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Rehman S, Antonovic AK, McIntire IE, Zheng H, Cleaver L, Baczynska M, Adams CO, Portlock T, Richardson K, Shaw R, Oregioni A, Mastroianni G, Whittaker SBM, Kelly G, Lorenz CD, Fornili A, Cianciotto NP, Garnett JA. The Legionella collagen-like protein employs a distinct binding mechanism for the recognition of host glycosaminoglycans. Nat Commun 2024; 15:4912. [PMID: 38851738 PMCID: PMC11162425 DOI: 10.1038/s41467-024-49255-4] [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: 09/16/2023] [Accepted: 05/30/2024] [Indexed: 06/10/2024] Open
Abstract
Bacterial adhesion is a fundamental process which enables colonisation of niche environments and is key for infection. However, in Legionella pneumophila, the causative agent of Legionnaires' disease, these processes are not well understood. The Legionella collagen-like protein (Lcl) is an extracellular peripheral membrane protein that recognises sulphated glycosaminoglycans on the surface of eukaryotic cells, but also stimulates bacterial aggregation in response to divalent cations. Here we report the crystal structure of the Lcl C-terminal domain (Lcl-CTD) and present a model for intact Lcl. Our data reveal that Lcl-CTD forms an unusual trimer arrangement with a positively charged external surface and negatively charged solvent exposed internal cavity. Through molecular dynamics simulations, we show how the glycosaminoglycan chondroitin-4-sulphate associates with the Lcl-CTD surface via distinct binding modes. Our findings show that Lcl homologs are present across both the Pseudomonadota and Fibrobacterota-Chlorobiota-Bacteroidota phyla and suggest that Lcl may represent a versatile carbohydrate-binding mechanism.
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Affiliation(s)
- Saima Rehman
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
| | - Anna Katarina Antonovic
- Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, London, UK
| | - Ian E McIntire
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Huaixin Zheng
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Leanne Cleaver
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
| | - Maria Baczynska
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
- Biological Physics & Soft Matter Research Group, Department of Physics, King's College London, London, UK
| | - Carlton O Adams
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Theo Portlock
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Katherine Richardson
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Rosie Shaw
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Alain Oregioni
- The Medical Research Council Biomedical NMR Centre, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Giulia Mastroianni
- Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, London, UK
| | - Sara B-M Whittaker
- School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Geoff Kelly
- The Medical Research Council Biomedical NMR Centre, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Christian D Lorenz
- Biological Physics & Soft Matter Research Group, Department of Physics, King's College London, London, UK
| | - Arianna Fornili
- Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, London, UK.
| | - Nicholas P Cianciotto
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| | - James A Garnett
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK.
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2
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Singh D. Revolutionizing Lung Cancer Treatment: Innovative CRISPR-Cas9 Delivery Strategies. AAPS PharmSciTech 2024; 25:129. [PMID: 38844700 DOI: 10.1208/s12249-024-02834-6] [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: 01/15/2024] [Accepted: 05/08/2024] [Indexed: 06/11/2024] Open
Abstract
Lung carcinoma, including both non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), remains a significant global health challenge due to its high morbidity and mortality rates. The objsective of this review is to meticulously examine the current advancements and strategies in the delivery of CRISPR-Cas9 gene-editing technology for the treatment of lung carcinoma. This technology heralds a new era in molecular biology, offering unprecedented precision in genomic modifications. However, its therapeutic potential is contingent upon the development of effective delivery mechanisms that ensure the efficient and specific transport of gene-editing tools to tumor cells. We explore a variety of delivery approaches, such as viral vectors, lipid-based nanoparticles, and physical methods, highlighting their respective advantages, limitations, and recent breakthroughs. This review also delves into the translational and clinical significance of these strategies, discussing preclinical and clinical studies that investigate the feasibility, efficacy, and safety of CRISPR-Cas9 delivery for lung carcinoma. By scrutinizing the landscape of ongoing clinical trials and offering translational perspectives, we aim to elucidate the current state and future directions of this rapidly evolving field. The review is structured to first introduce the problem and significance of lung carcinoma, followed by an overview of CRISPR-Cas9 technology, a detailed examination of delivery strategies, and an analysis of clinical applications and regulatory considerations. Our discussion concludes with future perspectives and challenges, such as optimizing delivery strategies, enhancing specificity, mitigating immunogenicity concerns, and addressing regulatory issues. This comprehensive overview seeks to provide insights into the potential of CRISPR-Cas9 as a revolutionary approach for targeted therapies and personalized medicine in lung carcinoma, emphasizing the importance of delivery strategy development in realizing the full potential of this groundbreaking technology.
