1
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Wickramasinghe HC, Lincoln JN, D'Armond AE, Noble SA, Shen L, Macnaughtan MA. Insights into the association of the Chlamydia trachomatis type III secretion chaperone complex, Scc4:Scc1, from sequential expression in Escherichia coli. Protein Expr Purif 2024; 222:106532. [PMID: 38857716 DOI: 10.1016/j.pep.2024.106532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 06/03/2024] [Accepted: 06/08/2024] [Indexed: 06/12/2024]
Abstract
Chlamydia trachomatis (CT) is the bacterial pathogen responsible for causing the most common sexually transmitted disease in the United States. This obligate, intracellular Gram-negative bacterium has a type III secretion system (T3SS) to invade host cells. CopN is an important effector, plug protein that mediates early interactions between the host and Chlamydia. CopN is chaperoned by a heterodimer, T3SS chaperone complex containing Scc4 and Scc1. Scc4 is a unique, bifunctional protein that, in addition to its T3SS chaperone activity, acts as an RNA polymerase (RNAP) binding protein. We hypothesized that the two functions occur at different points in CT's developmental cycle with Scc4 acting alone in the early-to-mid stages and the Scc4:Scc1 complex chaperoning CopN in the mid-to-late stages. To study the Scc4:Scc1 complex by NMR, we previously explored various methods of associating Scc4 and Scc1 in vitro to produce the complex with chain-selective isotopic labeling. Though co-expressed Scc4 and Scc1 form a stable complex, the in vitro association studies suggest that partial protein denaturation and/or components in E. coli lysate are necessary to form the stable complex. In this study Scc4 and Scc1 were sequentially expressed in E. coli under the control of different promoters, allowing separate isotopic labeling of each chain and complex formation in vivo. Sequential expression resulted in no or unstable complex formation depending on the culture medium used. These results, taken together with previous in vitro association studies, suggest that Scc4 and Scc1 assemble co-translationally to form the stable Scc4:Scc1 complex in E. coli.
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Affiliation(s)
| | - Juliette N Lincoln
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, United States
| | - Anne E D'Armond
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, United States
| | - Sadie A Noble
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, United States
| | - Li Shen
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, United States
| | - Megan A Macnaughtan
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, United States; Department of Chemistry and Biochemistry, John Carroll University, University Heights, OH, 44118, United States.
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2
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Pereira IS, da Cunha M, Leal IP, Luís MP, Gonçalves P, Gonçalves C, Mota LJ. Identification of homologs of the Chlamydia trachomatis effector CteG reveals a family of Chlamydiaceae type III secreted proteins that can be delivered into host cells. Med Microbiol Immunol 2024; 213:15. [PMID: 39008129 PMCID: PMC11249467 DOI: 10.1007/s00430-024-00798-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 07/06/2024] [Indexed: 07/16/2024]
Abstract
Chlamydiae are a large group of obligate endosymbionts of eukaryotes that includes the Chlamydiaceae family, comprising several animal pathogens. Among Chlamydiaceae, Chlamydia trachomatis causes widespread ocular and urogenital infections in humans. Like many bacterial pathogens, all Chlamydiae manipulate host cells by injecting them with type III secretion effector proteins. We previously characterized the C. trachomatis effector CteG, which localizes at the host cell Golgi and plasma membrane during distinct phases of the chlamydial infectious cycle. Here, we show that CteG is a Chlamydiaceae-specific effector with over 60 homologs phylogenetically categorized into two distinct clades (CteG I and CteG II) and exhibiting several inparalogs and outparalogs. Notably, cteG I homologs are syntenic to C. trachomatis cteG, whereas cteG II homologs are syntenic among themselves but not with C. trachomatis cteG. This indicates a complex evolution of cteG homologs, which is unique among C. trachomatis effectors, marked by numerous events of gene duplication and loss. Despite relatively modest sequence conservation, nearly all tested CteG I and CteG II proteins were identified as type III secretion substrates using Yersinia as a heterologous bacterial host. Moreover, most of the type III secreted CteG I and CteG II homologs were delivered by C. trachomatis into host cells, where they localized at the Golgi region and cell periphery. Overall, this provided insights into the evolution of bacterial effectors and revealed a Chlamydiaceae family of type III secreted proteins that underwent substantial divergence during evolution while conserving the capacity to localize at specific host cell compartments.
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Affiliation(s)
- Inês Serrano Pereira
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO - Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Maria da Cunha
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO - Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Inês Pacheco Leal
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO - Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Maria Pequito Luís
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO - Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Paula Gonçalves
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO - Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Carla Gonçalves
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- UCIBIO - Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Luís Jaime Mota
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal.
- UCIBIO - Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal.
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3
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Zhang Y, Ren Y, Wang B, Guo S, Wang S, Jin J, Yang L, Gao W. Purification, crystallization and preliminary crystallographic analysis of Chlamydophila pneumoniae AP endonuclease IV. Protein Expr Purif 2024; 219:106476. [PMID: 38521114 DOI: 10.1016/j.pep.2024.106476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 03/25/2024]
Abstract
Base excision is a crucial DNA repair process mediated by endonuclease IV in nucleotide excision. In Chlamydia pneumoniae, CpendoIV is the exclusive AP endonuclease IV, exhibiting DNA replication error-proofreading capabilities, making it a promising target for anti-chlamydial drug development. Predicting the structure of CpendoIV, molecular docking with DNA was performed, analyzing complex binding sites and protein surface electrostatic potential. Comparative structural studies were conducted with E. coli EndoIV and DNA complex containing AP sites.CpendoIV was cloned, expressed in E. coli, and purified via Ni-NTA chelation and size-exclusion chromatography. Low NaCl concentrations induced aggregation during purification, while high concentrations enhanced purity.CpendoIV recognizes and cleaving AP sites on dsDNA, and Zn2+ influences the activity. Crystallization was achieved under 8% (v/v) Tacsimate pH 5.2, 25% (w/v) polyethylene glycol 3350, and 1.91 Å resolution X-ray diffraction data was obtained at 100 K. This research is significant for provides a deeper understanding of CpendoIV involvement in the base excision repair process, offering insights into Chlamydia pneumoniae.
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Affiliation(s)
- Yitong Zhang
- School of Science, Beijing Forestry University, 35 Qinghuadong Road, Beijing, 100083, China.
| | - Yangjie Ren
- School of Science, Beijing Forestry University, 35 Qinghuadong Road, Beijing, 100083, China.
| | - Ben Wang
- School of Science, Beijing Forestry University, 35 Qinghuadong Road, Beijing, 100083, China.
| | - Shiyang Guo
- School of Science, Beijing Forestry University, 35 Qinghuadong Road, Beijing, 100083, China.
| | - Siqi Wang
- School of Science, Beijing Forestry University, 35 Qinghuadong Road, Beijing, 100083, China.
| | - Jinglin Jin
- School of Science, Beijing Forestry University, 35 Qinghuadong Road, Beijing, 100083, China.
| | - Lihong Yang
- School of Science, Beijing Forestry University, 35 Qinghuadong Road, Beijing, 100083, China.
| | - Wei Gao
- School of Science, Beijing Forestry University, 35 Qinghuadong Road, Beijing, 100083, China.
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4
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Lee J, Ouellette SP. Cyclic di-AMP drives developmental cycle progression in Chlamydia trachomatis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.24.595738. [PMID: 38826436 PMCID: PMC11142226 DOI: 10.1101/2024.05.24.595738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
The obligate intracellular bacterium Chlamydia alternates between two functional forms during its developmental cycle: elementary body (EB) and reticulate body (RB). However, the molecular mechanisms governing the transitions between these forms are unknown. Here, we present evidence cyclic di-AMP (c-di-AMP) is a key factor in triggering the transition from RB to EB (i.e., secondary differentiation) in the chlamydial developmental cycle. We made strains producing different levels of c-di-AMP, which we linked to changes in secondary differentiation status. Increases in c-di-AMP resulted in an earlier increase in transcription of EB-associated genes, and this was further manifested in earlier production of EBs. In contrast, when c-di-AMP levels were decreased, secondary differentiation was delayed. Based on these data, we conclude there is a threshold level of c-di-AMP needed to trigger secondary differentiation in Chlamydia . This is the first study to identify a physiological function for c-di-AMP production in Chlamydia as well as a mechanism by which secondary differentiation is initiated in these pathogens. Importance The second messenger molecule, cyclic di-AMP, shows diverse functions in bacteria. This molecule is usually detected in Gram-positive bacteria and is related to the osmotic stress response, DNA replication, and sporulation. Chlamydia trachomatis , a Gram-negative bacterium, encodes genes related to cyclic di-AMP synthesis. Cyclic di-AMP has been detected in C. trachomatis , where it has been shown to trigger a STING-dependent immune response in host cells. However, its physiological function in C. trachomatis is unknown. In this study, we identify a function for cyclic di-AMP in triggering gene expression linked to secondary differentiation in chlamydial developmental cycle. Our findings are important in understanding the molecular mechanism of the chlamydial developmental cycle and contribute to providing new therapeutic strategies for chlamydial infectious diseases.
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Wan D, Cheng A, Wang Y, Zhong G, Li WV, Fan H. Analyzing RNA-Seq Data from Chlamydia with Super Broad Transcriptomic Activation: Challenges, Solutions, and Implications for Other Systems. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.16.594566. [PMID: 38826265 PMCID: PMC11142123 DOI: 10.1101/2024.05.16.594566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Motivation RNA sequencing (RNA-Seq) offers profound insights into the complex transcriptomes of diverse biological systems. However, standard differential expression analysis pipelines based on DESeq2 and edgeR encounter challenges when applied to the immediate early transcriptomes of Chlamydia spp., obligate intracellular bacteria. These challenges arise from their reliance on assumptions that do not hold in scenarios characterized by extensive transcriptomic activation and limited repression. Standard analyses using unique chlamydial RNA-Seq reads alone identify nearly 300 upregulated and about 300 downregulated genes, significantly deviating from actual RNA-Seq read trends. Results By incorporating both chlamydial and host reads or adjusting for total sequencing depth, the revised normalization methods each detected over 700 upregulated genes and 30 or fewer downregulated genes, closely aligned with observed RNA-Seq data. Further validation through qRT-PCR analysis confirmed the effectiveness of these adjusted approaches in capturing the true extent of transcriptomic activation during the immediate early phase of chlamydial infection. While the strategies employed are developed in the context of Chlamydia, the principles of flexible and context-aware normalization may inform adjustments in other systems with unbalanced gene expression dynamics, such as bacterial spore germination. Availability and implementation The code for reproducing the presented bioinformatic analysis is available at https://zenodo.org/records/11201379.
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Affiliation(s)
- Danny Wan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Andrew Cheng
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Yuxuan Wang
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Guangming Zhong
- Department of Microbiology and Immunology, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Wei Vivian Li
- Department of Statistics, University of California Riverside, Riverside, CA92521, USA
| | - Huizhou Fan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
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6
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Cifuente JO, Colleoni C, Kalscheuer R, Guerin ME. Architecture, Function, Regulation, and Evolution of α-Glucans Metabolic Enzymes in Prokaryotes. Chem Rev 2024; 124:4863-4934. [PMID: 38606812 PMCID: PMC11046441 DOI: 10.1021/acs.chemrev.3c00811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Bacteria have acquired sophisticated mechanisms for assembling and disassembling polysaccharides of different chemistry. α-d-Glucose homopolysaccharides, so-called α-glucans, are the most widespread polymers in nature being key components of microorganisms. Glycogen functions as an intracellular energy storage while some bacteria also produce extracellular assorted α-glucans. The classical bacterial glycogen metabolic pathway comprises the action of ADP-glucose pyrophosphorylase and glycogen synthase, whereas extracellular α-glucans are mostly related to peripheral enzymes dependent on sucrose. An alternative pathway of glycogen biosynthesis, operating via a maltose 1-phosphate polymerizing enzyme, displays an essential wiring with the trehalose metabolism to interconvert disaccharides into polysaccharides. Furthermore, some bacteria show a connection of intracellular glycogen metabolism with the genesis of extracellular capsular α-glucans, revealing a relationship between the storage and structural function of these compounds. Altogether, the current picture shows that bacteria have evolved an intricate α-glucan metabolism that ultimately relies on the evolution of a specific enzymatic machinery. The structural landscape of these enzymes exposes a limited number of core catalytic folds handling many different chemical reactions. In this Review, we present a rationale to explain how the chemical diversity of α-glucans emerged from these systems, highlighting the underlying structural evolution of the enzymes driving α-glucan bacterial metabolism.
