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Subedi L, Gaire BP, Koronyo Y, Koronyo-Hamaoui M, Crother TR. Chlamydia pneumoniae in Alzheimer's disease pathology. Front Neurosci 2024; 18:1393293. [PMID: 38770241 PMCID: PMC11102982 DOI: 10.3389/fnins.2024.1393293] [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: 02/28/2024] [Accepted: 04/22/2024] [Indexed: 05/22/2024] Open
Abstract
While recent advances in diagnostics and therapeutics offer promising new approaches for Alzheimer's disease (AD) diagnosis and treatment, there is still an unmet need for an effective remedy, suggesting new avenues of research are required. Besides many plausible etiologies for AD pathogenesis, mounting evidence supports a possible role for microbial infections. Various microbes have been identified in the postmortem brain tissues of human AD patients. Among bacterial pathogens in AD, Chlamydia pneumoniae (Cp) has been well characterized in human AD brains and is a leading candidate for an infectious involvement. However, no definitive studies have been performed proving or disproving Cp's role as a causative or accelerating agent in AD pathology and cognitive decline. In this review, we discuss recent updates for the role of Cp in human AD brains as well as experimental models of AD. Furthermore, based on the current literature, we have compiled a list of potential mechanistic pathways which may connect Cp with AD pathology.
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Affiliation(s)
- Lalita Subedi
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children's at Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Infectious and Immunologic Diseases Research Center (IIDRC), Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Bhakta Prasad Gaire
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Timothy R. Crother
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children's at Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Infectious and Immunologic Diseases Research Center (IIDRC), Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
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2
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Abstract
Type III secretion systems (T3SSs) are utilized by Gram-negative pathogens to enhance their pathogenesis. This secretion system is associated with the delivery of effectors through a needle-like structure from the bacterial cytosol directly into a target eukaryotic cell. These effector proteins then manipulate specific eukaryotic cell functions to benefit pathogen survival within the host. The obligate intracellular pathogens of the family Chlamydiaceae have a highly evolutionarily conserved nonflagellar T3SS that is an absolute requirement for their survival and propagation within the host with about one-seventh of the genome dedicated to genes associated with the T3SS apparatus, chaperones, and effectors. Chlamydiae also have a unique biphasic developmental cycle where the organism alternates between an infectious elementary body (EB) and replicative reticulate body (RB). T3SS structures have been visualized on both EBs and RBs. And there are effector proteins that function at each stage of the chlamydial developmental cycle, including entry and egress. This review will discuss the history of the discovery of chlamydial T3SS and the biochemical characterization of components of the T3SS apparatus and associated chaperones in the absence of chlamydial genetic tools. These data will be contextualized into how the T3SS apparatus functions throughout the chlamydial developmental cycle and the utility of heterologous/surrogate models to study chlamydial T3SS. Finally, there will be a targeted discussion on the history of chlamydial effectors and recent advances in the field.
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Affiliation(s)
- Elizabeth A. Rucks
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Durham Research Center II, Omaha, Nebraska, USA
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3
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Collingro A, Köstlbacher S, Siegl A, Toenshoff ER, Schulz F, Mitchell SO, Weinmaier T, Rattei T, Colquhoun DJ, Horn M. The Fish Pathogen "Candidatus Clavichlamydia salmonicola"-A Missing Link in the Evolution of Chlamydial Pathogens of Humans. Genome Biol Evol 2023; 15:evad147. [PMID: 37615694 PMCID: PMC10448858 DOI: 10.1093/gbe/evad147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2023] [Indexed: 08/25/2023] Open
Abstract
Chlamydiae like Chlamydia trachomatis and Chlamydia psittaci are well-known human and animal pathogens. Yet, the chlamydiae are a much larger group of evolutionary ancient obligate intracellular bacteria that includes predominantly symbionts of protists and diverse animals. This makes them ideal model organisms to study evolutionary transitions from symbionts in microbial eukaryotes to pathogens of humans. To this end, comparative genome analysis has served as an important tool. Genome sequence data for many chlamydial lineages are, however, still lacking, hampering our understanding of their evolutionary history. Here, we determined the first high-quality draft genome sequence of the fish pathogen "Candidatus Clavichlamydia salmonicola", representing a separate genus within the human and animal pathogenic Chlamydiaceae. The "Ca. Clavichlamydia salmonicola" genome harbors genes that so far have been exclusively found in Chlamydia species suggesting that basic mechanisms important for the interaction with chordate hosts have evolved stepwise in the history of chlamydiae. Thus, the genome sequence of "Ca. Clavichlamydia salmonicola" allows to constrain candidate genes to further understand the evolution of chlamydial virulence mechanisms required to infect mammals.
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Affiliation(s)
- Astrid Collingro
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Stephan Köstlbacher
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Alexander Siegl
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Elena R Toenshoff
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich (ETH), Zürich, Switzerland
| | - Frederik Schulz
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- DOE Joint Genome Institute, Berkeley, California, USA
| | | | - Thomas Weinmaier
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Thomas Rattei
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | | | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
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4
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Luu LDW, Kasimov V, Phillips S, Myers GSA, Jelocnik M. Genome organization and genomics in Chlamydia: whole genome sequencing increases understanding of chlamydial virulence, evolution, and phylogeny. Front Cell Infect Microbiol 2023; 13:1178736. [PMID: 37287464 PMCID: PMC10242142 DOI: 10.3389/fcimb.2023.1178736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/10/2023] [Indexed: 06/09/2023] Open
Abstract
The genus Chlamydia contains important obligate intracellular bacterial pathogens to humans and animals, including C. trachomatis and C. pneumoniae. Since 1998, when the first Chlamydia genome was published, our understanding of how these microbes interact, evolved and adapted to different intracellular host environments has been transformed due to the expansion of chlamydial genomes. This review explores the current state of knowledge in Chlamydia genomics and how whole genome sequencing has revolutionised our understanding of Chlamydia virulence, evolution, and phylogeny over the past two and a half decades. This review will also highlight developments in multi-omics and other approaches that have complemented whole genome sequencing to advance knowledge of Chlamydia pathogenesis and future directions for chlamydial genomics.
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Affiliation(s)
- Laurence Don Wai Luu
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Vasilli Kasimov
- Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Samuel Phillips
- Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Garry S. A. Myers
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia
| | - Martina Jelocnik
- Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD, Australia
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5
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Yanikoglu A. The Probable Role of Chlamydia pneumoniae Infection in Acute Stroke. Infect Dis (Lond) 2023. [DOI: 10.5772/intechopen.109582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Cardiovascular diseases are the most leading cause of worldwide mortality. According to USA statistics, about 1 of 6 cardiovascular deaths is due to stroke. Stroke is the second most common cause of death and a chief cause of disability due to EU data. Treatment, care providing, rehabilitation costs and with the labor loss, the overall cost in EU due to stroke was estimated about €45 billion in year 2017. Acute stroke due to infectious diseases via several possible mechanisms with various clinical presentations were previously reported in the literature. Chlamydia pneumoniae is an obligate intracellular bacteria and extremely common in adult individuals. Besides it being a major cause of pneumonia in adults, association between atherosclerosis and vascular diseases was demonstrated by several sero-epidemiological studies and by direct detection of organism in atherosclerotic lesions by electron microscopy, immunohistochemistry, polymerase chain reaction. Also, several sero-epidemiological studies have demonstrated a link between Chlamydia pneumoniae infection and acute stroke. In this chapter, we will summarize the data in literature regarding the association between Chlamydia pneumoniae infection and acute stroke and we will try to explain the possible mechanisms that could be responsible in pathophysiology of stroke in these patients.
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6
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Dharamshi JE, Köstlbacher S, Schön ME, Collingro A, Ettema TJG, Horn M. Gene gain facilitated endosymbiotic evolution of Chlamydiae. Nat Microbiol 2023; 8:40-54. [PMID: 36604515 PMCID: PMC9816063 DOI: 10.1038/s41564-022-01284-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 11/07/2022] [Indexed: 01/07/2023]
Abstract
Chlamydiae is a bacterial phylum composed of obligate animal and protist endosymbionts. However, other members of the Planctomycetes-Verrucomicrobia-Chlamydiae superphylum are primarily free living. How Chlamydiae transitioned to an endosymbiotic lifestyle is still largely unresolved. Here we reconstructed Planctomycetes-Verrucomicrobia-Chlamydiae species relationships and modelled superphylum genome evolution. Gene content reconstruction from 11,996 gene families suggests a motile and facultatively anaerobic last common Chlamydiae ancestor that had already gained characteristic endosymbiont genes. Counter to expectations for genome streamlining in strict endosymbionts, we detected substantial gene gain within Chlamydiae. We found that divergence in energy metabolism and aerobiosis observed in extant lineages emerged later during chlamydial evolution. In particular, metabolic and aerobic genes characteristic of the more metabolically versatile protist-infecting chlamydiae were gained, such as respiratory chain complexes. Our results show that metabolic complexity can increase during endosymbiont evolution, adding an additional perspective for understanding symbiont evolutionary trajectories across the tree of life.
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Affiliation(s)
- Jennah E Dharamshi
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Stephan Köstlbacher
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
- University of Vienna, Doctoral School in Microbiology and Environmental Science, Vienna, Austria
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Max E Schön
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Astrid Collingro
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
| | - Thijs J G Ettema
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands.
| | - Matthias Horn
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria.
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7
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Halter T, Köstlbacher S, Collingro A, Sixt BS, Tönshoff ER, Hendrickx F, Kostanjšek R, Horn M. Ecology and evolution of chlamydial symbionts of arthropods. ISME COMMUNICATIONS 2022; 2:45. [PMID: 37938728 PMCID: PMC9723776 DOI: 10.1038/s43705-022-00124-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 03/31/2022] [Accepted: 04/08/2022] [Indexed: 05/08/2023]
Abstract
The phylum Chlamydiae consists of obligate intracellular bacteria including major human pathogens and diverse environmental representatives. Here we investigated the Rhabdochlamydiaceae, which is predicted to be the largest and most diverse chlamydial family, with the few described members known to infect arthropod hosts. Using published 16 S rRNA gene sequence data we identified at least 388 genus-level lineages containing about 14 051 putative species within this family. We show that rhabdochlamydiae are mainly found in freshwater and soil environments, suggesting the existence of diverse, yet unknown hosts. Next, we used a comprehensive genome dataset including metagenome assembled genomes classified as members of the family Rhabdochlamydiaceae, and we added novel complete genome sequences of Rhabdochlamydia porcellionis infecting the woodlouse Porcellio scaber, and of 'Candidatus R. oedothoracis' associated with the linyphiid dwarf spider Oedothorax gibbosus. Comparative analysis of basic genome features and gene content with reference genomes of well-studied chlamydial families with known host ranges, namely Parachlamydiaceae (protist hosts) and Chlamydiaceae (human and other vertebrate hosts) suggested distinct niches for members of the Rhabdochlamydiaceae. We propose that members of the family represent intermediate stages of adaptation of chlamydiae from protists to vertebrate hosts. Within the genus Rhabdochlamydia, pronounced genome size reduction could be observed (1.49-1.93 Mb). The abundance and genomic distribution of transposases suggests transposable element expansion and subsequent gene inactivation as a mechanism of genome streamlining during adaptation to new hosts. This type of genome reduction has never been described before for any member of the phylum Chlamydiae. This study provides new insights into the molecular ecology, genomic diversity, and evolution of representatives of one of the most divergent chlamydial families.
