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Kempher ML, Shadid TM, Larabee JL, Ballard JD. A sequence invariable region in TcdB2 is required for toxin escape from Clostridioides difficile. J Bacteriol 2024; 206:e0009624. [PMID: 38888328 PMCID: PMC11323933 DOI: 10.1128/jb.00096-24] [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: 03/06/2024] [Accepted: 05/23/2024] [Indexed: 06/20/2024] Open
Abstract
Sequence differences among the subtypes of Clostridioides difficile toxin TcdB (2,366 amino acids) are broadly distributed across the entire protein, with the notable exception of 76 residues at the protein's carboxy terminus. This sequence invariable region (SIR) is identical at the DNA and protein level among the TcdB variants, suggesting this string of amino acids has undergone selective pressure to prevent alterations. The functional role of the SIR domain in TcdB has not been determined. Analysis of a recombinantly constructed TcdB mutant lacking the SIR domain did not identify changes in TcdB's enzymatic or cytopathic activities. To further assess the SIR region, we constructed a C. difficile strain with the final 228 bp deleted from the tcdB gene, resulting in the production of a truncated form of TcdB lacking the SIR (TcdB2∆2291-2366). Using a combination of approaches, we found in the absence of the SIR sequence TcdB2∆2291-2366 retained cytotoxic activity but was not secreted from C. difficile. TcdB2∆2291-2366 was not released from the cell under autolytic conditions, indicating the SIR is involved in a more discrete step in toxin escape from the bacterium. Fractionation experiments combined with antibody detection found that TcdB2∆2291-2366 accumulates at the cell membrane but is unable to complete steps in secretion beyond this point. These data suggest conservation of the SIR domain across variants of TcdB could be influenced by the sequence's role in efficient escape of the toxin from C. difficile. IMPORTANCE Clostridioides difficile is a leading cause of antibiotic associated disease in the United States. The primary virulence factors produced by C. difficile are two large glucosylating toxins TcdA and TcdB. To date, several sequence variants of TcdB have been identified that differ in various functional properties. Here, we identified a highly conserved region among TcdB subtypes that is required for release of the toxin from C. difficile. This study reveals a putative role for the longest stretch of invariable sequence among TcdB subtypes and provides new details regarding toxin release into the extracellular environment. Improving our understanding of the functional roles of the conserved regions of TcdB variants aids in the development of new, broadly applicable strategies to treat CDI.
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Affiliation(s)
- Megan L. Kempher
- Department of
Microbiology and Immunology, University of Oklahoma Health Sciences
Center, Oklahoma City,
Oklahoma, USA
- Department of
Chemistry and Biochemistry, University of
Oklahoma, Norman,
Oklahoma, USA
| | - Tyler M. Shadid
- Department of
Microbiology and Immunology, University of Oklahoma Health Sciences
Center, Oklahoma City,
Oklahoma, USA
| | - Jason L. Larabee
- Department of
Microbiology and Immunology, University of Oklahoma Health Sciences
Center, Oklahoma City,
Oklahoma, USA
| | - Jimmy D. Ballard
- Department of
Microbiology and Immunology, University of Oklahoma Health Sciences
Center, Oklahoma City,
Oklahoma, USA
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2
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Di Bella S, Sanson G, Monticelli J, Zerbato V, Principe L, Giuffrè M, Pipitone G, Luzzati R. Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options. Clin Microbiol Rev 2024; 37:e0013523. [PMID: 38421181 PMCID: PMC11324037 DOI: 10.1128/cmr.00135-23] [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] [Indexed: 03/02/2024] Open
Abstract
SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.
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Affiliation(s)
- Stefano Di Bella
- Clinical Department of
Medical, Surgical and Health Sciences, Trieste
University, Trieste,
Italy
| | - Gianfranco Sanson
- Clinical Department of
Medical, Surgical and Health Sciences, Trieste
University, Trieste,
Italy
| | - Jacopo Monticelli
- Infectious Diseases
Unit, Trieste University Hospital
(ASUGI), Trieste,
Italy
| | - Verena Zerbato
- Infectious Diseases
Unit, Trieste University Hospital
(ASUGI), Trieste,
Italy
| | - Luigi Principe
- Microbiology and
Virology Unit, Great Metropolitan Hospital
“Bianchi-Melacrino-Morelli”,
Reggio Calabria, Italy
| | - Mauro Giuffrè
- Clinical Department of
Medical, Surgical and Health Sciences, Trieste
University, Trieste,
Italy
- Department of Internal
Medicine (Digestive Diseases), Yale School of Medicine, Yale
University, New Haven,
Connecticut, USA
| | - Giuseppe Pipitone
- Infectious Diseases
Unit, ARNAS Civico-Di Cristina
Hospital, Palermo,
Italy
| | - Roberto Luzzati
- Clinical Department of
Medical, Surgical and Health Sciences, Trieste
University, Trieste,
Italy
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3
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Zheng Y, Yang Q, Luo J, Zhang Y, Li X, He L, Ma C, Tao L. Identification of a hemorrhagic determinant in Clostridioides difficile TcdA and Paeniclostridium sordellii TcsH. Microbiol Spectr 2024; 12:e0035424. [PMID: 38709085 PMCID: PMC11237598 DOI: 10.1128/spectrum.00354-24] [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: 02/07/2024] [Accepted: 04/18/2024] [Indexed: 05/07/2024] Open
Abstract
Paeniclostridium sordellii hemorrhagic toxin (TcsH) and Clostridioides difficile toxin A (TcdA) are two major members of the large clostridial toxin (LCT) family. These two toxins share ~87% similarity and are known to cause severe hemorrhagic pathology in animals. Yet, the pathogenesis of their hemorrhagic toxicity has been mysterious for decades. Here, we examined the liver injury after systemic exposure to different LCTs and found that only TcsH and TcdA induce overt hepatic hemorrhage. By investigating the chimeric and truncated toxins, we demonstrated that the enzymatic domain of TcsH alone is not sufficient to determine its potent hepatic hemorrhagic toxicity in mice. Likewise, the combined repetitive oligopeptide (CROP) domain of TcsH/TcdA alone also failed to explain their strong hemorrhagic activity in mice. Lastly, we showed that disrupting the first two short repeats of CROPs in TcsH and TcdA impaired hemorrhagic toxicity without causing overt changes in cytotoxicity and lethality. These findings lead to a deeper understanding of toxin-induced hemorrhage and the pathogenesis of LCTs and could be insightful in developing therapeutic avenues against clostridial infections. IMPORTANCE Paeniclostridium sordellii and Clostridioides difficile infections often cause hemorrhage in the affected tissues and organs, which is mainly attributed to their hemorrhagic toxins, TcsH and TcdA. In this study, we demonstrate that TcsH and TcdA, but not other related toxins. including Clostridioides difficile toxin B and TcsL, induce severe hepatic hemorrhage in mice. We further determine that a small region in TcsH and TcdA is critical for the hemorrhagic toxicity but not cytotoxicity or lethality of these toxins. Based on these results, we propose that the hemorrhagic toxicity of TcsH and TcdA is due to an uncharacterized mechanism, such as the presence of an unknown receptor, and future studies to identify the interactive host factors are warranted.