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Affiliation(s)
- Javier O. Cifuente
- Instituto
Biofisika (UPV/EHU, CSIC), University of
the Basque Country, E-48940 Leioa, Spain
| | - Christophe Colleoni
- University
of Lille, CNRS, UMR8576-UGSF -Unité de Glycobiologie Structurale
et Fonctionnelle, F-59000 Lille, France
| | - Rainer Kalscheuer
- Institute
of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, 40225 Dusseldorf, Germany
| | - Marcelo E. Guerin
- Structural
Glycobiology Laboratory, Department of Structural and Molecular Biology, Molecular Biology Institute of Barcelona (IBMB), Spanish
National Research Council (CSIC), Barcelona Science Park, c/Baldiri Reixac 4-8, Tower R, 08028 Barcelona, Catalonia, Spain
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7
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Bastidas RJ, Kędzior M, Davidson RK, Walsh SC, Dolat L, Sixt BS, Pruneda JN, Coers J, Valdivia RH. The acetylase activity of Cdu1 regulates bacterial exit from infected cells by protecting Chlamydia effectors from degradation. eLife 2024; 12:RP87386. [PMID: 38358795 PMCID: PMC10942603 DOI: 10.7554/elife.87386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Abstract
Many cellular processes are regulated by ubiquitin-mediated proteasomal degradation. Pathogens can regulate eukaryotic proteolysis through the delivery of proteins with de-ubiquitinating (DUB) activities. The obligate intracellular pathogen Chlamydia trachomatis secretes Cdu1 (ChlaDUB1), a dual deubiquitinase and Lys-acetyltransferase, that promotes Golgi remodeling and survival of infected host cells presumably by regulating the ubiquitination of host and bacterial proteins. Here, we determined that Cdu1's acetylase but not its DUB activity is important to protect Cdu1 from ubiquitin-mediated degradation. We further identified three C. trachomatis proteins on the pathogen-containing vacuole (InaC, IpaM, and CTL0480) that required Cdu1's acetylase activity for protection from degradation and determined that Cdu1 and these Cdu1-protected proteins are required for optimal egress of Chlamydia from host cells. These findings highlight a non-canonical mechanism of pathogen-mediated protection of virulence factors from degradation after their delivery into host cells and the coordinated regulation of secreted effector proteins.
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Affiliation(s)
- Robert J Bastidas
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
| | - Mateusz Kędzior
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
| | - Robert K Davidson
- Department of Molecular Genetics and Microbiology, Duke UniversityDukeUnited States
| | - Stephen C Walsh
- Department of Molecular Genetics and Microbiology, Duke UniversityDukeUnited States
| | - Lee Dolat
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
| | - Barbara S Sixt
- Deparment of Molecular Biology, Umeå UniversityUmeåSweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå UniversityUmeåSweden
- Umeå Centre for Microbial Research (UCMR), Umeå UniversityUmeåSweden
| | - Jonathan N Pruneda
- Department of Molecular Microbiology & Immunology, Oregon Health & Science UniversityPortlandUnited States
| | - Jorn Coers
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
- Department of Molecular Genetics and Microbiology, Duke UniversityDukeUnited States
| | - Raphael H Valdivia
- Department of Integrative Immunobiology, Duke UniversityDurhamUnited States
- Department of Molecular Genetics and Microbiology, Duke UniversityDukeUnited States
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Shen L, Gao L, Swoboda AR, Ouellette SP. Targeted repression of topA by CRISPRi reveals a critical function for balanced DNA topoisomerase I activity in the Chlamydia trachomatis developmental cycle. mBio 2024; 15:e0258423. [PMID: 38265209 PMCID: PMC10865786 DOI: 10.1128/mbio.02584-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 12/06/2023] [Indexed: 01/25/2024] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that is responsible for the most prevalent bacterial sexually transmitted infection. Changes in DNA topology in this pathogen have been linked to its pathogenicity-associated developmental cycle. Here, evidence is provided that the balanced activity of DNA topoisomerases contributes to controlling Chlamydia developmental processes. Utilizing catalytically inactivated Cas12 (dCas12)-based clustered regularly interspaced short palindromic repeats interference (CRISPRi) technology, we demonstrate targeted knockdown of chromosomal topA transcription in C. trachomatis without detected toxicity of dCas12. Repression of topA impaired the developmental cycle of C. trachomatis mostly through disruption of its differentiation from a replicative form to an infectious form. Consistent with this, expression of late developmental genes of C. trachomatis was downregulated, while early genes maintained their expression. Importantly, the developmental defect associated with topA knockdown was rescued by overexpressing topA at an appropriate degree and time, directly linking the growth patterns to the levels of topA expression. Interestingly, topA knockdown had effects on DNA gyrase expression, indicating a potential compensatory mechanism for survival to offset TopA deficiency. C. trachomatis with topA knocked down displayed hypersensitivity to moxifloxacin that targets DNA gyrase in comparison with the wild type. These data underscore the requirement of integrated topoisomerase actions to support the essential developmental and transcriptional processes of C. trachomatis.IMPORTANCEWe used genetic and chemical tools to demonstrate the relationship of topoisomerase activities and their obligatory role for the chlamydial developmental cycle. Successfully targeting the essential gene topA with a CRISPRi approach, using dCas12, in C. trachomatis indicates that this method will facilitate the characterization of the essential genome. These findings have an important impact on our understanding of the mechanisms by which well-balanced topoisomerase functions in adaptation of C. trachomatis to unfavorable growth conditions imposed by antibiotics.
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Affiliation(s)
- Li Shen
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Leiqiong Gao
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Abigail R. Swoboda
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Scot P. Ouellette
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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9
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Rockey DD, Wang X, Debrine A, Grieshaber N, Grieshaber SS. Metabolic dormancy in Chlamydia trachomatis treated with different antibiotics. Infect Immun 2024; 92:e0033923. [PMID: 38214508 PMCID: PMC10863404 DOI: 10.1128/iai.00339-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/11/2023] [Indexed: 01/13/2024] Open
Abstract
Diseases caused by Chlamydia spp. are often associated with persistent infections. Chlamydial persistence is commonly associated with a unique non-infectious intracellular developmental form, termed an aberrant form. Although infectious chlamydiae can be cultured consistently in cells stressed to aberrancy, their role in persistence is not clear. Recovery from antibiotic stress was explored as a model to determine how survival of non-aberrant chlamydiae, in the presence of fully inhibitory drug concentrations, may participate in persistence. Assays included incubation in quinolones, tetracyclines, or chloramphenicol for differing lengths of time, followed by an extended recovery period in antibiotic-free media. Culturable elementary bodies were not detected during treatment with each antibiotic, but viable and culturable Chlamydia trachomatis emerged after the drug was removed. Time-lapse imaging of live, antibiotic-treated infected cells identified metabolically dormant developmental forms within cells that emerged to form typical productive inclusions. The effects of the increasing concentration of most tested antibiotics led to predictable inhibitory activity, in which the survival rate decreased with increasing drug concentration. In contrast, in fluoroquinolone-treated cells, there was a paradoxical increase in productive development that was directly correlated with drug concentration and inversely associated with aberrant form production. This model system uncovers a unique chlamydial persistence pathway that does not involve the chlamydial aberrant form. The association between productive latency and metabolic dormancy is consistent with models for many bacterial species and may lead to a different interpretation of mechanisms of chlamydial persistence in patients.IMPORTANCEThe life history of most pathogens within the genus Chlamydia relies on lengthy persistence in the host. The most generally accepted model for Chlamydia spp. persistence involves an unusual developmental stage, termed the aberrant form, which arises during conditions that mimic a stressful host environment. In this work, we provide an alternate model for chlamydial persistence in the face of antibiotic stress. This model may be relevant to antibiotic treatment failures in patients infected with C. trachomatis.
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Affiliation(s)
- Daniel D. Rockey
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Xisheng Wang
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Abigail Debrine
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Nicole Grieshaber
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA
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10
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Murthy AK, Wright-McAfee E, Warda K, Moy LN, Bui N, Musunuri T, Manam S, Chako CZ, Ramsey KH, Li W. Protective anti-chlamydial vaccine regimen-induced CD4+ T cell response mediates early inhibition of pathogenic CD8+ T cell response following genital challenge. Pathog Dis 2024; 82:ftae008. [PMID: 38684476 PMCID: PMC11149721 DOI: 10.1093/femspd/ftae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/19/2024] [Accepted: 04/26/2024] [Indexed: 05/02/2024] Open
Abstract
We have demonstrated previously that TNF-α-producing CD8+ T cells mediate chlamydial pathogenesis, likely in an antigen (Ag)-specific fashion. Here we hypothesize that inhibition of Ag-specific CD8+ T cell response after immunization and/or challenge would correlate with protection against oviduct pathology induced by a protective vaccine regimen. Intranasal (i.n.) live chlamydial elementary body (EB), intramuscular (i.m.) live EB, or i.n. irrelevant antigen, bovine serum albumin (BSA), immunized animals induced near-total protection, 50% protection, or no protection, respectively against oviduct pathology following i.vag. C. muridarum challenge. In these models, we evaluated Ag-specific CD8+ T cell cytokine response at various time-periods after immunization or challenge. The results show protective efficacy of vaccine regimens correlated with reduction of Ag-specific CD8+ T cell TNF-α responses following i.vag. chlamydial challenge, not after immunization. Depletion of CD4+ T cells abrogated, whereas adoptive transfer of Ag-specific CD4+ T cells induced the significant reduction of Ag-specific CD8+ T cell TNF-α response after chlamydial challenge. In conclusion, protective anti-chlamydial vaccine regimens induce Ag-specific CD4+ T cell response that mediate early inhibition of pathogenic CD8+ T cell response following challenge and may serve as a predictive biomarker of protection against Chlamydia -induced chronic pathologies.
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Affiliation(s)
- Ashlesh K Murthy
- College of Veterinary Medicine, Midwestern University, Glendale, AZ 85308, USA
| | - Erika Wright-McAfee
- College of Veterinary Medicine, Midwestern University, Glendale, AZ 85308, USA
| | - Katerina Warda
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA
| | - Lindsay N Moy
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA
| | - Nhi Bui
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA
| | - Tarakarama Musunuri
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA
| | - Srikanth Manam
- College of Veterinary Medicine, Midwestern University, Glendale, AZ 85308, USA
| | - Clemence Z Chako
- College of Veterinary Medicine, Midwestern University, Glendale, AZ 85308, USA
| | - Kyle H Ramsey
- College of Veterinary Medicine, Midwestern University, Glendale, AZ 85308, USA
- College of Graduate Studies, Midwestern University, Glendale, AZ 85308, USA
| | - Weidang Li
- College of Veterinary Medicine, Midwestern University, Glendale, AZ 85308, USA
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11
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Zhou Z, Liu Y, Yang C, Saka HA. Editorial: Chlamydia-host interaction and its pathogenic mechanism. Front Cell Infect Microbiol 2024; 14:1372714. [PMID: 38379769 PMCID: PMC10877369 DOI: 10.3389/fcimb.2024.1372714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 01/25/2024] [Indexed: 02/22/2024] Open
Affiliation(s)
- Zhou Zhou
- Institute of Pathogenic Biology, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical College, University of South China, Hengyan, China
| | - Yuanjun Liu
- Department of Dermatovenereology, Tianjin Medical University General Hospital, Tianjin, China
| | - Chunfu Yang
- School of Public Health and Emergency Management, Southern University of Science and Technology, Shenzhen, China
| | - Hector Alex Saka
- Laboratory of Cellular and Molecular Microbiology, Centre for Research in Clinical Biochemistry and Immunology (CIBICI), National Council on Scientific and Technical Research (CONICET), Cordoba, Argentina
- Department of Clinical Biochemistry, School of Chemical Sciences, National University of Cordoba, Cordoba, Argentina
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12
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Walker FC, Derré I. Contributions of diverse models of the female reproductive tract to the study of Chlamydia trachomatis-host interactions. Curr Opin Microbiol 2024; 77:102416. [PMID: 38103413 PMCID: PMC10922760 DOI: 10.1016/j.mib.2023.102416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/19/2023]
Abstract
Chlamydia trachomatis is a common cause of sexually transmitted infections in humans with devastating sequelae. Understanding of disease on all scales, from molecular details to the immunology underlying pathology, is essential for identifying new ways of preventing and treating chlamydia. Infection models of various complexity are essential to understand all aspects of chlamydia pathogenesis. Cell culture systems allow for research into molecular details of infection, including characterization of the unique biphasic Chlamydia developmental cycle and the role of type-III-secreted effectors in modifying the host environment to allow for infection. Multicell type and organoid culture provide means to investigate how cells other than the infected cells contribute to the control of infection. Emerging comprehensive three-dimensional biomimetic systems may fill an important gap in current models to provide information on complex phenotypes that cannot be modeled in simpler in vitro models.
