The obligate intracellular bacteria Chlamydia trachomatis store glycogen in the lumen of the vacuoles in which they grow. Glycogen catabolism generates glucose-1-phosphate (Glc1P), while the bacteria can take up only glucose-6-phosphate (Glc6P). We tested whether the conversion of Glc1P into Glc6P could be catalyzed by a phosphoglucomutase (PGM) of host or bacterial origin. We found no evidence for the presence of the host PGM in the vacuole. Two C. trachomatis proteins, CT295 and CT815, are potential PGMs. By reconstituting the reaction using purified proteins, and by complementing PGM deficient fibroblasts, we demonstrated that only CT295 displayed robust PGM activity. Intriguingly, we showed that glycogen accumulation in the lumen of the vacuole of a subset of Chlamydia species (C. trachomatis, C. muridarum, C. suis) correlated with the presence, in CT295 orthologs, of a secretion signal recognized by the type three secretion (T3S) machinery of Shigella. C. caviae and C. pneumoniae do not accumulate glycogen, and their CT295 orthologs lack T3S signals. In conclusion, we established that the conversion of Glc1P into Glc6P was accomplished by a bacterial PGM, through the acquisition of a T3S signal in a “housekeeping” protein. Acquisition of this signal likely contributed to shaping glycogen metabolism within Chlamydiaceae.
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Affiliation(s)
- Sébastien Triboulet
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, Unité de Biologie Cellulaire de l’Infection Microbienne, Paris, France
| | - Maimouna D. N’Gadjaga
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, Unité de Biologie Cellulaire de l’Infection Microbienne, Paris, France
- Sorbonne Université, Collège Doctoral, Paris, France
| | - Béatrice Niragire
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, Unité de Biologie Cellulaire de l’Infection Microbienne, Paris, France
| | - Stephan Köstlbacher
- Centre for Microbiology and Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Matthias Horn
- Centre for Microbiology and Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Vishukumar Aimanianda
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Unité de Mycologie Moléculaire, Paris, France
| | - Agathe Subtil
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, Unité de Biologie Cellulaire de l’Infection Microbienne, Paris, France
- *Correspondence: Agathe Subtil,
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López-Pintor JM, Martínez-García L, Maruri A, Menéndez B, Puerta T, Rodríguez C, González-Alba JM, Rodríguez-Domínguez M, Galán JC. Quantification of plasmid copy number as surrogate marker of virulence among different invasive and non-invasive genotypes of Chlamydia trachomatis. Diagn Microbiol Infect Dis 2022; 102:115610. [DOI: 10.1016/j.diagmicrobio.2021.115610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/20/2021] [Accepted: 11/23/2021] [Indexed: 02/04/2023]
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14
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Tucker AN, Carlson TJ, Sarkar A. Challenges in Drug Discovery for Intracellular Bacteria. Pathogens 2021; 10:pathogens10091172. [PMID: 34578204 PMCID: PMC8468363 DOI: 10.3390/pathogens10091172] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/26/2021] [Accepted: 09/04/2021] [Indexed: 01/04/2023] Open
Abstract
Novel drugs are needed to treat a variety of persistent diseases caused by intracellular bacterial pathogens. Virulence pathways enable many functions required for the survival of these pathogens, including invasion, nutrient acquisition, and immune evasion. Inhibition of virulence pathways is an established route for drug discovery; however, many challenges remain. Here, we propose the biggest problems that must be solved to advance the field meaningfully. While it is established that we do not yet understand the nature of chemicals capable of permeating into the bacterial cell, this problem is compounded when targeting intracellular bacteria because we are limited to only those chemicals that can permeate through both human and bacterial outer envelopes. Unfortunately, many chemicals that permeate through the outer layers of mammalian cells fail to penetrate the bacterial cytoplasm. Another challenge is the lack of publicly available information on virulence factors. It is virtually impossible to know which virulence factors are clinically relevant and have broad cross-species and cross-strain distribution. In other words, we have yet to identify the best drug targets. Yes, standard genomics databases have much of the information necessary for short-term studies, but the connections with patient outcomes are yet to be established. Without comprehensive data on matters such as these, it is difficult to devise broad-spectrum, effective anti-virulence agents. Furthermore, anti-virulence drug discovery is hindered by the current state of technologies available for experimental investigation. Antimicrobial drug discovery was greatly advanced by the establishment and standardization of broth microdilution assays to measure the effectiveness of antimicrobials. However, the currently available models used for anti-virulence drug discovery are too broad, as they must address varied phenotypes, and too expensive to be generally adopted by many research groups. Therefore, we believe drug discovery against intracellular bacterial pathogens can be advanced significantly by overcoming the above hurdles.
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A Chlamydial Plasmid-Dependent Secretion System for the Delivery of Virulence Factors to the Host Cytosol. mBio 2021; 12:e0117921. [PMID: 34101486 PMCID: PMC8262877 DOI: 10.1128/mbio.01179-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Chlamydia are obligate intracellular Gram-negative bacteria distinguished by a unique developmental biology confined within a parasitophorous vacuole termed an inclusion. The chlamydial plasmid is a central virulence factor in the pathogenesis of infection. Plasmid gene protein 4 (Pgp4) regulates the expression of plasmid gene protein 3 (Pgp3) and chromosomal glycogen synthase (GlgA), virulence factors secreted from the inclusion to the host cytosol by an unknown mechanism. Here, we identified a plasmid-dependent secretion system for the cytosolic delivery of Pgp3 and GlgA. The secretion system consisted of a segregated population of globular structures originating from midcycle reticulate bodies. Globular structures contained the Pgp4-regulated proteins CT143, CT144, and CT050 in addition to Pgp3 and GlgA. Genetic replacement of Pgp4 with Pgp3 or GlgA negated the formation of globular structures, resulting in retention of Pgp3 and GlgA in chlamydial organisms. The generation of globular structures and secretion of virulence factors occurred independently of type 2 and type 3 secretion systems. Globular structures were enriched with lipopolysaccharide but lacked detectable major outer membrane protein and heat shock protein 60, implicating them as outer membrane vesicles. Thus, we have discovered a novel chlamydial plasmid-dependent secretion system that transports virulence factor cargo from the chlamydial inclusion to the host cytosol.
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16
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Banerjee A, Nelson DE. The growing repertoire of genetic tools for dissecting chlamydial pathogenesis. Pathog Dis 2021; 79:ftab025. [PMID: 33930127 PMCID: PMC8112481 DOI: 10.1093/femspd/ftab025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/28/2021] [Indexed: 01/29/2023] Open
Abstract
Multiple species of obligate intracellular bacteria in the genus Chlamydia are important veterinary and/or human pathogens. These pathogens all share similar biphasic developmental cycles and transition between intracellular vegetative reticulate bodies and infectious elementary forms, but vary substantially in their host preferences and pathogenic potential. A lack of tools for genetic engineering of these organisms has long been an impediment to the study of their biology and pathogenesis. However, the refinement of approaches developed in C. trachomatis over the last 10 years, and adaptation of some of these approaches to other Chlamydia spp. in just the last few years, has opened exciting new possibilities for studying this ubiquitous group of important pathogens.
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Affiliation(s)
- Arkaprabha Banerjee
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - David E Nelson
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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17
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Köstlbacher S, Collingro A, Halter T, Domman D, Horn M. Coevolving Plasmids Drive Gene Flow and Genome Plasticity in Host-Associated Intracellular Bacteria. Curr Biol 2021; 31:346-357.e3. [PMID: 33157023 PMCID: PMC7846284 DOI: 10.1016/j.cub.2020.10.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/30/2020] [Accepted: 10/09/2020] [Indexed: 12/30/2022]
Abstract
Plasmids are important in microbial evolution and adaptation to new environments. Yet, carrying a plasmid can be costly, and long-term association of plasmids with their hosts is poorly understood. Here, we provide evidence that the Chlamydiae, a phylum of strictly host-associated intracellular bacteria, have coevolved with their plasmids since their last common ancestor. Current chlamydial plasmids are amalgamations of at least one ancestral plasmid and a bacteriophage. We show that the majority of plasmid genes are also found on chromosomes of extant chlamydiae. The most conserved plasmid gene families are predominantly vertically inherited, while accessory plasmid gene families show significantly increased mobility. We reconstructed the evolutionary history of plasmid gene content of an entire bacterial phylum over a period of around one billion years. Frequent horizontal gene transfer and chromosomal integration events illustrate the pronounced impact of coevolution with these extrachromosomal elements on bacterial genome dynamics in host-dependent microbes.
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Affiliation(s)
- Stephan Köstlbacher
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Althanstrasse 14, Vienna 1090, Austria
| | - Astrid Collingro
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Althanstrasse 14, Vienna 1090, Austria
| | - Tamara Halter
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Althanstrasse 14, Vienna 1090, Austria
| | - Daryl Domman
- Wellcome Sanger Institute, Parasites and Microbes Programme, Hinxton, Cambridge CB10 1SA, UK; Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Matthias Horn
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Althanstrasse 14, Vienna 1090, Austria.
