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Kocher F, Applegate V, Reiners J, Port A, Spona D, Hänsch S, Mirzaiebadizi A, Ahmadian MR, Smits SHJ, Hegemann JH, Mölleken K. The Chlamydia pneumoniae effector SemD exploits its host's endocytic machinery by structural and functional mimicry. Nat Commun 2024; 15:7294. [PMID: 39181890 PMCID: PMC11344771 DOI: 10.1038/s41467-024-51681-3] [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: 02/12/2024] [Accepted: 08/15/2024] [Indexed: 08/27/2024] Open
Abstract
To enter epithelial cells, the obligate intracellular pathogen Chlamydia pneumoniae secretes early effector proteins, which bind to and modulate the host-cell's plasma membrane and recruit several pivotal endocytic host proteins. Here, we present the high-resolution structure of an entry-related chlamydial effector protein, SemD. Co-crystallisation of SemD with its host binding partners demonstrates that SemD co-opts the Cdc42 binding site to activate the actin cytoskeleton regulator N-WASP, making active, GTP-bound Cdc42 superfluous. While SemD binds N-WASP much more strongly than Cdc42 does, it does not bind the Cdc42 effector protein FMNL2, indicating effector protein specificity. Furthermore, by identifying flexible and structured domains, we show that SemD can simultaneously interact with the membrane, the endocytic protein SNX9, and N-WASP. Here, we show at the structural level how a single effector protein can hijack central components of the host's endocytic system for efficient internalization.
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Affiliation(s)
- Fabienne Kocher
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Institute for Functional Microbial Genomics, Düsseldorf, Germany
| | - Violetta Applegate
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Center for Structural Studies, Düsseldorf, Germany
| | - Jens Reiners
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Center for Structural Studies, Düsseldorf, Germany
| | - Astrid Port
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Center for Structural Studies, Düsseldorf, Germany
| | - Dominik Spona
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Institute for Functional Microbial Genomics, Düsseldorf, Germany
| | - Sebastian Hänsch
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Center for Advanced Imaging, Düsseldorf, Germany
| | - Amin Mirzaiebadizi
- Institute of Biochemistry and Molecular Biology II, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Mohammad Reza Ahmadian
- Institute of Biochemistry and Molecular Biology II, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sander H J Smits
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Center for Structural Studies, Düsseldorf, Germany
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Institute of Biochemistry, Düsseldorf, Germany
| | - Johannes H Hegemann
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Institute for Functional Microbial Genomics, Düsseldorf, Germany.
| | - Katja Mölleken
- Heinrich Heine University Düsseldorf, Faculty of Mathematics and Natural Sciences, Institute for Functional Microbial Genomics, Düsseldorf, Germany
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Reigada I, Kapp K, Kaudela T, García Soria M, Oksanen T, Hanski L. Tracking Chlamydia - Host interactions and antichlamydial activity in Caenorhabditis elegans. Biomed Pharmacother 2024; 177:116956. [PMID: 38901202 DOI: 10.1016/j.biopha.2024.116956] [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: 02/20/2024] [Revised: 06/02/2024] [Accepted: 06/15/2024] [Indexed: 06/22/2024] Open
Abstract
The fading efficacy of antibiotics is a growing global health concern due to its life-threatening consequences and increased healthcare costs. Non-genetic mechanisms of antimicrobial resistance, such as those employed by Chlamydia pneumoniae and Chlamydia trachomatis, complicate treatment as these bacteria can enter a non-replicative, persistent state under stress, evading antibiotics and linking to inflammatory conditions. Understanding chlamydial persistence at the molecular level is challenging, and new models for studying Chlamydia-host interactions in vivo are urgently needed. Caenorhabditis elegans offers an alternative given its immune system and numerous orthologues of human genes. This study established C. elegans as an in vivo model for chlamydial infection. Both Chlamydia species reduced the worm's lifespan, their DNA being detectable at three- and six-days post-infection. Azithromycin at its MIC (25 nM) failed to prevent the infection-induced lifespan reduction, indicating a persister phenotype. In contrast, the methanolic extract of Schisandra chinensis berries showed anti-chlamydial activity both in vitro (in THP-1 macrophages) and in vivo, significantly extending the lifespan of infected C. elegans and reducing the bacterial load. Moreover, S. chinensis increased the transcriptional activity of SKN-1 in the worms, but was unable to impact the bacterial load or lifespan in a sek-1 defective C. elegans strain. In summary, this study validated C. elegans as a chlamydial infection model and showcased S. chinensis berries' in vivo anti-chlamydial potential, possibly through SEK/SKN-1 signaling modulation.