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Affiliation(s)
- Yangling Zheng
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Qi Yang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Jianhua Luo
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Yuanyuan Zhang
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Xingxing Li
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Liuqing He
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Chao Ma
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Liang Tao
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
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Alam MZ, Madan R. Clostridioides difficile Toxins: Host Cell Interactions and Their Role in Disease Pathogenesis. Toxins (Basel) 2024; 16:241. [PMID: 38922136 PMCID: PMC11209539 DOI: 10.3390/toxins16060241] [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: 04/17/2024] [Revised: 05/20/2024] [Accepted: 05/22/2024] [Indexed: 06/27/2024] Open
Abstract
Clostridioides difficile, a Gram-positive anaerobic bacterium, is the leading cause of hospital-acquired antibiotic-associated diarrhea worldwide. The severity of C. difficile infection (CDI) varies, ranging from mild diarrhea to life-threatening conditions such as pseudomembranous colitis and toxic megacolon. Central to the pathogenesis of the infection are toxins produced by C. difficile, with toxin A (TcdA) and toxin B (TcdB) as the main virulence factors. Additionally, some strains produce a third toxin known as C. difficile transferase (CDT). Toxins damage the colonic epithelium, initiating a cascade of cellular events that lead to inflammation, fluid secretion, and further tissue damage within the colon. Mechanistically, the toxins bind to cell surface receptors, internalize, and then inactivate GTPase proteins, disrupting the organization of the cytoskeleton and affecting various Rho-dependent cellular processes. This results in a loss of epithelial barrier functions and the induction of cell death. The third toxin, CDT, however, functions as a binary actin-ADP-ribosylating toxin, causing actin depolymerization and inducing the formation of microtubule-based protrusions. In this review, we summarize our current understanding of the interaction between C. difficile toxins and host cells, elucidating the functional consequences of their actions. Furthermore, we will outline how this knowledge forms the basis for developing innovative, toxin-based strategies for treating and preventing CDI.
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Affiliation(s)
- Md Zahidul Alam
- Department of Pathology and Laboratory Medicine, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27858, USA
| | - Rajat Madan
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA;
- Veterans Affairs Medical Center, Cincinnati, OH 45220, USA
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5
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Pourliotopoulou E, Karampatakis T, Kachrimanidou M. Exploring the Toxin-Mediated Mechanisms in Clostridioides difficile Infection. Microorganisms 2024; 12:1004. [PMID: 38792835 PMCID: PMC11124097 DOI: 10.3390/microorganisms12051004] [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: 04/20/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024] Open
Abstract
Clostridioides difficile infection (CDI) is the leading cause of nosocomial antibiotic-associated diarrhea, and colitis, with increasing incidence and healthcare costs. Its pathogenesis is primarily driven by toxins produced by the bacterium C. difficile, Toxin A (TcdA) and Toxin B (TcdB). Certain strains produce an additional toxin, the C. difficile transferase (CDT), which further enhances the virulence and pathogenicity of C. difficile. These toxins disrupt colonic epithelial barrier integrity, and induce inflammation and cellular damage, leading to CDI symptoms. Significant progress has been made in the past decade in elucidating the molecular mechanisms of TcdA, TcdB, and CDT, which provide insights into the management of CDI and the future development of novel treatment strategies based on anti-toxin therapies. While antibiotics are common treatments, high recurrence rates necessitate alternative therapies. Bezlotoxumab, targeting TcdB, is the only available anti-toxin, yet limitations persist, prompting ongoing research. This review highlights the current knowledge of the structure and mechanism of action of C. difficile toxins and their role in disease. By comprehensively describing the toxin-mediated mechanisms, this review provides insights for the future development of novel treatment strategies and the management of CDI.
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Affiliation(s)
- Evdokia Pourliotopoulou
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece;
| | | | - Melania Kachrimanidou
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece;
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6
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Liu ML, Liang XM, Jin MY, Huang HW, Luo L, Wang H, Shen X, Xu ZL. Food-Borne Biotoxin Neutralization in Vivo by Nanobodies: Current Status and Prospects. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:10753-10771. [PMID: 38706131 DOI: 10.1021/acs.jafc.4c02257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
Food-borne biotoxins from microbes, plants, or animals contaminate unclean, spoiled, and rotten foods, posing significant health risks. Neutralizing such toxins is vital for human health, especially after food poisoning. Nanobodies (Nbs), a type of single-domain antibodies derived from the genetic cloning of a variable domain of heavy chain antibodies (VHHs) in camels, offer unique advantages in toxin neutralization. Their small size, high stability, and precise binding enable effective neutralization. The use of Nbs in neutralizing food-borne biotoxins offers numerous benefits, and their genetic malleability allows tailored optimization for diverse toxins. As nanotechnology continues to evolve and improve, Nbs are poised to become increasingly efficient and safer tools for toxin neutralization, playing a pivotal role in safeguarding human health and environmental safety. This review not only highlights the efficacy of these agents in neutralizing toxins but also proposes innovative solutions to address their current challenges. It lays a solid foundation for their further development in this crucial field and propels their commercial application, thereby contributing significantly to advancements in this domain.
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Affiliation(s)
- Min-Ling Liu
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Xiao-Min Liang
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Ming-Yu Jin
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
- School of Life and Health Technology, Dongguan, University of Technology, Dongguan 523808, China
| | - Hui-Wei Huang
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Lin Luo
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Hong Wang
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Xing Shen
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Zhen-Lin Xu
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
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7
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Popoff MR. Overview of Bacterial Protein Toxins from Pathogenic Bacteria: Mode of Action and Insights into Evolution. Toxins (Basel) 2024; 16:182. [PMID: 38668607 PMCID: PMC11054074 DOI: 10.3390/toxins16040182] [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: 02/16/2024] [Revised: 03/29/2024] [Accepted: 03/30/2024] [Indexed: 04/29/2024] Open
Abstract
Bacterial protein toxins are secreted by certain bacteria and are responsible for mild to severe diseases in humans and animals. They are among the most potent molecules known, which are active at very low concentrations. Bacterial protein toxins exhibit a wide diversity based on size, structure, and mode of action. Upon recognition of a cell surface receptor (protein, glycoprotein, and glycolipid), they are active either at the cell surface (signal transduction, membrane damage by pore formation, or hydrolysis of membrane compound(s)) or intracellularly. Various bacterial protein toxins have the ability to enter cells, most often using an endocytosis mechanism, and to deliver the effector domain into the cytosol, where it interacts with an intracellular target(s). According to the nature of the intracellular target(s) and type of modification, various cellular effects are induced (cell death, homeostasis modification, cytoskeleton alteration, blockade of exocytosis, etc.). The various modes of action of bacterial protein toxins are illustrated with representative examples. Insights in toxin evolution are discussed.