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Chlamydia trachomatis Plasmid Gene Protein 3 Is Essential for the Establishment of Persistent Infection and Associated Immunopathology. mBio 2020; 11:mBio.01902-20. [PMID: 32817110 PMCID: PMC7439461 DOI: 10.1128/mbio.01902-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Chlamydia trachomatis can cause persistent infection that drives damaging inflammatory responses resulting in infertility and blindness. Little is known about chlamydial genes that cause persistence or factors that drive damaging pathology. In this work, we show that the C. trachomatis plasmid protein gene 3 (Pgp3) is the essential virulence factor for establishing persistent female genital tract infection and provide supportive evidence that Pgp3 functions similarly in a nonhuman primate trachoma model. We further show that persistent Ppg3-dependent infection drives damaging immunopathology. These results are important advances in understanding the pathophysiology of chlamydial persistence. Chlamydia trachomatis is an obligate intracellular bacterial pathogen that causes blinding trachoma and sexually transmitted disease afflicting hundreds of millions of people globally. A fundamental but poorly understood pathophysiological characteristic of chlamydial infection is the propensity to cause persistent infection that drives damaging inflammatory disease. The chlamydial plasmid is a virulence factor, but its role in the pathogenesis of persistent infection capable of driving immunopathology is unknown. Here, we show by using mouse and nonhuman primate infection models that the secreted plasmid gene protein 3 (Pgp3) is essential for establishing persistent infection. Ppg3-dependent persistent genital tract infection resulted in a severe endometritis caused by an intense infiltration of endometrial submucosal macrophages. Pgp3 released from the cytosol of lysed infected oviduct epithelial cells, not organism outer membrane-associated Pgp3, inhibited the chlamydial killing activity of antimicrobial peptides. Genetic Pgp3 rescue experiments in cathelin-related antimicrobial peptide (CRAMP)-deficient mice showed Pgp3-targeted antimicrobial peptides to subvert innate immunity as a pathogenic strategy to establish persistent infection. These findings provide important advances in understanding the role of Pgp3 in the pathogenesis of persistent chlamydial infection and associated immunopathology.
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19
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Jones CA, Hadfield J, Thomson NR, Cleary DW, Marsh P, Clarke IN, O’Neill CE. The Nature and Extent of Plasmid Variation in Chlamydia trachomatis. Microorganisms 2020; 8:microorganisms8030373. [PMID: 32155798 PMCID: PMC7143637 DOI: 10.3390/microorganisms8030373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 01/03/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular pathogen of humans, causing both the sexually transmitted infection, chlamydia, and the most common cause of infectious blindness, trachoma. The majority of sequenced C. trachomatis clinical isolates carry a 7.5-Kb plasmid, and it is becoming increasingly evident that this is a key determinant of pathogenicity. The discovery of the Swedish New Variant and the more recent Finnish variant highlight the importance of understanding the natural extent of variation in the plasmid. In this study we analysed 524 plasmid sequences from publicly available whole-genome sequence data. Single nucleotide polymorphisms (SNP) in each of the eight coding sequences (CDS) were identified and analysed. There were 224 base positions out of a total 7550 bp that carried a SNP, which equates to a SNP rate of 2.97%, nearly three times what was previously calculated. After normalising for CDS size, CDS8 had the highest SNP rate at 3.97% (i.e., number of SNPs per total number of nucleotides), whilst CDS6 had the lowest at 1.94%. CDS5 had the highest total number of SNPs across the 524 sequences analysed (2267 SNPs), whereas CDS6 had the least SNPs with only 85 SNPs. Calculation of the genetic distances identified CDS6 as the least variable gene at the nucleotide level (d = 0.001), and CDS5 as the most variable (d = 0.007); however, at the amino acid level CDS2 was the least variable (d = 0.001), whilst CDS5 remained the most variable (d = 0.013). This study describes the largest in-depth analysis of the C. trachomatis plasmid to date, through the analysis of plasmid sequence data mined from whole genome sequences spanning 50 years and from a worldwide distribution, providing insights into the nature and extent of existing variation within the plasmid as well as guidance for the design of future diagnostic assays. This is crucial at a time when single-target diagnostic assays are failing to detect natural mutants, putting those infected at risk of a serious long-term and life-changing illness.
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Affiliation(s)
- Charlotte A. Jones
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO166YD, UK; (C.A.J.); (D.W.C.); (I.N.C.)
| | - James Hadfield
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA;
| | - Nicholas R. Thomson
- Pathogen Genomics, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK;
| | - David W. Cleary
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO166YD, UK; (C.A.J.); (D.W.C.); (I.N.C.)
| | - Peter Marsh
- Public Health England, Porton Down, Wiltshire SP40JG, UK;
| | - Ian N. Clarke
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO166YD, UK; (C.A.J.); (D.W.C.); (I.N.C.)
| | - Colette E. O’Neill
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO166YD, UK; (C.A.J.); (D.W.C.); (I.N.C.)
- Correspondence:
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20
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Gitsels A, Van Lent S, Sanders N, Vanrompay D. Chlamydia: what is on the outside does matter. Crit Rev Microbiol 2020; 46:100-119. [PMID: 32093536 DOI: 10.1080/1040841x.2020.1730300] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This review summarises major highlights on the structural biology of the chlamydial envelope. Chlamydiae are obligate intracellular bacteria, characterised by a unique biphasic developmental cycle. Depending on the stage of their lifecycle, they appear in the form of elementary or reticulate bodies. Since these particles have distinctive functions, it is not surprising that their envelope differs in lipid as well as in protein content. Vice versa, by identifying surface proteins, specific characteristics of the particles such as rigidity or immunogenicity may be deduced. Detailed information on the bacterial membranes will increase our understanding on the host-pathogen interactions chlamydiae employ to survive and grow and might lead to new strategies to battle chlamydial infections.
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Affiliation(s)
- Arlieke Gitsels
- Laboratory of Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Sarah Van Lent
- Laboratory of 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 of Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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21
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Vial L, Hommais F. Plasmid-chromosome cross-talks. Environ Microbiol 2019; 22:540-556. [PMID: 31782608 DOI: 10.1111/1462-2920.14880] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/25/2019] [Accepted: 11/27/2019] [Indexed: 12/16/2022]
Abstract
Plasmids can be acquired by recipient bacteria at a significant cost while conferring them advantageous traits. To counterbalance the costs of plasmid carriage, both plasmids and host bacteria have developed a tight regulatory network that may involve a cross-talk between the chromosome and the plasmids. Although plasmid regulation by chromosomal regulators is generally well known, chromosome regulation by plasmid has been far less investigated. Yet, a growing number of studies have highlighted an impact of plasmids on their host bacteria. Here, we describe the plasmid-chromosome cross-talk from the plasmid point of view. We summarize data about the chromosomal adaptive mutations generated by plasmid carriage; the impact of the loss of a domesticated plasmid or the gain of a new plasmid. Then, we present the control of plasmid-encoded regulators on chromosomal gene expression. The involvement of regulators homologous to chromosome-encoded proteins is illustrated by the H-NS-like proteins, and by the Rap-Phr system. Finally, plasmid-specific regulators of chromosomal gene expression are presented, which highlight the involvement of transcription factors and sRNAs. A comprehensive analysis of the mechanisms that allow a given plasmid to impact the chromosome of bacterium will help to understand the tight cross-talk between plasmids and the chromosome.
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Affiliation(s)
- Ludovic Vial
- Université de Lyon, 69622, Lyon, France.,Université Lyon 1, 69622, Villeurbanne, France.,CNRS, UMR 5557 Ecologie Microbienne, 69622, Villeurbanne, France.,INRA, UMR1418 Ecologie Microbienne, 69622, Villeurbanne, France
| | - Florence Hommais
- Université de Lyon, 69622, Lyon, France.,Université Lyon 1, 69622, Villeurbanne, France.,CNRS, UMR 5240 Microbiologie Adaptation et Pathogénie, 69622, Villeurbanne, France
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22
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Development of Transposon Mutagenesis for Chlamydia muridarum. J Bacteriol 2019; 201:JB.00366-19. [PMID: 31501283 DOI: 10.1128/jb.00366-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 08/27/2019] [Indexed: 12/18/2022] Open
Abstract
Functional genetic analysis of Chlamydia has been a challenge due to the historical genetic intractability of Chlamydia, although recent advances in chlamydial genetic manipulation have begun to remove these barriers. Here, we report the development of the Himar C9 transposon system for Chlamydia muridarum, a mouse-adapted Chlamydia species that is widely used in Chlamydia infection models. We demonstrate the generation and characterization of an initial library of 33 chloramphenicol (Cam)-resistant, green fluorescent protein (GFP)-expressing C. muridarum transposon mutants. The majority of the mutants contained single transposon insertions spread throughout the C. muridarum chromosome. In all, the library contained 31 transposon insertions in coding open reading frames (ORFs) and 7 insertions in intergenic regions. Whole-genome sequencing analysis of 17 mutant clones confirmed the chromosomal locations of the insertions. Four mutants with transposon insertions in glgB, pmpI, pmpA, and pmpD were investigated further for in vitro and in vivo phenotypes, including growth, inclusion morphology, and attachment to host cells. The glgB mutant was shown to be incapable of complete glycogen biosynthesis and accumulation in the lumen of mutant inclusions. Of the 3 pmp mutants, pmpI was shown to have the most pronounced growth attenuation defect. This initial library demonstrates the utility and efficacy of stable, isogenic transposon mutants for C. muridarum The generation of a complete library of C. muridarum mutants will ultimately enable comprehensive identification of the functional genetic requirements for Chlamydia infection in vivo IMPORTANCE Historical issues with genetic manipulation of Chlamydia have prevented rigorous functional genetic characterization of the ∼1,000 genes in chlamydial genomes. Here, we report the development of a transposon mutagenesis system for C. muridarum, a mouse-adapted Chlamydia species that is widely used for in vivo investigations of chlamydial pathogenesis. This advance builds on the pioneering development of this system for C. trachomatis We demonstrate the generation of an initial library of 33 mutants containing stable single or double transposon insertions. Using these mutant clones, we characterized in vitro phenotypes associated with genetic disruptions in glycogen biosynthesis and three polymorphic outer membrane proteins.