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Affiliation(s)
- Dilpreet Singh
- University Institute of Pharma Sciences, Chandigarh University, Gharuan, Mohali, 140413, India.
- University Centre for Research and Development, Chandigarh University, Gharuan, Mohali, 140413, India.
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3
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Tang X, Luo L, Wang S. TSE-ARF: An adaptive prediction method of effectors across secretion system types. Anal Biochem 2024; 686:115407. [PMID: 38030053 DOI: 10.1016/j.ab.2023.115407] [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: 09/02/2023] [Revised: 11/12/2023] [Accepted: 11/20/2023] [Indexed: 12/01/2023]
Abstract
Bacterial effector proteins are secreted by a variety of protein secretion systems and play an important role in the interaction between the host and pathogenic bacteria. Therefore, it is important to find a fast and inexpensive method to discover bacterial effectors. In this study, we propose a multi-type secretion effector adaptive random forest (TSE-ARF) to adaptively identify secretion effectors across T1SE-T4SE and T6SE based only on protein sequences. First, we proposed two new feature descriptors by considering some characteristic protein information and fused them with some universal features to form a 290-dimensional feature vector with good versatility. Then, the TSE-ARF model was used to make classification predictions by parameter adaptation of different secretion effectors integrating Shuffled Frog Leaping Algorithm and random forest. The perfect performance in TSE-ARF under different data sets and settings shows its considerable generalization ability, with which more candidate effectors were screened in the whole genome. Source code is available at https://github.com/AIMOVE/TSE-ARF.
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Affiliation(s)
- Xianjun Tang
- Department of Computer Science and Engineering, School of Information Science and Engineering, Yunnan University, Kunming, 650504, Yunnan, China
| | - Longfei Luo
- Department of Computer Science and Engineering, School of Information Science and Engineering, Yunnan University, Kunming, 650504, Yunnan, China
| | - Shunfang Wang
- Department of Computer Science and Engineering, School of Information Science and Engineering, Yunnan University, Kunming, 650504, Yunnan, China; Yunnan Key Laboratory of Intelligent Systems and Computing, Yunnan University, Kunming, Yunnan, China.
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4
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Graham CI, MacMartin TL, de Kievit TR, Brassinga AKC. Molecular regulation of virulence in Legionella pneumophila. Mol Microbiol 2024; 121:167-195. [PMID: 37908155 DOI: 10.1111/mmi.15172] [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: 05/31/2023] [Revised: 09/15/2023] [Accepted: 09/17/2023] [Indexed: 11/02/2023]
Abstract
Legionella pneumophila is a gram-negative bacteria found in natural and anthropogenic aquatic environments such as evaporative cooling towers, where it reproduces as an intracellular parasite of cohabiting protozoa. If L. pneumophila is aerosolized and inhaled by a susceptible person, bacteria may colonize their alveolar macrophages causing the opportunistic pneumonia Legionnaires' disease. L. pneumophila utilizes an elaborate regulatory network to control virulence processes such as the Dot/Icm Type IV secretion system and effector repertoire, responding to changing nutritional cues as their host becomes depleted. The bacteria subsequently differentiate to a transmissive state that can survive in the environment until a replacement host is encountered and colonized. In this review, we discuss the lifecycle of L. pneumophila and the molecular regulatory network that senses nutritional depletion via the stringent response, a link to stationary phase-like metabolic changes via alternative sigma factors, and two-component systems that are homologous to stress sensors in other pathogens, to regulate differentiation between the intracellular replicative phase and more transmissible states. Together, we highlight how this prototypic intracellular pathogen offers enormous potential in understanding how molecular mechanisms enable intracellular parasitism and pathogenicity.
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Affiliation(s)
- Christopher I Graham
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Teassa L MacMartin
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Teresa R de Kievit
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ann Karen C Brassinga
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
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5
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Rehman S, Antonovic AK, McIntire IE, Zheng H, Cleaver L, Adams CO, Portlock T, Richardson K, Shaw R, Oregioni A, Mastroianni G, Whittaker SBM, Kelly G, Fornili A, Cianciotto NP, Garnett JA. The Legionella collagen-like protein employs a unique binding mechanism for the recognition of host glycosaminoglycans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.10.570962. [PMID: 38106198 PMCID: PMC10723406 DOI: 10.1101/2023.12.10.570962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Bacterial adhesion is a fundamental process which enables colonisation of niche environments and is key for infection. However, in Legionella pneumophila, the causative agent of Legionnaires' disease, these processes are not well understood. The Legionella collagen-like protein (Lcl) is an extracellular peripheral membrane protein that recognises sulphated glycosaminoglycans (GAGs) on the surface of eukaryotic cells, but also stimulates bacterial aggregation in response to divalent cations. Here we report the crystal structure of the Lcl C-terminal domain (Lcl-CTD) and present a model for intact Lcl. Our data reveal that Lcl-CTD forms an unusual dynamic trimer arrangement with a positively charged external surface and a negatively charged solvent exposed internal cavity. Through Molecular Dynamics (MD) simulations, we show how the GAG chondroitin-4-sulphate associates with the Lcl-CTD surface via unique binding modes. Our findings show that Lcl homologs are present across both the Pseudomonadota and Fibrobacterota-Chlorobiota-Bacteroidota phyla and suggest that Lcl may represent a versatile carbohydrate binding mechanism.