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Affiliation(s)
- Tamara Halter
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
| | - Stephan Köstlbacher
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
| | - Astrid Collingro
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Barbara S Sixt
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Elena R Tönshoff
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich (ETH), Zurich, Switzerland
| | | | - Rok Kostanjšek
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
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8
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Aranjuez GF, Kim J, Jewett TJ. The Chlamydia trachomatis Early Effector Tarp Outcompetes Fascin in Forming F-Actin Bundles In Vivo. Front Cell Infect Microbiol 2022; 12:811407. [PMID: 35300377 PMCID: PMC8921475 DOI: 10.3389/fcimb.2022.811407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/10/2022] [Indexed: 11/13/2022] Open
Abstract
The intracellular pathogen Chlamydia trachomatis secretes multiple early effectors into the host cell to promote invasion. A key early effector during host cell entry, Tarp (translocated actin-recruiting phosphoprotein) is comprised of multiple protein domains known to have roles in cell signaling, G-actin nucleation and F-actin bundle formation. In vitro, the actin bundles generated by Tarp are uncharacteristically flexible, however, in vivo, the biological significance of Tarp-mediated actin bundles remains unknown. We hypothesize that Tarp's ability to generate unique actin bundles, in part, facilitates chlamydial entry into epithelial cells. To study the in vivo interaction between Tarp and F-actin, we transgenically expressed Tarp in Drosophila melanogaster tissues. Tarp expressed in Drosophila is phosphorylated and forms F-actin-enriched aggregates in tissues. To gain insight into the significance of Tarp actin bundles in vivo, we utilized the well-characterized model system of mechanosensory bristle development in Drosophila melanogaster. Tarp expression in wild type flies produced curved bristles, indicating a perturbation in F-actin dynamics during bristle development. Two F-actin bundlers, Singed/Fascin and Forked/Espin, are important for normal bristle shape. Surprisingly, Tarp expression in the bristles displaced Singed/Fascin away from F-actin bundles. Tarp's competitive behavior against Fascin during F-actin bundling was confirmed in vitro. Loss of either singed or forked in flies leads to highly deformed bristles. Strikingly, Tarp partially rescued the loss of singed, reducing the severity of the bristle morphology defect. This work provides in vivo confirmation of Tarp's F-actin bundling activity and further uncovers a competitive behavior against the host bundler Singed/Fascin during bundle assembly. Also, we demonstrate the utility of Drosophila melanogaster as an in vivo cell biological platform to study bacterial effector function.
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Affiliation(s)
- George F. Aranjuez
- Division of Immunity and Pathogenesis, Burnett School of Biomedical Sciences, University of Central Florida College of Medicine, Orlando, FL, United States
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9
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Sixt BS. Host cell death during infection with Chlamydia: a double-edged sword. FEMS Microbiol Rev 2021; 45:5902849. [PMID: 32897321 PMCID: PMC7794043 DOI: 10.1093/femsre/fuaa043] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022] Open
Abstract
The phylum Chlamydiae constitutes a group of obligate intracellular bacteria that infect a remarkably diverse range of host species. Some representatives are significant pathogens of clinical or veterinary importance. For instance, Chlamydia trachomatis is the leading infectious cause of blindness and the most common bacterial agent of sexually transmitted diseases. Chlamydiae are exceptionally dependent on their eukaryotic host cells as a consequence of their developmental biology. At the same time, host cell death is an integral part of the chlamydial infection cycle. It is therefore not surprising that the bacteria have evolved exquisite and versatile strategies to modulate host cell survival and death programs to their advantage. The recent introduction of tools for genetic modification of Chlamydia spp., in combination with our increasing awareness of the complexity of regulated cell death in eukaryotic cells, and in particular of its connections to cell-intrinsic immunity, has revived the interest in this virulence trait. However, recent advances also challenged long-standing assumptions and highlighted major knowledge gaps. This review summarizes current knowledge in the field and discusses possible directions for future research, which could lead us to a deeper understanding of Chlamydia's virulence strategies and may even inspire novel therapeutic approaches.
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Affiliation(s)
- Barbara S Sixt
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
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10
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Köstlbacher S, Collingro A, Halter T, Schulz F, Jungbluth SP, Horn M. Pangenomics reveals alternative environmental lifestyles among chlamydiae. Nat Commun 2021; 12:4021. [PMID: 34188040 PMCID: PMC8242063 DOI: 10.1038/s41467-021-24294-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 06/10/2021] [Indexed: 02/07/2023] Open
Abstract
Chlamydiae are highly successful strictly intracellular bacteria associated with diverse eukaryotic hosts. Here we analyzed metagenome-assembled genomes of the "Genomes from Earth's Microbiomes" initiative from diverse environmental samples, which almost double the known phylogenetic diversity of the phylum and facilitate a highly resolved view at the chlamydial pangenome. Chlamydiae are defined by a relatively large core genome indicative of an intracellular lifestyle, and a highly dynamic accessory genome of environmental lineages. We observe chlamydial lineages that encode enzymes of the reductive tricarboxylic acid cycle and for light-driven ATP synthesis. We show a widespread potential for anaerobic energy generation through pyruvate fermentation or the arginine deiminase pathway, and we add lineages capable of molecular hydrogen production. Genome-informed analysis of environmental distribution revealed lineage-specific niches and a high abundance of chlamydiae in some habitats. Together, our data provide an extended perspective of the variability of chlamydial biology and the ecology of this phylum of intracellular microbes.
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Affiliation(s)
- Stephan Köstlbacher
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Astrid Collingro
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Tamara Halter
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | | | | | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
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11
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Application of a C. trachomatis expression system to identify C. pneumoniae proteins translocated into host cells. J Bacteriol 2021; 203:JB.00511-20. [PMID: 33685970 PMCID: PMC8117517 DOI: 10.1128/jb.00511-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Chlamydia pneumoniae is a Gram-negative, obligate intracellular pathogen that causes community-acquired respiratory infections. C. pneumoniae uses a cell contact-dependent type-III secretion (T3S) system to translocate pathogen effector proteins that manipulate host cellular functions. While several C. pneumoniae T3S effectors have been proposed, few have been experimentally confirmed in Chlamydia In this study, we expressed 382 C. pneumoniae genes in C. trachomatis as fusion proteins to an epitope tag derived from glycogen synthase kinase 3β (GSK3β) which is the target of phosphorylation by mammalian kinases. Based on the detection of the tagged C. pneumoniae protein with anti-phospho GSK3β antibodies, we identified 49 novel C. pneumoniae-specific proteins that are translocated by C. trachomatis into the host cytoplasm and thus likely play a role as modifiers of host cellular functions. In this manner, we identified and characterized a new C. pneumoniae effector CPj0678 that recruits the host cell protein PACSIN2 to the plasma membrane. These findings indicate that C. trachomatis provides a powerful screening system to detect candidate effector proteins encoded by other pathogenic and endosymbiotic Chlamydia species.Importance Chlamydia injects numerous effector proteins into host cells to manipulate cellular functions important for bacterial survival. Based on findings in C. trachomatis, it has been proposed that between 5-10% of the C. pneumoniae genome, a related respiratory pathogen, encodes secreted effectors. However only a few C. pneumoniae effectors have been identified and experimentally validated. With the development of methods for the stable genetic transformation of C. trachomatis, it is now possible to use C. trachomatis shuttle plasmids to express and explore the function of proteins from other Chlamydia in a more relevant bacterial system. In this study, we experimentally determined that 49 C. pneumoniae-specific proteins are translocated into the host cytoplasm by Chlamydia secretion systems, and identify a novel effector required to recruit the host factor PACSIN2 to the plasma membrane during infection.
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12
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Collingro A, Köstlbacher S, Horn M. Chlamydiae in the Environment. Trends Microbiol 2020; 28:877-888. [PMID: 32591108 DOI: 10.1016/j.tim.2020.05.020] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/25/2020] [Accepted: 05/28/2020] [Indexed: 12/19/2022]
Abstract
Chlamydiae have been known for more than a century as major pathogens of humans. Yet they are also found ubiquitously in the environment where they thrive within protists and in an unmatched wide range of animals. This review summarizes recent advances in understanding chlamydial diversity and distribution in nature. Studying these environmental chlamydiae provides a novel perspective on basic chlamydial biology and evolution. A picture is beginning to emerge with chlamydiae representing one of the evolutionarily most ancient and successful groups of obligate intracellular bacteria.
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Affiliation(s)
- Astrid Collingro
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Stephan Köstlbacher
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
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13
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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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14
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A predation assay using amoebae to screen for virulence factors unearthed the first W. chondrophila inclusion membrane protein. Sci Rep 2019; 9:19485. [PMID: 31862969 PMCID: PMC6925127 DOI: 10.1038/s41598-019-55511-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 11/11/2019] [Indexed: 01/21/2023] Open
Abstract
Waddlia chondrophila is an intracellular bacterium phylogenetically related to the well-studied human and animal pathogens of the Chlamydiaceae family. In the last decade, W. chondrophila was convincingly demonstrated to be associated with adverse pregnancy outcomes in humans and abortions in animals. All members of the phylum Chlamydiae possess a Type Three Secretion System that they use for delivering virulence proteins into the host cell cytosol to modulate their environment and create optimal conditions to complete their life cycle. To identify W. chondrophila virulence proteins, we used an original screening approach that combines a cosmid library with an assay monitoring resistance to predation by phagocytic amoebae. This technique combined with bioinformatic data allowed the identification of 28 candidate virulence proteins, including Wimp1, the first identified inclusion membrane protein of W. chondrophila.
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15
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Insertional mutagenesis in the zoonotic pathogen Chlamydia caviae. PLoS One 2019; 14:e0224324. [PMID: 31697687 PMCID: PMC6837515 DOI: 10.1371/journal.pone.0224324] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 10/11/2019] [Indexed: 11/19/2022] Open
Abstract
The ability to introduce targeted genetic modifications in microbial genomes has revolutionized our ability to study the role and mode of action of individual bacterial virulence factors. Although the fastidious lifestyle of obligate intracellular bacterial pathogens poses a technical challenge to such manipulations, the last decade has produced significant advances in our ability to conduct molecular genetic analysis in Chlamydia trachomatis, a major bacterial agent of infertility and blindness. Similar approaches have not been established for the closely related veterinary Chlamydia spp., which cause significant economic damage, as well as rare but potentially life-threatening infections in humans. Here we demonstrate the feasibility of conducting site-specific mutagenesis for disrupting virulence genes in C. caviae, an agent of guinea pig inclusion conjunctivitis that was recently identified as a zoonotic agent in cases of severe community-acquired pneumonia. Using this approach, we generated C. caviae mutants deficient for the secreted effector proteins IncA and SinC. We demonstrate that C. caviae IncA plays a role in mediating fusion of the bacteria-containing vacuoles inhabited by C. caviae. Moreover, using a chicken embryo infection model, we provide first evidence for a role of SinC in C. caviae virulence in vivo.