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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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24
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Hadfield J, Bénard A, Domman D, Thomson N. The Hidden Genomics of Chlamydia trachomatis. Curr Top Microbiol Immunol 2019; 412:107-131. [PMID: 29071471 DOI: 10.1007/82_2017_39] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The application of whole-genome sequencing has moved us on from sequencing single genomes to defining unravelling population structures in different niches, and at the -species, -serotype or even -genus level, and in local, national and global settings. This has been instrumental in cataloguing and revealing a huge a range of diversity in this bacterium, when at first we thought there was little. Genomics has challenged assumptions, added insight, as well as confusion and glimpses of truths. What is clear is that at a time when we start to realise the extent and nature of the diversity contained within a genus or a species like this, the huge depth of knowledge communities have developed, through cell biology, as well as the new found molecular approaches will be more precious than ever to link genotype to phenotype. Here we detail the technological developments and insights we have seen during the relatively short time since we began to see the hidden genome of Chlamydia trachomatis.
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Affiliation(s)
- James Hadfield
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
| | - Angèle Bénard
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
| | - Daryl Domman
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
| | - Nicholas Thomson
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK.
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.
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25
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Phillips S, Robbins A, Loader J, Hanger J, Booth R, Jelocnik M, Polkinghorne A, Timms P. Chlamydia pecorum gastrointestinal tract infection associations with urogenital tract infections in the koala (Phascolarctos cinereus). PLoS One 2018; 13:e0206471. [PMID: 30383822 PMCID: PMC6211709 DOI: 10.1371/journal.pone.0206471] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 10/12/2018] [Indexed: 11/21/2022] Open
Abstract
Background Chlamydia infects multiple sites within hosts, including the gastrointestinal tract (GIT). In certain hosts, gastrointestinal infection is linked to treatment avoidance and self-infection at disease susceptible sites. GIT C. pecorum has been detected in livestock and koalas, however GIT prevalence rates within the koala are yet to be established. Methods Paired conjunctival, urogenital and rectal samples from 33 koalas were screened for C. pecorum and C. pecorum plasmid using 16S rRNA and CDS5-specific quantitative PCR assays, respectively. Amplicon sequencing of 359 bp ompA fragment was used to identify site-specific genotypes. Results The overall C. pecorum prevalence collectively (healthy and clinically diseased koalas) was 51.5%, 57.6% and 42.4% in urogenital, conjunctival and gastrointestinal sites, respectively. Concurrent urogenital and rectal Chlamydia was identified in 14 koalas, with no cases of GIT only Chlamydia shedding. The ompA genotype G dominated the GIT positive samples, and genotypes A and E’ were dominant in urogenital tract (UGT) positive samples. Increases in C. pecorum plasmid per C. pecorum load (detected by PCR) showed clustering in the clinically diseased koala group (as assessed by scatter plot analysis). There was also a low correlation between plasmid positivity and C. pecorum infected animals at any site, with a prevalence of 47% UGT, 36% rectum and 40% faecal pellet. Conclusions GIT C. pecorum PCR positivity suggests that koala GIT C. pecorum infections are common and occur regularly in animals with concurrent genital tract infections. GIT dominant genotypes were identified and do not appear to be related to plasmid positivity. Preliminary results indicated a possible association between C. pecorum plasmid load and clinical UGT disease.
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Affiliation(s)
- Samuel Phillips
- Genecology Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
- * E-mail:
| | - Amy Robbins
- Genecology Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
- Endeavour Veterinary Ecology Pty Ltd, Toorbul, Australia
| | - Joanne Loader
- Endeavour Veterinary Ecology Pty Ltd, Toorbul, Australia
| | | | | | - Martina Jelocnik
- Animal Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
| | - Adam Polkinghorne
- Animal Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
| | - Peter Timms
- Genecology Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
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26
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Beder T, Saluz HP. Virulence-related comparative transcriptomics of infectious and non-infectious chlamydial particles. BMC Genomics 2018; 19:575. [PMID: 30068313 PMCID: PMC6090853 DOI: 10.1186/s12864-018-4961-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 07/25/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Members of the phylum Chlamydiae are obligate intracellular pathogens of humans and animals and have a serious impact on host health. They comprise several zoonotic species with varying disease outcomes and prevalence. To investigate differences in virulence, we focused on Chlamydia psittaci, C. abortus and Waddlia chondrophila. Most threatening is C. psittaci, which frequently infects humans and causes psittacosis associated with severe pneumonia. The closest relative of C. psittaci is C. abortus, which shares the vast majority of genes but less frequently infects humans, and causes stillbirth and sepsis. W. chondrophila is more distantly related, and occasional human infections are associated with respiratory diseases or miscarriage. One possible explanation for differences in virulence originate from species-specific genes as well as differentially expressed homologous virulence factors. RESULTS RNA-sequencing (RNA-Seq) was applied to purified infectious elementary bodies (EBs) and non-infectious reticulate bodies (RBs) in order to elucidate the transcriptome of the infectious and replicative chlamydial states. The results showed that approximately half of all genes were differentially expressed. For a descriptive comparison, genes were categorised according to their function in the RAST database. This list was extended by the inclusion of inclusion membrane proteins, outer membrane proteins, polymorphic membrane proteins and type III secretion system effectors. In addition, the expression of fifty-six known and a variety of predicted virulence and immunogenic factors with homologs in C. psittaci, C. abortus and W. chondrophila was analysed. To confirm the RNA-Seq results, the expression of nine factors was validated using real-time quantitative polymerase chain reaction (RT-qPCR). Comparison of RNA-Seq and RT-qPCR results showed a high mean Pearson correlation coefficient of 0.95. CONCLUSIONS It was shown that both the replicative and infectious chlamydial state contained distinctive transcriptomes and the cellular processes emphasised in EBs and RBs differed substantially based on the chlamydial species. In addition, the very first interspecies transcriptome comparison is presented here, and the considerable differences in expression of homologous virulence factors might contribute to the differing infection rates and disease outcomes of the pathogens. The RNA-Seq results were confirmed by RT-qPCR and demonstrate the feasibility of interspecies transcriptome comparisons in chlamydia.
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Affiliation(s)
- Thomas Beder
- Department of Cell and Molecular Biology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Beutenbergstraße 11A, 07745, Jena, Germany.,Network Modelling, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Beutenbergstraße 11A, 07745, Jena, Germany.,Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Hans Peter Saluz
- Department of Cell and Molecular Biology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Beutenbergstraße 11A, 07745, Jena, Germany. .,Friedrich Schiller University, Fürstengraben 1, 07743, Jena, Germany.
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Khurshid S, Govada L, Wills G, McClure MO, Helliwell JR, Chayen NE. Chlamydia protein Pgp3 studied at high resolution in a new crystal form. IUCRJ 2018; 5:439-448. [PMID: 30002845 PMCID: PMC6038952 DOI: 10.1107/s2052252518007637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 05/22/2018] [Indexed: 06/08/2023]
Abstract
The protein Pgp3 is implicated in the sexually transmitted disease chlamydia and comprises an extended complex arrangement of a C-terminal domain (CTD) and an N-terminal domain (NTD) linked by a triple-helix coiled coil (THCC). Here, the X-ray crystal structure of Pgp3 from an LGV1 strain is reported at the highest X-ray diffraction resolution obtained to date for the full protein. The protein was crystallized using a high concentration of potassium bromide, which resulted in a new crystal form with relatively low solvent content that diffracted to a resolution of 1.98 Å. The three-dimensional structure of this new crystal form is described and compared with those of other crystal forms, and the potassium bromide binding sites and the relevance to chlamydia isolates from around the globe are described. The crystal packing is apparently driven by the CTDs. Since the threefold axes of the THCC and NTD are not collinear with the threefold axis of a CTD, this naturally leads to disorder in the THCC and the portion of the NTD that does not directly interact with the CTD via crystal packing. The key avenue to resolving these oddities in the crystal structure analysis was a complete new analysis in space group P1 and determining the space group as P212121. This space-group assignment was that originally determined from the diffraction pattern but was perhaps complicated by translational noncrystallographic symmetry. This crystal structure of a three-domain multi-macromolecular complex with two misaligned threefold axes was a unique challenge and has not been encountered before. It is suggested that a specific intermolecular interaction, possibly of functional significance in receptor binding in chlamydia, might allow the design of a new chemotherapeutic agent against chlamydia.