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Affiliation(s)
- Forrest C Walker
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, United States of America
| | - Isabelle Derré
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, United States of America.
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13
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Lu B, Wang Y, Wurihan W, Cheng A, Yeung S, Fondell JD, Lai Z, Wan D, Wu X, Li WV, Fan H. Requirement of GrgA for Chlamydia infectious progeny production, optimal growth, and efficient plasmid maintenance. mBio 2024; 15:e0203623. [PMID: 38112466 PMCID: PMC10790707 DOI: 10.1128/mbio.02036-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/16/2023] [Indexed: 12/21/2023] Open
Abstract
IMPORTANCE Hallmarks of the developmental cycle of the obligate intracellular pathogenic bacterium Chlamydia are the primary differentiation of the infectious elementary body (EB) into the proliferative reticulate body (RB) and the secondary differentiation of RBs back into EBs. The mechanisms regulating these transitions remain unclear. In this report, we developed an effective novel strategy termed dependence on plasmid-mediated expression (DOPE) that allows for the knockdown of essential genes in Chlamydia. We demonstrate that GrgA, a Chlamydia-specific transcription factor, is essential for the secondary differentiation and optimal growth of RBs. We also show that GrgA, a chromosome-encoded regulatory protein, controls the maintenance of the chlamydial virulence plasmid. Transcriptomic analysis further indicates that GrgA functions as a critical regulator of all three sigma factors that recognize different promoter sets at developmental stages. The DOPE strategy outlined here should provide a valuable tool for future studies examining chlamydial growth, development, and pathogenicity.
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Affiliation(s)
- Bin Lu
- Department of Parasitology, Central South University Xiangya Medical School, Changsha, Hunan, China
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Yuxuan Wang
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Wurihan Wurihan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Andrew Cheng
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Sydney Yeung
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Joseph D. Fondell
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Zhao Lai
- Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, Texas, USA
- Department of Molecular Medicine, University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Danny Wan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Xiang Wu
- Department of Parasitology, Central South University Xiangya Medical School, Changsha, Hunan, China
| | - Wei Vivian Li
- Department of Statistics, University of California Riverside, Riverside, California, USA
| | - Huizhou Fan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
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14
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Debrine AM, Karplus PA, Rockey DD. A structural foundation for studying chlamydial polymorphic membrane proteins. Microbiol Spectr 2023; 11:e0324223. [PMID: 37882824 PMCID: PMC10715098 DOI: 10.1128/spectrum.03242-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 09/18/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE Infections by bacteria in the genus Chlamydia cause a range of widespread and potentially debilitating conditions in humans and other animals. We analyzed predicted structures of a family of proteins that are potential vaccine targets found in all Chlamydia spp. Our findings deepen the understanding of protein structure, provide a descriptive framework for discussion of the protein structure, and outline regions of the proteins that may be key targets in host-microbe interactions and anti-chlamydial immunity.
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Affiliation(s)
- Abigail M. Debrine
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon, USA
| | - P. Andrew Karplus
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon, USA
| | - Daniel D. Rockey
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
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15
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Ardizzone CM, Taylor CM, Toh E, Lillis RA, Elnaggar JH, Lammons JW, Mott PD, Duffy EL, Shen L, Quayle AJ. Association of Chlamydia trachomatis burden with the vaginal microbiota, bacterial vaginosis, and metronidazole treatment. Front Cell Infect Microbiol 2023; 13:1289449. [PMID: 38149008 PMCID: PMC10750252 DOI: 10.3389/fcimb.2023.1289449] [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: 09/05/2023] [Accepted: 11/21/2023] [Indexed: 12/28/2023] Open
Abstract
Bacterial vaginosis (BV), a dysbiosis of the vaginal microbiota, is a common coinfection with Chlamydia trachomatis (Ct), and BV-associated bacteria (BVAB) and their products have been implicated in aiding Ct evade natural immunity. Here, we determined if a non-optimal vaginal microbiota was associated with a higher genital Ct burden and if metronidazole, a standard treatment for BV, would reduce Ct burden or aid in natural clearance of Ct infection. Cervicovaginal samples were collected from women at enrollment and, if testing positive for Ct infection, at a follow-up visit approximately one week later. Cervical Ct burden was assessed by inclusion forming units (IFU) and Ct genome copy number (GCN), and 16S rRNA gene sequencing was used to determine the composition of the vaginal microbiota. We observed a six-log spectrum of IFU and an eight-log spectrum of GCN in our study participants at their enrollment visit, but BV, as indicated by Amsel's criteria, Nugent scoring, or VALENCIA community state typing, did not predict infectious and total Ct burden, although IFU : GCN increased with Amsel and Nugent scores and in BV-like community state types. Ct burden was, however, associated with the abundance of bacterial species in the vaginal microbiota, negatively with Lactobacillus crispatus and positively with Prevotella bivia. Women diagnosed with BV were treated with metronidazole, and Ct burden was significantly reduced in those who resolved BV with treatment. A subset of women naturally cleared Ct infection in the interim, typified by low Ct burden at enrollment and resolution of BV. Abundance of many BVAB decreased, and Lactobacillus increased, in response to metronidazole treatment, but no changes in abundances of specific vaginal bacteria were unique to women who spontaneously cleared Ct infection.
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Affiliation(s)
- Caleb M. Ardizzone
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Christopher M. Taylor
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Evelyn Toh
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Rebecca A. Lillis
- Department of Medicine, Section of Infectious Diseases, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Jacob H. Elnaggar
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - John W. Lammons
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Patricia Dehon Mott
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Emily L. Duffy
- Department of Medicine, Section of Infectious Diseases, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Li Shen
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Alison J. Quayle
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
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16
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Hakiem OR, Rizvi SMA, Ramirez C, Tan M. Euo is a developmental regulator that represses late genes and activates midcycle genes in Chlamydia trachomatis. mBio 2023; 14:e0046523. [PMID: 37565751 PMCID: PMC10653925 DOI: 10.1128/mbio.00465-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/22/2023] [Indexed: 08/12/2023] Open
Abstract
IMPORTANCE In this study, we developed a correlative approach that combined DNA immunoprecipitation-seq and RNA-seq analyses to define the regulon of the Chlamydia trachomatis transcription factor Euo. We confirmed the proposed role of Euo as a transcriptional repressor of late chlamydial genes but also showed that Euo activates transcription of a subset of midcycle genes and autoregulates its own expression via negative feedback. This study validates and expands the role of Euo as an important developmental regulator in C. trachomatis. In addition, this genome-wide correlative approach can be applied to study transcription factors in other pathogenic bacteria.
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Affiliation(s)
- Owais R. Hakiem
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, California, USA
| | - Syed M. A. Rizvi
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, California, USA
| | - Cuper Ramirez
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, California, USA
| | - Ming Tan
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, California, USA
- Department of Medicine, University of California Irvine, Irvine, California, USA
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17
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Bastidas RJ, Kędzior M, Davidson RK, Walsh SC, Dolat L, Sixt BS, Pruneda JN, Coers J, Valdivia RH. The acetylase activity of Cdu1 regulates bacterial exit from infected cells by protecting Chlamydia effectors from degradation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.28.530337. [PMID: 36909574 PMCID: PMC10002621 DOI: 10.1101/2023.02.28.530337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Many cellular processes are regulated by ubiquitin-mediated proteasomal degradation. Pathogens can regulate eukaryotic proteolysis through the delivery of proteins with de-ubiquitinating (DUB) activities. The obligate intracellular pathogen Chlamydia trachomatis secretes Cdu1 (ChlaDUB1), a dual deubiquitinase and Lys-acetyltransferase, that promotes Golgi remodeling and survival of infected host cells presumably by regulating the ubiquitination of host and bacterial proteins. Here we determined that Cdu1's acetylase but not its DUB activity is important to protect Cdu1 from ubiquitin-mediated degradation. We further identified three C. trachomatis proteins on the pathogen-containing vacuole (InaC, IpaM, and CTL0480) that required Cdu1's acetylase activity for protection from degradation and determined that Cdu1 and these Cdu1-protected proteins are required for optimal egress of Chlamydia from host cells. These findings highlight a non-canonical mechanism of pathogen-mediated protection of virulence factors from degradation after their delivery into host cells and the coordinated regulation of secreted effector proteins.
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Affiliation(s)
- Robert J. Bastidas
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
| | - Mateusz Kędzior
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
| | - Robert K. Davidson
- Department of Molecular Genetics and Microbiology, Duke University, Durham, N.C 27708, USA
| | - Stephen C. Walsh
- Department of Molecular Genetics and Microbiology, Duke University, Durham, N.C 27708, USA
| | - Lee Dolat
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
| | - Barbara S. Sixt
- Deparment of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Jonathan N. Pruneda
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Jörn Coers
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, N.C 27708, USA
| | - Raphael H. Valdivia
- Department of Integrative Immunobiology, Duke University, Durham, N.C 27708, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, N.C 27708, USA
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18
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Hatch ND, Ouellette SP. Identification of the alternative sigma factor regulons of Chlamydia trachomatis using multiplexed CRISPR interference. mSphere 2023; 8:e0039123. [PMID: 37747235 PMCID: PMC10597470 DOI: 10.1128/msphere.00391-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 08/07/2023] [Indexed: 09/26/2023] Open
Abstract
Chlamydia trachomatis is a developmentally regulated, obligate intracellular bacterium that encodes three sigma factors: σ66, σ54, and σ28. σ66 is the major sigma factor controlling most transcription initiation during early- and mid-cycle development as the infectious elementary body (EB) transitions to the non-infectious reticulate body (RB) that replicates within an inclusion inside the cell. The roles of the minor sigma factors, σ54 and σ28, have not been well characterized to date; however, there are data to suggest each functions in late-stage development and secondary differentiation as RBs transition to EBs. As the process of secondary differentiation itself is poorly characterized, clarifying the function of these alternative sigma factors by identifying the genes regulated by them will further our understanding of chlamydial differentiation. We hypothesize that σ54 and σ28 have non-redundant and essential functions for initiating late gene transcription thus mediating secondary differentiation in Chlamydia. Here, we demonstrate the necessity of each minor sigma factor in successfully completing the developmental cycle. We have implemented and validated multiplexed Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) interference techniques, novel to the chlamydial field to examine the effects of knocking down each alternative sigma factor individually and simultaneously. In parallel, we also overexpressed each sigma factor. Altering transcript levels for either or both alternative sigma factors resulted in a severe defect in EB production as compared to controls. Furthermore, RNA sequencing identified differentially expressed genes during alternative sigma factor dysregulation, indicating the putative regulons of each. These data demonstrate that the levels of alternative sigma factors must be carefully regulated to facilitate chlamydial growth and differentiation. IMPORTANCE Chlamydia trachomatis is a significant human pathogen in both developed and developing nations. Due to the organism's unique developmental cycle and intracellular niche, basic research has been slow and arduous. However, recent advances in chlamydial genetics have allowed the field to make significant progress in experimentally interrogating the basic physiology of Chlamydia. Broadly speaking, the driving factors of chlamydial development are poorly understood, particularly regarding how the later stages of development are regulated. Here, we employ a novel genetic tool for use in Chlamydia while investigating the effects of dysregulating the two alternative sigma factors in the organism that help control transcription initiation. We provide further evidence for both sigma factors' essential roles in late-stage development and their potential regulons, laying the foundation for deeper experimentation to uncover the molecular pathways involved in chlamydial differentiation.