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16
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Proteomic characterisation of the Chlamydia abortus outer membrane complex (COMC) using combined rapid monolithic column liquid chromatography and fast MS/MS scanning. PLoS One 2019; 14:e0224070. [PMID: 31647835 PMCID: PMC6812762 DOI: 10.1371/journal.pone.0224070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/01/2019] [Indexed: 11/22/2022] Open
Abstract
Data are presented on the identification and partial characterisation of proteins comprising the chlamydial outer membrane complex (COMC) fraction of Chlamydia abortus (C. abortus)—the aetiological agent of ovine enzootic abortion. Inoculation with the COMC fraction is known to be highly effective in protecting sheep against experimental challenge and its constituent proteins are therefore of interest as potential vaccine candidates. Sodium N-lauroylsarcosine (sarkosyl) insoluble COMC proteins resolved by SDS-PAGE were interrogated by mass spectrometry using combined rapid monolithic column liquid chromatography and fast MS/MS scanning. Downstream database mining of processed tandem MS data revealed the presence of 67 proteins in total, including putative membrane associated proteins (n = 36), such as porins, polymorphic membrane proteins (Pmps), chaperonins and hypothetical membrane proteins, in addition to others (n = 22) that appear more likely to have originated from other subcellular compartments. Electrophoretic mobility data combined with detailed amino acid sequence information derived from secondary fragmentation spectra for 8 Pmps enabled peptides originating from protein cleavage fragments to be mapped to corresponding regions of parent precursor molecules yielding preliminary evidence in support of endogenous post-translational processing of outer membrane proteins in C. abortus. The data presented here will facilitate a deeper understanding of the pathogenesis of C. abortus infection and represent an important step towards the elucidation of the mechanisms of immunoprotection against C. abortus infection and the identification of potential target vaccine candidate antigens.
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17
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Gitsels A, Sanders N, Vanrompay D. Chlamydial Infection From Outside to Inside. Front Microbiol 2019; 10:2329. [PMID: 31649655 PMCID: PMC6795091 DOI: 10.3389/fmicb.2019.02329] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 09/24/2019] [Indexed: 12/16/2022] Open
Abstract
Chlamydia are obligate intracellular bacteria, characterized by a unique biphasic developmental cycle. Specific interactions with the host cell are crucial for the bacteria’s survival and amplification because of the reduced chlamydial genome. At the start of infection, pathogen-host interactions are set in place in order for Chlamydia to enter the host cell and reach the nutrient-rich peri-Golgi region. Once intracellular localization is established, interactions with organelles and pathways of the host cell enable the necessary hijacking of host-derived nutrients. Detailed information on the aforementioned processes will increase our understanding on the intracellular pathogenesis of chlamydiae and hence might lead to new strategies to battle chlamydial infection. This review summarizes how chlamydiae generate their intracellular niche in the host cell, acquire host-derived nutrients in order to enable their growth and finally exit the host cell in order to infect new cells. Moreover, the evolution in the development of molecular genetic tools, necessary for studying the chlamydial infection biology in more depth, is discussed in great detail.
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Affiliation(s)
- Arlieke Gitsels
- Laboratory for Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Niek Sanders
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Daisy Vanrompay
- Laboratory for Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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18
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Stringlis IA, Zamioudis C, Berendsen RL, Bakker PAHM, Pieterse CMJ. Type III Secretion System of Beneficial Rhizobacteria Pseudomonas simiae WCS417 and Pseudomonas defensor WCS374. Front Microbiol 2019; 10:1631. [PMID: 31379783 PMCID: PMC6647874 DOI: 10.3389/fmicb.2019.01631] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/02/2019] [Indexed: 11/13/2022] Open
Abstract
Plants roots host myriads of microbes, some of which enhance the defense potential of plants by activating a broad-spectrum immune response in leaves, known as induced systemic resistance (ISR). Nevertheless, establishment of this mutualistic interaction requires active suppression of local root immune responses to allow successful colonization. To facilitate host colonization, phytopathogenic bacteria secrete immune-suppressive effectors into host cells via the type III secretion system (T3SS). Previously, we searched the genomes of the ISR-inducing rhizobacteria Pseudomonas simiae WCS417 and Pseudomonas defensor WCS374 for the presence of a T3SS and identified the components for a T3SS in the genomes of WCS417 and WCS374. By performing a phylogenetic and gene cluster alignment analysis we show that the T3SS of WCS417 and WCS374 are grouped in a clade that is enriched for beneficial rhizobacteria. We also found sequences of putative novel effectors in their genomes, which may facilitate future research on the role of T3SS effectors in plant-beneficial microbe interactions in the rhizosphere.
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Affiliation(s)
- Ioannis A Stringlis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Christos Zamioudis
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Roeland L Berendsen
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Peter A H M Bakker
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Corné M J Pieterse
- Plant-Microbe Interactions, Department of Biology, Science4Life, Utrecht University, Utrecht, Netherlands
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19
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Rother M, Teixeira da Costa AR, Zietlow R, Meyer TF, Rudel T. Modulation of Host Cell Metabolism by Chlamydia trachomatis. Microbiol Spectr 2019; 7:10.1128/microbiolspec.bai-0012-2019. [PMID: 31111817 PMCID: PMC11026074 DOI: 10.1128/microbiolspec.bai-0012-2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Indexed: 11/20/2022] Open
Abstract
Propagation of the intracellular bacterial pathogen Chlamydia trachomatis is strictly bound to its host cells. The bacterium has evolved by minimizing its genome size at the cost of being completely dependent on its host. Many of the vital nutrients are synthesized only by the host, and this has complex implications. Recent advances in loss-of-function analyses and the metabolomics of human infected versus noninfected cells have provided comprehensive insight into the molecular changes that host cells undergo during the stage of infection. Strikingly, infected cells acquire a stage of high metabolic activity, featuring distinct aspects of the Warburg effect, a condition originally assigned to cancer cells. This condition is characterized by aerobic glycolysis and an accumulation of certain metabolites, altogether promoting the synthesis of crucial cellular building blocks, such as nucleotides required for DNA and RNA synthesis. The altered metabolic program enables tumor cells to rapidly proliferate as well as C. trachomatis-infected cells to feed their occupants and still survive. This program is largely orchestrated by a central control board, the tumor suppressor protein p53. Its downregulation in C. trachomatis-infected cells or mutation in cancer cells not only alters the metabolic state of cells but also conveys the prevention of programmed cell death involving mitochondrial pathways. While this points toward common features in the metabolic reprogramming of infected and rapidly proliferating cells, it also forwards novel treatment options against chronic intracellular infections involving well-characterized host cell targets and established drugs.
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Affiliation(s)
- Marion Rother
- Steinbeis Innovation Center for Systems Biomedicine, 14612 Berlin-Falkensee, Germany
- Institute of Experimental Internal Medicine, Otto von Guericke University Magdeburg, 39120 Magdeburg, Germany
- Max Planck Institute for Infection Biology, Department of Molecular Biology, 10117 Berlin, Germany
| | | | - Rike Zietlow
- Max Planck Institute for Infection Biology, Department of Molecular Biology, 10117 Berlin, Germany
| | - Thomas F Meyer
- Max Planck Institute for Infection Biology, Department of Molecular Biology, 10117 Berlin, Germany
| | - Thomas Rudel
- Department of Microbiology, Biocenter, University of Wuerzburg, 97074 Wuerzburg, Germany
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20
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Dhroso A, Eidson S, Korkin D. Genome-wide prediction of bacterial effector candidates across six secretion system types using a feature-based statistical framework. Sci Rep 2018; 8:17209. [PMID: 30464223 PMCID: PMC6249201 DOI: 10.1038/s41598-018-33874-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 10/06/2018] [Indexed: 01/12/2023] Open
Abstract
Gram-negative bacteria are responsible for hundreds of millions infections worldwide, including the emerging hospital-acquired infections and neglected tropical diseases in the third-world countries. Finding a fast and cheap way to understand the molecular mechanisms behind the bacterial infections is critical for efficient diagnostics and treatment. An important step towards understanding these mechanisms is the discovery of bacterial effectors, the proteins secreted into the host through one of the six common secretion system types. Unfortunately, current prediction methods are designed to specifically target one of three secretion systems, and no accurate "secretion system-agnostic" method is available. Here, we present PREFFECTOR, a computational feature-based approach to discover effector candidates in Gram-negative bacteria, without prior knowledge on bacterial secretion system(s) or cryptic secretion signals. Our approach was first evaluated using several assessment protocols on a manually curated, balanced dataset of experimentally determined effectors across all six secretion systems, as well as non-effector proteins. The evaluation revealed high accuracy of the top performing classifiers in PREFFECTOR, with the small false positive discovery rate across all six secretion systems. Our method was also applied to six bacteria that had limited knowledge on virulence factors or secreted effectors. PREFFECTOR web-server is freely available at: http://korkinlab.org/preffector .
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Affiliation(s)
- Andi Dhroso
- Department of Computer Science, and Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Samantha Eidson
- Mathematics and Computer Science Department, Fontbonne University, St. Louis, MO, USA
| | - Dmitry Korkin
- Department of Computer Science, and Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA, USA.
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21
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Heterogeneous expression of Chlamydia pneumoniae antigen candidates and high-level soluble expression of its inclusion membrane proteins in Escherichia coli. Mol Cell Toxicol 2017. [DOI: 10.1007/s13273-017-0043-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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22
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Guo W, Jelocnik M, Li J, Sachse K, Polkinghorne A, Pannekoek Y, Kaltenboeck B, Gong J, You J, Wang C. From genomes to genotypes: molecular epidemiological analysis of Chlamydia gallinacea reveals a high level of genetic diversity for this newly emerging chlamydial pathogen. BMC Genomics 2017; 18:949. [PMID: 29212448 PMCID: PMC5717833 DOI: 10.1186/s12864-017-4343-9] [Citation(s) in RCA: 12] [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: 03/17/2017] [Accepted: 11/21/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chlamydia (C.) gallinacea is a recently identified bacterium that mainly infects domestic chickens. Demonstration of C. gallinacea in human atypical pneumonia suggests its zoonotic potential. Its prevalence in chickens exceeds that of C. psittaci, but genetic and genomic research on C. gallinacea is still at the beginning. In this study, we conducted whole-genome sequencing of C. gallinacea strain JX-1 isolated from an asymptomatic chicken, and comparative genomic analysis between C. gallinacea strains and related chlamydial species. RESULTS The genome of C. gallinacea JX-1 was sequenced by single-molecule, real-time technology and is comprised of a 1,059,522-bp circular chromosome with an overall G + C content of 37.93% and sequence similarity of 99.4% to type strain 08-1274/3. In addition, a plasmid designated pJX-1, almost identical to p1274 of the type strain, except for two point mutations, was only found in field strains from chicken, but not in other hosts. In contrast to chlamydial species with notably variable polymorphic membrane protein (pmp) genes and plasticity zone (PZ), these regions were conserved in both C. gallinacea strains. There were 15 predicted pmp genes, but only B, A, E1, H, G1 and G2 were apparently intact in both strains. In comparison to chlamydial species where the PZ may be up to 50 kbp, C. gallinacea strains displayed gene content reduction in the PZ (14 kbp), with strain JX-1 having a premature STOP codon in the cytotoxin (tox) gene, while tox gene is intact in the type strain. In multilocus sequence typing (MLST), 15 C. gallinacea STs were identified among 25 strains based on cognate MLST allelic profiles of the concatenated sequences. The type strain and all Chinese strains belong to two distinct phylogenetic clades. Clade of the Chinese strains separated into 14 genetically distinct lineages, thus revealing considerable genetic diversity of C. gallinacea strains in China. CONCLUSIONS In this first detailed comparative genomic analysis of C. gallinacea, we have provided evidence for substantial genetic diversity among C. gallinacea strains. How these genetic polymorphisms affect C. gallinacea biology and pathogenicity should be addressed in future studies that focus on phylogenetics and host adaption of this enigmatic bacterial agent.