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Affiliation(s)
- Sahir Khurshid
- Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, England
| | - Lata Govada
- Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, England
| | - Gillian Wills
- Department of Medicine, Imperial College London, St Mary’s Campus, London W2 1PG, England
| | - Myra O. McClure
- Department of Medicine, Imperial College London, St Mary’s Campus, London W2 1PG, England
| | - John R. Helliwell
- School of Chemistry, The University of Manchester, Manchester M13 9PL, England
| | - Naomi E. Chayen
- Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, England
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Morrison SG, Giebel AM, Toh EC, Spencer HJ, Nelson DE, Morrison RP. Chlamydia muridarum Genital and Gastrointestinal Infection Tropism Is Mediated by Distinct Chromosomal Factors. Infect Immun 2018; 86:e00141-18. [PMID: 29661932 PMCID: PMC6013670 DOI: 10.1128/iai.00141-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/12/2018] [Indexed: 02/07/2023] Open
Abstract
Some members of the genus Chlamydia, including the human pathogen Chlamydia trachomatis, infect multiple tissues, including the genital and gastrointestinal (GI) tracts. However, it is unknown if bacterial targeting to these sites is mediated by multifunctional or distinct chlamydial factors. We previously showed that disruption of individual large clostridial toxin homologs encoded within the Chlamydia muridarum plasticity zone were not critical for murine genital tract infection. Here, we assessed whether cytotoxin genes contribute to C. muridarum GI tropism. Infectivity and shedding of wild-type (WT) C. muridarum and three mutants containing nonsense mutations in different cytotoxin genes, tc0437, tc0438, and tc0439, were compared in mouse genital and GI infection models. One mutant, which had a nonsense mutation in tc0439, was highly attenuated for GI infection and had a GI 50% infectious dose (ID50) that was 1,000 times greater than that of the WT. GI inoculation with this mutant failed to elicit anti-chlamydial antibodies or to protect against subsequent genital tract infection. Genome sequencing of the tc0439 mutant revealed additional chromosomal mutations, and phenotyping of additional mutants suggested that the GI attenuation might be linked to a nonsense mutation in tc0600 The molecular mechanism underlying this dramatic difference in tissue-tropic virulence is not fully understood. However, isolation of these mutants demonstrates that distinct chlamydial chromosomal factors mediate chlamydial tissue tropism and provides a basis for vaccine initiatives to isolate chlamydia strains that are attenuated for genital infection but retain the ability to colonize the GI tract and elicit protective immune responses.
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Affiliation(s)
- Sandra G Morrison
- Department of Microbiology & Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Amanda M Giebel
- Department of Microbiology & Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Evelyn C Toh
- Department of Microbiology & Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Horace J Spencer
- Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - David E Nelson
- Department of Microbiology & Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Richard P Morrison
- Department of Microbiology & Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Chlamydial plasmid-encoded virulence factor Pgp3 interacts with human cathelicidin peptide LL-37 to modulate immune response. Microbes Infect 2018; 21:50-55. [PMID: 29959096 DOI: 10.1016/j.micinf.2018.06.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/17/2018] [Accepted: 06/19/2018] [Indexed: 11/23/2022]
Abstract
We have previously reported that Chlamydia trachomatis plasmid-encoded Pgp3 is able to neutralize anti-chlamydial activity of human cathelicidin peptide LL-37 by binding to and forming stable complex with LL-37. Besides its microbicidal activity, LL-37 also modulates immune response, including inducing cytokine/chemokine production in fibroblast/epithelial cells and recruitment of inflammatory cells. We now report that LL-37 was significantly induced in the genital tracts of women diagnosed positive for C. trachomatis. Both the LL-37-stimulated IL-6/8 production in human endometrial epithelial cells and the LL-37-induced neutrophil chemotaxis were blocked by Pgp3. Interestingly, although Pgp3 itself alone could not induce cytokines in epithelial cell cells, it did so in neutrophils. Importantly, the Pgp3 proinflammatory activity in neutrophils was significantly enhanced by forming complex with LL-37 although LL-37 alone failed to induce cytokine production in neutrophils. Thus, we have demonstrated that Pgp3 can modulate the proinflammatory activities of LL-37 on epithelial cells by forming stable complex with LL-37 but the Pgp3's own proinflammatory activity on myeloid cells is enhanced by forming the same complex. We hypothesize that Chlamydia may use Pgp3 to both block detrimental inflammation for improving its own fitness in the genital tract epithelial tissue and activate myeloid cell-mediated inflammation for potentially promoting spreading between the hosts, the latter of which may inevitably contribute to the development of inflammatory sequelae such as tubal fibrosis.
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Zou Y, Dai W, Lei W, Su S, Huang Q, Zhou Z, Chen C, Li Z. Identification of proteins interacting with pORF5 in the pathogenesis of C. trachomatis. Am J Transl Res 2018; 10:1633-1647. [PMID: 30018706 PMCID: PMC6038076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 03/21/2017] [Indexed: 06/08/2023]
Abstract
OBJECTIVE This study is to identify and investigate the proteins interacting with pORF5 implicated in the pathogenesis of C. trachomatis. METHODS The isobaric tags for relative and absolute quantitation (iTRAQ) approach combined with nano liquid chromatography-tandem mass spectrometry (NanoLC-MS/MS) analysis was applied to identify and quantify the differentially expressed proteins in the pORF5-transfected HeLa (pORF5-HeLa) cells and the control vector-transfected HeLa (vector-HeLa) cells. Quantitative real-time PCR (qRT-PCR) and Western blot analysis were performed to detect the mRNA and protein expression levels. RESULTS Totally 3355 proteins were quantified by employing biological replicates, 314 of which were differentially expressed between the pORF5-HeLa and vector-HeLa cells. Nine differentially expressed proteins (HIST1H1C, HBA1, PARK7, HMGB1, HMGB2, CLIC1, KRT7, SFN, and CDKN2A) were subjected to qRT-PCR, and two over-expressed proteins (HMGB1 and PRAK7) were subjected to the Western blot analysis, to validate the proteomic results. The results from the qRT-PCR and Western blot analysis were consistent with the findings from the proteomic analysis. Moreover, pORF5 could inhibit the TNF-α-induced apoptosis in HeLa cells. Through siRNA-mediated functional screening, the high-mobility group box 1 (HMGB1) was shown to be relevant to the inhibition of the apoptotic response in the host cells. CONCLUSION Identification of key proteins interacting with pORF5 could contribute to the understanding and further exploration of the function of pORF5 in the pathogenic mechanisms of C. trachomatis.
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Affiliation(s)
- Yan Zou
- Pathogenic Biology Institute, School of Medicine, University of South ChinaHengyang 421001, Hunan, China
| | - Wenting Dai
- Pathogenic Biology Institute, School of Medicine, University of South ChinaHengyang 421001, Hunan, China
| | - Wenbo Lei
- Pathogenic Biology Institute, School of Medicine, University of South ChinaHengyang 421001, Hunan, China
| | - Shengmei Su
- Pathogenic Biology Institute, School of Medicine, University of South ChinaHengyang 421001, Hunan, China
| | - Qiulin Huang
- Department of General Surgery, The First Affiliated Hospital of University of South ChinaHengyang 421001, Hunan, China
| | - Zhou Zhou
- Pathogenic Biology Institute, School of Medicine, University of South ChinaHengyang 421001, Hunan, China
| | - Chaoqun Chen
- Pathogenic Biology Institute, School of Medicine, University of South ChinaHengyang 421001, Hunan, China
| | - Zhongyu Li
- Pathogenic Biology Institute, School of Medicine, University of South ChinaHengyang 421001, Hunan, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug StudyHengyang 421001, Hunan, China
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Patton DL, Sweeney YC, Baldessari AE, Cles L, Kari L, Sturdevant GL, Yang C, Caldwell HD. The Chlamydia trachomatis Plasmid and CT135 Virulence Factors Are Not Essential for Genital Tract Infection or Pathology in Female Pig-Tailed Macaques. Infect Immun 2018; 86:e00121-18. [PMID: 29463617 PMCID: PMC5913843 DOI: 10.1128/iai.00121-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 02/11/2018] [Indexed: 11/20/2022] Open
Abstract
The Chlamydia trachomatis plasmid and inclusion membrane protein CT135 are virulence factors in the pathogenesis of murine female genital tract infection. To determine if these virulence factors play a similar role in female nonhuman primates, we infected pig-tailed macaques with the same C. trachomatis strains shown to be important in the murine model. Wild-type C. trachomatis and its isogenic mutant strain deficient in both plasmid and CT135 were used to infect macaques. Macaques were given primary and repeated cervicovaginal challenges with the wild-type and mutant strains. The infection rate, infection duration, and antibody response were similar among macaques infected with both strains. Unexpectedly, colposcopy, laparoscopy, and histologic analysis revealed no substantial genital tract pathology following either primary or repeated cervicovaginal challenges. Cytokine analysis of cervicovaginal secretions from both challenged groups revealed low concentrations of interleukin 1β (IL-1β) and elevated levels of the interleukin 1 receptor agonist (IL-1RA). We propose that an imbalance of IL-1β and IL-1RA in macaques is the reason for the mild inflammatory responses observed in infected urogenital tissues. Thus, understanding the pathobiology of chlamydial infection requires a better understanding of host epigenetic and chlamydial genetic factors. Our findings also have implications for understanding the high frequency of asymptomatic infections in humans.