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Affiliation(s)
- Inés Reigada
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
| | - Karmen Kapp
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
| | - Theresa Kaudela
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
| | - María García Soria
- Department of Pharmacy, Faculty of Health Sciences, Universidad San Jorge (San Jorge University), Zaragoza 50830, Spain
| | - Timo Oksanen
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
| | - Leena Hanski
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland.
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Taavitsainen-Wahlroos E, Reigada I, Sulmona I, Hanski L. Impact of azithromycin, doxycycline and redox-active small molecules on amoxicillin-induced Chlamydia pneumoniae persistence. Biomed Pharmacother 2023; 167:115451. [PMID: 37690390 DOI: 10.1016/j.biopha.2023.115451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/25/2023] [Accepted: 09/04/2023] [Indexed: 09/12/2023] Open
Abstract
Amoxicillin is recommended as primary treatment for community-acquired bacterial pneumonia (CABP). 5-10% of CABP cases are caused by Chlamydia pneumoniae, an obligate intracellular bacterium which responds to beta-lactam antibiotics by converting to a persistent phenotype. To support rational pharmacotherapy of C. pneumoniae infections, we investigated how clinically relevant concentrations of azithromycin and doxycycline affect amoxicillin induced C. pneumoniae persistence. Given the known role of redox state alterations in the action of bactericidal antibiotics and widespread use of redox-active dietary supplements when experiencing respiratory symptoms, we also studied how redox active compounds affect the studied antibiotic treatments. Our data demonstrate that clinically applied amoxicillin concentrations (10 and 25 mg/l) fail to eradicate C. pneumoniae infection in respiratory epithelial cells. Transmission electron microscopy (TEM) of amoxicillin-treated C. pneumoniae infected cells reveal aberrant bacterial morphology characteristic of chlamydial stress response. Amoxicillin was also found to significantly limit the antichlamydial effect of azithromycin or doxycycline. However, based on quantitative culture and quantitative PCR data, azithromycin was superior to doxycycline in C. pneumoniae eradication either as monotherapy or in combination with amoxicillin. Amoxicillin was also found to decrease respiratory epithelial cell glutathione (GSH) levels, whereas redox-active dibenzocyclooctadiene lignans increased C. pneumoniae load in amoxicillin-treated cultures up to two-fold. These data highlight the impact of relative administration time on the efficacy of antichlamydial antibiotics and indicate unfavorable interactions between amoxicillin and redox-active small molecules.
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Affiliation(s)
- Eveliina Taavitsainen-Wahlroos
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, 00790 Helsinki, Finland
| | - Inés Reigada
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, 00790 Helsinki, Finland
| | - Ilaria Sulmona
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples "Federico II", Via Tommaso De Amicis 95, 80131, Naples, Italy
| | - Leena Hanski
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, 00790 Helsinki, Finland.
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Spona D, Hanisch PT, Hegemann JH, Mölleken K. A single chlamydial protein reshapes the plasma membrane and serves as recruiting platform for central endocytic effector proteins. Commun Biol 2023; 6:520. [PMID: 37179401 PMCID: PMC10182996 DOI: 10.1038/s42003-023-04913-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
Uptake of obligate intracellular bacterial pathogens into mammalian epithelial cells is critically dependent on modulation of the host's endocytic machinery. It is an open question how the invading pathogens generate a membrane-bound vesicle appropriate to their size. This requires extensive deformation of the host plasma membrane itself by pathogen-derived membrane-binding proteins, accompanied by substantial F-actin-based forces to further expand and finally pinch off the vesicle. Here we show that upon adhesion to the host cell, the human pathogenic bacterium Chlamydia pneumoniae secretes the scaffolding effector protein CPn0677, which binds to the inner leaflet of the invaginating host's PM, induces inwardly directed, negative membrane curvature, and forms a recruiting platform for the membrane-deforming BAR-domain containing proteins Pacsin and SNX9. In addition, while bound to the membrane, CPn0677 recruits monomeric G-actin, and its C-terminal region binds and activates N-WASP, which initiates branching actin polymerization via the Arp2/3 complex. Together, these membrane-bound processes enable the developing endocytic vesicle to engulf the infectious elementary body, while the associated actin network generates the forces required to reshape and detach the nascent vesicle from the PM. Thus, Cpn0677 (now renamed SemD) acts as recruiting platform for central components of the endocytic machinery during uptake of chlamydia.