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Affiliation(s)
- Michel R Popoff
- Unité des Toxines Bactériennes, Institut Pasteur, Université Paris Cité, CNRS UMR 2001 INSERM U1306, F-75015 Paris, France
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8
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Srinivas T, Siqueira E, Guil S. Techniques for investigating lncRNA transcript functions in neurodevelopment. Mol Psychiatry 2024; 29:874-890. [PMID: 38145986 PMCID: PMC11176085 DOI: 10.1038/s41380-023-02377-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 12/05/2023] [Accepted: 12/12/2023] [Indexed: 12/27/2023]
Abstract
Long noncoding RNAs (lncRNAs) are sequences of 200 nucleotides or more that are transcribed from a large portion of the mammalian genome. While hypothesized to have a variety of biological roles, many lncRNAs remain largely functionally uncharacterized due to unique challenges associated with their investigation. For example, some lncRNAs overlap with other genomic loci, are expressed in a cell-type-specific manner, and/or are differentially processed at the post-transcriptional level. The mammalian CNS contains a vast diversity of lncRNAs, and lncRNAs are highly abundant in the mammalian brain. However, interrogating lncRNA function in models of the CNS, particularly in vivo, can be complex and challenging. Here we review the breadth of methods used to investigate lncRNAs in the CNS, their merits, and the understanding they can provide with respect to neurodevelopment and pathophysiology. We discuss remaining challenges in the field and provide recommendations to assay lncRNAs based on current methods.
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Affiliation(s)
- Tara Srinivas
- Josep Carreras Leukaemia Research Institute (IJC), 08916, Badalona, Barcelona, Catalonia, Spain
| | - Edilene Siqueira
- Josep Carreras Leukaemia Research Institute (IJC), 08916, Badalona, Barcelona, Catalonia, Spain
| | - Sonia Guil
- Josep Carreras Leukaemia Research Institute (IJC), 08916, Badalona, Barcelona, Catalonia, Spain.
- Germans Trias i Pujol Health Science Research Institute, 08916, Badalona, Barcelona, Catalonia, Spain.
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Zheng N, Liu S, Chen J, Xu Y, Cao W, Lin J, Lu G, Zhang G. SARS-CoV-2 NSP2 as a Potential Delivery Vehicle for Proteins. Mol Pharm 2024; 21:1149-1159. [PMID: 38288708 DOI: 10.1021/acs.molpharmaceut.3c00680] [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] [Indexed: 03/05/2024]
Abstract
The development of biomolecule delivery systems is essential for the treatment of various diseases such as cancer, immunological diseases, and metabolic disorders. For the first time, we found that SARS-CoV-2-encoded nonstructural protein 2 (NSP2) can be secreted from the cells, where it is synthesized. Brefeldin A and H89, inhibitors of ER/Golgi secretion pathways, did not inhibit NSP2 secretion. NSP2 is likely secreted via an unconventional secretory pathway. Moreover, both secreted and purified NSP2 proteins were able to traverse the plasma membrane barrier and enter both immortalized human umbilical vein endothelial cells and tumor cell lines. After entry, the NSP2 protein was localized in only the cytoplasm. Cytochalasin D, a potent inhibitor of actin polymerization, inhibited the entry of NSP2. NSP2 can carry other molecules into cells. Burkholderia lethal factor 1, a monomeric toxin from the intracellular pathogen Burkholderia pseudomallei, has demonstrated antitumor activity by targeting host eukaryotic initiation translation factor 4A. An NSP2-BLF1 fusion protein was translocated across the cellular membranes of Huh7 cells and mediated cell killing. By using different approaches, including protein purification, chemical inhibition, and cell imaging, we confirm that NSP2 is able to deliver heterologous proteins into cells. NSP2 can act as a potential delivery vehicle for proteins.
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Affiliation(s)
- Ningze Zheng
- Institute of Human Virology, Department of Pathogen Biology and Biosecurity, and Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Shurui Liu
- Institute of Human Virology, Department of Pathogen Biology and Biosecurity, and Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Jianheng Chen
- Institute of Human Virology, Department of Pathogen Biology and Biosecurity, and Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Yue Xu
- Institute of Human Virology, Department of Pathogen Biology and Biosecurity, and Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Wenyin Cao
- Institute of Human Virology, Department of Pathogen Biology and Biosecurity, and Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Jinyi Lin
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Guang Lu
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Guigen Zhang
- Institute of Human Virology, Department of Pathogen Biology and Biosecurity, and Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
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10
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Shen Y, Lin S, You P, Chen Y, Luo Y, Song X, Chen Y, Jin D. Rapid discrimination between clinical Clostridioides difficile infection and colonization by quantitative detection of TcdB toxin using a real-time cell analysis system. Front Microbiol 2024; 15:1348892. [PMID: 38322317 PMCID: PMC10844495 DOI: 10.3389/fmicb.2024.1348892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/08/2024] [Indexed: 02/08/2024] Open
Abstract
Objectives It is important to accurately discriminate between clinical Clostridioides difficile infection (CDI) and colonization (CDC) for effective antimicrobial treatment. Methods In this study, 37 stool samples were collected from 17 CDC and 20 CDI cases, and each sample were tested in parallel through the real-time cell analysis (RTCA) system, real-time PCR assay (PCR), and enzyme-linked immunosorbent assay (ELISA). Results RTCA-measured functional and toxical C. difficile toxin B (TcdB) concentrations in the CDI group (302.58 ± 119.15 ng/mL) were significantly higher than those in the CDC group (18.15 ± 11.81 ng/mL) (p = 0.0008). Conversely, ELISA results revealed no significant disparities in TcdB concentrations between the CDC (26.21 ± 3.57 ng/mL) and the CDI group (17.07 ± 3.10 ng/mL) (p = 0.064). PCR results indicated no significant differences in tcdB gene copies between the CDC (774.54 ± 357.89 copies/μL) and the CDI group (4,667.69 ± 3,069.87 copies/μL) (p = 0.407). Additionally, the functional and toxical TcdB concentrations secreted from C. difficile isolates were measured by the RTCA. The results from the CDC (490.00 ± 133.29 ng/mL) and the CDI group (439.82 ± 114.66 ng/mL) showed no significant difference (p = 0.448). Notably, RTCA-measured functional and toxical TcdB concentration was significantly decreased when mixed with pooled CDC samples supernatant (p = 0.030). Conclusion This study explored the novel application of the RTCA assay in effectively discerning clinical CDI from CDC cases.
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Affiliation(s)
- Yuhang Shen
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
- Institute of Ageing Research, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, China
| | - Shan Lin
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Peijun You
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
| | - Yu Chen
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
| | - Yun Luo
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Xiaojun Song
- Laboratory Medicine Center, Department of Clinical Laboratory, Zhejiang Provincial People’s Hospital, Hangzhou Medical College, Hangzhou, China
| | - Yunbo Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Dazhi Jin
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
- Laboratory Medicine Center, Department of Clinical Laboratory, Zhejiang Provincial People’s Hospital, Hangzhou Medical College, Hangzhou, China
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11
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Papatheodorou P, Minton NP, Aktories K, Barth H. An Updated View on the Cellular Uptake and Mode-of-Action of Clostridioides difficile Toxins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1435:219-247. [PMID: 38175478 DOI: 10.1007/978-3-031-42108-2_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Research on the human gut pathogen Clostridioides (C.) difficile and its toxins continues to attract much attention as a consequence of the threat to human health posed by hypervirulent strains. Toxin A (TcdA) and Toxin B (TcdB) are the two major virulence determinants of C. difficile. Both are single-chain proteins with a similar multidomain architecture. Certain hypervirulent C. difficile strains also produce a third toxin, namely binary toxin CDT (C. difficile transferase). C. difficile toxins are the causative agents of C. difficile-associated diseases (CDADs), such as antibiotics-associated diarrhea and pseudomembranous colitis. For that reason, considerable efforts have been expended to unravel their molecular mode-of-action and the cellular mechanisms responsible for their uptake. Many of these studies have been conducted in European laboratories. Here, we provide an update on our previous review (Papatheodorou et al. Adv Exp Med Biol, 2018) on important advances in C. difficile toxins research.