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Affiliation(s)
- Dorothy L Patton
- Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington, USA
| | - Yvonne C Sweeney
- Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington, USA
| | - Audrey E Baldessari
- Washington National Primate Research Center, University of Washington, Seattle, Washington, USA
| | - Linda Cles
- Chlamydia Reference Laboratory, University of Washington, Seattle, Washington, USA
| | - Laszlo Kari
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, USA
| | - Gail L Sturdevant
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, USA
| | - Chunfu Yang
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - Harlan D Caldwell
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
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Escobedo-Guerra MR, Katoku-Herrera M, Lopez-Hurtado M, Villagrana-Zesati JR, de Haro-Cruz MDJ, Guerra-Infante FM. Identification of a new variant of Chlamydia trachomatis in Mexico. Enferm Infecc Microbiol Clin 2018; 37:93-99. [PMID: 29636285 DOI: 10.1016/j.eimc.2018.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 02/13/2018] [Accepted: 02/16/2018] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Chlamydia trachomatis is one of the main etiological agents of sexually transmitted infections worldwide. In 2006, a Swedish variant of C. trachomatis (Swedish-nvCT), which has a deletion of 377bp in the plasmid, was reported. In Latin America, Swedish-nvCT infections have not been reported. We investigated the presence of Swedish-nvCT in women with infertility in Mexico. METHODS Swedish-nvCT was searched in 69C. trachomatis positive samples from 2339 endocervical specimens. We designed PCR primers to identify the deletion in the plasmid in the ORF1, and the presence of a repeated 44bp in the ORF3. The sample with the deletion was genotyped with the genes of the major outer membrane protein A (ompA) and the polymorphic membrane protein (pmpH). RESULTS The deletion was detected in one of the 69 samples positive C. trachomatis of 2339 endocervical exudates. The nucleotide sequence analysis of the ompA shows a high degree of similarity with the Swedish nvCT (98%), however the variant found belongs to serovar D. The nucleotide sequence of the pmpH gene associates to the variant found in the genitourinary pathotype of the Swedish-nvCT but in different clusters. CONCLUSIONS Our results revealed the presence of a new variant of C. trachomatis in Mexican patients. This variant found in Mexico belongs to serovar D based on the in silico analysis of the ompA and pmpH genes and differs to the Swedish-nvCT (serovars E). For these variants of C. trachomatis that have been found it is necessary to carry out a more detailed analysis, although the role of this mutation has not been demonstrated in the pathogenesis.
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Affiliation(s)
- Marcos R Escobedo-Guerra
- Departamento de Infectología, Instituto Nacional de Perinatología, CDMX, Mexico; Unidad Médica de Alta Especialidad, Hospital de Especialidades, Centro Médico Nacional La Raza, IMSS, CDMX, Mexico
| | | | | | | | - María de J de Haro-Cruz
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, del Instituto Politécnico Nacional, CDMX, Mexico
| | - Fernando M Guerra-Infante
- Departamento de Infectología, Instituto Nacional de Perinatología, CDMX, Mexico; Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, del Instituto Politécnico Nacional, CDMX, Mexico.
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Skilton RJ, Wang Y, O'Neill C, Filardo S, Marsh P, Bénard A, Thomson NR, Ramsey KH, Clarke IN. The Chlamydia muridarum plasmid revisited : new insights into growth kinetics. Wellcome Open Res 2018; 3:25. [PMID: 29657985 PMCID: PMC5871946 DOI: 10.12688/wellcomeopenres.13905.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2018] [Indexed: 11/23/2022] Open
Abstract
Background: Research in chlamydial genetics is challenging because of its obligate intracellular developmental cycle.
In vivo systems exist that allow studies of different aspects of basic biology of chlamydiae, the murine
Chlamydia muridarum model is one of great importance and thus an essential research tool.
C. muridarum carries a plasmid that has a role in virulence. Our aim was to compare and contrast the
C. muridarum plasmid-free phenotype with that of a chromosomally isogenic plasmid-bearing strain, through the inclusion phase of the developmental cycle. Methods: We measured infectivity for plasmid bearing and plasmid-cured
C. muridarum by inclusion forming assays in McCoy cells and in parallel bacterial chromosome replication by quantitative PCR, throughout the developmental cycle. In addition to these studies, we have carefully monitored chlamydial inclusion formation by confocal microscopy and transmission electron microscopy. A new
E.coli/chlamydial shuttle vector (pNigg::GFP) was constructed using standard cloning technology and used to transform
C. muridarum for further phenotypic studies. Results: We have advanced the definition of the chlamydial phenotype away from the simple static observation of mature inclusions and redefined the
C. muridarum plasmid-based phenotype on growth profile and inclusion morphology. Our observations on the growth properties of plasmid-cured
C. muridarum challenge the established interpretations, especially with regard to inclusion growth kinetics. Introduction of the shuttle plasmid pNigg::GFP into plasmid-cured
C. muridarum restored the wild-type plasmid-bearing phenotype and confirmed that loss of the plasmid was the sole cause for the changes in growth and chromosomal replication. Conclusions: Accurate growth curves and sampling at multiple time points throughout the developmental cycle is necessary to define plasmid phenotypes. There are subtle but important (previously unnoticed) differences in the overall growth profile of plasmid-bearing and plasmid-free
C. muridarum. We have proven that the differences described are solely due to the plasmid pNigg.
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Affiliation(s)
- Rachel J Skilton
- Molecular Microbiology Group, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Yibing Wang
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Colette O'Neill
- Molecular Microbiology Group, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Simone Filardo
- Department of Public Health and Infectious Diseases, Section of Microbiology, Sapienza University, Rome, Italy
| | - Peter Marsh
- Public Health England, Public Health Laboratory Southampton, Southampton General Hospital, Southampton, UK
| | - Angèle Bénard
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Nicholas R Thomson
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK.,London School of Hygiene and Tropical Medicine, London, UK
| | - Kyle H Ramsey
- Department of Microbiology & Immunology, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL, USA
| | - Ian N Clarke
- Molecular Microbiology Group, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
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Last AR, Pickering H, Roberts CH, Coll F, Phelan J, Burr SE, Cassama E, Nabicassa M, Seth-Smith HMB, Hadfield J, Cutcliffe LT, Clarke IN, Mabey DCW, Bailey RL, Clark TG, Thomson NR, Holland MJ. Population-based analysis of ocular Chlamydia trachomatis in trachoma-endemic West African communities identifies genomic markers of disease severity. Genome Med 2018; 10:15. [PMID: 29482619 PMCID: PMC5828069 DOI: 10.1186/s13073-018-0521-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 02/13/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Chlamydia trachomatis (Ct) is the most common infectious cause of blindness and bacterial sexually transmitted infection worldwide. Ct strain-specific differences in clinical trachoma suggest that genetic polymorphisms in Ct may contribute to the observed variability in severity of clinical disease. METHODS Using Ct whole genome sequences obtained directly from conjunctival swabs, we studied Ct genomic diversity and associations between Ct genetic polymorphisms with ocular localization and disease severity in a treatment-naïve trachoma-endemic population in Guinea-Bissau, West Africa. RESULTS All Ct sequences fall within the T2 ocular clade phylogenetically. This is consistent with the presence of the characteristic deletion in trpA resulting in a truncated non-functional protein and the ocular tyrosine repeat regions present in tarP associated with ocular tissue localization. We have identified 21 Ct non-synonymous single nucleotide polymorphisms (SNPs) associated with ocular localization, including SNPs within pmpD (odds ratio, OR = 4.07, p* = 0.001) and tarP (OR = 0.34, p* = 0.009). Eight synonymous SNPs associated with disease severity were found in yjfH (rlmB) (OR = 0.13, p* = 0.037), CTA0273 (OR = 0.12, p* = 0.027), trmD (OR = 0.12, p* = 0.032), CTA0744 (OR = 0.12, p* = 0.041), glgA (OR = 0.10, p* = 0.026), alaS (OR = 0.10, p* = 0.032), pmpE (OR = 0.08, p* = 0.001) and the intergenic region CTA0744-CTA0745 (OR = 0.13, p* = 0.043). CONCLUSIONS This study demonstrates the extent of genomic diversity within a naturally circulating population of ocular Ct and is the first to describe novel genomic associations with disease severity. These findings direct investigation of host-pathogen interactions that may be important in ocular Ct pathogenesis and disease transmission.
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Affiliation(s)
- A. R. Last
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - H. Pickering
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - C. h. Roberts
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - F. Coll
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - J. Phelan
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - S. E. Burr
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Fajara, Gambia
| | - E. Cassama
- Programa Nacional de Saúde de Visão, Ministério de Saúde Publica, Bissau, Guinea-Bissau
| | - M. Nabicassa
- Programa Nacional de Saúde de Visão, Ministério de Saúde Publica, Bissau, Guinea-Bissau
| | - H. M. B. Seth-Smith
- Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
- Clinical Microbiology, Universitätsspital Basel, Basel, Switzerland
- Applied Microbiology Research, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - J. Hadfield
- Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - L. T. Cutcliffe
- Molecular Microbiology Group, University of Southampton Medical School, Southampton, UK
| | - I. N. Clarke
- Molecular Microbiology Group, University of Southampton Medical School, Southampton, UK
| | - D. C. W. Mabey
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - R. L. Bailey
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - T. G. Clark
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Department of Infectious Diseases Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - N. R. Thomson
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - M. J. Holland
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
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Versteeg B, Bruisten SM, Pannekoek Y, Jolley KA, Maiden MCJ, van der Ende A, Harrison OB. Genomic analyses of the Chlamydia trachomatis core genome show an association between chromosomal genome, plasmid type and disease. BMC Genomics 2018; 19:130. [PMID: 29426279 PMCID: PMC5810182 DOI: 10.1186/s12864-018-4522-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/31/2018] [Indexed: 12/02/2022] Open
Abstract
Background Chlamydia trachomatis (Ct) plasmid has been shown to encode genes essential for infection. We evaluated the population structure of Ct using whole-genome sequence data (WGS). In particular, the relationship between the Ct genome, plasmid and disease was investigated. Results WGS data from 157 Ct isolates deposited in the Chlamydiales pubMLST database (http://pubMLST.org/chlamydiales/) were annotated with 902 genes including the core and accessory genome. Plasmid associated genes were annotated and a plasmid MLST scheme was defined allowing plasmid sequence types to be determined. Plasmid allelic variation was investigated. Phylogenetic relationships were examined using the Genome Comparator tool available in pubMLST. Phylogenetic analyses identified four distinct Ct core genome clusters and six plasmid clusters, with a strong association between the chromosomal genotype and plasmid. This in turn was linked to ompA genovars and disease phenotype. Horizontal genetic transfer of plasmids was observed for three urogenital-associated isolates, which possessed plasmids more commonly found in isolates resulting from ocular infections. The pgp3 gene was identified as the most polymorphic plasmid gene and pgp4 was the most conserved. Conclusion A strong association between chromosomal genome, plasmid type and disease was observed, consistent with previous studies. This suggests co-evolution of the Ct chromosome and their plasmids, but we confirmed that plasmid transfer can occur between isolates. These data provide a better understanding of the genetic diversity occurring across the Ct genome in association with the plasmid content. Electronic supplementary material The online version of this article (10.1186/s12864-018-4522-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bart Versteeg
- Public Health Laboratory, Department of Infectious Diseases, Public Health Service Amsterdam, Amsterdam, the Netherlands.