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Affiliation(s)
- Weina Guo
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu 225009 People’s Republic of China
- College of Animal Science, Anhui Science and Technology University, Maanshan, Anhui China
| | - Martina Jelocnik
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, QLD Australia
| | - Jing Li
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu 225009 People’s Republic of China
| | - Konrad Sachse
- Institute of Bioinformatics, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Adam Polkinghorne
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, QLD Australia
| | - Yvonne Pannekoek
- Department of Microbiology, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Jiansen Gong
- Poultry Institute, Chinese Academy of Agricultural Sciences, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu China
| | - Jinfeng You
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu 225009 People’s Republic of China
| | - Chengming Wang
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu 225009 People’s Republic of China
- College of Veterinary Medicine, Auburn University, Auburn, AL USA
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23
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Soupene E, Kuypers FA. Phosphatidylserine decarboxylase CT699, lysophospholipid acyltransferase CT775, and acyl-ACP synthase CT776 provide membrane lipid diversity to Chlamydia trachomatis. Sci Rep 2017; 7:15767. [PMID: 29150677 PMCID: PMC5693948 DOI: 10.1038/s41598-017-16116-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/07/2017] [Indexed: 02/08/2023] Open
Abstract
De novo lipid synthesis and scavenging of fatty acids (FA) are processes essential for the formation of the membrane of the human pathogen Chlamydia trachomatis (C.t.). Host FA are assimilated via esterification by the bacterial acyl-acyl carrier protein (ACP) synthase AasC but inhibitors of the host acyl-CoA synthetase enymes ACSL also impaired growth of C.t. in human cells. In E. coli, activity of AasC was sensitive to triacsin C and rosiglitazone G. The absence of a triacsin C-insensitive pathway and the increased inhibition by rosiglitazone G confirmed the sensitivity of the bacterial acyl-ACP synthase to these drugs in infected human cells. We found no evidence that the human ACSL enzymes are required for lipid formation by C.t. The broad substrate specificity of acyltransferase CT775 provides C.t. with the capacity to incorporate straight-chain and bacterial specific branched-chain fatty acids. CT775 accepts both acyl-ACP and acyl-CoA as acyl donors and, 1- or 2-acyl isomers of lysophosphoplipids as acyl acceptors. The enzyme responsible for remodeling of human phosphatidylserine to bacterial phosphatidylethanolamine was identified as CT699. These findings provide evidence that the pathogen has the ability to extend the lipid diversity of its membrane.
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Affiliation(s)
- Eric Soupene
- Children's Hospital Oakland Research Institute, Oakland, CA, USA.
| | - Frans A Kuypers
- Children's Hospital Oakland Research Institute, Oakland, CA, USA
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24
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Haferkamp I. Crossing the border - Solute entry into the chlamydial inclusion. Int J Med Microbiol 2017; 308:41-48. [PMID: 28864236 DOI: 10.1016/j.ijmm.2017.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/10/2017] [Accepted: 08/17/2017] [Indexed: 10/19/2022] Open
Abstract
Chlamydiales comprise important human and animal pathogens as well as endosymbionts of amoebae. Generally, these obligate intracellular living bacteria are characterized by a biphasic developmental cycle, a reduced genome and a restricted metabolic capacity. Because of their metabolic impairment, Chlamydiales essentially rely on the uptake of diverse metabolites from their hosts. Chlamydiales thrive in a special compartment, the inclusion, and hence are surrounded by an additional membrane. Solutes might enter the inclusion through pores and open channels or by redirection of host vesicles, which fuse with the inclusion membrane and release their internal cargo. Recent investigations shed new light on the chlamydia-host interaction and identified an additional way for nutrient uptake into the inclusion. Proteome studies and targeting analyses identified chlamydial and host solute carriers in inclusions of Chlamydia trachomatis infected cells. These transporters are involved in the provision of UDP-glucose and biotin, and probably deliver further metabolites to the inclusion. By the controlled recruitment of specific solute carriers to the inclusion, the chlamydial resident thus can actively manipulate the metabolite availability and composition in the inclusion. This review summarizes recent findings and new ideas on carrier mediated solute uptake into the chlamydial inclusion in the context of the bacterial and host metabolism.
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Affiliation(s)
- Ilka Haferkamp
- Universität Kaiserslautern, Pflanzenphysiologie, Erwin-Schrödinger Str. 22, 67663 Kaiserslautern, Germany.
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25
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Collingro A, Köstlbacher S, Mussmann M, Stepanauskas R, Hallam SJ, Horn M. Unexpected genomic features in widespread intracellular bacteria: evidence for motility of marine chlamydiae. ISME JOURNAL 2017. [PMID: 28644443 PMCID: PMC5604735 DOI: 10.1038/ismej.2017.95] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Chlamydiae are obligate intracellular bacteria comprising important human pathogens and symbionts of protists. Molecular evidence indicates a tremendous diversity of chlamydiae particularly in marine environments, yet our current knowledge is based mainly on terrestrial representatives. Here we provide first insights into the biology of marine chlamydiae representing three divergent clades. Our analysis of single-cell amplified genomes revealed hallmarks of the chlamydial lifestyle, supporting the ancient origin of their characteristic developmental cycle and major virulence mechanisms. Surprisingly, these chlamydial genomes encode a complete flagellar apparatus, a previously unreported feature. We show that flagella are an ancient trait that was subject to differential gene loss among extant chlamydiae. Together with a chemotaxis system, these marine chlamydiae are likely motile, with flagella potentially playing a role during host cell infection. This study broadens our view on chlamydial biology and indicates a largely underestimated potential to adapt to different hosts and environments.
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Affiliation(s)
- Astrid Collingro
- Department of Microbial and Ecosystems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Stephan Köstlbacher
- Department of Microbial and Ecosystems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Marc Mussmann
- Department of Microbial and Ecosystems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | | | - Steven J Hallam
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada.,Genome Science and Technology Program, University of British Columbia, Vancouver, British Columbia, Canada.,Graduate Program in Bioinformatics, University of British Columbia, Vancouver, British Columbia, Canada.,Peter Wall Institute for Advanced Studies, University of British Columbia, Vancouver, British Columbia, Canada.,ECOSCOPE Training Program, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthias Horn
- Department of Microbial and Ecosystems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
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26
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Ran O, Liang M, Yu J, Yu M, Song Y, Yimou W. Recombinant protein CPSIT_0846 induces protective immunity against Chlamydia psittaci infection in BALB/c mice. Pathog Dis 2017; 75:2996645. [PMID: 28204474 DOI: 10.1093/femspd/ftx018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 02/12/2017] [Indexed: 11/14/2022] Open
Abstract
Chlamydia psittaci is an obligate intracellular bacteria that causes respiratory disease in poultry and humans. Currently, there are no licensed vaccines against chlamydial infection in humans. The transmembrane head protein CPSIT_0846 of C. psittaci is a putative member of the larger Inc protein family. In this study, we investigated immunogenicity and protective efficacy of the recombinant CPSIT_0846 protein in BALB/c mice. Mice immunized with CPSIT_0846 developed strong T-lymphocyte responses that were recalled by the immunogen CPSIT_0846 in an in vitro restimulation assay. These T cells displayed a strong Th1-biased cytokine profile with high levels of IFN-γ. At the same time, a strong humoral immune response was also detected in the immunized mice with high titers of Chlamydia psittaci-specific serum IgG antibodies. More importantly, the robust immune responses correlated well with significantly reduced chlamydial burden and inflammatory pathology in the mouse lungs upon an airway challenge infection. The above results together suggest that the CPSIT_0846 protein may be a potential vaccine candidate antigen for inducing protection against C. psittaci infection and disease in the airway.
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Affiliation(s)
- Ou Ran
- Pathogenic Biology Institute, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang 421001, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang 421001, China.,Department of Clinical Laboratory, Central Hospital of Xiangtan, Xiangtan 411100, China
| | - Mingxing Liang
- Department of Clinical Laboratory, the First People's Hospital of Huaihua, Huaihua 418000, China
| | - Jian Yu
- Department of Experimental Zoology, Medical College, University of South China, Hengyang 421001, China
| | - Minjun Yu
- Pathogenic Biology Institute, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang 421001, China
| | - Ying Song
- Department of Pathology, University of South China, Hengyang 421001, China
| | - Wu Yimou
- Pathogenic Biology Institute, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang 421001, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang 421001, China
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27
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Taylor-Brown A, Pillonel T, Bridle A, Qi W, Bachmann NL, Miller TL, Greub G, Nowak B, Seth-Smith HMB, Vaughan L, Polkinghorne A. Culture-independent genomics of a novel chlamydial pathogen of fish provides new insight into host-specific adaptations utilized by these intracellular bacteria. Environ Microbiol 2017; 19:1899-1913. [PMID: 28205377 DOI: 10.1111/1462-2920.13694] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 02/02/2017] [Accepted: 02/07/2017] [Indexed: 12/12/2022]
Abstract
Several Chlamydiales families are associated with epitheliocystis, a common condition of the fish gill epithelium. These families share common ancestors with the Chlamydiaceae and environmental Chlamydiae. Due to the lack of culture systems, little is known about the biology of these chlamydial fish pathogens. We investigated epitheliocystis in cultured Orange-spotted grouper (Epinephelus coioides) from North Queensland, Australia. Basophilic inclusions were present in the gills of 22/31 fish and the presence of the chlamydial pathogen in the cysts was confirmed by in situ hybridization. Giant grouper (Epinephelus lanceolatus) cultured in the same systems were epitheliocystis free. 16S rRNA gene sequencing revealed a novel member of the Candidatus Parilichlamydiaceae: Ca. Similichlamydia epinephelii. Using metagenomic approaches, we obtained an estimated 68% of the chlamydial genome, revealing that this novel chlamydial pathogen shares a number of key pathogenic hallmarks with the Chlamydiaceae, including an intact Type III Secretion system and several chlamydial virulence factors. This provides additional evidence that these pathogenic mechanisms were acquired early in the evolution of this unique bacterial phylum. The identification and genomic characterization of Ca. S. epinephelii provides new opportunities to study the biology of distantly-related chlamydial pathogens while shining a new light on the evolution of pathogenicity of the Chlamydiaceae.