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Affiliation(s)
- Dominik Spona
- Institute for Functional Microbial Genomics, Heinrich-Heine-University, Düsseldorf, Germany
| | - Philipp T Hanisch
- Institute for Functional Microbial Genomics, Heinrich-Heine-University, Düsseldorf, Germany
| | - Johannes H Hegemann
- Institute for Functional Microbial Genomics, Heinrich-Heine-University, Düsseldorf, Germany
| | - Katja Mölleken
- Institute for Functional Microbial Genomics, Heinrich-Heine-University, Düsseldorf, Germany.
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Are ELISA and PCR Discrepancies in the Identification of Chlamydia pneumoniae Caused by the Presence of " Chlamydia-Related Bacteria"? Microorganisms 2023; 11:microorganisms11010187. [PMID: 36677479 PMCID: PMC9865915 DOI: 10.3390/microorganisms11010187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Chlamydia are Gram-negative, intracellular pathogens colonizing the epithelial mucosa. They cause primarily atypical pneumonia and have recently been associated with chronic diseases. Diagnostics rely almost exclusively on serological methods; PCR tests are used rarely because in patients with positive ELISA, it is nearly impossible to identify chlamydial DNA. To understand this issue, we elaborated a reliable and sensitive nested PCR method (panNPCR) for identifying all Chlamydiales species, not only in sputa, but also in clotted blood. Sequencing of the PCR product revealed that 41% of positive sputa samples and 66% of positive blood samples were not infected by Chlamydia but with "Chlamydia-related bacteria" such as Rhabdochlamydia sp., Parachlamydia sp., Protochlamydia sp., Neochlamydia sp., Mesochlamydia elodeae and lacustris, Piscichlamydia salmonis, and Estrella lausannensis. Consequently, we propose that there might be more than four human pathogenic Chlamydia species. We did not find any clear correlation between increased levels of antibodies and the presence of their DNA. Chlamydialles DNA was found in sputa samples from individuals positive for IgG or IgA but not in blood samples. Thus, elevated IgG and IgA levels are not reliable markers of chronic infection, and the presence of persistent forms should be proved by panNPCR. Apparently, the differences between ELISA and DNA amplification results have three main methodological reasons. The first one is the threshold occurrence of chlamydial genetic material in sputum and blood. The second one is the fact that a significant part of the samples can have DNA with sequences different from those of other species of the order Chlamydiales. The third one is the high background characteristic for ELISA, the absence of paired sera, and the vague interpretation of the gray zone.
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Zhou X, Zhang P, Tan H, Dong B, Jing Z, Wu H, Luo J, Zhang Y, Zhang J, Sun X. Progress in diagnosis and treatment of difficult-to-treat asthma in children. Ther Adv Respir Dis 2023; 17:17534666231213637. [PMID: 38069568 PMCID: PMC10710755 DOI: 10.1177/17534666231213637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/23/2023] [Indexed: 12/18/2023] Open
Abstract
At present, medications containing inhaled corticosteroids (ICS-containing) are the keystones of asthma treatment. The majority of asthmatic children can significantly improve clinical outcomes with little worsening by standardized inhaled glucocorticoid treatment, but there is still a small proportion of children who are unable to achieve good symptom control even after the maximum standardized treatment, known as 'children with difficult-to-treat asthma (DA)'. The high heterogeneity of DA makes therapy challenging and expensive, which poses a serious risk to children's health and makes it extremely difficult for clinical physicians to accurately identify and treat children with DA. This article reviews the definition, evaluation, and treatment of this asthma in order to provide a reference for optimal clinical decision-making.