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Affiliation(s)
- Saima Rehman
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, UK
| | - Anna K. Antonovic
- School of Physical and Chemical Sciences, Queen Mary University of London, London, UK
| | - Ian E. McIntire
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Huaixin Zheng
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Leanne Cleaver
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, UK
| | - Carlton O. Adams
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Theo Portlock
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, UK
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Katherine Richardson
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Rosie Shaw
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Alain Oregioni
- The Medical Research Council Biomedical NMR Centre, the Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Giulia Mastroianni
- School of Physical and Chemical Sciences, Queen Mary University of London, London, UK
| | - Sara B-M. Whittaker
- School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Geoff Kelly
- The Medical Research Council Biomedical NMR Centre, the Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Arianna Fornili
- School of Physical and Chemical Sciences, Queen Mary University of London, London, UK
| | - Nicholas P. Cianciotto
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - James A. Garnett
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, UK
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6
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Scheithauer L, Karagöz MS, Mayer BE, Steinert M. Protein sociology of ProA, Mip and other secreted virulence factors at the Legionella pneumophila surface. Front Cell Infect Microbiol 2023; 13:1140688. [PMID: 36936764 PMCID: PMC10017501 DOI: 10.3389/fcimb.2023.1140688] [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: 01/09/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023] Open
Abstract
The pathogenicity of L. pneumophila, the causative agent of Legionnaires' disease, depends on an arsenal of interacting proteins. Here we describe how surface-associated and secreted virulence factors of this pathogen interact with each other or target extra- and intracellular host proteins resulting in host cell manipulation and tissue colonization. Since progress of computational methods like AlphaFold, molecular dynamics simulation, and docking allows to predict, analyze and evaluate experimental proteomic and interactomic data, we describe how the combination of these approaches generated new insights into the multifaceted "protein sociology" of the zinc metalloprotease ProA and the peptidyl-prolyl cis/trans isomerase Mip (macrophage infectivity potentiator). Both virulence factors of L. pneumophila interact with numerous proteins including bacterial flagellin (FlaA) and host collagen, and play important roles in virulence regulation, host tissue degradation and immune evasion. The recent progress in protein-ligand analyses of virulence factors suggests that machine learning will also have a beneficial impact in early stages of drug discovery.
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Affiliation(s)
- Lina Scheithauer
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Mustafa Safa Karagöz
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Benjamin E. Mayer
- Computational Biology & Simulation, Technische Universität Darmstadt, Darmstadt, Germany
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
- *Correspondence: Michael Steinert,
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7
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Yang JL, Li D, Zhan XY. Concept about the Virulence Factor of Legionella. Microorganisms 2022; 11:microorganisms11010074. [PMID: 36677366 PMCID: PMC9867486 DOI: 10.3390/microorganisms11010074] [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: 11/30/2022] [Revised: 12/23/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
Pathogenic species of Legionella can infect human alveolar macrophages through Legionella-containing aerosols to cause a disease called Legionellosis, which has two forms: a flu-like Pontiac fever and severe pneumonia named Legionnaires' disease (LD). Legionella is an opportunistic pathogen that frequently presents in aquatic environments as a biofilm or protozoa parasite. Long-term interaction and extensive co-evolution with various genera of amoebae render Legionellae pathogenic to infect humans and also generate virulence differentiation and heterogeneity. Conventionally, the proteins involved in initiating replication processes and human macrophage infections have been regarded as virulence factors and linked to pathogenicity. However, because some of the virulence factors are associated with the infection of protozoa and macrophages, it would be more accurate to classify them as survival factors rather than virulence factors. Given that the molecular basis of virulence variations among non-pathogenic, pathogenic, and highly pathogenic Legionella has not yet been elaborated from the perspective of virulence factors, a comprehensive explanation of how Legionella infects its natural hosts, protozoans, and accidental hosts, humans is essential to show a novel concept regarding the virulence factor of Legionella. In this review, we overviewed the pathogenic development of Legionella from protozoa, the function of conventional virulence factors in the infections of protozoa and macrophages, the host's innate immune system, and factors involved in regulating the host immune response, before discussing a probably new definition for the virulence factors of Legionella.