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Affiliation(s)
- Alyce Taylor-Brown
- Centre for Animal Health Innovation, Faculty of Science, Engineering and Education, University of the Sunshine Coast, Sippy Downs, Queensland, 4556, Australia
| | - Trestan Pillonel
- Institute of Microbiology, University of Lausanne, Lausanne, CH-1011, Switzerland
| | - Andrew Bridle
- Institute of Marine and Antarctic Studies, University of Tasmania, Newnham, Tasmania, 7248, Australia
| | - Weihong Qi
- Functional Genomics Centre, University of Zurich, Zurich, CH-8057, Switzerland
| | - Nathan L Bachmann
- Centre for Animal Health Innovation, Faculty of Science, Engineering and Education, University of the Sunshine Coast, Sippy Downs, Queensland, 4556, Australia
| | - Terrence L Miller
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, 4878, Australia
| | - Gilbert Greub
- Institute of Microbiology, University of Lausanne, Lausanne, CH-1011, Switzerland
| | - Barbara Nowak
- Institute of Marine and Antarctic Studies, University of Tasmania, Newnham, Tasmania, 7248, Australia
| | - Helena M B Seth-Smith
- Functional Genomics Centre, University of Zurich, Zurich, CH-8057, Switzerland.,Institute of Veterinary Pathology, University of Zurich, Zurich, CH-8057, Switzerland
| | - Lloyd Vaughan
- Institute of Veterinary Pathology, University of Zurich, Zurich, CH-8057, Switzerland
| | - Adam Polkinghorne
- Centre for Animal Health Innovation, Faculty of Science, Engineering and Education, University of the Sunshine Coast, Sippy Downs, Queensland, 4556, Australia
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Diseases of the Alimentary Tract. Vet Med (Auckl) 2017. [PMCID: PMC7167529 DOI: 10.1016/b978-0-7020-5246-0.00007-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Østergaard O, Follmann F, Olsen AW, Heegaard NH, Andersen P, Rosenkrands I. Quantitative Protein Profiling of Chlamydia trachomatis Growth Forms Reveals Defense Strategies Against Tryptophan Starvation. Mol Cell Proteomics 2016; 15:3540-3550. [PMID: 27784728 PMCID: PMC5141270 DOI: 10.1074/mcp.m116.061986] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 10/04/2016] [Indexed: 01/09/2023] Open
Abstract
Chlamydia trachomatis is one of the most common sexually transmitted bacterial pathogens in humans. The infection is often asymptomatic and can lead to chronic manifestations. The infectious elementary body and the replicating reticulate body are the two growth forms in the normal developmental cycle. Under the influence of interferon-γ, the normal cycle is disrupted because of tryptophan degradation, leading to a third persistent form, the aberrant reticulate body. For the genital strain C. trachomatis D/UW-3/CX we established a quantitative, label-free proteomic approach, and identified in total 655 out of 903 (73%) predicted proteins, allowing the first quantitative comparison of all three growth forms. Inclusion membrane proteins and proteins involved in translation were more abundant in the reticulate body (RB)1 and aberrant reticulate body (ARB) forms, whereas proteins of the type III Secretion System and the cell envelope were more abundant in the elementary body (EB) form, reflecting the need for these proteins to establish infection and for host interactions. In the interferon-γ induced ARB proteome, the tryptophan synthase subunits were identified as biomarkers with a strong increase from less than 0.05% to 9% of the total protein content, reflecting an inherent defense strategy for the pathogen to escape interferon-γ mediated immune pressure. Furthermore, the total tryptophan content in the ARB form was 1.9-fold lower compared with the EB form, and we demonstrate that modulation of the protein repertoire toward lower abundance of proteins with high tryptophan content, is a mechanism which contributes to establish and maintain chlamydial persistence. Thus, quantitative proteomics provides insights in the Chlamydia defense mechanisms to escape interferon-γ mediated immune pressure.
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Affiliation(s)
- Ole Østergaard
- From the ‡Department of Autoimmunology and Biomarkers, Statens Serum Institut, DK 2300 Copenhagen, Denmark
| | - Frank Follmann
- §Department of Infectious Disease Immunology, Statens Serum Institut, DK 2300 Copenhagen, Denmark
| | - Anja W Olsen
- §Department of Infectious Disease Immunology, Statens Serum Institut, DK 2300 Copenhagen, Denmark
| | - Niels H Heegaard
- From the ‡Department of Autoimmunology and Biomarkers, Statens Serum Institut, DK 2300 Copenhagen, Denmark
| | - Peter Andersen
- §Department of Infectious Disease Immunology, Statens Serum Institut, DK 2300 Copenhagen, Denmark
| | - Ida Rosenkrands
- §Department of Infectious Disease Immunology, Statens Serum Institut, DK 2300 Copenhagen, Denmark
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Zigangirova NA, Kost EA, Didenko LV, Kapotina LN, Zayakin ES, Luyksaar SI, Morgunova EY, Fedina ED, Artyukhova OA, Samorodov AV, Kobets NV. A small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones inhibits intracellular growth and persistence of Chlamydia trachomatis. J Med Microbiol 2016; 65:91-98. [PMID: 26489840 DOI: 10.1099/jmm.0.000189] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Chlamydia trachomatis is one of the most common sexually transmitted pathogens in the world and often causes chronic inflammatory diseases that are insensitive to antibiotics. The type 3 secretion system (T3SS) of pathogenic bacteria is a promising target for therapeutic intervention aimed at bacterial virulence and can be an attractive alternative for the treatment of chronic infections. Recently, we have shown that a small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones produced through the chemical modification of the thiohydrazides of oxamic acids, designated CL-55, inhibited the intracellular growth of C. trachomatis in a T3SS-dependent manner. To assess the feasibility of CL-55 as a therapeutic agent, our aim was to determine which point(s) in the developmental cycle CL-55 affects. We found that CL-55 had no effect on the adhesion of elementary bodies (EBs) to host cells but significantly suppressed EB internalization. We further found that CL-55 inhibited the intracellular division of reticulate bodies (RBs). An ultrastructural analysis revealed loss of contact between the RBs and the inclusion membrane in the presence of CL-55. Finally, we found that our T3SS inhibitor prevented the persistence of Chlamydia in cell culture and its reversion to the infectious state. Our findings indicate that our T3SS inhibitor may be effective in the treatment of both productive and persistent infections.
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Affiliation(s)
- Naylia A Zigangirova
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Elena A Kost
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Lubov V Didenko
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Lydia N Kapotina
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Egor S Zayakin
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Sergei I Luyksaar
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Elena Y Morgunova
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Elena D Fedina
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Olga A Artyukhova
- Bauman Moscow State Technical University, 105005, 2nd Baumanskaya Str. 5, Moscow, Russian Federation
| | - Andrey V Samorodov
- Bauman Moscow State Technical University, 105005, 2nd Baumanskaya Str. 5, Moscow, Russian Federation
| | - Natalya V Kobets
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
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From multiple pathogenicity islands to a unique organized pathogenicity archipelago. Sci Rep 2016; 6:27978. [PMID: 27302835 PMCID: PMC4908373 DOI: 10.1038/srep27978] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/25/2016] [Indexed: 12/24/2022] Open
Abstract
Pathogenicity islands are sets of successive genes in a genome that determine the virulence of a bacterium. In a growing number of studies, bacterial virulence appears to be determined by multiple islands scattered along the genome. This is the case in a family of seven plant pathogens and a human pathogen that, under KdgR regulation, massively secrete enzymes such as pectinases that degrade plant cell wall. Here we show that their multiple pathogenicity islands form together a coherently organized, single “archipelago” at the genome scale. Furthermore, in half of the species, most genes encoding secreted pectinases are expressed from the same DNA strand (transcriptional co-orientation). This genome architecture favors DNA conformations that are conducive to genes spatial co-localization, sometimes complemented by co-orientation. As proteins tend to be synthetized close to their encoding genes in bacteria, we propose that this architecture would favor the efficient funneling of pectinases at convergent points within the cell. The underlying functional hypothesis is that this convergent funneling of the full blend of pectinases constitutes a crucial strategy for successful degradation of the plant cell wall. Altogether, our work provides a new approach to describe and predict, at the genome scale, the full virulence complement.
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Waguia Kontchou C, Tzivelekidis T, Gentle IE, Häcker G. Infection of epithelial cells withChlamydia trachomatisinhibits TNF-induced apoptosis at the level of receptor internalization while leaving non-apoptotic TNF-signalling intact. Cell Microbiol 2016; 18:1583-1595. [DOI: 10.1111/cmi.12598] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 01/19/2016] [Accepted: 01/21/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Collins Waguia Kontchou
- Institute of Medical Microbiology and Hygiene; University Medical Centre Freiburg; Hermann-Herder-Str. 11 D-79104 Freiburg Germany
| | - Tina Tzivelekidis
- Institute of Medical Microbiology and Hygiene; University Medical Centre Freiburg; Hermann-Herder-Str. 11 D-79104 Freiburg Germany
| | - Ian E Gentle
- Institute of Medical Microbiology and Hygiene; University Medical Centre Freiburg; Hermann-Herder-Str. 11 D-79104 Freiburg Germany
| | - Georg Häcker
- Institute of Medical Microbiology and Hygiene; University Medical Centre Freiburg; Hermann-Herder-Str. 11 D-79104 Freiburg Germany
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Metabolic Adaptations of Intracellullar Bacterial Pathogens and their Mammalian Host Cells during Infection ("Pathometabolism"). Microbiol Spectr 2016; 3. [PMID: 26185075 DOI: 10.1128/microbiolspec.mbp-0002-2014] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several bacterial pathogens that cause severe infections in warm-blooded animals, including humans, have the potential to actively invade host cells and to efficiently replicate either in the cytosol or in specialized vacuoles of the mammalian cells. The interaction between these intracellular bacterial pathogens and the host cells always leads to multiple physiological changes in both interacting partners, including complex metabolic adaptation reactions aimed to promote proliferation of the pathogen within different compartments of the host cells. In this chapter, we discuss the necessary nutrients and metabolic pathways used by some selected cytosolic and vacuolar intracellular pathogens and--when available--the links between the intracellular bacterial metabolism and the expression of the virulence genes required for the intracellular bacterial replication cycle. Furthermore, we address the growing evidence that pathogen-specific factors may also trigger metabolic responses of the infected mammalian cells affecting the carbon and nitrogen metabolism as well as defense reactions. We also point out that many studies on the metabolic host cell responses induced by the pathogens have to be scrutinized due to the use of established cell lines as model host cells, as these cells are (in the majority) cancer cells that exhibit a dysregulated primary carbon metabolism. As the exact knowledge of the metabolic host cell responses may also provide new concepts for antibacterial therapies, there is undoubtedly an urgent need for host cell models that more closely reflect the in vivo infection conditions.
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Bergeron JR. Structural modeling of the flagellum MS ring protein FliF reveals similarities to the type III secretion system and sporulation complex. PeerJ 2016; 4:e1718. [PMID: 26925337 PMCID: PMC4768692 DOI: 10.7717/peerj.1718] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 01/31/2016] [Indexed: 11/29/2022] Open
Abstract
The flagellum is a large proteinaceous organelle found at the surface of many bacteria, whose primary role is to allow motility through the rotation of a long extracellular filament. It is an essential virulence factor in many pathogenic species, and is also a priming component in the formation of antibiotic-resistant biofilms. The flagellum consists of the export apparatus on the cytosolic side; the basal body and rotor, spanning the bacterial membrane(s) and periplasm; and the hook-filament, that protrudes away from the bacterial surface. Formation of the basal body MS ring region, constituted of multiple copies of the protein FliF, is one of the initial steps of flagellum assembly. However, the precise architecture of FliF is poorly understood. Here, I report a bioinformatics analysis of the FliF sequence from various bacterial species, suggesting that its periplasmic region is composed of three globular domains. The first two are homologous to that of the type III secretion system injectisome proteins SctJ, and the third possesses a similar fold to that of the sporulation complex component SpoIIIAG. I also describe that Chlamydia possesses an unusual FliF protein, lacking part of the SctJ homology domain and the SpoIIIAG-like domain, and fused to the rotor component FliG at its C-terminus. Finally, I have combined the sequence analysis of FliF with the EM map of the MS ring, to propose the first atomic model for the FliF oligomer, suggesting that FliF is structurally akin to a fusion of the two injectisome components SctJ and SctD. These results further define the relationship between the flagellum, injectisome and sporulation complex, and will facilitate future structural characterization of the flagellum basal body.