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Affiliation(s)
- Panagiotis Papatheodorou
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, Ulm, Germany.
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre, University of Nottingham, Nottingham, UK
| | - Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
| | - Holger Barth
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, Ulm, Germany
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12
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Zhou Y, Zhan X, Luo J, Li D, Zhou R, Zhang J, Pan Z, Zhang Y, Jia T, Zhang X, Li Y, Tao L. Structural dynamics of the CROPs domain control stability and toxicity of Paeniclostridium sordellii lethal toxin. Nat Commun 2023; 14:8426. [PMID: 38114525 PMCID: PMC10730571 DOI: 10.1038/s41467-023-44169-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 12/04/2023] [Indexed: 12/21/2023] Open
Abstract
Paeniclostridium sordellii lethal toxin (TcsL) is a potent exotoxin that causes lethal toxic shock syndrome associated with fulminant bacterial infections. TcsL belongs to the large clostridial toxin (LCT) family. Here, we report that TcsL with varied lengths of combined repetitive oligopeptides (CROPs) deleted show increased autoproteolysis as well as higher cytotoxicity. We next present cryo-EM structures of full-length TcsL, at neutral (pH 7.4) and acidic (pH 5.0) conditions. The TcsL at neutral pH exhibits in the open conformation, which resembles reported TcdB structures. Low pH induces the conformational change of partial TcsL to the closed form. Two intracellular interfaces are observed in the closed conformation, which possibly locks the cysteine protease domain and hinders the binding of the host receptor. Our findings provide insights into the structure and function of TcsL and reveal mechanisms for CROPs-mediated modulation of autoproteolysis and cytotoxicity, which could be common across the LCT family.
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Affiliation(s)
- Yao Zhou
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
- Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, 310024, China
| | - Xiechao Zhan
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China.
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China.
| | - Jianhua Luo
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
- Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, 310024, China
| | - Diyin Li
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
- Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, 310024, China
| | - Ruoyu Zhou
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Jiahao Zhang
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Zhenrui Pan
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Yuanyuan Zhang
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Tianhui Jia
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
- Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, 310024, China
| | - Xiaofeng Zhang
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Yanyan Li
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China
| | - Liang Tao
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China.
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.
- Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China.
- Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, 310024, China.
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13
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Belyy A, Heilen P, Hagel P, Hofnagel O, Raunser S. Structure and activation mechanism of the Makes caterpillars floppy 1 toxin. Nat Commun 2023; 14:8226. [PMID: 38086871 PMCID: PMC10716152 DOI: 10.1038/s41467-023-44069-2] [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: 07/10/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
The bacterial Makes caterpillars floppy 1 (Mcf1) toxin promotes apoptosis in insects, leading to loss of body turgor and death. The molecular mechanism underlying Mcf1 intoxication is poorly understood. Here, we present the cryo-EM structure of Mcf1 from Photorhabdus luminescens, revealing a seahorse-like shape with a head and tail. While the three head domains contain two effectors, as well as an activator-binding domain (ABD) and an autoprotease, the tail consists of two putative translocation and three putative receptor-binding domains. Rearrangement of the tail moves the C-terminus away from the ABD and allows binding of the host cell ADP-ribosylation factor 3, inducing conformational changes that position the cleavage site closer to the protease. This distinct activation mechanism that is based on a hook-loop interaction results in three autocleavage reactions and the release of two toxic effectors. Unexpectedly, the BH3-like domain containing ABD is not an active effector. Our findings allow us to understand key steps of Mcf1 intoxication at the molecular level.
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Affiliation(s)
- Alexander Belyy
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227, Dortmund, Germany
| | - Philipp Heilen
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227, Dortmund, Germany
| | - Philine Hagel
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227, Dortmund, Germany
| | - Oliver Hofnagel
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227, Dortmund, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227, Dortmund, Germany.
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14
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Lin Q, Li Z, Ke H, Fei J, Zhang T, Wang P, Chen Y. Linked mutations within the pathogenicity locus of Clostridioides difficile increase virulence. Infect Dis (Lond) 2023; 55:847-856. [PMID: 37615633 DOI: 10.1080/23744235.2023.2249551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 08/14/2023] [Indexed: 08/25/2023] Open
Abstract
BACKGROUND The clinical manifestations of Clostridioides difficile infections range from diarrhoea to pseudomembranous colitis (PMC) and death. We evaluated the association between gene content in C. difficile clinical isolates and disease severity. METHODS Fifty-three C. difficile isolates were subjected to Sanger sequencing, clinical data were used to analyse the association of gene content with disease severity, and 83 non-duplicate isolates were collected to confirm the results. Virulence was further examined by functional in vitro and in vivo experiments. RESULTS Among the 53 C. difficile isolates, ribotypes 017 (n = 9, 17.0%) and 012 (n = 8, 15.1%) were predominant. Fifteen strains exhibited a correlation between mutations of pathogenicity locus genes (tcdB, tcdC, tcdR, and tcdE) and were named linked-mutation strains. Ribotypes are not associated with clinical PMC and Linked-mutation strains. The proportion of patients with PMC was higher in the group infected with linked-mutation strains than in the non-linked-mutation group (57.14% vs. 0%, p < 0.001). The linked-mutation rate of C. difficile was higher in patients with PMC than in patients without PMC (89.47% vs. 7.8%, p < 0.0001). Linked-mutation strains showed greater cytotoxicity in vitro and caused more severe tissue damage in a mouse model. CONCLUSIONS Linked-mutation strains are associated with high virulence and PMC development. This result will help monitor the clinical prognosis of C. difficile infection and provide key insights for developing therapeutic targets and monoclonal antibodies.
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Affiliation(s)
- Qianyun Lin
- Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zitong Li
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Haoran Ke
- Hepatology Unit, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jiaxi Fei
- Graceland Medical Center, the, Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ting Zhang
- Department of Gastroenterology, the Third Affiliated Hospital of Southern Medical University, Guangzhou, China
| | - Pu Wang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ye Chen
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
- Integrative Microecology Center, Department of Gastroenterology, Shenzhen Hospital, Southern Medical University, Shenzhen, China
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15
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Buddle JE, Fagan RP. Pathogenicity and virulence of Clostridioides difficile. Virulence 2023; 14:2150452. [PMID: 36419222 DOI: 10.1080/21505594.2022.2150452] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/02/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
Clostridioides difficile is the most common cause of nosocomial antibiotic-associated diarrhea, and is responsible for a spectrum of diseases characterized by high levels of recurrence, morbidity, and mortality. Treatment is complex, since antibiotics constitute both the main treatment and the major risk factor for infection. Worryingly, resistance to multiple antibiotics is becoming increasingly widespread, leading to the classification of this pathogen as an urgent threat to global health. As a consummate opportunist, C. difficile is well equipped for promoting disease, owing to its arsenal of virulence factors: transmission of this anaerobe is highly efficient due to the formation of robust endospores, and an array of adhesins promote gut colonization. C. difficile produces multiple toxins acting upon gut epithelia, resulting in manifestations typical of diarrheal disease, and severe inflammation in a subset of patients. This review focuses on such virulence factors, as well as the importance of antimicrobial resistance and genome plasticity in enabling pathogenesis and persistence of this important pathogen.