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8
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Talapko J, Frauenheim E, Juzbašić M, Tomas M, Matić S, Jukić M, Samardžić M, Škrlec I. Legionella pneumophila-Virulence Factors and the Possibility of Infection in Dental Practice. Microorganisms 2022; 10:microorganisms10020255. [PMID: 35208710 PMCID: PMC8879694 DOI: 10.3390/microorganisms10020255] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/08/2022] [Accepted: 01/21/2022] [Indexed: 02/07/2023] Open
Abstract
Legionella pneumophila is defined as a bacterium that can cause severe pneumonia. It is found in the natural environment and in water, and is often found in water tanks. It can be an integral part of biofilms in nature, and the protozoa in which it can live provide it with food and protect it from harmful influences; therefore, it has the ability to move into a sustainable but uncultured state (VBNC). L. pneumophila has been shown to cause infections in dental practices. The most common transmission route is aerosol generated in dental office water systems, which can negatively affect patients and healthcare professionals. The most common way of becoming infected with L. pneumophila in a dental office is through water from dental instruments, and the dental unit. In addition to these bacteria, patients and the dental team may be exposed to other harmful bacteria and viruses. Therefore, it is vital that the dental team regularly maintains and decontaminates the dental unit, and sterilizes all accessories that come with it. In addition, regular water control in dental offices is necessary.
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Affiliation(s)
- Jasminka Talapko
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Erwin Frauenheim
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Martina Juzbašić
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Matej Tomas
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Suzana Matić
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Josipa Huttlera 4, HR-31000 Osijek, Croatia
| | - Melita Jukić
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
- General Hospital Vukovar, Županijska 35, HR-32000 Vukovar, Croatia
| | - Marija Samardžić
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Ivana Škrlec
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
- Correspondence:
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9
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Iyer S, Das C. The unity of opposites: Strategic interplay between bacterial effectors to regulate cellular homeostasis. J Biol Chem 2021; 297:101340. [PMID: 34695417 PMCID: PMC8605245 DOI: 10.1016/j.jbc.2021.101340] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 10/15/2021] [Accepted: 10/20/2021] [Indexed: 11/23/2022] Open
Abstract
Legionella pneumophila is a facultative intracellular pathogen that uses the Dot/Icm Type IV secretion system (T4SS) to translocate many effectors into its host and establish a safe, replicative lifestyle. The bacteria, once phagocytosed, reside in a vacuolar structure known as the Legionella-containing vacuole (LCV) within the host cells and rapidly subvert organelle trafficking events, block inflammatory responses, hijack the host ubiquitination system, and abolish apoptotic signaling. This arsenal of translocated effectors can manipulate the host factors in a multitude of different ways. These proteins also contribute to bacterial virulence by positively or negatively regulating the activity of one another. Such effector-effector interactions, direct and indirect, provide the delicate balance required to maintain cellular homeostasis while establishing itself within the host. This review summarizes the recent progress in our knowledge of the structure-function relationship and biochemical mechanisms of select effector pairs from Legionella that work in opposition to one another, while highlighting the diversity of biochemical means adopted by this intracellular pathogen to establish a replicative niche within host cells.
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Affiliation(s)
- Shalini Iyer
- Department of Chemistry, Purdue University, West Lafayette, Indiana, USA.
| | - Chittaranjan Das
- Department of Chemistry, Purdue University, West Lafayette, Indiana, USA.