| | - Sylvia M Bruisten
- Public Health Laboratory, Department of Infectious Diseases, Public Health Service Amsterdam, Amsterdam, the Netherlands.,Amsterdam Infection & Immunity Institute, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Yvonne Pannekoek
- Amsterdam Infection & Immunity Institute, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,Department of Medical Microbiology, Academic Medical Center, Amsterdam, the Netherlands
| | - Keith A Jolley
- Peter Medawar building, Department of Zoology, University of Oxford, Oxford, UK
| | - Martin C J Maiden
- Peter Medawar building, Department of Zoology, University of Oxford, Oxford, UK
| | - Arie van der Ende
- Amsterdam Infection & Immunity Institute, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,Department of Medical Microbiology, Academic Medical Center, Amsterdam, the Netherlands
| | - Odile B Harrison
- Peter Medawar building, Department of Zoology, University of Oxford, Oxford, UK
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Plasmid Negative Regulation of CPAF Expression Is Pgp4 Independent and Restricted to Invasive Chlamydia trachomatis Biovars. mBio 2018; 9:mBio.02164-17. [PMID: 29382731 PMCID: PMC5790913 DOI: 10.1128/mbio.02164-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterial pathogen that causes blinding trachoma and sexually transmitted disease. C. trachomatis isolates are classified into 2 biovars—lymphogranuloma venereum (LGV) and trachoma—which are distinguished biologically by their natural host cell infection tropism. LGV biovars infect macrophages and are invasive, whereas trachoma biovars infect oculo-urogenital epithelial cells and are noninvasive. The C. trachomatis plasmid is an important virulence factor in the pathogenesis of these infections. Central to its pathogenic role is the transcriptional regulatory function of the plasmid protein Pgp4, which regulates the expression of plasmid and chromosomal virulence genes. As many gene regulatory functions are post-transcriptional, we employed a comparative proteomic study of cells infected with plasmid-cured C. trachomatis serovars A and D (trachoma biovar), a L2 serovar (LGV biovar), and the L2 serovar transformed with a plasmid containing a nonsense mutation in pgp4 to more completely elucidate the effects of the plasmid on chlamydial infection biology. Our results show that the Pgp4-dependent elevations in the levels of Pgp3 and a conserved core set of chromosomally encoded proteins are remarkably similar for serovars within both C. trachomatis biovars. Conversely, we found a plasmid-dependent, Pgp4-independent, negative regulation in the expression of the chlamydial protease-like activity factor (CPAF) for the L2 serovar but not the A and D serovars. The molecular mechanism of plasmid-dependent negative regulation of CPAF expression in the LGV serovar is not understood but is likely important to understanding its macrophage infection tropism and invasive infection nature. The Chlamydia trachomatis plasmid is an important virulence factor in the pathogenesis of chlamydial infection. It is known that plasmid protein 4 (Pgp4) functions in the transcriptional regulation of the plasmid virulence protein 3 (Pgp3) and multiple chromosomal loci of unknown function. Since many gene regulatory functions can be post-transcriptional, we undertook a comparative proteomic analysis to better understand the plasmid’s role in chlamydial and host protein expression. We report that Pgp4 is a potent and specific master positive regulator of a common core of plasmid and chromosomal virulence genes shared by multiple C. trachomatis serovars. Notably, we show that the plasmid is a negative regulator of the expression of the chlamydial virulence factor CPAF. The plasmid regulation of CPAF is independent of Pgp4 and restricted to a C. trachomatis macrophage-tropic strain. These findings are important because they define a previously unknown role for the plasmid in the pathophysiology of invasive chlamydial infection.
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Hafner LM, Timms P. Development of a Chlamydia trachomatis vaccine for urogenital infections: novel tools and new strategies point to bright future prospects. Expert Rev Vaccines 2017; 17:57-69. [PMID: 29264970 DOI: 10.1080/14760584.2018.1417044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
INTRODUCTION The "cloaked" bacterial pathogen that is Chlamydia trachomatis continues to cause sexually transmitted infections (STIs) that adversely affect the health and well-being of children, adolescents and adults globally. The reproductive disease sequelae follow unresolved or untreated chronic or recurrent asymptomatic C.trachomatis infections of the lower female genital tract (FGT) and can include pelvic pain, pelvic inflammatory disease (PID) and ectopic pregnancy. Tubal Factor Infertility (TFI) can also occur since protective and long-term natural immunity to chlamydial infection is incomplete, allowing for ascension of the organism to the upper FGT. Developing countries including the WHO African (8.3 million cases) and South-East Asian regions (7.2 million cases) bear the highest burden of chlamydial STIs. AREAS COVERED Genetic advances for Chlamydia have provided tools for transformation (including dendrimer-enabled transformation), lateral gene transfer and chemical mutagenesis. Recent progress in these areas is reviewed with a focus on vaccine development for Chlamydia infections of the female genital tract. EXPERT COMMENTARY A vaccine that can elicit immuno-protective responses whilst avoiding adverse immuno-pathologic host responses is required. The current technological advances in chlamydial genetics and proteomics, as well as novel and improved adjuvants and delivery systems, provide new hope that the elusive chlamydial vaccine is an imminent and realistic goal.
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Affiliation(s)
- Louise M Hafner
- a School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Faculty of Health , Queensland University of Technology , Brisbane , Australia
| | - Peter Timms
- b Faculty of Science, Health, Education and Engineering , University of the Sunshine Coast , Maroochydore DC , Australia
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38
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Abstract
Species of Chlamydia are the etiologic agent of endemic blinding trachoma, the leading cause of bacterial sexually transmitted diseases, significant respiratory pathogens, and a zoonotic threat. Their dependence on an intracellular growth niche and their peculiar developmental cycle are major challenges to elucidating their biology and virulence traits. The last decade has seen tremendous advances in our ability to perform a molecular genetic analysis of Chlamydia species. Major achievements include the generation of large collections of mutant strains, now available for forward- and reverse-genetic applications, and the introduction of a system for plasmid-based transformation enabling complementation of mutations; expression of foreign, modified, or reporter genes; and even targeted gene disruptions. This review summarizes the current status of the molecular genetic toolbox for Chlamydia species and highlights new insights into their biology and new challenges in the nascent field of Chlamydia genetics.
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Affiliation(s)
- Barbara S Sixt
- Department for Molecular Genetics and Microbiology, Duke University, Durham, North Carolina 27710; .,Centre de Recherche des Cordeliers, INSERM U1138, Paris 75006, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris 75006, France.,Université Pierre et Marie Curie, Paris 75005, France
| | - Raphael H Valdivia
- Department for Molecular Genetics and Microbiology, Duke University, Durham, North Carolina 27710;
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39
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da Cunha M, Pais SV, Bugalhão JN, Mota LJ. The Chlamydia trachomatis type III secretion substrates CT142, CT143, and CT144 are secreted into the lumen of the inclusion. PLoS One 2017. [PMID: 28622339 PMCID: PMC5473537 DOI: 10.1371/journal.pone.0178856] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Chlamydia trachomatis is a human bacterial pathogen causing ocular and genital infections. It multiplies exclusively within an intracellular membrane-bound vacuole, the inclusion, and uses a type III secretion system to manipulate host cells by injecting them with bacterially-encoded effector proteins. In this work, we characterized the expression and subcellular localization in infected host cells of the C. trachomatis CT142, CT143, and CT144 proteins, which we previously showed to be type III secretion substrates. Transcriptional analyses in C. trachomatis confirmed the prediction that ct142, ct143 and ct144 are organized in an operon and revealed that their expression is likely driven by the main σ factor, σ66. In host cells infected by C. trachomatis, production of CT142 and CT143 could be detected by immunoblotting from 20–26 h post-infection. Immunofluorescence microscopy of infected cells revealed that from 20 h post-infection CT143 appeared mostly as globular structures outside of the bacterial cells but within the lumen of the inclusion. Furthermore, immunofluorescence microscopy of cells infected by C. trachomatis strains carrying plasmids producing CT142, CT143, or CT144 under the control of the ct142 promoter and with a C-terminal double hemagglutinin (2HA) epitope tag revealed that CT142-2HA, CT143-2HA or CT144-2HA showed an identical localization to chromosomally-encoded CT143. Moreover, CT142-2HA or CT144-2HA and CT143 produced by the same bacteria co-localized in the lumen of the inclusion. Overall, these data suggest that the CT142, CT143, and CT144 type III secretion substrates are secreted into the lumen of the inclusion where they might form a protein complex.