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Affiliation(s)
- Nathan D. Hatch
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Scot P. Ouellette
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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19
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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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20
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Ghasemian E, Harding-Esch E, Mabey D, Holland MJ. When Bacteria and Viruses Collide: A Tale of Chlamydia trachomatis and Sexually Transmitted Viruses. Viruses 2023; 15:1954. [PMID: 37766360 PMCID: PMC10536055 DOI: 10.3390/v15091954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/02/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
The global incidence of sexually transmitted infections (STIs) remains high, with the World Health Organization (WHO) estimating that over 1 million people acquire STIs daily. STIs can lead to infertility, pregnancy complications, and cancers. Co-infections with multiple pathogens are prevalent among individuals with an STI and can lead to heightened infectivity and more severe clinical manifestations. Chlamydia trachomatis (CT) is the most reported bacterial STI worldwide in both men and women, and several studies have demonstrated co-infection of CT with viral and other bacterial STIs. CT is a gram-negative bacterium with a unique biphasic developmental cycle including infectious extracellular elementary bodies (EBs) and metabolically active intracellular reticulate bodies (RBs). The intracellular form of this organism, RBs, has evolved mechanisms to persist for long periods within host epithelial cells in a viable but non-cultivable state. The co-infections of CT with the most frequently reported sexually transmitted viruses: human immunodeficiency virus (HIV), human papillomavirus (HPV), and herpes simplex virus (HSV) have been investigated through in vitro and in vivo studies. These research studies have made significant strides in unraveling the intricate interactions between CT, these viral STIs, and their eukaryotic host. In this review, we present an overview of the epidemiology of these co-infections, while specifically delineating the underlying mechanisms by which CT influences the transmission and infection dynamics of HIV and HSV. Furthermore, we explore the intricate relationship between CT and HPV infection, with a particular emphasis on the heightened risk of cervical cancer. By consolidating the current body of knowledge, we provide valuable insights into the complex dynamics and implications of co-infection involving CT and sexually transmitted viruses.
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Affiliation(s)
- Ehsan Ghasemian
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK; (E.H.-E.); (D.M.); (M.J.H.)
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21
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Dembek ZF, Mothershead JL, Owens AN, Chekol T, Wu A. Psittacosis: An Underappreciated and Often Undiagnosed Disease. Pathogens 2023; 12:1165. [PMID: 37764973 PMCID: PMC10536718 DOI: 10.3390/pathogens12091165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/02/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
The bacterial agent Chlamydia psittaci, and the resulting disease of psittacosis, is a little-known and underappreciated infectious disease by healthcare practitioners and in public health in general. C. psittaci infections can cause significant psittacosis outbreaks, with person-to-person transmission documented in the last decade. In this publication, we review the pathogen and its disease, as well as examine the potential for genetic manipulation in this organism to create a more deadly pathogen. Recent disease surveys indicate that currently, the highest incidences of human disease exist in Australia, Germany and the UK. We recommend the universal public health reporting of C. psittaci and psittacosis disease and increasing the promotion of public health awareness.
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Affiliation(s)
- Zygmunt F. Dembek
- Battelle Memorial Institute, Support to DTRA Technical Reachback, Columbus, OH 43201, USA; (Z.F.D.); (T.C.)
| | - Jerry L. Mothershead
- Applied Research Associates (ARA), Support to DTRA Technical Reachback, Albuquerque, NM 87110, USA;
| | - Akeisha N. Owens
- Defense Threat Reduction Agency (DTRA), Fort Belvoir, VA 22060, USA;
| | - Tesema Chekol
- Battelle Memorial Institute, Support to DTRA Technical Reachback, Columbus, OH 43201, USA; (Z.F.D.); (T.C.)
| | - Aiguo Wu
- Defense Threat Reduction Agency (DTRA), Fort Belvoir, VA 22060, USA;
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22
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Hashemian SMM, Madani SA, Allymehr M, Talebi A. A molecular survey of Chlamydia spp. infection in commercial poultry and detection of Chlamydia pneumoniae in a commercial turkey flock in Iran. Vet Med Sci 2023; 9:2168-2175. [PMID: 37602896 PMCID: PMC10508571 DOI: 10.1002/vms3.1244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 05/15/2023] [Accepted: 07/31/2023] [Indexed: 08/22/2023] Open
Abstract
BACKGROUND Chlamydiaceae are a group of gram-negative intracellular bacteria which can infect a wide variety of hosts. Some chlamydial agents are capable of crossing the host barrier and though they are potentially a risk to very different species. They also pose a zoonotic risk for human and different chlamydial agents are linked to several medical maladies. OBJECTIVES In this study, the presence of chlamydial agents in different commercial poultry flocks in Iran was investigated. METHODS Swab and tissue samples were collected from 435 birds in 24 different commercial poultry flocks. These samples were examined using a Chlamydiaceae-specific real-time PCR assay targeting 23S rRNA gene. Positive samples then were subjected to intergenic spacer rRNA (IGS) gene and major outer membrane protein gene (ompA) PCRs. Finally, positive PCR products were sequenced and analysed. RESULTS Only one flock of commercial turkey became positive. Partial DNA sequencing of IGS gene revealed that all positive samples from the infected flock were Chlamydia pneumoniae and were identical to previously studied isolates from koala (LPCoLN) and frog (DC9). Further investigations showed slight dissimilarity in ompA gene of C. pneumoniae from different hosts. The detected turkey isolates were located in a different clade of phylogenetic tree, close to Western barred bandicoot and koala isolates. CONCLUSION C. pneumoniae has passed the cross-species barrier in the past and therefor it could potentially be zoonotic. To the best of authors' knowledge, this is the first report of C. pneumoniae infection in commercial turkey.
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Affiliation(s)
| | - Seyed Ahmad Madani
- Department of Animal and Poultry Health and Nutrition, Faculty of Veterinary MedicineUniversity of TehranTehranIran
| | - Manoochehr Allymehr
- Department of Poultry Health and Diseases, Faculty of Veterinary MedicineUniversity of UrmiaUrmiaIran
| | - Alireza Talebi
- Department of Poultry Health and Diseases, Faculty of Veterinary MedicineUniversity of UrmiaUrmiaIran
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23
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Feng J, Janaína de Campos L, Seleem MA, Conda-Sheridan M. Synthesis and biological evaluation of sulfonylpyridine derivatives as potential anti-chlamydia agents. Bioorg Med Chem 2023; 91:117401. [PMID: 37453189 DOI: 10.1016/j.bmc.2023.117401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 07/18/2023]
Abstract
Chlamydia trachomatis is the most prevalent sexually transmitted bacterial infection in the United States and the world. This pathogen can cause health problems ranging from trachoma (blindness) to damage of the fallopian tubes or ectopic pregnancy, which can be life-threatening if not treated properly. To this day, there is no chlamydia-specific drug on the market. Previously, we reported the activity and basic structure-activity relationships (SAR) of sulfonylpyridine molecules that possess antichlamydial action. Based on those results, we prepared a new series of derivatives. Our data indicate the new analogs can halt the growth of C. trachomatis. The lead compound, 22, was more active than our previous molecules and did not affect the growth of S. aureus and E. coli, suggesting bacterial selectivity. We performed docking studies on the presumed target, the cylindrical protease of Chlamydia. The in-silico studies partially explained the in vitro biological result as well as predicted a possible binding pose in the binding pocket. The top compound displayed a good cytotoxicity profile towards mammalian cell lines and was stable in both serum and stimulated gastric fluid. The presented data suggests the sulfonylpyridines are promising and selective anti-chlamydial compounds that merit further structural optimization.
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Affiliation(s)
- Jiachen Feng
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-6125, United States
| | - Luana Janaína de Campos
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-6125, United States
| | - Mohamed A Seleem
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-6125, United States
| | - Martin Conda-Sheridan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-6125, United States.
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Di Pietro M, Filardo S, Mattioli R, Bozzuto G, Molinari A, Mosca L, Sessa R. Extra Virgin Olive Oil-Based Formulations: A "Green" Strategy against Chlamydia trachomatis. Int J Mol Sci 2023; 24:12701. [PMID: 37628881 PMCID: PMC10454370 DOI: 10.3390/ijms241612701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/04/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
In recent decades, antibiotic misuse has emerged as an important risk factor for the appearance of multi-drug-resistant bacteria, and, recently, antimicrobial resistance has also been described in Chlamydia trachomatis as the leading cause of bacterial sexually transmitted diseases worldwide. Herein, we investigated, for the first time, the antibacterial activity against C. trachomatis of a polyphenolic extract of extra virgin olive oil (EVOO), alongside purified oleocanthal and oleacein, two of its main components, in natural deep eutectic solvent (NaDES), a biocompatible solvent. The anti-chlamydial activity of olive-oil polyphenols (OOPs) was tested in the different phases of chlamydial developmental cycle by using an in vitro infection model. Transmission and scanning electron microscopy analysis were performed for investigating potential alterations of adhesion and invasion, as well as morphology, of chlamydial elementary bodies (EBs) to host cells. The main result of our study is the anti-bacterial activity of OOPs towards C. trachomatis EBs down to a total polyphenol concentration of 1.7 μg/mL, as shown by a statistically significant decrease (93.53%) of the total number of chlamydial-inclusion-forming units (p < 0.0001). Transmission and scanning electron microscopy analysis supported its anti-chlamydial effect, suggesting that OOP might damage the chlamydial outer layers, impairing their structural integrity and hindering EB capability to infect the host cell. In conclusion, OOPs may represent an interesting alternative therapeutic option toward C. trachomatis, although further studies are necessary for exploring its clinical applications.
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Affiliation(s)
- Marisa Di Pietro
- Department of Public Health and Infectious Diseases, Section of Microbiology, Sapienza University of Rome, 00185 Rome, Italy; (M.D.P.); (R.S.)
| | - Simone Filardo
- Department of Public Health and Infectious Diseases, Section of Microbiology, Sapienza University of Rome, 00185 Rome, Italy; (M.D.P.); (R.S.)
| | - Roberto Mattioli
- Department of Biochemical Sciences, Faculty of Pharmacy and Medicine, Sapienza University of Rome, 00185 Rome, Italy; (R.M.); (L.M.)
| | - Giuseppina Bozzuto
- National Centre for Drug Research and Evaluation, Italian National Institute of Health, 00161 Rome, Italy; (G.B.); (A.M.)
| | - Agnese Molinari
- National Centre for Drug Research and Evaluation, Italian National Institute of Health, 00161 Rome, Italy; (G.B.); (A.M.)
| | - Luciana Mosca
- Department of Biochemical Sciences, Faculty of Pharmacy and Medicine, Sapienza University of Rome, 00185 Rome, Italy; (R.M.); (L.M.)
| | - Rosa Sessa
- Department of Public Health and Infectious Diseases, Section of Microbiology, Sapienza University of Rome, 00185 Rome, Italy; (M.D.P.); (R.S.)
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25
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Lu B, Wang Y, Wurihan W, Cheng A, Yeung S, Fondell JD, Lai Z, Wan D, Wu X, Li WV, Fan H. Requirement of GrgA for Chlamydia infectious progeny production, optimal growth, and efficient plasmid maintenance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.02.551707. [PMID: 37577610 PMCID: PMC10418237 DOI: 10.1101/2023.08.02.551707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Chlamydia, an obligate intracellular bacterial pathogen, has a unique developmental cycle involving the differentiation of invading elementary bodies (EBs) to noninfectious reticulate bodies (RBs), replication of RBs, and redifferentiation of RBs into progeny EBs. Progression of this cycle is regulated by three sigma factors, which direct the RNA polymerase to their respective target gene promoters. We hypothesized that the Chlamydia-specific transcriptional regulator GrgA, previously shown to activate σ66 and σ28, plays an essential role in chlamydial development and growth. To test this hypothesis, we applied a novel genetic tool known as dependence on plasmid-mediated expression (DOPE) to create Chlamydia trachomatis with conditional GrgA-deficiency. We show that GrgA-deficient C. trachomatis RBs have a growth rate that is approximately half of the normal rate and fail to transition into progeny EBs. In addition, GrgA-deficient C. trachomatis fail to maintain its virulence plasmid. Results of RNA-seq analysis indicate that GrgA promotes RB growth by optimizing tRNA synthesis and expression of nutrient-acquisition genes, while it enables RB-to-EB conversion by facilitating the expression of a histone and outer membrane proteins required for EB morphogenesis. GrgA also regulates numerous other late genes required for host cell exit and subsequent EB invasion into host cells. Importantly, GrgA stimulates the expression of σ54, the third and last sigma factor, and its activator AtoC, and thereby indirectly upregulating the expression of σ54-dependent genes. In conclusion, our work demonstrates that GrgA is a master transcriptional regulator in Chlamydia and plays multiple essential roles in chlamydial pathogenicity.