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10
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Budowa i znaczenie II systemu sekrecji białek w ekologii i patogenezie Legionella pneumophila. POSTEP HIG MED DOSW 2021. [DOI: 10.2478/ahem-2021-0034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Pałeczki Legionella pneumophila pasożytują w komórkach odległych filogenetycznie gospodarzy, w środowisku wodnym w pierwotniakach, a w organizmie człowieka w makrofagach alweolarnych. Zdolność tych bakterii do wewnątrzkomórkowego namnażania się w komórkach fagocytujących, wyspecjalizowanych do niszczenia mikroorganizmów, ma podstawowe znaczenie dla rozwoju nietypowego zapalenia płuc zwanego chorobą legionistów. Umiejscowione na kilku różnych loci chromosomu bakteryjnego geny II systemu sekrecji L. pneumophila kodują co najmniej 25 białek, w tym enzymy o aktywności lipolitycznej, proteolitycznej, rybonukleazy oraz białka unikalne bakterii Legionella. W środowisku naturalnym T2SS L. pneumophila odgrywa decydującą rolę w ekologii tych drobnoustrojów determinując ich zdolność do przeżycia zarówno w postaci planktonicznej, jak i w strukturach biofilmu w słodkowodnych zbiornikach o niskiej temperaturze. Białka T2SS umożliwiają L. pneumophila zakażenie różnych gatunków pierwotniaków, a substraty tego systemu określają zakres pierwotniaczego gospodarza. Namnażanie się bakterii w różnorodnych pierwotniakach przyczynia się do ich rozsiewania oraz transmisji do antropogenicznych źródeł. Białka wydzielane za pomocą II systemu sekrecji determinują również zdolność L. pneumophila do zakażania mysich makrofagów alweolarnych i szpiku kostnego, ludzkich makrofagów linii U937 i THP-1 oraz komórek nabłonkowych pęcherzyków płucnych. Enzymy wydzielane za pomocą tego systemu, takie jak: proteazy, aminopeptydazy czy fosfolipazy umożliwiają pozyskanie substancji pokarmowych oraz powodują destrukcję tkanki płucnej myszy. W organizmie człowieka białka T2SS przyczyniają się do osłabienia wrodzonej odpowiedzi immunologicznej na zakażenie L. pneumophila przez hamowanie indukcji prozapalnych cytokin (IL-6, TNF-α, IL-1 oraz IL-8).
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11
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Chauhan D, Shames SR. Pathogenicity and Virulence of Legionella: Intracellular replication and host response. Virulence 2021; 12:1122-1144. [PMID: 33843434 PMCID: PMC8043192 DOI: 10.1080/21505594.2021.1903199] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Bacteria of the genus Legionella are natural pathogens of amoebae that can cause a severe pneumonia in humans called Legionnaires’ Disease. Human disease results from inhalation of Legionella-contaminated aerosols and subsequent bacterial replication within alveolar macrophages. Legionella pathogenicity in humans has resulted from extensive co-evolution with diverse genera of amoebae. To replicate intracellularly, Legionella generates a replication-permissive compartment called the Legionella-containing vacuole (LCV) through the concerted action of hundreds of Dot/Icm-translocated effector proteins. In this review, we present a collective overview of Legionella pathogenicity including infection mechanisms, secretion systems, and translocated effector function. We also discuss innate and adaptive immune responses to L. pneumophila, the implications of Legionella genome diversity and future avenues for the field.
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Affiliation(s)
- Deepika Chauhan
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
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12
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The Role of Lipids in Legionella-Host Interaction. Int J Mol Sci 2021; 22:ijms22031487. [PMID: 33540788 PMCID: PMC7867332 DOI: 10.3390/ijms22031487] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 12/24/2022] Open
Abstract
Legionella are Gram-stain-negative rods associated with water environments: either natural or man-made systems. The inhalation of aerosols containing Legionella bacteria leads to the development of a severe pneumonia termed Legionnaires' disease. To establish an infection, these bacteria adapt to growth in the hostile environment of the host through the unusual structures of macromolecules that build the cell surface. The outer membrane of the cell envelope is a lipid bilayer with an asymmetric composition mostly of phospholipids in the inner leaflet and lipopolysaccharides (LPS) in the outer leaflet. The major membrane-forming phospholipid of Legionella spp. is phosphatidylcholine (PC)-a typical eukaryotic glycerophospholipid. PC synthesis in Legionella cells occurs via two independent pathways: the N-methylation (Pmt) pathway and the Pcs pathway. The utilisation of exogenous choline by Legionella spp. leads to changes in the composition of lipids and proteins, which influences the physicochemical properties of the cell surface. This phenotypic plasticity of the Legionella cell envelope determines the mode of interaction with the macrophages, which results in a decrease in the production of proinflammatory cytokines and modulates the interaction with antimicrobial peptides and proteins. The surface-exposed O-chain of Legionella pneumophila sg1 LPS consisting of a homopolymer of 5-acetamidino-7-acetamido-8-O-acetyl-3,5,7,9-tetradeoxy-l-glycero-d-galacto-non-2-ulosonic acid is probably the first component in contact with the host cell that anchors the bacteria in the host membrane. Unusual in terms of the structure and function of individual LPS regions, it makes an important contribution to the antigenicity and pathogenicity of Legionella bacteria.
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