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Affiliation(s)
- Maria da Cunha
- UCIBIO—REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Sara V. Pais
- UCIBIO—REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Joana N. Bugalhão
- UCIBIO—REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Luís Jaime Mota
- UCIBIO—REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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40
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Waugh CA, Hanger J, Loader J, King A, Hobbs M, Johnson R, Timms P. Infection with koala retrovirus subgroup B (KoRV-B), but not KoRV-A, is associated with chlamydial disease in free-ranging koalas (Phascolarctos cinereus). Sci Rep 2017; 7:134. [PMID: 28273935 PMCID: PMC5427818 DOI: 10.1038/s41598-017-00137-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/09/2017] [Indexed: 02/02/2023] Open
Abstract
The virulence of chlamydial infection in wild koalas is highly variable between individuals. Some koalas can be infected (PCR positive) with Chlamydia for long periods but remain asymptomatic, whereas others develop clinical disease. Chlamydia in the koala has traditionally been studied without regard to coinfection with other pathogens, although koalas are usually subject to infection with koala retrovirus (KoRV). Retroviruses can be immunosuppressive, and there is evidence of an immunosuppressive effect of KoRV in vitro. Originally thought to be a single endogenous strain, a new, potentially more virulent exogenous variant (KoRV-B) was recently reported. We hypothesized that KoRV-B might significantly alter chlamydial disease outcomes in koalas, presumably via immunosuppression. By studying sub-groups of Chlamydia and KoRV infected koalas in the wild, we found that neither total KoRV load (either viraemia or proviral copies per genome), nor chlamydial infection level or strain type, was significantly associated with chlamydial disease risk. However, PCR positivity with KoRV-B was significantly associated with chlamydial disease in koalas (p = 0.02961). This represents an example of a recently evolved virus variant that may be predisposing its host (the koala) to overt clinical disease when co-infected with an otherwise asymptomatic bacterial pathogen (Chlamydia).
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Affiliation(s)
- Courtney A Waugh
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, 4558, Queensland, Australia.,Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, Norway
| | - Jonathan Hanger
- Endeavour Veterinary Ecology, 1695 Pumicestone Rd, Toorbul, 4510, Queensland, Australia
| | - Joanne Loader
- Endeavour Veterinary Ecology, 1695 Pumicestone Rd, Toorbul, 4510, Queensland, Australia
| | - Andrew King
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, NSW, 2010, Australia
| | - Matthew Hobbs
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, NSW, 2010, Australia
| | - Rebecca Johnson
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, NSW, 2010, Australia
| | - Peter Timms
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, 4558, Queensland, Australia.
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41
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Winstanley CE, Ramsey KH, Marsh P, Clarke IN. Development and evaluation of an enzyme-linked immunosorbent assay for the detection of antibodies to a common urogenital derivative of Chlamydia trachomatis plasmid-encoded PGP3. J Immunol Methods 2017; 445:23-30. [PMID: 28283408 DOI: 10.1016/j.jim.2017.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/19/2017] [Accepted: 03/03/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND Urogenital infection with Chlamydia trachomatis is the most commonly diagnosed sexually transmitted infection in the developed world. Accurate measurement and therefore understanding the seroprevalence of urogenital C. trachomatis infections requires a rigorously optimised and validated ELISA. Previous ELISAs based on the C. trachomatis plasmid-encoded protein, PGP3, have been described but lack standardisation and critical controls or use a less common PGP3 as the capture antigen. METHODOLOGY/PRINCIPAL FINDINGS A sensitive and specific indirect ELISA was developed based on recombinant PGP3 derived from a urogenital strain of C. trachomatis, serovar E (pSW2), using a rigorous validation protocol. Serum samples were collected from 166 genitourinary medicine (GUM) clinic patients diagnosed as positive or negative for urogenital C. trachomatis infection by nucleic acid amplification testing (NAATs). Overall sensitivity and specificity compared to NAATs was 68.18% and 98.0%, respectively. Sensitivities for female and male samples were 71.93% and 64.15%, respectively. Comparison of samples from these patients diagnosed positive for C. trachomatis by NAAT and patients diagnosed negative by NAAT revealed statistical significance (p≤0.0001). CONCLUSIONS We have developed and validated a sensitive and specific ELISA to detect anti-PGP3 antibodies as an indicator of past and current infection to C. trachomatis using PGP3 from a common urogenital strain. It is anticipated that this assay will be used for seroepidemiological analysis of urogenital C. trachomatis in populations.
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Affiliation(s)
- Catherine E Winstanley
- Molecular Microbiology Group, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, Hampshire, United Kingdom.
| | - Kyle H Ramsey
- Department of Microbiology & Immunology, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL, USA
| | - Peter Marsh
- Public Health England Regional Microbiology Laboratory, Southampton General Hospital, Southampton, Hampshire, United Kingdom
| | - Ian N Clarke
- Molecular Microbiology Group, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, Hampshire, United Kingdom
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42
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Advances and Obstacles in the Genetic Dissection of Chlamydial Virulence. Curr Top Microbiol Immunol 2017; 412:133-158. [PMID: 29090367 DOI: 10.1007/82_2017_76] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Obligate intracellular pathogens in the family Chlamydiaceae infect taxonomically diverse eukaryotes ranging from amoebae to mammals. However, many fundamental aspects of chlamydial cell biology and pathogenesis remain poorly understood. Genetic dissection of chlamydial biology has historically been hampered by a lack of genetic tools. Exploitation of the ability of chlamydia to recombine genomic material by lateral gene transfer (LGT) ushered in a new era in chlamydia research. With methods to map mutations in place, genetic screens were able to assign functions and phenotypes to specific chlamydial genes. Development of an approach for stable transformation of chlamydia also provided a mechanism for gene delivery and platforms for disrupting chromosomal genes. Here, we explore how these and other tools have been used to test hypotheses concerning the functions of known chlamydial virulence factors and discover the functions of completely uncharacterized genes. Refinement and extension of the existing genetic tools to additional Chlamydia spp. will substantially advance understanding of the biology and pathogenesis of this important group of pathogens.
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43
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Vouga M, Baud D, Greub G. Simkania negevensis, an insight into the biology and clinical importance of a novel member of the Chlamydiales order. Crit Rev Microbiol 2016; 43:62-80. [PMID: 27786615 DOI: 10.3109/1040841x.2016.1165650] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Simkania negevensis is a Chlamydia-related bacterium discovered in 1993 and represents the founding member of the Simkaniaceae family within the Chlamydiales order. As other Chlamydiales, it is an obligate intracellular bacterium characterized by a biphasic developmental cycle. Its similarities with the pathogenic Chlamydia trachomatis and Chlamydia pneumoniae make it an interesting bacterium. So far, little is known about its biology, but S. negevensis harbors various microbiological characteristics of interest, including a strong association of the Simkania-containing vacuole with the ER and the presence of an intron in the 23S rRNA encoding gene. Evidence of human exposition has been reported worldwide. However, there is a lack of robust clinical studies evaluating its implication in human diseases; current data suggest an association with pneumonia and bronchiolitis making S. negevensis a potential emerging pathogen. Owing to its fastidious growth requirements, the clinical relevance of S. negevensis is probably underestimated. In this review, we summarize the current knowledge on S. negevensis and explore future research challenges.
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Affiliation(s)
- Manon Vouga
- a Institute of Microbiology , Center for Research on Intracellular Bacteria, Faculty of Biology and Medicine, University and University Hospital of Lausanne , Lausanne , Switzerland.,b Department "Femme-Mère-Enfant" , Materno-Fetal and Obstetrics Research Unit, University Hospital , Lausanne , Switzerland
| | - David Baud
- a Institute of Microbiology , Center for Research on Intracellular Bacteria, Faculty of Biology and Medicine, University and University Hospital of Lausanne , Lausanne , Switzerland.,b Department "Femme-Mère-Enfant" , Materno-Fetal and Obstetrics Research Unit, University Hospital , Lausanne , Switzerland
| | - Gilbert Greub
- a Institute of Microbiology , Center for Research on Intracellular Bacteria, Faculty of Biology and Medicine, University and University Hospital of Lausanne , Lausanne , Switzerland.,c Infectious Diseases Unit , University hospital , Lausanne , Switzerland
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44
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Zhong G. Chlamydial Plasmid-Dependent Pathogenicity. Trends Microbiol 2016; 25:141-152. [PMID: 27712952 DOI: 10.1016/j.tim.2016.09.006] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/11/2016] [Accepted: 09/19/2016] [Indexed: 10/20/2022]
Abstract
Most Chlamydia species carry a 7.5kb plasmid encoding eight open reading frames conventionally called plasmid glycoproteins 1-8 or pGP1-8. Although the plasmid is not critical for chlamydial growth in vitro, its role in chlamydial pathogenesis is clearly demonstrated in the genital tracts of mice infected with Chlamydia muridarum, a model for investigating the human pathogen Chlamydia trachomatis. Plasmid-free C. trachomatis is also attenuated in both the mouse genital tract and nonhuman primate ocular tissue. Deficiency in pGP3 alone, which is regulated by pGP4, largely reproduced the in vivo but not in vitro phenotypes of the plasmid-free organisms, suggesting that pGP3 is a key in vivo virulence factor. The positive and negative regulations of some chromosomal genes by pGP4 and pGP5, respectively, may allow the plasmid to promote chlamydial adaptation to varied animal tissue environments. The focus of this review is to summarize the progress on the pathogenic functions of the plasmid-encoded open reading frames, which may motivate further investigation of the molecular mechanisms of chlamydial pathogenicity and development of medical utility of the chlamydial plasmid system.