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Affiliation(s)
- Jessica E Buddle
- Molecular Microbiology, School of Biosciences, University of Sheffield, Sheffield, UK
| | - Robert P Fagan
- Molecular Microbiology, School of Biosciences, University of Sheffield, Sheffield, UK
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16
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Schneemann M, Heils L, Moos V, Weiß F, Krug SM, Weiner J, Beule D, Gerhard R, Schulzke JD, Bücker R. A Colonic Organoid Model Challenged with the Large Toxins of Clostridioides difficile TcdA and TcdB Exhibit Deregulated Tight Junction Proteins. Toxins (Basel) 2023; 15:643. [PMID: 37999506 PMCID: PMC10674794 DOI: 10.3390/toxins15110643] [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: 10/05/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 11/25/2023] Open
Abstract
BACKGROUND Clostridioides difficile toxins TcdA and TcdB are responsible for diarrhea and colitis. Lack of functional studies in organoid models of the gut prompted us to elucidate the toxin's effects on epithelial barrier function and the molecular mechanisms for diarrhea and inflammation. METHODS Human adult colon organoids were cultured on membrane inserts. Tight junction (TJ) proteins and actin cytoskeleton were analyzed for expression via Western blotting and via confocal laser-scanning microscopy for subcellular localization. RESULTS Polarized intestinal organoid monolayers were established from stem cell-containing colon organoids to apply toxins from the apical side and to perform functional measurements in the organoid model. The toxins caused a reduction in transepithelial electrical resistance in human colonic organoid monolayers with sublethal concentrations. Concomitantly, we detected increased paracellular permeability fluorescein and FITC-dextran-4000. Human colonic organoid monolayers exposed to the toxins exhibited redistribution of barrier-forming TJ proteins claudin-1, -4 and tricellulin, whereas channel-forming claudin-2 expression was increased. Perijunctional F-actin cytoskeleton organization was affected. CONCLUSIONS Adult stem cell-derived human colonic organoid monolayers were applicable as a colon infection model for electrophysiological measurements. The TJ changes noted can explain the epithelial barrier dysfunction and diarrhea in patients, as well as increased entry of luminal antigens triggering inflammation.
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Affiliation(s)
- Martina Schneemann
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Lucas Heils
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Verena Moos
- Department of Gastroenterology, Infectious Diseases and Rheumatology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Franziska Weiß
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Susanne M. Krug
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - January Weiner
- Core Unit Bioinformatics (CUBI), Berlin Institute of Health at Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Dieter Beule
- Core Unit Bioinformatics (CUBI), Berlin Institute of Health at Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany
| | - Jörg-Dieter Schulzke
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Roland Bücker
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
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17
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He A, Tian S, Kopper O, Horan DJ, Chen P, Bronson RT, Sheng R, Wu H, Sui L, Zhou K, Tao L, Wu Q, Huang Y, Shen Z, Han S, Chen X, Chen H, He X, Robling AG, Jin R, Clevers H, Xiang D, Li Z, Dong M. Targeted inhibition of Wnt signaling with a Clostridioides difficile toxin B fragment suppresses breast cancer tumor growth. PLoS Biol 2023; 21:e3002353. [PMID: 37943878 PMCID: PMC10635564 DOI: 10.1371/journal.pbio.3002353] [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] [Received: 09/11/2022] [Accepted: 09/27/2023] [Indexed: 11/12/2023] Open
Abstract
Wnt signaling pathways are transmitted via 10 homologous frizzled receptors (FZD1-10) in humans. Reagents broadly inhibiting Wnt signaling pathways reduce growth and metastasis of many tumors, but their therapeutic development has been hampered by the side effect. Inhibitors targeting specific Wnt-FZD pair(s) enriched in cancer cells may reduce side effect, but the therapeutic effect of narrow-spectrum Wnt-FZD inhibitors remains to be established in vivo. Here, we developed a fragment of C. difficile toxin B (TcdBFBD), which recognizes and inhibits a subclass of FZDs, FZD1/2/7, and examined whether targeting this FZD subgroup may offer therapeutic benefits for treating breast cancer models in mice. Utilizing 2 basal-like and 1 luminal-like breast cancer models, we found that TcdBFBD reduces tumor-initiating cells and attenuates growth of basal-like mammary tumor organoids and xenografted tumors, without damaging Wnt-sensitive tissues such as bones in vivo. Furthermore, FZD1/2/7-positive cells are enriched in chemotherapy-resistant cells in both basal-like and luminal mammary tumors treated with cisplatin, and TcdBFBD synergizes strongly with cisplatin in inhibiting both tumor types. These data demonstrate the therapeutic value of narrow-spectrum Wnt signaling inhibitor in treating breast cancers.
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Affiliation(s)
- Aina He
- Department of Oncology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, People’s Republic of China
- Department of Urology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Songhai Tian
- Department of Urology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts, United States of America
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China
| | - Oded Kopper
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Daniel J. Horan
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Barnhill, Indianapolis, United States of America
| | - Peng Chen
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Roderick T. Bronson
- Rodent Histopathology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ren Sheng
- Kirby Neurobiology Center, Boston Children’s Hospital, Department of Neurology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Hao Wu
- Department of Vascular Biology, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Lufei Sui
- Department of Vascular Biology, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Kun Zhou
- Department of Vascular Biology, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Liang Tao
- Department of Urology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Quan Wu
- Department of Urology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts, United States of America
- Central Laboratory of Medical Research Centre, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, People’s Republic of China
| | - Yujing Huang
- Department of Oncology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, People’s Republic of China
| | - Zan Shen
- Department of Oncology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, People’s Republic of China
| | - Sen Han
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Xueqing Chen
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Hong Chen
- Department of Vascular Biology, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Xi He
- Kirby Neurobiology Center, Boston Children’s Hospital, Department of Neurology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Alexander G. Robling
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Barnhill, Indianapolis, United States of America
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Hans Clevers
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Dongxi Xiang
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
- Department of Biliary-Pancreatic Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
| | - Zhe Li
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Min Dong
- Department of Urology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts, United States of America
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18
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Childress KO, Cencer CS, Tyska MJ, Lacy DB. Nectin-3 and shed forms of CSPG4 can serve as epithelial cell receptors for Clostridioides difficile TcdB. mBio 2023; 14:e0185723. [PMID: 37747247 PMCID: PMC10653914 DOI: 10.1128/mbio.01857-23] [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: 07/14/2023] [Accepted: 07/26/2023] [Indexed: 09/26/2023] Open
Abstract
IMPORTANCE Toxin B (TcdB) is a major virulence factor of Clostridioides difficile, a Gram-positive pathogen that is a leading cause of hospital-acquired diarrhea. While previous studies have established that TcdB can engage multiple cell surface receptors in vitro, little is known about how these interactions promote disease and where these receptors localize on colonic tissue. Here, we used immunofluorescence microscopy to visualize Nectin-3 and CSPG4 on tissue, revealing unexpected localization of both receptors on colonic epithelial cells. We show that Nectin-3, which was previously characterized as an adherens junction protein, is also localized to the brush border of colonocytes. Staining for CSPG4 revealed that it is present along epithelial cell junctions, suggesting that it is shed by fibroblasts along the crypt-surface axis. Collectively, our study provides new insights into how TcdB can gain access to the receptors Nectin-3 and CSPG4 to intoxicate colonic epithelial cells.