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Affiliation(s)
- Xuehua Zhou
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Panpan Zhang
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Hong Tan
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Bo Dong
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Zenghui Jing
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Huajie Wu
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Jianfeng Luo
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Yao Zhang
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Juan Zhang
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, No. 127, Changle West Road, Xi’an, Shaanxi 710032, China
| | - Xin Sun
- Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, No. 127, Changle West Road, Xi’an, Shaanxi 710032, China
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Hahn DL, Webley W. U-BIOPRED/BIOAIR proteins: inflammation or infection? Eur Respir J 2022; 60:2200571. [PMID: 36202417 DOI: 10.1183/13993003.00571-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/19/2022] [Indexed: 12/14/2022]
Affiliation(s)
| | - Wilmore Webley
- University of Massachusetts Amherst, Department of Microbiology, Amherst, MA, USA
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Hahn DL. Does the asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) exist? A narrative review from epidemiology and practice. Allergol Immunopathol (Madr) 2022; 50:100-106. [PMID: 36335452 DOI: 10.15586/aei.v50i6.678] [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: 05/21/2022] [Accepted: 08/21/2022] [Indexed: 06/16/2023]
Abstract
Asthma and chronic obstructive pulmonary disease (COPD) have traditionally been approached as separate entities that must be researched and treated separately. There is growing recognition, however, that a substantial proportion of patients with obstructive lung disease have characteristics of both asthma and COPD (termed the asthma-COPD overlap syndrome (ACOS)). Lung disease experts have difficulty defining ACOS, and many still resist accepting the possibility that asthma and COPD may be linked. It is likely that practicing clinicians may be equally confused about how to identify and treat ACOS. This narrative review aims to clarify concepts of ACOS definition, argues that the best way to understand ACOS is to view the chronic lung disease process longitudinally rather than cross-sectionally, and presents evidence that ACOS can be the end result of the natural history of severe asthma. The review also points out the serious gaps in knowledge regarding therapy for ACOS and presents emerging data supporting the intracellular respiratory pathogen Chlamydia pneumoniae as a possible common etiologic agent in severe asthma and ACOS.
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Affiliation(s)
- David L Hahn
- Intracell Research Group, Town of Wake Forest, NC, United States;
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Hahn DL, Schultek NM. Infectious Asthma: An Easily Identified Clinical Presentation with Implications for Diagnosis, Prognosis, Treatment, and Prevention of Asthma. J Asthma Allergy 2022; 15:1269-1272. [PMID: 36164333 PMCID: PMC9508995 DOI: 10.2147/jaa.s379890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/25/2022] [Indexed: 11/23/2022] Open
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Wagshul FA, Brown DT, Schultek NM, Hahn DL. Outcomes of Antibiotics in Adults with "Difficult to Treat" Asthma or the Overlap Syndrome. J Asthma Allergy 2021; 14:703-712. [PMID: 34163182 PMCID: PMC8216074 DOI: 10.2147/jaa.s313480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/26/2021] [Indexed: 01/10/2023] Open
Abstract
Purpose Macrolides are a recommended treatment option for severe asthma, but data for “difficult-to-treat” asthma, the asthma-COPD “overlap” syndrome, and treatment duration beyond one year are lacking. We present long-term data from community practice experience providing insights for practice and research. Methods We report data from (1) baseline (pre-treatment) chart review of antibiotic-treated asthma patients and (2) follow-up telephone interviews documenting severe exacerbations (NIH criteria), Asthma Control Test (ACT) scores, and asthma controller use at baseline and follow-up, analyzed using a “before-after” model. Results A total of 101 patients (mean age 55.6 years (Sd 16.8), 66 females) were included. None had ever taken high dose inhaled corticosteroids and 79 (78.2%) were severely uncontrolled (ACT score ≤15) before treatment. Coexisting COPD was present in 62 (61.4%) patients. Azithromycin or azithromycin plus doxycycline was primarily prescribed with a median treatment duration of 12 months and median follow-up duration of 22 months. Severe exacerbations in the month before treatment occurred in 50.5% vs 17.8% at follow-up (P<0.0001). Mean ACT score increased from 12.2 to 20.6 (P<0.0001). The number of patients taking controller medications decreased (P<0.0001 for inhaled corticosteroids; P<0.001 for long-acting beta agonist/long-acting muscarinic antagonist; P<0.05 for leukotriene receptor antagonists). Of the 79 severely uncontrolled patients, 51 (64.6%) became controlled at follow-up, and of these 51, 27 (52.9%) continued to take antibiotics while 24 (47.1%) had discontinued antibiotics earlier yet remained controlled. Conclusion Antibiotic treatment may be beneficial in a significant proportion of “difficult to treat” asthma patients beyond one year, including some patients with the overlap syndrome and/or who fail to meet criteria for refractoriness. ![]()
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