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Affiliation(s)
- Bin Lu
- Department of Parasitology, Central South University Xiangya Medical School, Changsha, Hunan 410013, China
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Yuxuan Wang
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Wurihan Wurihan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Andrew Cheng
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Sydney Yeung
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Joseph D. Fondell
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Zhao Lai
- Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, TX 78229, USA
- Department of Molecular Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Danny Wan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Xiang Wu
- Department of Parasitology, Central South University Xiangya Medical School, Changsha, Hunan 410013, China
| | - Wei Vivian Li
- Department of Statistics, University of California Riverside, Riverside, CA 92521, USA
| | - Huizhou Fan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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26
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Hüsler D, Stauffer P, Hilbi H. Tapping lipid droplets: A rich fat diet of intracellular bacterial pathogens. Mol Microbiol 2023; 120:194-209. [PMID: 37429596 DOI: 10.1111/mmi.15120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/12/2023]
Abstract
Lipid droplets (LDs) are dynamic and versatile organelles present in most eukaryotic cells. LDs consist of a hydrophobic core of neutral lipids, a phospholipid monolayer coat, and a variety of associated proteins. LDs are formed at the endoplasmic reticulum and have diverse roles in lipid storage, energy metabolism, membrane trafficking, and cellular signaling. In addition to their physiological cellular functions, LDs have been implicated in the pathogenesis of several diseases, including metabolic disorders, cancer, and infections. A number of intracellular bacterial pathogens modulate and/or interact with LDs during host cell infection. Members of the genera Mycobacterium, Legionella, Coxiella, Chlamydia, and Salmonella exploit LDs as a source of intracellular nutrients and membrane components to establish their distinct intracellular replicative niches. In this review, we focus on the biogenesis, interactions, and functions of LDs, as well as on their role in lipid metabolism of intracellular bacterial pathogens.
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Affiliation(s)
- Dario Hüsler
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Pia Stauffer
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
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27
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Bastidas RJ, Valdivia RH. The emerging complexity of Chlamydia trachomatis interactions with host cells as revealed by molecular genetic approaches. Curr Opin Microbiol 2023; 74:102330. [PMID: 37247566 PMCID: PMC10988583 DOI: 10.1016/j.mib.2023.102330] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/31/2023]
Abstract
Chlamydia trachomatis (Ct) is an intracellular bacterial pathogen that relies on the activity of secreted proteins known as effectors to promote replication and avoidance of immune clearance. Understanding the contribution of Ct effectors to pathogenesis has proven to be challenging, given that these proteins often perform multiple functions during intracellular infection. Recent advances in molecular genetic analysis of Ct have provided valuable insights into the multifaceted nature of secreted effector proteins and their impact on the interaction between Ct and host cells and tissues. This review highlights significant findings from genetic analysis of Ct effector functions, shedding light on their diverse roles. We also discuss the challenges faced in this field of study and explore potential opportunities for further research.
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Affiliation(s)
- Robert J Bastidas
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Raphael H Valdivia
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
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28
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Scanlon KR, Keb G, Wolf K, Jewett TJ, Fields KA. Chlamydia trachomatis TmeB antagonizes actin polymerization via direct interference with Arp2/3 activity. Front Cell Infect Microbiol 2023; 13:1232391. [PMID: 37483386 PMCID: PMC10360934 DOI: 10.3389/fcimb.2023.1232391] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 06/26/2023] [Indexed: 07/25/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular pathogen that actively promotes invasion of epithelial cells. A virulence-associated type III secretion system contributes to chlamydial entry and at least four effectors have been described that are deployed during this time. Two of these invasion-related effectors, the translocated membrane-associated effectors A and B (TmeA and TmeB), are encoded in a bi-cistronic operon. TmeA directly activates host N-WASP to stimulate Arp2/3-dependent actin polymerization. According to current working models, TmeA-mediated N-WASP activation contributes to invasion. TmeB has not been functionally characterized. Unlike a tmeA null strain, loss of tmeB does not impact invasion efficiency of C. trachomatis. Using strains deficient for multiple genes, we provide evidence that TmeA is dispensable for invasion in the absence of TmeB. Our data indicate that overabundance of TmeB interferes with invasion and that this activity requires active Arp2/3 complex. We further show that TmeB is capable of interfering with Arp2/3-mediated actin polymerization. In aggregate, these data point to opposing functions for TmeA and TmeB that manifest during the invasion process. These studies raise intriguing questions regarding the dynamic interplay between TmeA, TmeB, and branched actin polymerization during chlamydial entry.
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Affiliation(s)
- Kaylyn R. Scanlon
- Division of Immunity and Pathogenesis, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, United States
| | - Gabrielle Keb
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Katerina Wolf
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Travis J. Jewett
- Division of Immunity and Pathogenesis, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, United States
| | - Kenneth A. Fields
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, United States
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29
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Wolff BJ, Gaines A, Conley AB, Norris E, Rishishwar L, Chande AT, Yang E, Diaz MH, Winchell JM. Multiplex Real-time PCR Assay for the Detection of all Chlamydia Species and Simultaneous Differentiation of C. psittaci and C. pneumoniae in Human Clinical Specimens. Ann Lab Med 2023; 43:375-380. [PMID: 36843406 PMCID: PMC9989537 DOI: 10.3343/alm.2023.43.4.375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/04/2022] [Accepted: 01/10/2023] [Indexed: 02/28/2023] Open
Abstract
We developed and assessed the performance of a new multiplex real-time PCR assay for the detection of all Chlamydia species and simultaneous differentiation of Chlamydia psittaci and Chlamydia pneumoniae-two important human respiratory pathogens-in human clinical specimens. Next-generation sequencing was used to identify unique targets to design real-time PCR assays targeting all Chlamydia species, C. psittaci, and C. pneumoniae. To validate the assay, we used a panel of 49 culture isolates comprising seven C. psittaci genotypes, eight C. pneumoniae isolates, seven other Chlamydia species, and 22 near-neighbor bacterial and viral isolates, along with 22 specimens from external quality assessment (EQA) panels and 34 nasopharyngeal and oropharyngeal swabs and cerebrospinal fluid, stool, and sputum specimens previously identified as positive or negative for C. psittaci or C. pneumoniae. The assays were 100% specific, with limits of detection of 7.64- 9.02 fg/μL. The assay results matched with historical assay results for all specimens, except for one owing to the increased sensitivity of the new C. psittaci assay; the results of the EQA specimens were 100% accurate. This assay may improve the timely and accurate clinical diagnosis of Chlamydia infections and provide a greater understanding of the burden of disease caused by these agents.
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Affiliation(s)
- Bernard J Wolff
- Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Anna Gaines
- Applied Bioinformatics Laboratory, Atlanta, GA, USA
| | | | - Emily Norris
- Applied Bioinformatics Laboratory, Atlanta, GA, USA
| | - Lavanya Rishishwar
- Applied Bioinformatics Laboratory, Atlanta, GA, USA.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Aroon T Chande
- Applied Bioinformatics Laboratory, Atlanta, GA, USA.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Eungi Yang
- Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Maureen H Diaz
- Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jonas M Winchell
- Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
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30
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Lee J, Cox JV, Ouellette SP. The Unique N-Terminal Domain of Chlamydial Bactofilin Mediates Its Membrane Localization and Ring-Forming Properties. J Bacteriol 2023; 205:e0009223. [PMID: 37191556 PMCID: PMC10294636 DOI: 10.1128/jb.00092-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/01/2023] [Indexed: 05/17/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterial pathogen. In evolving to the intracellular niche, Chlamydia has reduced its genome size compared to other bacteria and, as a consequence, has a number of unique features. For example, Chlamydia engages the actin-like protein MreB, rather than the tubulin-like protein FtsZ, to direct peptidoglycan (PG) synthesis exclusively at the septum of cells undergoing polarized cell division. Interestingly, Chlamydia possesses another cytoskeletal element-a bactofilin ortholog, BacA. Recently, we reported BacA is a cell size-determining protein that forms dynamic membrane-associated ring structures in Chlamydia that have not been observed in other bacteria with bactofilins. Chlamydial BacA possesses a unique N-terminal domain, and we hypothesized this domain imparts the membrane-binding and ring-forming properties of BacA. We show that different truncations of the N terminus result in distinct phenotypes: removal of the first 50 amino acids (ΔN50) results in large ring structures at the membrane whereas removal of the first 81 amino acids (ΔN81) results in an inability to form filaments and rings and a loss of membrane association. Overexpression of the ΔN50 isoform altered cell size, similar to loss of BacA, suggesting that the dynamic properties of BacA are essential for the regulation of cell size. We further show that the region from amino acid 51 to 81 imparts membrane association as appending it to green fluorescent protein (GFP) resulted in the relocalization of GFP from the cytosol to the membrane. Overall, our findings suggest two important functions for the unique N-terminal domain of BacA and help explain its role as a cell size determinant. IMPORTANCE Bacteria use a variety of filament-forming cytoskeletal proteins to regulate and control various aspects of their physiology. For example, the tubulin-like FtsZ recruits division proteins to the septum whereas the actin-like MreB recruits peptidoglycan (PG) synthases to generate the cell wall in rod-shaped bacteria. Recently, a third class of cytoskeletal protein has been identified in bacteria-bactofilins. These proteins have been primarily linked to spatially localized PG synthesis. Interestingly, Chlamydia, an obligate intracellular bacterium, does not have PG in its cell wall and yet possesses a bactofilin ortholog. In this study, we characterize a unique N-terminal domain of chlamydial bactofilin and show that this domain controls two important functions that affect cell size: its ring-forming and membrane-associating properties.
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Affiliation(s)
- Junghoon Lee
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - John V. Cox
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Scot P. Ouellette
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
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31
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Fisher DJ, Beare PA. Recent advances in genetic systems in obligate intracellular human-pathogenic bacteria. Front Cell Infect Microbiol 2023; 13:1202245. [PMID: 37404720 PMCID: PMC10315504 DOI: 10.3389/fcimb.2023.1202245] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 05/22/2023] [Indexed: 07/06/2023] Open
Abstract
The ability to genetically manipulate a pathogen is fundamental to discovering factors governing host-pathogen interactions at the molecular level and is critical for devising treatment and prevention strategies. While the genetic "toolbox" for many important bacterial pathogens is extensive, approaches for modifying obligate intracellular bacterial pathogens were classically limited due in part to the uniqueness of their obligatory lifestyles. Many researchers have confronted these challenges over the past two and a half decades leading to the development of multiple approaches to construct plasmid-bearing recombinant strains and chromosomal gene inactivation and deletion mutants, along with gene-silencing methods enabling the study of essential genes. This review will highlight seminal genetic achievements and recent developments (past 5 years) for Anaplasma spp., Rickettsia spp., Chlamydia spp., and Coxiella burnetii including progress being made for the still intractable Orientia tsutsugamushi. Alongside commentary of the strengths and weaknesses of the various approaches, future research directions will be discussed to include methods for C. burnetii that should have utility in the other obligate intracellular bacteria. Collectively, the future appears bright for unraveling the molecular pathogenic mechanisms of these significant pathogens.
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Affiliation(s)
- Derek J. Fisher
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, United States
| | - Paul A. Beare
- Rocky Mountain Laboratory, National Institute of Health, Hamilton, MT, United States
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32
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Figueroa-Cuilan WM, Irazoki O, Feeley M, Smith E, Nguyen T, Cava F, Goley ED. Quantitative analysis of morphogenesis and growth dynamics in an obligate intracellular bacterium. Mol Biol Cell 2023; 34:ar69. [PMID: 37017481 PMCID: PMC10295487 DOI: 10.1091/mbc.e23-01-0023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/23/2023] [Accepted: 03/29/2023] [Indexed: 04/06/2023] Open
Abstract
Obligate intracellular bacteria of the order Rickettsiales include important human pathogens. However, our understanding of the biology of Rickettsia species is limited by challenges imposed by their obligate intracellular lifestyle. To overcome this roadblock, we developed methods to assess cell wall composition, growth, and morphology of Rickettsia parkeri, a human pathogen in the spotted fever group of the Rickettsia genus. Analysis of the cell wall of R. parkeri revealed unique features that distinguish it from free-living alphaproteobacteria. Using a novel fluorescence microscopy approach, we quantified R. parkeri morphology in live host cells and found that the fraction of the population undergoing cell division decreased over the course of infection. We further demonstrated the feasibility of localizing fluorescence fusions, for example, to the cell division protein ZapA, in live R. parkeri for the first time. To evaluate population growth kinetics, we developed an imaging-based assay that improves on the throughput and resolution of other methods. Finally, we applied these tools to quantitatively demonstrate that the actin homologue MreB is required for R. parkeri growth and rod shape. Collectively, a toolkit was developed of high-throughput, quantitative tools to understand growth and morphogenesis of R. parkeri that is translatable to other obligate intracellular bacteria.