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Affiliation(s)
- Kevin O. Childress
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Caroline S. Cencer
- Department of Cell and Development Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Matthew J. Tyska
- Department of Cell and Development Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - D. Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
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19
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Aktories K. Clostridioides difficile infection drives neuronal inflammation. Nature 2023; 622:465-467. [PMID: 37833474 DOI: 10.1038/d41586-023-02640-3] [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] [Indexed: 10/15/2023]
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20
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Manion J, Musser MA, Kuziel GA, Liu M, Shepherd A, Wang S, Lee PG, Zhao L, Zhang J, Marreddy RKR, Goldsmith JD, Yuan K, Hurdle JG, Gerhard R, Jin R, Rakoff-Nahoum S, Rao M, Dong M. C. difficile intoxicates neurons and pericytes to drive neurogenic inflammation. Nature 2023; 622:611-618. [PMID: 37699522 PMCID: PMC11188852 DOI: 10.1038/s41586-023-06607-2] [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] [Received: 09/12/2022] [Accepted: 09/05/2023] [Indexed: 09/14/2023]
Abstract
Clostridioides difficile infection (CDI) is a major cause of healthcare-associated gastrointestinal infections1,2. The exaggerated colonic inflammation caused by C. difficile toxins such as toxin B (TcdB) damages tissues and promotes C. difficile colonization3-6, but how TcdB causes inflammation is unclear. Here we report that TcdB induces neurogenic inflammation by targeting gut-innervating afferent neurons and pericytes through receptors, including the Frizzled receptors (FZD1, FZD2 and FZD7) in neurons and chondroitin sulfate proteoglycan 4 (CSPG4) in pericytes. TcdB stimulates the secretion of the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) from neurons and pro-inflammatory cytokines from pericytes. Targeted delivery of the TcdB enzymatic domain, through fusion with a detoxified diphtheria toxin, into peptidergic sensory neurons that express exogeneous diphtheria toxin receptor (an approach we term toxogenetics) is sufficient to induce neurogenic inflammation and recapitulates major colonic histopathology associated with CDI. Conversely, mice lacking SP, CGRP or the SP receptor (neurokinin 1 receptor) show reduced pathology in both models of caecal TcdB injection and CDI. Blocking SP or CGRP signalling reduces tissue damage and C. difficile burden in mice infected with a standard C. difficile strain or with hypervirulent strains expressing the TcdB2 variant. Thus, targeting neurogenic inflammation provides a host-oriented therapeutic approach for treating CDI.
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Affiliation(s)
- John Manion
- Department of Urology, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Melissa A Musser
- Division of Gastroenterology, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Gavin A Kuziel
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
- Division of Infectious Diseases, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Min Liu
- Department of Urology, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Amy Shepherd
- Division of Gastroenterology, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Siyu Wang
- Department of Urology, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
- Department of Colorectal Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Pyung-Gang Lee
- Department of Urology, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Leo Zhao
- Department of Urology, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Jie Zhang
- Department of Urology, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Ravi K R Marreddy
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | | | - Ke Yuan
- Division of Pulmonary Medicine, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Julian G Hurdle
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Rongsheng Jin
- Department of Physiology and Biophysics, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Seth Rakoff-Nahoum
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
- Division of Gastroenterology, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Division of Infectious Diseases, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Meenakshi Rao
- Division of Gastroenterology, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Boston, MA, USA.
- Department of Surgery, Harvard Medical School, Boston, MA, USA.
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
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21
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Kordus SL, Kroh HK, Rodríguez RC, Shrem RA, Peritore-Galve FC, Shupe JA, Wadzinski BE, Lacy DB, Spiller BW. Nanobodies against C. difficile TcdA and TcdB reveal unexpected neutralizing epitopes and provide a toolkit for toxin quantitation in vivo. PLoS Pathog 2023; 19:e1011496. [PMID: 37871122 PMCID: PMC10621975 DOI: 10.1371/journal.ppat.1011496] [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] [Received: 06/20/2023] [Revised: 11/02/2023] [Accepted: 10/07/2023] [Indexed: 10/25/2023] Open
Abstract
Clostridioides difficile is a leading cause of antibiotic-associated diarrhea and nosocomial infection in the United States. The symptoms of C. difficile infection (CDI) are associated with the production of two homologous protein toxins, TcdA and TcdB. The toxins are considered bona fide targets for clinical diagnosis as well as the development of novel prevention and therapeutic strategies. While there are extensive studies that document these efforts, there are several gaps in knowledge that could benefit from the creation of new research tools. First, we now appreciate that while TcdA sequences are conserved, TcdB sequences can vary across the span of circulating clinical isolates. An understanding of the TcdA and TcdB epitopes that drive broadly neutralizing antibody responses could advance the effort to identify safe and effective toxin-protein chimeras and fragments for vaccine development. Further, an understanding of TcdA and TcdB concentration changes in vivo can guide research into how host and microbiome-focused interventions affect the virulence potential of C. difficile. We have developed a panel of alpaca-derived nanobodies that bind specific structural and functional domains of TcdA and TcdB. We note that many of the potent neutralizers of TcdA bind epitopes within the delivery domain, a finding that could reflect roles of the delivery domain in receptor binding and/or the conserved role of pore-formation in the delivery of the toxin enzyme domains to the cytosol. In contrast, neutralizing epitopes for TcdB were found in multiple domains. The nanobodies were also used for the creation of sandwich ELISA assays that allow for quantitation of TcdA and/or TcdB in vitro and in the cecal and fecal contents of infected mice. We anticipate these reagents and assays will allow researchers to monitor the dynamics of TcdA and TcdB production over time, and the impact of various experimental interventions on toxin production in vivo.