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Affiliation(s)
- Julien R Bergeron
- Department of Biochemistry, University of Washington , Seattle, WA , USA
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35
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Engel AC, Herbst F, Kerres A, Galle JN, Hegemann JH. The Type III Secretion System-Related CPn0809 from Chlamydia pneumoniae. PLoS One 2016; 11:e0148509. [PMID: 26895250 PMCID: PMC4760673 DOI: 10.1371/journal.pone.0148509] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 01/20/2016] [Indexed: 11/19/2022] Open
Abstract
Chlamydia pneumoniae is an intracellular Gram-negative bacterium that possesses a type III secretion system (T3SS), which enables the pathogen to deliver, in a single step, effector proteins for modulation of host-cell functions into the human host cell cytosol to establish a unique intracellular niche for replication. The translocon proteins located at the top of the T3SS needle filament are essential for its function, as they form pores in the host-cell membrane. Interestingly, unlike other Gram-negative bacteria, C. pneumoniae has two putative translocon operons, named LcrH_1 and LcrH_2. However, little is known about chlamydial translocon proteins. In this study, we analyzed CPn0809, one of the putative hydrophobic translocators encoded by the LcrH_1 operon, and identified an 'SseC-like family' domain characteristic of T3S translocators. Using bright-field and confocal microscopy, we found that CPn0809 is associated with EBs during early and very late phases of a C. pneumoniae infection. Furthermore, CPn0809 forms oligomers, and interacts with the T3SS chaperone LcrH_1, via its N-terminal segment. Moreover, expression of full-length CPn0809 in the heterologous host Escherichia coli causes a grave cytotoxic effect that leads to cell death. Taken together, our data indicate that CPn0809 likely represents one of the translocon proteins of the C. pneumoniae T3SS, and possibly plays a role in the translocation of effector proteins in the early stages of infection.
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Affiliation(s)
- Astrid C. Engel
- Lehrstuhl für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Frauke Herbst
- Lehrstuhl für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Anne Kerres
- Lehrstuhl für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Jan N. Galle
- Lehrstuhl für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Johannes H. Hegemann
- Lehrstuhl für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität, Düsseldorf, Germany
- * E-mail:
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36
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Quantitative Proteomics of the Infectious and Replicative Forms of Chlamydia trachomatis. PLoS One 2016; 11:e0149011. [PMID: 26871455 PMCID: PMC4752267 DOI: 10.1371/journal.pone.0149011] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 01/26/2016] [Indexed: 12/24/2022] Open
Abstract
The obligate intracellular developmental cycle of Chlamydia trachomatis presents significant challenges in defining its proteome. In this study we have applied quantitative proteomics to both the intracellular reticulate body (RB) and the extracellular elementary body (EB) from C. trachomatis. We used C. trachomatis L2 as a model chlamydial isolate for our study since it has a high infectivity:particle ratio and there is an excellent quality genome sequence. EBs and RBs (>99% pure) were quantified by chromosomal and plasmid copy number using PCR, from which the concentrations of chlamydial proteins per bacterial cell/genome were determined. RBs harvested at 15h post infection (PI) were purified by three successive rounds of gradient centrifugation. This is the earliest possible time to obtain purified RBs, free from host cell components in quantity, within the constraints of the technology. EBs were purified at 48h PI. We then used two-dimensional reverse phase UPLC to fractionate RB or EB peptides before mass spectroscopic analysis, providing absolute amount estimates of chlamydial proteins. The ability to express the data as molecules per cell gave ranking in both abundance and energy requirements for synthesis, allowing meaningful identification of rate-limiting components. The study assigned 562 proteins with high confidence and provided absolute estimates of protein concentration for 489 proteins. Interestingly, the data showed an increase in TTS capacity at 15h PI. Most of the enzymes involved in peptidoglycan biosynthesis were detected along with high levels of muramidase (in EBs) suggesting breakdown of peptidoglycan occurs in the non-dividing form of the microorganism. All the genome-encoded enzymes for glycolysis, pentose phosphate pathway and tricarboxylic acid cycle were identified and quantified; these data supported the observation that the EB is metabolically active. The availability of detailed, accurate quantitative proteomic data will be invaluable for investigations into gene regulation and function.
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37
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Membrane contact sites between pathogen-containing compartments and host organelles. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:895-899. [PMID: 26825687 DOI: 10.1016/j.bbalip.2016.01.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/20/2016] [Accepted: 01/25/2016] [Indexed: 11/23/2022]
Abstract
Intracellular pathogens survive and replicate within specialised membrane-bound compartments that can be considered as pseudo-organelles. Using the obligate intracellular bacterium Chlamydia as an illustrative example, we consider the modes of lipid transport between pathogen-containing compartments and host organelles, including the formation of static membrane contact sites. We discuss how lipid scavenging can be mediated via the reprogramming of cellular transporters at these interfaces and describe recent data suggesting that pathogen effectors modulate the formation of specific membrane contacts. Further study of these emerging mechanisms is likely to yield new insights into the cell biology of lipid transport and organelle communication, which highlights potential new targets and strategies for future therapeutics. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
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Jelocnik M, Bachmann NL, Kaltenboeck B, Waugh C, Woolford L, Speight KN, Gillett A, Higgins DP, Flanagan C, Myers GSA, Timms P, Polkinghorne A. Genetic diversity in the plasticity zone and the presence of the chlamydial plasmid differentiates Chlamydia pecorum strains from pigs, sheep, cattle, and koalas. BMC Genomics 2015; 16:893. [PMID: 26531162 PMCID: PMC4632680 DOI: 10.1186/s12864-015-2053-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/08/2015] [Indexed: 12/22/2022] Open
Abstract
Background Chlamydia pecorum is a globally recognised pathogen of livestock and koalas. To date, comparative genomics of C. pecorum strains from sheep, cattle and koalas has revealed that only single nucleotide polymorphisms (SNPs) and a limited number of pseudogenes appear to contribute to the genetic diversity of this pathogen. No chlamydial plasmid has been detected in these strains despite its ubiquitous presence in almost all other chlamydial species. Genomic analyses have not previously included C. pecorum from porcine hosts. We sequenced the genome of three C. pecorum isolates from pigs with differing pathologies in order to re-evaluate the genetic differences and to update the phylogenetic relationships between C. pecorum from each of the hosts. Methods Whole genome sequences for the three porcine C. pecorum isolates (L1, L17 and L71) were acquired using C. pecorum-specific sequence capture probes with culture-independent methods, and assembled in CLC Genomics Workbench. The pairwise comparative genomic analyses of 16 pig, sheep, cattle and koala C. pecorum genomes were performed using several bioinformatics platforms, while the phylogenetic analyses of the core C. pecorum genomes were performed with predicted recombination regions removed. Following the detection of a C. pecorum plasmid, a newly developed C. pecorum-specific plasmid PCR screening assay was used to evaluate the plasmid distribution in 227 C. pecorum samples from pig, sheep, cattle and koala hosts. Results Three porcine C. pecorum genomes were sequenced using C. pecorum-specific sequence capture probes with culture-independent methods. Comparative genomics of the newly sequenced porcine C. pecorum genomes revealed an increased average number of SNP differences (~11 500) between porcine and sheep, cattle, and koala C. pecorum strains, compared to previous C. pecorum genome analyses. We also identified a third copy of the chlamydial cytotoxin gene, found only in porcine C. pecorum isolates. Phylogenetic analyses clustered porcine isolates into a distinct clade, highlighting the polyphyletic origin of C. pecorum in livestock. Most surprising, we also discovered a plasmid in the porcine C. pecorum genome. Using this novel C. pecorum plasmid (pCpec) sequence, a) we developed a pCpec screening assay to evaluate the plasmid distribution in C. pecorum from different hosts; and b) to characterise the pCpec sequences from available previously sequenced C. pecorum genome data. pCpec screening showed that the pCpec is common in all hosts of C. pecorum, however not all C. pecorum strains carry pCpec. Conclusions This study provides further insight into the complexity of C. pecorum epidemiology and novel genomic regions that may be linked to host specificity. C. pecorum plasmid characterisation may aid in improving our understanding of C. pecorum pathogenesis across the variety of host species this animal pathogen infects. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2053-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Martina Jelocnik
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, 4558, Australia
| | - Nathan L Bachmann
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, 4558, Australia
| | | | - Courtney Waugh
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, 4558, Australia
| | - Lucy Woolford
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, 5371, Australia
| | - K Natasha Speight
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, 5371, Australia
| | - Amber Gillett
- Australia Zoo Wildlife Hospital, Beerwah, QLD, 4519, Australia
| | - Damien P Higgins
- Faculty of Veterinary Science, The University of Sydney, New South Wales, 2006, Australia
| | - Cheyne Flanagan
- Port Macquarie Koala Hospital, Port Macquarie, NSW, 2444, Australia
| | - Garry S A Myers
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Peter Timms
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, 4558, Australia
| | - Adam Polkinghorne
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, 4558, Australia.
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Nans A, Ford C, Hayward RD. Host-pathogen reorganisation during host cell entry by Chlamydia trachomatis. Microbes Infect 2015; 17:727-31. [PMID: 26320027 PMCID: PMC4670903 DOI: 10.1016/j.micinf.2015.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/20/2015] [Indexed: 12/12/2022]
Abstract
Chlamydia trachomatis is obligate intracellular bacterial pathogen that remains a significant public health burden worldwide. A critical early event during infection is chlamydial entry into non-phagocytic host epithelial cells. Like other Gram-negative bacteria, C. trachomatis uses a type III secretion system (T3SS) to deliver virulence effector proteins into host cells. These effectors trigger bacterial uptake and promote bacterial survival and replication within the host cell. In this review, we highlight recent cryo-electron tomography that has provided striking insights into the initial interactions between Chlamydia and its host. We describe the polarised structure of extracellular C. trachomatis elementary bodies (EBs), and the supramolecular organisation of T3SS complexes on the EB surface, in addition to the changes in host and pathogen architecture that accompany bacterial internalisation and EB encapsulation into early intracellular vacuoles. Finally, we consider the implications for further understanding the mechanism of C. trachomatis entry and how this might relate to those of other bacteria and viruses.
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Affiliation(s)
- Andrea Nans
- Institute of Structural and Molecular Biology, University College London & Birkbeck, Malet Street, London WC1E 7HX, UK
| | - Charlotte Ford
- Institute of Structural and Molecular Biology, University College London & Birkbeck, Malet Street, London WC1E 7HX, UK
| | - Richard D Hayward
- Institute of Structural and Molecular Biology, University College London & Birkbeck, Malet Street, London WC1E 7HX, UK.