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Affiliation(s)
- Guangming Zhong
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
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Abstract
Etiology, transmission and protection: Chlamydia
trachomatis is the leading cause of bacterial sexually transmitted
infection (STI) globally. However, C. trachomatis also causes
trachoma in endemic areas, mostly Africa and the Middle East, and is a leading
cause of preventable blindness worldwide. Epidemiology, incidence and
prevalence: The World Health Organization estimates 131 million
new cases of C. trachomatis genital infection occur annually.
Globally, infection is most prevalent in young women and men (14-25 years),
likely driven by asymptomatic infection, inadequate partner treatment and
delayed development of protective immunity.
Pathology/Symptomatology: C.
trachomatis infects susceptible squamocolumnar or transitional
epithelial cells, leading to cervicitis in women and urethritis in men. Symptoms
are often mild or absent but ascending infection in some women may lead to
Pelvic Inflammatory Disease (PID), resulting in reproductive sequelae such as
ectopic pregnancy, infertility and chronic pelvic pain. Complications of
infection in men include epididymitis and reactive arthritis.
Molecular mechanisms of infection: Chlamydiae
manipulate an array of host processes to support their obligate intracellular
developmental cycle. This leads to activation of signaling pathways resulting in
disproportionate influx of innate cells and the release of tissue damaging
proteins and pro-inflammatory cytokines. Treatment and
curability: Uncomplicated urogenital infection is treated with
azithromycin (1 g, single dose) or doxycycline (100 mg twice daily x 7 days).
However, antimicrobial treatment does not ameliorate established disease. Drug
resistance is rare but treatment failures have been described. Development of an
effective vaccine that protects against upper tract disease or that limits
transmission remains an important goal.
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Affiliation(s)
- Catherine M O'Connell
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Morgan E Ferone
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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46
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Chlamydia trachomatis Genital Tract Infections: When Host Immune Response and the Microbiome Collide. Trends Microbiol 2016; 24:750-765. [PMID: 27320172 DOI: 10.1016/j.tim.2016.05.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 05/06/2016] [Accepted: 05/25/2016] [Indexed: 02/08/2023]
Abstract
Genital infections with Chlamydia trachomatis continue to be a major health problem worldwide. While some individuals clear their infection (presumed to be the result of an effective Th1/interferon-γ response), others develop chronic infections and some are prone to repeat infections. In females in particular, chronic asymptomatic infections are common and can lead to pelvic inflammatory disease and infertility. Recent studies suggest that the genital tract microbiota could be a significant factor and explain person-to-person variation in C. trachomatis infections. One hypothesis suggests that C. trachomatis can use its trpBA genes to rescue tryptophan from indole, which is a product of anaerobic members of the genital tract microbiota. Women with particular microbiota types, such as seen in bacterial vaginosis, have increased numbers of anaerobes, and this would enable the chlamydia in these individuals to overcome the host's interferon-γ attempts to eliminate it, resulting in more repeat and/or chronic infections.
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47
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Chlamydia felis: Lack of association between clinical signs and the presence of the cryptic plasmid. Microb Pathog 2016; 97:14-8. [PMID: 27208751 DOI: 10.1016/j.micpath.2016.05.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 05/13/2016] [Accepted: 05/17/2016] [Indexed: 11/21/2022]
Abstract
Chlamydia felis is an obligate intracellular bacterial pathogen that infects cats, causing severe conjunctivitis associated with upper respiratory tract disease (URTD). In the present study, 186 cats from three non-commercial catteries in São Paulo, SP, Brazil were evaluated. The detection of Chlamydia felis was performed by PCR. The clinical severity was scored from 1 to 4, with a score of 4 as the most severe manifestation. The total occurrence of C. felis was of 18.82% (35/186) of cats overall, but notably, 58.06% (18/31) of infected cats originated from a single cattery. All animals harboring C. felis had URTD clinical signs and higher scores (3 and 4). In addition, C. felis occurrence was associated with the presence of cryptic plasmid. However, the virulence and clinical severity were not correlated.
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48
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Liang M, Wen Y, Ran O, Chen L, Wang C, Li L, Xie Y, Zhang Y, Chen C, Wu Y. Protective immunity induced by recombinant protein CPSIT_p8 of Chlamydia psittaci. Appl Microbiol Biotechnol 2016; 100:6385-6393. [PMID: 27052378 DOI: 10.1007/s00253-016-7494-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 03/17/2016] [Accepted: 03/22/2016] [Indexed: 10/22/2022]
Abstract
Chlamydia psittaci is a zoonotic pathogen with a broad host range that can lead to severe respiratory and systemic disease in humans. Currently, an effective commercial vaccine against C. psittaci infection is not available. The chlamydial plasmid is an important virulence factor and encodes plasmid proteins that play important roles in chlamydial infection and the corresponding immune response. In this study, we assessed the efficacy of vaccination with plasmid proteins at preventing C. psittaci lung infection in a murine model. BALB/c mice were immunized intraperitoneally, three times at 2-week intervals, with purified recombinant CPSIT_p8 protein and then infected with C. psittaci. Immunization significantly decreased chlamydial load in the lungs of infected mice, resulted in a lower level of IFN-γ, and reduced the extent of inflammation. In vivo or in vitro neutralization of C. psittaci with sera collected from immunized mice did not reduce the amount of viable C. psittaci in the lungs of mice, indicating that CPSIT_p8-specific antibodies do not have neutralizing capacity. Furthermore, confocal fluorescence microscopy using a mouse anti-CPSIT_p8 antibody revealed that CPSIT_p8 was localized inside the inclusion of C. psittaci 6BC-infected cells. Our results demonstrate that CPSIT_p8 protein induces significant protective immunity against challenge with C. psittaci in mice and represents a promising new vaccine candidate for the prevention of C. psittaci infection.
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Affiliation(s)
- Mingxing Liang
- Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, 421001, China
| | - Yating Wen
- Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China
| | - Ou Ran
- Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China.,Department of Clinical Laboratory, Central Hospital of Xiangtan, Xiangtan, 411100, China
| | - Liesong Chen
- Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China
| | - Chuan Wang
- Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China
| | - Li Li
- Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China
| | - Yafeng Xie
- Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China
| | - Yang Zhang
- Department of Pathology, University of South China, Hengyang, 421001, China
| | - Chaoqun Chen
- Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China. .,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, 421001, China.
| | - Yimou Wu
- Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China. .,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, 421001, China.
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Wali S, Gupta R, Yu JJ, Mfuh A, Gao X, Guentzel MN, Chambers JP, Abu Bakar S, Zhong G, Arulanandam BP. Guinea pig genital tract lipidome reveals in vivo and in vitro regulation of phosphatidylcholine 16:0/18:1 and contribution to Chlamydia trachomatis serovar D infectivity. Metabolomics 2016; 12:74. [PMID: 27642272 PMCID: PMC5022361 DOI: 10.1007/s11306-016-0998-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Chlamydia trachomatis (Ct), is the leading cause of sexually transmitted infections worldwide. Host transcriptomic- or proteomic profiling studies have identified key molecules involved in establishment of Ct infection or the generation of anti Ct-immunity. However, the contribution of the host metabolome is not known. OBJECTIVES The objective of this study was to determine the contribution of host metabolites in genital Ct infection. METHODS We used high-performance liquid chromatography-mass spectrometry, and mapped lipid profiles in genital swabs obtained from female guinea pigs at days 3, 9, 15, 30 and 65 post Ct serovar D intravaginal infection. RESULTS Across all time points assessed, 13 distinct lipid species including choline, ethanolamine and glycerol were detected. Amongst these metabolites, phosphatidylcholine (PC) was the predominant phospholipid detected from animals actively shedding bacteria i.e., at 3, 9, and 15 days post infection. However, at days 30 and 65 when the animals had cleared the infection, PC was observed to be decreased compared to previous time points. Mass spectrometry analyses of PC produced in guinea pigs (in vivo) and 104C1 guinea pig cell line (in vitro) revealed distinct PC species following Ct D infection. Amongst these, PC 16:0/18:1 was significantly upregulated following Ct D infection (p < 0.05, >twofold change) in vivo and in vitro infection models investigated in this report. Exogenous addition of PC 16:0/18:1 resulted in significant increase in Ct D in Hela 229 cells. CONCLUSION This study demonstrates a role for host metabolite, PC 16:0/18:1 in regulating genital Ct infection in vivo and in vitro.
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Affiliation(s)
- Shradha Wali
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - Rishein Gupta
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - Jieh-Juen Yu
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - Adelphe Mfuh
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - Xiaoli Gao
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - M. Neal Guentzel
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - James P. Chambers
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - Sazaly Abu Bakar
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai Kuala Lumpur, 50603 Kuala Lumpur, Malaysia
| | - Guangming Zhong
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, 7702 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Bernard P. Arulanandam
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
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Emancipating Chlamydia: Advances in the Genetic Manipulation of a Recalcitrant Intracellular Pathogen. Microbiol Mol Biol Rev 2016; 80:411-27. [PMID: 27030552 DOI: 10.1128/mmbr.00071-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Chlamydia species infect millions of individuals worldwide and are important etiological agents of sexually transmitted disease, infertility, and blinding trachoma. Historically, the genetic intractability of this intracellular pathogen has hindered the molecular dissection of virulence factors contributing to its pathogenesis. The obligate intracellular life cycle of Chlamydia and restrictions on the use of antibiotics as selectable markers have impeded the development of molecular tools to genetically manipulate these pathogens. However, recent developments in the field have resulted in significant gains in our ability to alter the genome of Chlamydia, which will expedite the elucidation of virulence mechanisms. In this review, we discuss the challenges affecting the development of molecular genetic tools for Chlamydia and the work that laid the foundation for recent advancements in the genetic analysis of this recalcitrant pathogen.
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