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Affiliation(s)
- Shannon L. Kordus
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Heather K. Kroh
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Rubén Cano Rodríguez
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Rebecca A. Shrem
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - F. Christopher Peritore-Galve
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - John A. Shupe
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Brian E. Wadzinski
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - D. Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, United States of America
| | - Benjamin W. Spiller
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States of America
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22
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Fettucciari K, Dini F, Marconi P, Bassotti G. Role of the Alteration in Calcium Homeostasis in Cell Death Induced by Clostridioides difficile Toxin A and Toxin B. BIOLOGY 2023; 12:1117. [PMID: 37627001 PMCID: PMC10452684 DOI: 10.3390/biology12081117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 08/05/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023]
Abstract
Clostridioides difficile (C. difficile), responsible for 15-25% of gastrointestinal infections, causes health problems mainly due to the toxic activity of toxins A and B (Tcds). These are responsible for its clinical manifestations, including diarrhea, pseudomembranous colitis, toxic megacolon and death, with a mortality of 5-30% in primary infection, that increase following relapses. Studies on Tcd-induced cell death have highlighted a key role of caspases, calpains, and cathepsins, with involvement of mitochondria and reactive oxygen species (ROS) in a complex signaling pathway network. The complex response in the execution of various types of cell death (apoptosis, necrosis, pyroptosis and pyknosis) depends on the amount of Tcd, cell types, and Tcd receptors involved, and could have as initial/precocious event the alterations in calcium homeostasis. The entities, peculiarities and cell types involved in these alterations will decide the signaling pathways activated and cell death type. Calcium homeostasis alterations can be caused by calcium influx through calcium channel activation, transient intracellular calcium oscillations, and leakage of calcium from intracellular stores. These increases in cytoplasmic calcium have important effects on all calcium-regulated molecules, which may play a direct role in several cell death types and/or activate other cell death effectors, such as caspases, calpains, ROS and proapoptotic Bcl-2 family members. Furthermore, some support for the possible role of the calcium homeostasis alteration in Tcd-induced cell death originates from the similarity with cytotoxic effects that cause pore-forming toxins, based mainly on calcium influx through plasma membrane pores.
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Affiliation(s)
- Katia Fettucciari
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy;
| | - Fabrizio Dini
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Matelica, Italy;
| | - Pierfrancesco Marconi
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy;
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy;
- Gastroenterology & Hepatology Unit, Santa Maria Della Misericordia Hospital, 06129 Perugia, Italy
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23
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Tian S, Zhou N. Gaining New Insights into Fundamental Biological Pathways by Bacterial Toxin-Based Genetic Screens. Bioengineering (Basel) 2023; 10:884. [PMID: 37627769 PMCID: PMC10451959 DOI: 10.3390/bioengineering10080884] [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: 05/15/2023] [Revised: 07/11/2023] [Accepted: 07/22/2023] [Indexed: 08/27/2023] Open
Abstract
Genetic screen technology has been applied to study the mechanism of action of bacterial toxins-a special class of virulence factors that contribute to the pathogenesis caused by bacterial infections. These screens aim to identify host factors that directly or indirectly facilitate toxin intoxication. Additionally, specific properties of certain toxins, such as membrane interaction, retrograde trafficking, and carbohydrate binding, provide robust probes to comprehensively investigate the lipid biosynthesis, membrane vesicle transport, and glycosylation pathways, respectively. This review specifically focuses on recent representative toxin-based genetic screens that have identified new players involved in and provided new insights into fundamental biological pathways, such as glycosphingolipid biosynthesis, protein glycosylation, and membrane vesicle trafficking pathways. Functionally characterizing these newly identified factors not only expands our current understanding of toxin biology but also enables a deeper comprehension of fundamental biological questions. Consequently, it stimulates the development of new therapeutic approaches targeting both bacterial infectious diseases and genetic disorders with defects in these factors and pathways.
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Affiliation(s)
- Songhai Tian
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA;
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Nini Zhou
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA;
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
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24
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Fettucciari K, Fruganti A, Stracci F, Spaterna A, Marconi P, Bassotti G. Clostridioides difficile Toxin B Induced Senescence: A New Pathologic Player for Colorectal Cancer? Int J Mol Sci 2023; 24:ijms24098155. [PMID: 37175861 PMCID: PMC10179142 DOI: 10.3390/ijms24098155] [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] [Received: 03/22/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 05/15/2023] Open
Abstract
Clostridioides difficile (C. difficile) is responsible for a high percentage of gastrointestinal infections and its pathological activity is due to toxins A and B. C. difficile infection (CDI) is increasing worldwide due to the unstoppable spread of C. difficile in the anthropized environment and the progressive human colonization. The ability of C. difficile toxin B to induce senescent cells and the direct correlation between CDI, irritable bowel syndrome (IBS), and inflammatory bowel diseases (IBD) could cause an accumulation of senescent cells with important functional consequences. Furthermore, these senescent cells characterized by long survival could push pre-neoplastic cells originating in the colon towards the complete neoplastic transformation in colorectal cancer (CRC) by the senescence-associated secretory phenotype (SASP). Pre-neoplastic cells could appear as a result of various pro-carcinogenic events, among which, are infections with bacteria that produce genotoxins that generate cells with high genetic instability. Therefore, subjects who develop IBS and/or IBD after CDI should be monitored, especially if they then have further CDI relapses, waiting for the availability of senolytic and anti-SASP therapies to resolve the pro-carcinogenic risk due to accumulation of senescent cells after CDI followed by IBS and/or IBD.
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Affiliation(s)
- Katia Fettucciari
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Matelica, Italy
| | - Fabrizio Stracci
- Public Health Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy
| | - Andrea Spaterna
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Matelica, Italy
| | - Pierfrancesco Marconi
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy
- Gastroenterology & Hepatology Unit, Santa Maria Della Misericordia Hospital, 06129 Perugia, Italy
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25
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Nakamura M, Shiga A, Iimori A, Matsuzaki T. Efficient endocytosis of the human lactoferrin N-lobe enhances its antiproliferative activity against human cancer cells. Biol Pharm Bull 2023. [PMID: 37088555 DOI: 10.1248/bpb.b23-00011] [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: 04/25/2023]
Abstract
Human lactoferrin (hLF) is a glycosylated globular iron-binding protein with high functional versatility that elicits anticancer, neuroprotective, and anti-inflammatory effects. Some of the diverse functions of hLF are induced after its internalization into various cells via cell surface endocytosis receptors, such as proteoglycans, which contain glycosaminoglycan (GAG) chains. We have previously demonstrated that an hLF derivative comprising the N-terminal half of hLF (referred to as the N-lobe) is internalized by intestinal enterocyte Caco-2 cells. However, the relationship between the intracellular uptake of the N-lobe and its pharmacological activity remains poorly understood. Here, we report that the N-lobe is efficiently internalized by lung cancer cells via endocytic pathways, suppressing their proliferation. Moreover, the N-lobe showed higher intracellular uptake than hLF. We found that the N-lobe was internalized into the human lung cancer cell lines PC-14 and PC-3 via clathrin- and/or caveolae-mediated endocytosis. Intracellular uptake of the N-lobe was inhibited when an equimolar concentration of chondroitin sulfate (CS)-E, a GAG subtype involved in malignant transformation and tumor metastasis, was added. The inhibitory effect of the N-lobe on PC-14 cell proliferation decreased with the addition of CS-E in a dose-dependent manner, suggesting that the CS-recognizing sequence on the N-lobe is necessary for its internalization or that the CS proteoglycan on cancer cells acts as an endocytosis receptor. These results suggest that the efficient endocytic uptake of the N-lobe is important for its antiproliferation effects on lung cancer cell lines. Thus, the N-lobe presents a promising drug candidate for cancer treatment.