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Shen L, Macnaughtan MA, Frohlich KM, Cong Y, Goodwin OY, Chou CW, LeCour L, Krup K, Luo M, Worthylake DK. Multipart Chaperone-Effector Recognition in the Type III Secretion System of Chlamydia trachomatis. J Biol Chem 2015; 290:28141-28155. [PMID: 26438824 DOI: 10.1074/jbc.m115.670232] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Indexed: 11/06/2022] Open
Abstract
Secretion of effector proteins into the eukaryotic host cell is required for Chlamydia trachomatis virulence. In the infection process, Scc1 and Scc4, two chaperones of the type III secretion (T3S) system, facilitate secretion of the important effector and plug protein, CopN, but little is known about the details of this event. Here we use biochemistry, mass spectrometry, nuclear magnetic resonance spectroscopy, and genetic analyses to characterize this trimolecular event. We find that Scc4 complexes with Scc1 and CopN in situ at the late developmental cycle of C. trachomatis. We show that Scc4 and Scc1 undergo dynamic interactions as part of the unique bacterial developmental cycle. Using alanine substitutions, we identify several amino acid residues in Scc4 that are critical for the Scc4-Scc1 interaction, which is required for forming the Scc4·Scc1·CopN ternary complex. These results, combined with our previous findings that Scc4 plays a role in transcription (Rao, X., Deighan, P., Hua, Z., Hu, X., Wang, J., Luo, M., Wang, J., Liang, Y., Zhong, G., Hochschild, A., and Shen, L. (2009) Genes Dev. 23, 1818-1829), reveal that the T3S process is linked to bacterial transcriptional events, all of which are mediated by Scc4 and its interacting proteins. A model describing how the T3S process may affect gene expression is proposed.
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Affiliation(s)
- Li Shen
- Department of Microbiology, Immunology, and Parasitology.
| | - Megan A Macnaughtan
- Department of Chemistry, Louisiana State University, Baton Range, Louisiana 70803
| | | | - Yanguang Cong
- Department of Microbiology, Immunology, and Parasitology
| | - Octavia Y Goodwin
- Department of Chemistry, Louisiana State University, Baton Range, Louisiana 70803
| | - Chau-Wen Chou
- Department of Chemistry, University of Georgia, Athens, Georgia 30602
| | - Louis LeCour
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112
| | - Kristen Krup
- Department of Microbiology, Immunology, and Parasitology
| | - Miao Luo
- Department of Microbiology, Immunology, and Parasitology
| | - David K Worthylake
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112
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Abstract
Regulation of gene expression ensures an organism responds to stimuli and undergoes proper development. Although the regulatory networks in bacteria have been investigated in model microorganisms, nearly nothing is known about the evolution and plasticity of these networks in obligate, intracellular bacteria. The phylum Chlamydiae contains a vast array of host-associated microbes, including several human pathogens. The Chlamydiae are unique among obligate, intracellular bacteria as they undergo a complex biphasic developmental cycle in which large swaths of genes are temporally regulated. Coupled with the low number of transcription factors, these organisms offer a model to study the evolution of regulatory networks in intracellular organisms. We provide the first comprehensive analysis exploring the diversity and evolution of regulatory networks across the phylum. We utilized a comparative genomics approach to construct predicted coregulatory networks, which unveiled genus- and family-specific regulatory motifs and architectures, most notably those of virulence-associated genes. Surprisingly, our analysis suggests that few regulatory components are conserved across the phylum, and those that are conserved are involved in the exploitation of the intracellular niche. Our study thus lends insight into a component of chlamydial evolution that has otherwise remained largely unexplored.
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Affiliation(s)
- D Domman
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - M Horn
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
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42
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Dumoux M, Menny A, Delacour D, Hayward RD. A Chlamydia effector recruits CEP170 to reprogram host microtubule organization. J Cell Sci 2015. [PMID: 26220855 PMCID: PMC4582400 DOI: 10.1242/jcs.169318] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The obligate intracellular bacterial pathogen Chlamydia trachomatis deploys virulence effectors to subvert host cell functions enabling its replication within a specialized membrane-bound compartment termed an inclusion. The control of the host cytoskeleton is crucial for Chlamydia uptake, inclusion biogenesis and cell exit. Here, we demonstrate how a Chlamydia effector rearranges the microtubule (MT) network by initiating organization of the MTs at the inclusion surface. We identified an inclusion-localized effector that is sufficient to interfere with MT assembly, which we named inclusion protein acting on MTs (IPAM). We established that IPAM recruits and stimulates the centrosomal protein 170 kDa (CEP170) to hijack the MT organizing functions of the host cell. We show that CEP170 is essential for chlamydial control of host MT assembly, and is required for inclusion morphogenesis and bacterial infectivity. Together, we demonstrate how a pathogen effector reprograms the host MT network to support its intracellular development.
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Affiliation(s)
- Maud Dumoux
- Institute of Structural and Molecular Biology, Birkbeck and University College London, Malet Street, London WC1E 7HX, UK
| | - Anais Menny
- Institute of Structural and Molecular Biology, Birkbeck and University College London, Malet Street, London WC1E 7HX, UK
| | - Delphine Delacour
- Cell Adhesion and Mechanics Group, Institut Jacques Monod, CNRS UMR7592, Université Paris Diderot, 15 rue Helene Brion, Paris 75013, France
| | - Richard D Hayward
- Institute of Structural and Molecular Biology, Birkbeck and University College London, Malet Street, London WC1E 7HX, UK
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43
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Chlamydia trachomatis In Vivo to In Vitro Transition Reveals Mechanisms of Phase Variation and Down-Regulation of Virulence Factors. PLoS One 2015. [PMID: 26207372 PMCID: PMC4514472 DOI: 10.1371/journal.pone.0133420] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Research on the obligate intracellular bacterium Chlamydia trachomatis demands culture in cell-lines, but the adaptive process behind the in vivo to in vitro transition is not understood. We assessed the genomic and transcriptomic dynamics underlying C. trachomatis in vitro adaptation of strains representing the three disease groups (ocular, epithelial-genital and lymphogranuloma venereum) propagated in epithelial cells over multiple passages. We found genetic features potentially underlying phase variation mechanisms mediating the regulation of a lipid A biosynthesis enzyme (CT533/LpxC), and the functionality of the cytotoxin (CT166) through an ON/OFF mechanism. We detected inactivating mutations in CT713/porB, a scenario suggesting metabolic adaptation to the available carbon source. CT135 was inactivated in a tropism-specific manner, with CT135-negative clones emerging for all epithelial-genital populations (but not for LGV and ocular populations) and rapidly increasing in frequency (~23% mutants per 10 passages). RNA-sequencing analyses revealed that a deletion event involving CT135 impacted the expression of multiple virulence factors, namely effectors known to play a role in the C. trachomatis host-cell invasion or subversion (e.g., CT456/Tarp, CT694, CT875/TepP and CT868/ChlaDub1). This reflects a scenario of attenuation of C. trachomatis virulence in vitro, which may take place independently or in a cumulative fashion with the also observed down-regulation of plasmid-related virulence factors. This issue may be relevant on behalf of the recent advances in Chlamydia mutagenesis and transformation where culture propagation for selecting mutants/transformants is mandatory. Finally, there was an increase in the growth rate for all strains, reflecting gradual fitness enhancement over time. In general, these data shed light on the adaptive process underlying the C. trachomatis in vivo to in vitro transition, and indicates that it would be prudent to restrict culture propagation to minimal passages and check the status of the CT135 genotype in order to avoid the selection of CT135-negative mutants, likely originating less virulent strains.
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44
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Fisher DJ, Adams NE, Maurelli AT. Phosphoproteomic analysis of the Chlamydia caviae elementary body and reticulate body forms. MICROBIOLOGY-SGM 2015; 161:1648-1658. [PMID: 25998263 DOI: 10.1099/mic.0.000116] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chlamydia are Gram-negative, obligate intracellular bacteria responsible for significant diseases in humans and economically important domestic animals. These pathogens undergo a unique biphasic developmental cycle transitioning between the environmentally stable elementary body (EB) and the replicative intracellular reticulate body (RB), a conversion that appears to require extensive regulation of protein synthesis and function. However, Chlamydia possess a limited number of canonical mechanisms of transcriptional regulation. Ser/Thr/Tyr phosphorylation of proteins in bacteria has been increasingly recognized as an important mechanism of post-translational control of protein function. We utilized 2D gel electrophoresis coupled with phosphoprotein staining and MALDI-TOF/TOF analysis to map the phosphoproteome of the EB and RB forms of Chlamydia caviae. Forty-two non-redundant phosphorylated proteins were identified (some proteins were present in multiple locations within the gels). Thirty-four phosphorylated proteins were identified in EBs, including proteins found in central metabolism and protein synthesis, Chlamydia-specific hypothetical proteins and virulence-related proteins. Eleven phosphorylated proteins were identified in RBs, mostly involved in protein synthesis and folding and a single virulence-related protein. Only three phosphoproteins were found in both EB and RB phosphoproteomes. Collectively, 41 of 42 C. caviae phosphoproteins were present across Chlamydia species, consistent with the existence of a conserved chlamydial phosphoproteome. The abundance of stage-specific phosphoproteins suggests that protein phosphorylation may play a role in regulating the function of developmental-stage-specific proteins and/or may function in concert with other factors in directing EB-RB transitions.
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Affiliation(s)
- Derek J Fisher
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA
| | - Nancy E Adams
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA
| | - Anthony T Maurelli
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA
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45
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Wolff BJ, Morrison SS, Pesti D, Ganakammal SR, Srinivasamoorthy G, Changayil S, Weil MR, MacCannell D, Rowe L, Frace M, Ritchie BW, Dean D, Winchell JM. Chlamydia psittaci comparative genomics reveals intraspecies variations in the putative outer membrane and type III secretion system genes. MICROBIOLOGY-SGM 2015; 161:1378-91. [PMID: 25887617 PMCID: PMC4635502 DOI: 10.1099/mic.0.000097] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chlamydia psittaci is an obligate intracellular bacterium that can cause significant disease among a broad range of hosts. In humans, this organism may cause psittacosis, a respiratory disease that can spread to involve multiple organs, and in rare untreated cases may be fatal. There are ten known genotypes based on sequencing the major outer-membrane protein gene, ompA, of C. psittaci. Each genotype has overlapping host preferences and virulence characteristics. Recent studies have compared C. psittaci among other members of the Chlamydiaceae family and showed that this species frequently switches hosts and has undergone multiple genomic rearrangements. In this study, we sequenced five genomes of C. psittaci strains representing four genotypes, A, B, D and E. Due to the known association of the type III secretion system (T3SS) and polymorphic outer-membrane proteins (Pmps) with host tropism and virulence potential, we performed a comparative analysis of these elements among these five strains along with a representative genome from each of the remaining six genotypes previously sequenced. We found significant genetic variation in the Pmps and tbl3SS genes that may partially explain differences noted in C. psittaci host infection and disease.