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Affiliation(s)
- Wanda M. Figueroa-Cuilan
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185
| | - Oihane Irazoki
- Laboratory for Molecular Infection Medicine, Umeå Center for Microbial Research, Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Sweden
| | - Marissa Feeley
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185
| | - Erika Smith
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185
| | - Trung Nguyen
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine, Umeå Center for Microbial Research, Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Sweden
| | - Erin D. Goley
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185
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33
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Swoboda AR, Wood NA, Saery EA, Fisher DJ, Ouellette SP. The Periplasmic Tail-Specific Protease, Tsp, Is Essential for Secondary Differentiation in Chlamydia trachomatis. J Bacteriol 2023; 205:e0009923. [PMID: 37092988 PMCID: PMC10210983 DOI: 10.1128/jb.00099-23] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 04/03/2023] [Indexed: 04/25/2023] Open
Abstract
The obligate intracellular human pathogen Chlamydia trachomatis (Ctr) undergoes a complex developmental cycle in which the bacterium differentiates between two functionally and morphologically distinct forms: the elementary body (EB) and the reticulate body (RB). The EB is the smaller, infectious, nondividing form which initiates infection of a susceptible host cell, whereas the RB is the larger, non-infectious form which replicates within a membrane-bound vesicle called an inclusion. The mechanism(s) which drives differentiation between these developmental forms is poorly understood. Bulk protein turnover is likely required for chlamydial differentiation given the significant differences in the protein repertoires and functions of the EB and RB. We hypothesize that periplasmic protein turnover is also critical for the reorganization of an RB into an EB, referred to as secondary differentiation. Ct441 is a periplasmic protease ortholog of tail-specific proteases (i.e., Tsp, Prc) and is expressed in Ctr during secondary differentiation. We investigated the effect of altering Tsp expression on developmental cycle progression. Through assessment of bacterial morphology and infectious progeny production, we found that both overexpression and CRISPR interference/dCas9 (CRISPRi)-mediated knockdown of Tsp negatively impacted chlamydial development through different mechanisms. We also confirmed that catalytic activity is required for the negative effect of overexpression and confirmed the effect of the mutation in in vitro assays. Electron microscopic assessments during knockdown experiments revealed a defect in EB morphology, directly linking Tsp function to secondary differentiation. These data implicate Ct441/Tsp as a critical factor in secondary differentiation. IMPORTANCE The human pathogen Chlamydia trachomatis is the leading cause of preventable infectious blindness and bacterial sexually transmitted infections worldwide. This pathogen has a unique developmental cycle that alternates between distinct forms. However, the key processes of chlamydial development remain obscure. Uncovering the mechanisms of differentiation between its metabolically and functionally distinct developmental forms may foster the discovery of novel Chlamydia-specific therapeutics and limit development of resistant bacterial populations derived from the clinical use of broad-spectrum antibiotics. In this study, we investigate chlamydial tail-specific protease (Tsp) and its function in chlamydial growth and development. Our work implicates Tsp as essential to chlamydial developmental cycle progression and indicates that Tsp is a potential drug target for Chlamydia infections.
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Affiliation(s)
- Abigail R. Swoboda
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Nicholas A. Wood
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Elizabeth A. Saery
- School of Biological Sciences, Southern Illinois University Carbondale, Carbondale, Illinois, USA
| | - Derek J. Fisher
- School of Biological Sciences, Southern Illinois University Carbondale, Carbondale, Illinois, USA
| | - Scot P. Ouellette
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
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34
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Riffaud CM, Rucks EA, Ouellette SP. Persistence of obligate intracellular pathogens: alternative strategies to overcome host-specific stresses. Front Cell Infect Microbiol 2023; 13:1185571. [PMID: 37284502 PMCID: PMC10239878 DOI: 10.3389/fcimb.2023.1185571] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/05/2023] [Indexed: 06/08/2023] Open
Abstract
In adapting to the intracellular niche, obligate intracellular bacteria usually undergo a reduction of genome size by eliminating genes not needed for intracellular survival. These losses can include, for example, genes involved in nutrient anabolic pathways or in stress response. Living inside a host cell offers a stable environment where intracellular bacteria can limit their exposure to extracellular effectors of the immune system and modulate or outright inhibit intracellular defense mechanisms. However, highlighting an area of vulnerability, these pathogens are dependent on the host cell for nutrients and are very sensitive to conditions that limit nutrient availability. Persistence is a common response shared by evolutionarily divergent bacteria to survive adverse conditions like nutrient deprivation. Development of persistence usually compromises successful antibiotic therapy of bacterial infections and is associated with chronic infections and long-term sequelae for the patients. During persistence, obligate intracellular pathogens are viable but not growing inside their host cell. They can survive for a long period of time such that, when the inducing stress is removed, reactivation of their growth cycles resumes. Given their reduced coding capacity, intracellular bacteria have adapted different response mechanisms. This review gives an overview of the strategies used by the obligate intracellular bacteria, where known, which, unlike model organisms such as E. coli, often lack toxin-antitoxin systems and the stringent response that have been linked to a persister phenotype and amino acid starvation states, respectively.
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35
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Hatch ND, Ouellette SP. Identification of the alternative sigma factor regulons of Chlamydia trachomatis using multiplexed CRISPR interference. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.27.538638. [PMID: 37162869 PMCID: PMC10168357 DOI: 10.1101/2023.04.27.538638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
C. trachomatis is a developmentally regulated, obligate intracellular bacterium that encodes three sigma factors: σ66, σ54, and σ28. σ66 is the major sigma factor controlling most transcription initiation during early and mid-cycle development as the infectious EB transitions to the non-infectious RB that replicates within an inclusion inside the cell. The roles of the minor sigma factors, σ54 and σ28, have not been well characterized to date - however, there are data to suggest each functions in late-stage development and secondary differentiation as RBs transition to EBs. As the process of secondary differentiation itself is poorly characterized, clarifying the function of these alternative sigma factors by identifying the genes regulated by them will further our understanding of chlamydial differentiation. We hypothesize that σ54 and σ28 have non-redundant and essential functions for initiating late gene transcription thus mediating secondary differentiation in Chlamydia . Here, we demonstrate the necessity of each minor sigma factor in successfully completing the developmental cycle. We have implemented and validated multiplexed CRISPRi techniques novel to the chlamydial field to examine effects of knocking down each alternative sigma factor individually and simultaneously. In parallel, we also overexpressed each sigma factor. Altering transcript levels for either or both alternative sigma factors resulted in a severe defect in EB production as compared to controls. Furthermore, RNA sequencing identified differentially expressed genes during alternative sigma factor dysregulation, indicating the putative regulons of each. These data demonstrate the levels of alternative sigma factors must be carefully regulated to facilitate chlamydial growth and differentiation. Importance Chlamydia trachomatis is a significant human pathogen in both developed and developing nations. Due to the organism's unique developmental cycle and intracellular niche, basic research has been slow and arduous. However, recent advances in chlamydial genetics have allowed the field to make significant progress in experimentally interrogating the basic physiology of Chlamydia . Broadly speaking, the driving factors of chlamydial development are poorly understood, particularly regarding how the later stages of development are regulated. Here, we employ a novel genetic tool for use in Chlamydia while investigating the effects of dysregulating the two alternative sigma factors in the organism that help control transcription initiation. We provide further evidence for both sigma factors' essential roles in late-stage development and their potential regulons, laying the foundation for deeper experimentation to uncover the molecular pathways involved in chlamydial differentiation.
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Chiarelli TJ, Grieshaber NA, Appa C, Grieshaber SS. Computational Modeling of the Chlamydial Developmental Cycle Reveals a Potential Role for Asymmetric Division. mSystems 2023; 8:e0005323. [PMID: 36927072 PMCID: PMC10134819 DOI: 10.1128/msystems.00053-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 02/15/2023] [Indexed: 03/18/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that progresses through an essential multicell form developmental cycle. Infection of the host is initiated by the elementary body (EB). Once in the host, the EB cell differentiates into the noninfectious, but replication-competent, reticulate body, or RB. After multiple rounds of replication, RBs undergo secondary differentiation, eventually producing newly infectious EBs. Here, we generated paired cell-type promoter reporter constructs and determined the kinetics of the activities of the euo, hctA, and hctB promoters. The paired constructs revealed that the developmental cycle produces at least three phenotypically distinct cell types, the RB (euoprom+), intermediate body (IB; hctAprom+), and EB (hctBprom+). The kinetic data from the three dual-promoter constructs were used to generate two computational agent-based models to reproduce the chlamydial developmental cycle. Both models simulated EB germination, RB amplification, IB formation, and EB production but differed in the mechanism that generated the IB. The direct conversion and the asymmetric production models predicted different behaviors for the RB population, which were experimentally testable. In agreement with the asymmetric production model, RBs acted as stem cells after the initial amplification stage, producing one IB and self-renewing after every division. We also demonstrated that IBs are a transient cell population, maturing directly into EBs after formation without the need for cell division. The culmination of these results suggests that the developmental cycle can be described by a four-stage model, EB germination, RB amplification/maturation, IB production, and EB formation. IMPORTANCE Chlamydia trachomatis is an obligate intracellular bacterial pathogen responsible for both ocular and sexually transmitted infections. All Chlamydiae are reliant on a complex developmental cycle, consisting of both infectious and noninfectious cell forms. The EB cell form initiates infection, whereas the RB cell replicates. The infectious cycle requires both cell types, as RB replication increases the cell population while EB formation disseminates the infection to new hosts. The mechanisms of RB-to-EB development are largely unknown. Here, we developed unique dual promoter reporters and used live-cell imaging and confocal microscopy to visualize the cycle at the single-cell and kinetic levels. These data were used to develop and test two agent-based models, simulating either direct conversion of RBs to EBs or production of EBs via asymmetric RB division. Our results suggest that RBs mature into a stem cell-like population producing intermediate cell forms through asymmetric division, followed by maturation of the intermediate cell type into the infectious EB. Ultimately, a more complete mechanistic understanding of the developmental cycle will lead to novel therapeutics targeting cell type development to eliminate chlamydial dissemination.
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Affiliation(s)
| | | | - Cody Appa
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA
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Luís MP, Pereira IS, Bugalhão JN, Simões CN, Mota C, Romão MJ, Mota LJ. The Chlamydia trachomatis IncM Protein Interferes with Host Cell Cytokinesis, Centrosome Positioning, and Golgi Distribution and Contributes to the Stability of the Pathogen-Containing Vacuole. Infect Immun 2023; 91:e0040522. [PMID: 36877064 PMCID: PMC10112248 DOI: 10.1128/iai.00405-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/13/2023] [Indexed: 03/07/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterial pathogen that causes ocular and urogenital infections in humans. The ability of C. trachomatis to grow intracellularly in a pathogen-containing vacuole (known as an inclusion) depends on chlamydial effector proteins transported into the host cell by a type III secretion system. Among these effectors, several inclusion membrane proteins (Incs) insert in the vacuolar membrane. Here, we show that human cell lines infected by a C. trachomatis strain deficient for Inc CT288/CTL0540 (renamed IncM) displayed less multinucleation than when infected by IncM-producing strains (wild type or complemented). This indicated that IncM is involved in the ability of Chlamydia to inhibit host cell cytokinesis. The capacity of IncM to induce multinucleation in infected cells was shown to be conserved among its chlamydial homologues and appeared to require its two larger regions predicted to be exposed to the host cell cytosol. C. trachomatis-infected cells also displayed IncM-dependent defects in centrosome positioning, Golgi distribution around the inclusion, and morphology and stability of the inclusion. The altered morphology of inclusions containing IncM-deficient C. trachomatis was further affected by depolymerization of host cell microtubules. This was not observed after depolymerization of microfilaments, and inclusions containing wild-type C. trachomatis did not alter their morphology upon depolymerization of microtubules. Overall, these findings suggest that IncM may exert its effector function by acting directly or indirectly on host cell microtubules.