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Affiliation(s)
- Bernard J Wolff
- 1Infectious Diseases Laboratory, College of Veterinary Medicine, University of Georgia, Athens, GA, USA 2Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Shatavia S Morrison
- 2Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Denise Pesti
- 1Infectious Diseases Laboratory, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Satishkumar Ranganathan Ganakammal
- 3The National Center for Emerging and Zoonotic Infectious Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ganesh Srinivasamoorthy
- 3The National Center for Emerging and Zoonotic Infectious Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Shankar Changayil
- 3The National Center for Emerging and Zoonotic Infectious Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - M Ryan Weil
- 3The National Center for Emerging and Zoonotic Infectious Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Duncan MacCannell
- 3The National Center for Emerging and Zoonotic Infectious Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Lori Rowe
- 3The National Center for Emerging and Zoonotic Infectious Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Michael Frace
- 3The National Center for Emerging and Zoonotic Infectious Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Branson W Ritchie
- 1Infectious Diseases Laboratory, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Deborah Dean
- 4Children's Hospital Oakland Research Institute, Oakland, CA 5UCSF and UC Berkeley Joint Graduate Program in Bioengineering, Oakland, CA
| | - Jonas M Winchell
- 2Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
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46
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Mojica SA, Hovis KM, Frieman MB, Tran B, Hsia RC, Ravel J, Jenkins-Houk C, Wilson KL, Bavoil PM. SINC, a type III secreted protein of Chlamydia psittaci, targets the inner nuclear membrane of infected cells and uninfected neighbors. Mol Biol Cell 2015; 26:1918-34. [PMID: 25788290 PMCID: PMC4436835 DOI: 10.1091/mbc.e14-11-1530] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 03/06/2015] [Indexed: 12/31/2022] Open
Abstract
SINC, a new type III secreted protein of the avian and human pathogen Chlamydia psittaci, uniquely targets the nuclear envelope of C. psittaci-infected cells and uninfected neighboring cells. Digitonin-permeabilization studies of SINC-GFP-transfected HeLa cells indicate that SINC targets the inner nuclear membrane. SINC localization at the nuclear envelope was blocked by importazole, confirming SINC import into the nucleus. Candidate partners were identified by proximity to biotin ligase-fused SINC in HEK293 cells and mass spectrometry (BioID). This strategy identified 22 candidates with high confidence, including the nucleoporin ELYS, lamin B1, and four proteins (emerin, MAN1, LAP1, and LBR) of the inner nuclear membrane, suggesting that SINC interacts with host proteins that control nuclear structure, signaling, chromatin organization, and gene silencing. GFP-SINC association with the native LEM-domain protein emerin, a conserved component of nuclear "lamina" structure, or with a complex containing emerin was confirmed by GFP pull down. Our findings identify SINC as a novel bacterial protein that targets the nuclear envelope with the capability of globally altering nuclear envelope functions in the infected host cell and neighboring uninfected cells. These properties may contribute to the aggressive virulence of C. psittaci.
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Affiliation(s)
- Sergio A Mojica
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201
| | - Kelley M Hovis
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201
| | - Matthew B Frieman
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 20201
| | - Bao Tran
- Mass Spectrometry Center, University of Maryland School of Pharmacy, Baltimore, MD 21201
| | - Ru-ching Hsia
- Core Imaging Facility and Department of Neural and Pain Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201
| | - Jacques Ravel
- Institute for Genome Science, University of Maryland School of Medicine, Baltimore, MD 20201
| | - Clifton Jenkins-Houk
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Katherine L Wilson
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Patrik M Bavoil
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201
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47
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Borges V, Gomes JP. Deep comparative genomics among Chlamydia trachomatis lymphogranuloma venereum isolates highlights genes potentially involved in pathoadaptation. INFECTION GENETICS AND EVOLUTION 2015; 32:74-88. [PMID: 25745888 DOI: 10.1016/j.meegid.2015.02.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/23/2015] [Accepted: 02/26/2015] [Indexed: 11/19/2022]
Abstract
Lymphogranuloma venereum (LGV) is a human sexually transmitted disease caused by the obligate intracellular bacterium Chlamydia trachomatis (serovars L1-L3). LGV clinical manifestations range from severe ulcerative proctitis (anorectal syndrome), primarily caused by the epidemic L2b strains, to painful inguinal lymphadenopathy (the typical LGV bubonic form). Besides potential host-related factors, the differential disease severity and tissue tropism among LGV strains is likely a function of the genetic backbone of the strains. We aimed to characterize the genetic variability among LGV strains as strain- or serovar-specific mutations may underlie phenotypic signatures, and to investigate the mutational events that occurred throughout the pathoadaptation of the epidemic L2b lineage. By analyzing 20 previously published genomes from L1, L2, L2b and L3 strains and two new genomes from L2b strains, we detected 1497 variant sites and about 100 indels, affecting 453 genes and 144 intergenic regions, with 34 genes displaying a clear overrepresentation of nonsynonymous mutations. Effectors and/or type III secretion substrates (almost all of those described in the literature) and inclusion membrane proteins showed amino acid changes that were about fivefold more frequent than silent changes. More than 120 variant sites occurred in plasmid-regulated virulence genes, and 66% yielded amino acid changes. The identified serovar-specific variant sites revealed that the L2b-specific mutations are likely associated with higher fitness and pointed out potential targets for future highly discriminatory diagnostic/typing tests. By evaluating the evolutionary pathway beyond the L2b clonal radiation, we observed that 90.2% of the intra-L2b variant sites occurring in coding regions involve nonsynonymous mutations, where CT456/tarp has been the main target. Considering the progress on C. trachomatis genetic manipulation, this study may constitute an important contribution for prioritizing study targets for functional genomics aiming to dissect the impact of the identified intra-LGV polymorphisms on virulence or tropism dissimilarities among LGV strains.
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Affiliation(s)
- Vítor Borges
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016 Lisbon, Portugal; Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016 Lisbon, Portugal
| | - João Paulo Gomes
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016 Lisbon, Portugal; Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016 Lisbon, Portugal.
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48
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Chlamydia abortus: New Aspects of Infectious Abortion in Sheep and Potential Risk for Pregnant Women. CURRENT CLINICAL MICROBIOLOGY REPORTS 2015. [DOI: 10.1007/s40588-015-0014-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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49
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Bertelli C, Aeby S, Chassot B, Clulow J, Hilfiker O, Rappo S, Ritzmann S, Schumacher P, Terrettaz C, Benaglio P, Falquet L, Farinelli L, Gharib WH, Goesmann A, Harshman K, Linke B, Miyazaki R, Rivolta C, Robinson-Rechavi M, van der Meer JR, Greub G. Sequencing and characterizing the genome of Estrella lausannensis as an undergraduate project: training students and biological insights. Front Microbiol 2015; 6:101. [PMID: 25745418 PMCID: PMC4333871 DOI: 10.3389/fmicb.2015.00101] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 01/26/2015] [Indexed: 12/25/2022] Open
Abstract
With the widespread availability of high-throughput sequencing technologies, sequencing projects have become pervasive in the molecular life sciences. The huge bulk of data generated daily must be analyzed further by biologists with skills in bioinformatics and by "embedded bioinformaticians," i.e., bioinformaticians integrated in wet lab research groups. Thus, students interested in molecular life sciences must be trained in the main steps of genomics: sequencing, assembly, annotation and analysis. To reach that goal, a practical course has been set up for master students at the University of Lausanne: the "Sequence a genome" class. At the beginning of the academic year, a few bacterial species whose genome is unknown are provided to the students, who sequence and assemble the genome(s) and perform manual annotation. Here, we report the progress of the first class from September 2010 to June 2011 and the results obtained by seven master students who specifically assembled and annotated the genome of Estrella lausannensis, an obligate intracellular bacterium related to Chlamydia. The draft genome of Estrella is composed of 29 scaffolds encompassing 2,819,825 bp that encode for 2233 putative proteins. Estrella also possesses a 9136 bp plasmid that encodes for 14 genes, among which we found an integrase and a toxin/antitoxin module. Like all other members of the Chlamydiales order, Estrella possesses a highly conserved type III secretion system, considered as a key virulence factor. The annotation of the Estrella genome also allowed the characterization of the metabolic abilities of this strictly intracellular bacterium. Altogether, the students provided the scientific community with the Estrella genome sequence and a preliminary understanding of the biology of this recently-discovered bacterial genus, while learning to use cutting-edge technologies for sequencing and to perform bioinformatics analyses.
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Affiliation(s)
- Claire Bertelli
- Center for Research on Intracellular Bacteria, Institute of Microbiology, University Hospital Center and University of Lausanne Lausanne, Switzerland ; SIB Swiss Institute of Bioinformatics Lausanne, Switzerland
| | - Sébastien Aeby
- Center for Research on Intracellular Bacteria, Institute of Microbiology, University Hospital Center and University of Lausanne Lausanne, Switzerland
| | | | - James Clulow
- School of Biology, University of Lausanne Lausanne, Switzerland
| | | | - Samuel Rappo
- School of Biology, University of Lausanne Lausanne, Switzerland
| | | | | | | | - Paola Benaglio
- Department of Medical Genetics, University of Lausanne Lausanne, Switzerland
| | - Laurent Falquet
- Division of Biochemistry, Department of Biology, University of Fribourg Fribourg, Switzerland ; SIB Swiss Institute of Bioinformatics Lausanne, Switzerland
| | | | - Walid H Gharib
- Department of Ecology and Evolution, University of Lausanne Lausanne, Switzerland ; SIB Swiss Institute of Bioinformatics Lausanne, Switzerland
| | - Alexander Goesmann
- Department of Bioinformatics and Systems Biology, Justus-Liebig-University Giessen Gießen, Germany
| | - Keith Harshman
- Lausanne Genomic Technologies Facility, Center for Integrative Genomics, University of Lausanne Lausanne, Switzerland
| | - Burkhard Linke
- Department of Bioinformatics and Systems Biology, Justus-Liebig-University Giessen Gießen, Germany
| | - Ryo Miyazaki
- Department of Fundamental Microbiology, University of Lausanne Lausanne, Switzerland
| | - Carlo Rivolta
- Department of Medical Genetics, University of Lausanne Lausanne, Switzerland
| | - Marc Robinson-Rechavi
- Department of Ecology and Evolution, University of Lausanne Lausanne, Switzerland ; SIB Swiss Institute of Bioinformatics Lausanne, Switzerland
| | | | - Gilbert Greub
- Center for Research on Intracellular Bacteria, Institute of Microbiology, University Hospital Center and University of Lausanne Lausanne, Switzerland
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50
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Amoebal endosymbiont Parachlamydia acanthamoebae Bn9 can grow in immortal human epithelial HEp-2 cells at low temperature; an in vitro model system to study chlamydial evolution. PLoS One 2015; 10:e0116486. [PMID: 25643359 PMCID: PMC4314085 DOI: 10.1371/journal.pone.0116486] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 12/08/2014] [Indexed: 01/07/2023] Open
Abstract
Ancient chlamydiae diverged into pathogenic and environmental chlamydiae 0.7–1.4 billion years ago. However, how pathogenic chlamydiae adapted to mammalian cells that provide a stable niche at approximately 37°C, remains unknown, although environmental chlamydiae have evolved as endosymbionts of lower eukaryotes in harsh niches of relatively low temperatures. Hence, we assessed whether an environmental chlamydia, Parachlamydia Bn9, could grow in human HEp-2 cells at a low culture temperature of 30°C. The assessment of inclusion formation by quantitative RT-PCR revealed that the numbers of bacterial inclusion bodies and the transcription level of 16SrRNA significantly increased after culture at 30°C compared to at 37°C. Confocal microscopy showed that the bacteria were located close to HEp-2 nuclei and were actively replicative. Transmission electron microscopy also revealed replicating bacteria consisting of reticular bodies, but with a few elementary bodies. Cytochalasin D and rifampicin inhibited inclusion formation. Lactacystin slightly inhibited bacterial inclusion formation. KEGG analysis using a draft genome sequence of the bacteria revealed that it possesses metabolic pathways almost identical to those of pathogenic chlamydia. Interestingly, comparative genomic analysis with pathogenic chlamydia revealed that the Parachlamydia similarly possess the genes encoding Type III secretion system, but lacking genes encoding inclusion membrane proteins (IncA to G) required for inclusion maturation. Taken together, we conclude that ancient chlamydiae had the potential to grow in human cells, but overcoming the thermal gap was a critical event for chlamydial adaptation to human cells.
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