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Affiliation(s)
- Maria Pequito Luís
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Inês Serrano Pereira
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Joana N. Bugalhão
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Catarina N. Simões
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - Cristiano Mota
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Chemistry, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Maria João Romão
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Chemistry, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Luís Jaime Mota
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
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Vormittag S, Ende RJ, Derré I, Hilbi H. Pathogen vacuole membrane contact sites - close encounters of the fifth kind. MICROLIFE 2023; 4:uqad018. [PMID: 37223745 PMCID: PMC10117887 DOI: 10.1093/femsml/uqad018] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/30/2023] [Accepted: 04/06/2023] [Indexed: 05/25/2023]
Abstract
Vesicular trafficking and membrane fusion are well-characterized, versatile, and sophisticated means of 'long range' intracellular protein and lipid delivery. Membrane contact sites (MCS) have been studied in far less detail, but are crucial for 'short range' (10-30 nm) communication between organelles, as well as between pathogen vacuoles and organelles. MCS are specialized in the non-vesicular trafficking of small molecules such as calcium and lipids. Pivotal MCS components important for lipid transfer are the VAP receptor/tether protein, oxysterol binding proteins (OSBPs), the ceramide transport protein CERT, the phosphoinositide phosphatase Sac1, and the lipid phosphatidylinositol 4-phosphate (PtdIns(4)P). In this review, we discuss how these MCS components are subverted by bacterial pathogens and their secreted effector proteins to promote intracellular survival and replication.
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Affiliation(s)
| | | | - Isabelle Derré
- Corresponding author. Department of Microbiology, Immunology and Cancer Biology, University of Virginia, 1340 Jefferson Park Ave, Charlottesville, VA 22908, United States. Tel: +1-434-924-2330; E-mail:
| | - Hubert Hilbi
- Corresponding author. Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006 Zürich, Switzerland. Tel: +41-44-634-2650; E-mail:
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Shen L, Gao L, Swoboda AR, Ouellette SP. Targeted repression of DNA topoisomerase I by CRISPRi reveals a critical function for it in the Chlamydia trachomatis developmental cycle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.14.532001. [PMID: 36993624 PMCID: PMC10054935 DOI: 10.1101/2023.03.14.532001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that is responsible for the most prevalent bacterial sexually transmitted infections. Changes in DNA topology in this pathogen have been linked to its pathogenicity-associated developmental cycle. Here, evidence is provided that the balanced activity of DNA topoisomerases (Topos) contributes to Chlamydia developmental processes. Utilizing catalytically inactivated Cas12 (dCas12) based-clustered regularly interspaced short palindromic repeats interference (CRISPRi) technology, we demonstrate targeted knockdown of chromosomal topA transcription in C. trachomatis without detected toxicity of dCas12. Repression of topA impaired the growth of C. trachomatis mostly through disruption of its differentiation from a replicative form to an infectious form. Consistent with this, expression of late developmental genes of C. trachomatis was downregulated while early genes maintained their expression. Importantly, the growth defect associated with topA knockdown was rescued by overexpressing topA at an appropriate degree and time, directly linking the growth patterns to the levels of topA expression. Interestingly, topA knockdown had pleiotropic effects on DNA gyrase expression, indicating a potential compensatory mechanism for survival to offset TopA deficiency. C. trachomatis with topA knocked down displayed hypersensitivity to moxifloxacin that targets DNA gyrase in comparison with the wild type. These data underscore the requirement of integrated topoisomerase actions to support the essential development and transcriptional processes of C. trachomatis.
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Affiliation(s)
- Li Shen
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Leiqiong Gao
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Abigail R. Swoboda
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Scot P. Ouellette
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Homologues of the Chlamydia trachomatis and Chlamydia muridarum Inclusion Membrane Protein IncS Are Interchangeable for Early Development but Not for Inclusion Stability in the Late Developmental Cycle. mSphere 2023; 8:e0000323. [PMID: 36853051 PMCID: PMC10117133 DOI: 10.1128/msphere.00003-23] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium, which undergoes a biphasic developmental cycle inside a vacuole termed the inclusion. Chlamydia-specific effector proteins embedded into the inclusion membrane, the Inc proteins, facilitate inclusion interaction with cellular organelles. A subset of Inc proteins engages with specific host factors at the endoplasmic reticulum (ER)-inclusion membrane contact site (MCS), which is a discrete point of contact between the inclusion membrane and the endoplasmic reticulum (ER). Here, we report that the C. trachomatis Inc protein CTL0402/IncSCt is a novel component of the ER-inclusion MCS that specifically interacts with and recruits STIM1, a previously identified host component of the ER-inclusion MCS with an unassigned interacting partner at the inclusion membrane. In comparison, the Chlamydia muridarum IncS homologue (TC0424/IncSCm) does not interact with or recruit STIM1 to the inclusion, indicating species specificity. To further investigate IncS function and overcome the recently reported early developmental defect of the incS mutant, we achieved temporal complementation by expressing IncS exclusively during the early stages of the developmental cycle. Additionally, we used allelic exchange to replace the incSCt open reading frame with incSCm in the C. trachomatis chromosome. Inclusions harboring either of these strains progressed through the developmental cycle but were STIM1 negative and displayed increased inclusion lysis 48 h postinfection. Expression of incSCt in trans complemented these phenotypes. Altogether, our results indicate that IncS is necessary and sufficient to recruit STIM1 to C. trachomatis inclusion and that IncS plays an early developmental role conserved in C. trachomatis and C. muridarum and a late role in inclusion stability specific to C. trachomatis. IMPORTANCE Obligate intracellular pathogens strictly rely on the host for replication. Specialized pathogen-encoded effector proteins play a central role in sophisticated mechanisms of host cell manipulation. In Chlamydia, a subset of these effector proteins, the inclusion membrane proteins, are embedded in the membrane of the vacuole in which the bacteria replicate. Chlamydia encodes 50 to 100 putative Inc proteins. Many are conserved among species, including the human and mouse pathogens Chlamydia trachomatis and Chlamydia muridarum, respectively. However, whether the function(s) of Inc proteins is indeed conserved among species is poorly understood. Here, we characterized the function of the Inc protein IncS conserved in C. trachomatis and C. muridarum. Our work reveals that a single effector protein can play multiple functions at various stages of the developmental cycle. However, these functions are not necessarily conserved across species, suggesting a complex evolutionary path among Chlamydia species.
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Tryptophan Availability during Persistence of Chlamydia trachomatis Directly Impacts Expression of Chlamydial Cell Division Proteins. Infect Immun 2023; 91:e0051322. [PMID: 36645295 PMCID: PMC9933654 DOI: 10.1128/iai.00513-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Chlamydia is an obligate intracellular pathogen with a highly reduced genome devoid of major stress response genes like relA and spoT, which mediate the stringent response. Interestingly, as an intracellular bacterium dependent on its host for nutrients and as a tryptophan (Trp) auxotroph, Chlamydia is very sensitive to Trp starvation, which is induced in vivo by the host cytokine interferon-γ. In response to Trp starvation, Chlamydia enters a viable but nonreplicating state called persistence. A major characteristic of chlamydial persistence is a block in cell division. We hypothesized that cell division is blocked during persistence by the inability to translate Trp-rich cell division proteins. To test this, we first investigated the translation of various cell division proteins under Trp starvation conditions using inducible expression strains. We observed that the Trp-poor protein MurG and the Trp-neutral protein FtsL were still expressed during persistence, while the expression of the Trp-rich proteins Pbp2, RodA, FtsI/Pbp3, and MraY was significantly reduced. As proof of concept for our hypothesis, we compared expression of a wild-type and mutant isoform of RodZ in which its four Trp codons were mutated. These experiments demonstrated that decreased expression of RodZ during persistence was reversed when no Trp was present in the protein, thus directly linking its expression to its Trp content. Together, these experiments indicate that specific cell division proteins are not produced during persistence. For the first time, our data provide a mechanism that explains the inhibition of cell division during chlamydial persistence mediated by Trp starvation.
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Jorgenson LM, Knight L, Widner RE, Rucks EA. Eukaryotic Clathrin Adapter Protein and Mediator of Cholesterol Homeostasis, PICALM, Affects Trafficking to the Chlamydial Inclusion. Mol Cell Biol 2023; 43:1-13. [PMID: 36779337 PMCID: PMC9980547 DOI: 10.1080/10985549.2023.2171695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/19/2022] [Accepted: 01/16/2023] [Indexed: 02/14/2023] Open
Abstract
The obligate intracellular pathogen Chlamydia trachomatis has unique metabolic requirements as it proceeds through its biphasic developmental cycle from within the inclusion within the host cell. In our previous study, we identified a host protein, PICALM, which localizes to the chlamydial inclusion. PICALM functions in many host pathways including the recycling of receptors, specific SNARE proteins, and molecules like transferrin, and maintaining cholesterol homeostasis. Hence, we hypothesized that PICALM functions to maintain the cholesterol content and to moderate trafficking from the endosomal recycling pathway to the inclusion, which controls chlamydial access to this pathway. In uninfected cells, siRNA knockdown of PICALM resulted in increased cholesterol within the Golgi and transferrin receptor (TfR) positive vesicles (recycling endosomes). PICALM knockdown in cells infected with C. trachomatis resulted in increased levels of Golgi-derived lipid and protein, TfR, transferrin, and Rab11-FIP1 localized to inclusions and a decrease of Golgi fragmentation at and Rab11 trafficking to the inclusion. Interestingly, chlamydial infection alone also increases cholesterol in TfR and Rab11-associated vesicles, and PICALM knockdown reverses this effect. Our data suggest that PICALM functions to balance or limit chlamydial access to multiple subcellular trafficking pathways to maintain the health of the host cell during chlamydial infection.
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Affiliation(s)
- Lisa M. Jorgenson
- UNeMed Corporation, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Lindsey Knight
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Ray E. Widner
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Elizabeth A. Rucks
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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de Campos LJ, Seleem MA, Feng J, Pires de Oliveira KM, de Andrade Dos Santos JV, Hayer S, Clayton JB, Kathi S, Fisher DJ, Ouellette SP, Conda-Sheridan M. Design, Biological Evaluation, and Computer-Aided Analysis of Dihydrothiazepines as Selective Antichlamydial Agents. J Med Chem 2023; 66:2116-2142. [PMID: 36696579 PMCID: PMC10056257 DOI: 10.1021/acs.jmedchem.2c01894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chlamydia trachomatis (CT) causes the most prevalent sexually transmitted bacterial disease in the United States. The lack of drug selectivity is one of the main challenges of the current antichlamydial pharmacotherapy. The metabolic needs of CT are controlled, among others, by cylindrical proteases and their chaperones (e.g., ClpX). It has been shown that dihydrothiazepines can disrupt CT-ClpXP. Based on this precedent, we synthesized a dihydrothiazepine library and characterized its antichlamydial activity using a modified semi-high-throughput screening assay. Then, we demonstrated their ability to inhibit ClpX ATPase activity in vitro, supporting ClpX as a target. Further, our lead compound displayed a promising selectivity profile against CT, acceptable cytotoxicity, no mutagenic potential, and good in vitro stability. A two-dimensional quantitative structure-activity relationship (2D QSAR) model was generated as a support tool in the identification of more potent antichlamydial molecules. This study suggests dihydrothiazepines are a promising starting point for the development of new and selective antichlamydial drugs.
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Affiliation(s)
- Luana Janaína de Campos
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Mohamed A Seleem
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Jiachen Feng
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Kelly Mari Pires de Oliveira
- Faculty of Biological and Environmental Science, Federal University of Grande Dourados, Dourados, MS 79804-970, Brazil
| | | | - Shivdeep Hayer
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska 68182, United States
| | - Jonathan B Clayton
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska 68182, United States
- Department of Food Science and Technology, University of Nebraska─Lincoln, Lincoln, Nebraska 68588, United States
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
- Nebraska Food for Health Center, University of Nebraska─Lincoln, Lincoln, Nebraska 68508, United States
| | - Sharvath Kathi
- School of Biological Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Derek J Fisher
- School of Biological Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Scot P Ouellette
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Martin Conda-Sheridan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
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Diversity of σ 66-Specific Promoters Contributes to Regulation of Developmental Gene Expression in Chlamydia trachomatis. J Bacteriol 2023; 205:e0031022. [PMID: 36598485 PMCID: PMC9879106 DOI: 10.1128/jb.00310-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Promoter recognition by the RNA polymerase (RNAP) holoenzyme is a key step in gene regulation. In Chlamydia trachomatis, a medically important obligate intracellular bacterium, σ66 allows the RNAP to initiate promoter-specific transcription throughout the chlamydial developmental cycle. Here, we investigated the intrinsic properties of σ66-specific promoters with emphasis on their role in the developmental gene expression of C. trachomatis. First, we examined whether promoters that contain a 5'-T(-15)G(-14)-3' (TG) motif upstream from the -10 element appear more often than others in genes that are preferentially expressed during the early, middle, or late stages of the C. trachomatis developmental cycle. We then determined the critical genetic elements that are required for transcription initiation in vitro. We also assessed the activity of promoters in the presence of Scc4, which can directly interact with σ66RNAP. Finally, we evaluated the promoter-specific dynamics during C. trachomatis infection using a reporter assay. These results reveal that the TG motif is an important determinant in certain early or late promoters. The TG promoters that have the -35 element are recognized by σ66RNAP and Scc4 differently from those lacking the -35 element. Based on these properties, the σ66-specific promoters can fall into three classes. Architectural diversity, behavioral plasticity, and the specific interplays between promoters and the σ66RNAP likely contribute to developmental gene transcription in C. trachomatis. IMPORTANCE Meticulous promoter elucidation is required to understand the foundations of transcription initiation. However, knowledge of promoter-specific transcription remains limited in C. trachomatis. This work underscores the structural and functional plasticity of σ66-specific promoters that are regulated by σ66RNAP, as well as their importance in the developmental gene regulation of C. trachomatis.
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Besir Akpinar M. A Hidden Organism, Chlamydia in the Age of Atherosclerosis. Infect Dis (Lond) 2023. [DOI: 10.5772/intechopen.109745] [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: 01/31/2023] Open
Abstract
Atherosclerosis is a chronic inflammatory disease. It is still the leading cause of mortality and morbidity in the world. Inflammation in the vessels plays the most important role in the pathogenesis of atherosclerosis. Many studies have been emphasized that Chlamydia pneumoniae triggers inflammation in the vessels and associated with atherosclerosis. It is stated that most of the chlamydial infections are asymptomatic and around 40% of adult individuals are infected. Chlamydia has different subgroups. It was thought to be a virus due to its intracellular pathogenicity, but it was included in the bacteria genus because it contains DNA and RNA chromosomes and has enzymatic activity. Chlamidya can easily be transmitted through the respiratory tract and sexual transmission. Seroepidemiological and pathological studies of atherosclerotic plaques showed the presence of Chlamydia in the plaque. This section will provide relationship between Chlamydia and atherosclerosis on the recent researces and current information will be discussed.
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Stein RA, Thompson LM. Epigenetic changes induced by pathogenic Chlamydia spp. Pathog Dis 2023; 81:ftad034. [PMID: 38031337 DOI: 10.1093/femspd/ftad034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 11/16/2023] [Accepted: 11/28/2023] [Indexed: 12/01/2023] Open
Abstract
Chlamydia trachomatis, C. pneumoniae, and C. psittaci, the three Chlamydia species known to cause human disease, have been collectively linked to several pathologies, including conjunctivitis, trachoma, respiratory disease, acute and chronic urogenital infections and their complications, and psittacosis. In vitro, animal, and human studies also established additional correlations, such as between C. pneumoniae and atherosclerosis and between C. trachomatis and ovarian cancer. As part of their survival and pathogenesis strategies as obligate intracellular bacteria, Chlamydia spp. modulate all three major types of epigenetic changes, which include deoxyribonucleic acid (DNA) methylation, histone post-translational modifications, and microRNA-mediated gene silencing. Some of these epigenetic changes may be implicated in key aspects of pathogenesis, such as the ability of the Chlamydia spp. to induce epithelial-to-mesenchymal transition, interfere with DNA damage repair, suppress cholesterol efflux from infected macrophages, act as a co-factor in human papillomavirus (HPV)-mediated cervical cancer, prevent apoptosis, and preserve the integrity of mitochondrial networks in infected host cells. A better understanding of the individual and collective contribution of epigenetic changes to pathogenesis will enhance our knowledge about the biology of Chlamydia spp. and facilitate the development of novel therapies and biomarkers. Pathogenic Chlamydia spp. contribute to epigenetically-mediated gene expression changes in host cells by multiple mechanisms.
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Affiliation(s)
- Richard A Stein
- NYU Tandon School of Engineering, Department of Chemical and Biomolecular Engineering, 6 MetroTech Center, Brooklyn, NY 11201, United States
| | - Lily M Thompson
- NYU Tandon School of Engineering, Department of Chemical and Biomolecular Engineering, 6 MetroTech Center, Brooklyn, NY 11201, United States
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47
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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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Azadmanesh J, Seleem MA, Struble L, Wood NA, Fisher DJ, Lovelace JJ, Artigues A, Fenton AW, Borgstahl GEO, Ouellette SP, Conda-Sheridan M. The structure of caseinolytic protease subunit ClpP2 reveals a functional model of the caseinolytic protease system from Chlamydia trachomatis. J Biol Chem 2023; 299:102762. [PMID: 36463962 PMCID: PMC9823225 DOI: 10.1016/j.jbc.2022.102762] [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: 08/17/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 12/05/2022] Open
Abstract
Chlamydia trachomatis (ct) is the most reported bacterial sexually transmitted infection worldwide and the leading cause of preventable blindness. Caseinolytic proteases (ClpP) from pathogenic bacteria are attractive antibiotic targets, particularly for bacterial species that form persister colonies with phenotypic resistance against common antibiotics. ClpP functions as a multisubunit proteolytic complex, and bacteria are eradicated when ClpP is disrupted. Although crucial for chlamydial development and the design of agents to treat chlamydia, the structures of ctClpP1 and ctClpP2 have yet to be solved. Here, we report the first crystal structure of full-length ClpP2 as an inactive homotetradecamer in a complex with a candidate antibiotic at 2.66 Å resolution. The structure details the functional domains of the ClpP2 protein subunit and includes the handle domain, which is integral to proteolytic activation. In addition, hydrogen-deuterium exchange mass spectroscopy probed the dynamics of ClpP2, and molecular modeling of ClpP1 predicted an assembly with ClpP2. By leveraging previous enzymatic experiments, we constructed a model of ClpP2 activation and its interaction with the protease subunits ClpP1 and ClpX. The structural information presented will be relevant for future rational drug design against these targets and will lead to a better understanding of ClpP complex formation and activation within this important human pathogen.
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Affiliation(s)
- Jahaun Azadmanesh
- The Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Mohamed A Seleem
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986125 Nebraska Medical Center, Omaha, Nebraska, USA
| | - Lucas Struble
- The Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Nicholas A Wood
- Department of Pathology and Microbiology, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska, USA
| | - Derek J Fisher
- School of Biological Sciences, Southern Illinois University Carbondale, Carbondale, Illinois, USA
| | - Jeffrey J Lovelace
- The Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Antonio Artigues
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Aron W Fenton
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Gloria E O Borgstahl
- The Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Scot P Ouellette
- Department of Pathology and Microbiology, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska, USA
| | - Martin Conda-Sheridan
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986125 Nebraska Medical Center, Omaha, Nebraska, USA.
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Mayavannan A, Shantz E, Haidl ID, Wang J, Marshall JS. Mast cells selectively produce inflammatory mediators and impact the early response to Chlamydia reproductive tract infection. Front Immunol 2023; 14:1166068. [PMID: 37138882 PMCID: PMC10150091 DOI: 10.3389/fimmu.2023.1166068] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 03/28/2023] [Indexed: 05/05/2023] Open
Abstract
Introduction Chlamydia trachomatis (C. trachomatis) is a Gram-negative obligate intracellular bacterium that causes reproductive tract complications in women, including ectopic pregnancies and tubal factor infertility. We hypothesized that mast cells, which are common at mucosal barriers, may contribute to responses to Chlamydia infection and aimed to define human mast cell responses to C. trachomatis. Methods Human cord blood-derived mast cells (CBMCs) were exposed to C. trachomatis to assess bacterial uptake, mast cell degranulation, gene expression, and production of inflammatory mediators. The role of formyl peptide receptors and Toll-like receptor 2 (TLR2) were investigated using pharmacological inhibitors and soluble TLR2. Mast cell-deficient mice and littermate controls were used to examine the in vivo role of mast cells in influencing the immune response to Chlamydia infection in the female reproductive tract. Results C. trachomatis bacteria were taken up by human mast cells but did not replicate efficiently inside CBMCs. C. trachomatis-activated mast cells did not degranulate but maintained viability and exhibited cellular activation with homotypic aggregation and upregulation of ICAM-1. However, they significantly enhanced the gene expression of IL1B, CCL3, NFKB1, CXCL8, and IL6. Inflammatory mediators were produced, including TNF, IL-1β, IL-1RA, IL-6, GM-CSF, IL-23, CCL3, CCL5, and CXCL8. Endocytic blockade resulted in reduced gene expression of IL6, IL1B, and CCL3, suggesting C. trachomatis induced mast cell activation in both extracellular and intracellular locations. The IL-6 response to C. trachomatis was reduced when CBMCs were treated with C. trachomatis coated with soluble TLR2. Mast cells derived from TLR2-deficient mice also demonstrated a reduced IL-6 response to C. muridarum. Five days following C. muridarum infection, mast cell-deficient mice showed attenuated CXCL2 production and significantly reduced numbers of neutrophils, eosinophils, and B cells in the reproductive tract when compared with mast cell-containing littermates. Discussion Taken together, these data demonstrate that mast cells are reactive to Chlamydia spp. through multiple mechanisms that include TLR2-dependent pathways. Mast cells also play an important role in shaping in vivo immune responses in Chlamydia reproductive tract infection through both effector cell recruitment and modification of the chemokine microenvironment.
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Affiliation(s)
- Animamalar Mayavannan
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - Emily Shantz
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - Ian D. Haidl
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - Jun Wang
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
- Canadian Center for Vaccinology, Izaak Walton Killam (IWK) Health Centre, Halifax, NS, Canada
| | - Jean S. Marshall
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
- Department of Pathology, Dalhousie University, Halifax, NS, Canada
- *Correspondence: Jean S. Marshall,
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Host Cell Amplification of Nutritional Stress Contributes To Persistence in Chlamydia trachomatis. mBio 2022; 13:e0271922. [PMID: 36377897 PMCID: PMC9765610 DOI: 10.1128/mbio.02719-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Persistence, a viable but non-replicating growth state, has been implicated in diseases caused by Chlamydia trachomatis. Starvation of distinct nutrients produces a superficially similar persistent state, implying convergence on a common intracellular environment. We employed host-pathogen dual RNA-sequencing under both iron- and tryptophan-starved conditions to systematically characterize the persistent chlamydial transcriptome and to define common contributions of the host cell transcriptional stress response in shaping the intracellular environment. The transcriptome of the infected host cells was highly specific to each nutritional stress, despite comparable effects on chlamydial growth and development in each condition. In contrast, the chlamydial transcriptomes between nutritional conditions were highly similar, suggesting some overlap in host cell responses to iron limitation and tryptophan starvation that contribute to a common persistent phenotype. We demonstrate that a commonality in the host cell responses is the suppression of GTP biosynthesis, a nucleotide for which Chlamydia are auxotrophic. Pharmacological inhibition of host IMP dehydrogenase (IMPDH1), which catalyzes the rate-limiting step in de novo guanine nucleotide synthesis, resulted in comparable GTP depletion to both iron and tryptophan starvation and induced chlamydial persistence. Moreover, IMPDH1 inhibition and iron starvation acted synergistically to control chlamydial growth. Thus, host cell reduction in GTP levels amplifies the nutritional stress to intracellular chlamydiae in infection-relevant models of persistence, illustrating the determinative role the infected host cell plays in bacterial stress responses. IMPORTANCE Bacteria respond to nutritional stress through universal and unique mechanisms. Genome reduction in the Chlamydiaceae, a consequence of coevolution with their obligate eukaryotic hosts, has reduced their repertoire of stress response mechanisms. Here, we demonstrate that the infected host cell may provide the context within which universal stress responses emerge for Chlamydia trachomatis. We report that during starvation of the essential nutrients iron or tryptophan, a common response of the infected epithelial cell is the suppression of GTP biosynthesis, which induces a persistent developmental state in the pathogen. Thus, chlamydial persistence results from the combined effects of primary stresses on the pathogen and the host, with the latter eliciting a secondary host cell response that intensifies the inhospitable intracellular environment.
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