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Affiliation(s)
- Masao Nakamura
- Department of Peptidomics, Sasaki Institute, Sasaki Foundation
- School of Bioscience and Biotechnology, Tokyo University of Technology
| | - Akira Shiga
- School of Bioscience and Biotechnology, Tokyo University of Technology
| | - Ami Iimori
- School of Bioscience and Biotechnology, Tokyo University of Technology
| | - Takumi Matsuzaki
- School of Bioscience and Biotechnology, Tokyo University of Technology
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26
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Larabee JL, Doyle DA, Ahmed UKB, Shadid TM, Sharp RR, Jones KL, Kim YM, Li S, Ballard JD. Discovery of Hippo signaling as a regulator of CSPG4 expression and as a therapeutic target for Clostridioides difficile disease. PLoS Pathog 2023; 19:e1011272. [PMID: 36972308 PMCID: PMC10079225 DOI: 10.1371/journal.ppat.1011272] [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] [Received: 01/09/2023] [Revised: 04/06/2023] [Accepted: 03/08/2023] [Indexed: 03/29/2023] Open
Abstract
The signaling pathways and networks regulating expression of chondroitin sulfate proteoglycan 4 (CSPG4), a cancer-related protein that serves as a receptor for Clostridiodes difficile TcdB, are poorly defined. In this study, TcdB-resistant/CSPG4-negative HeLa cells were generated by exposure to increasing concentrations of the toxin. The cells that emerged (HeLa R5) lost expression of CSPG4 mRNA and were resistant to binding by TcdB. mRNA expression profiles paired with integrated pathway analysis correlated changes in the Hippo and estrogen signaling pathways with a CSPG4 decrease in HeLa R5 cells. Both signaling pathways altered CSPG4 expression when modulated chemically or through CRISPR-mediated deletion of key transcriptional regulators in the Hippo pathway. Based on the in vitro findings, we predicted and experimentally confirmed that a Hippo pathway inactivating drug (XMU-MP-1) provides protection from C. difficile disease in a mouse model. These results provide insights into key regulators of CSPG4 expression and identify a therapeutic for C. difficile disease.
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Affiliation(s)
- Jason L. Larabee
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - D. Annie Doyle
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Ummey Khalecha Bintha Ahmed
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Tyler M. Shadid
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Rachel R. Sharp
- Laboratory for Molecular Biology and Cytometry Research, Harold Hamm Diabetes Center, Oklahoma City, Oklahoma, United States of America
| | - Kenneth L. Jones
- Laboratory for Molecular Biology and Cytometry Research, Harold Hamm Diabetes Center, Oklahoma City, Oklahoma, United States of America
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Young Mi Kim
- Department of Pediatrics, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Shibo Li
- Department of Pediatrics, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Jimmy D. Ballard
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
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27
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Csukovich G, Kramer N, Pratscher B, Gotic I, Freund P, Hahn R, Himmler G, Brandt S, Burgener IA. Neutralising Effects of Different Antibodies on Clostridioides difficile Toxins TcdA and TcdB in a Translational Approach. Int J Mol Sci 2023; 24:ijms24043867. [PMID: 36835278 PMCID: PMC9962434 DOI: 10.3390/ijms24043867] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/30/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
Given the high prevalence of intestinal disease in humans and animals, there is a strong need for clinically relevant models recapitulating gastrointestinal systems, ideally replacing in vivo models in accordance with the principles of the 3R. We established a canine organoid system and analysed the neutralising effects of recombinant versus natural antibodies on Clostridioides difficile toxins A and B in this in vitro system. Sulforhodamine B cytotoxicity assays in 2D and FITC-dextran barrier integrity assays on basal-out and apical-out organoids revealed that recombinant, but not natural antibodies, effectively neutralised C. difficile toxins. Our findings emphasise that canine intestinal organoids can be used to test different components and suggest that they can be further refined to also mirror complex interactions between the intestinal epithelium and other cells.
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Affiliation(s)
- Georg Csukovich
- Small Animal Internal Medicine, Department for Companion Animals and Horses, Vetmeduni, 1210 Vienna, Austria
| | - Nina Kramer
- Small Animal Internal Medicine, Department for Companion Animals and Horses, Vetmeduni, 1210 Vienna, Austria
| | - Barbara Pratscher
- Small Animal Internal Medicine, Department for Companion Animals and Horses, Vetmeduni, 1210 Vienna, Austria
| | | | - Patricia Freund
- Small Animal Internal Medicine, Department for Companion Animals and Horses, Vetmeduni, 1210 Vienna, Austria
| | - Rainer Hahn
- Department for Biotechnology, University of Natural Resources and Life Sciences Vienna, 1190 Vienna, Austria
| | | | - Sabine Brandt
- Research Group Oncology (RGO), Clinical Unit of Equine Surgery, Department for Companion Animals and Horses, Vetmeduni, 1210 Vienna, Austria
| | - Iwan Anton Burgener
- Small Animal Internal Medicine, Department for Companion Animals and Horses, Vetmeduni, 1210 Vienna, Austria
- Correspondence:
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28
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Cheng JKJ, Unnikrishnan M. Clostridioides difficile infection: traversing host-pathogen interactions in the gut. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36848200 DOI: 10.1099/mic.0.001306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
C. difficile is the primary cause for nosocomial infective diarrhoea. For a successful infection, C. difficile must navigate between resident gut bacteria and the harsh host environment. The perturbation of the intestinal microbiota by broad-spectrum antibiotics alters the composition and the geography of the gut microbiota, deterring colonization resistance, and enabling C. difficile to colonize. This review will discuss how C. difficile interacts with and exploits the microbiota and the host epithelium to infect and persist. We provide an overview of C. difficile virulence factors and their interactions with the gut to aid adhesion, cause epithelial damage and mediate persistence. Finally, we document the host responses to C. difficile, describing the immune cells and host pathways that are associated and triggered during C. difficile infection.
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Affiliation(s)
- Jeffrey K J Cheng
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| | - Meera Unnikrishnan
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
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29
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Aktories K. From signal transduction to protein toxins-a narrative review about milestones on the research route of C. difficile toxins. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:173-190. [PMID: 36203094 PMCID: PMC9831965 DOI: 10.1007/s00210-022-02300-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/22/2022] [Indexed: 01/29/2023]
Abstract
Selected findings about Clostridioides difficile (formerly Clostridium difficile) toxins are presented in a narrative review. Starting with a personal view on research about G proteins, adenylyl cyclase, and ADP-ribosylating toxins in the laboratory of Günter Schultz in Heidelberg, milestones of C. difficile toxin research are presented with the focus on toxin B (TcdB), covering toxin structure, receptor binding, toxin up-take and refolding, the intracellular actions of TcdB, and the treatment of C. difficile infection.
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Affiliation(s)
- Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Albertstr. 25, 79104, Freiburg, Germany.
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30
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Chen P, Jin R. Receptor binding mechanisms of Clostridioides difficile toxin B and implications for therapeutics development. FEBS J 2023; 290:962-969. [PMID: 34862749 PMCID: PMC9344982 DOI: 10.1111/febs.16310] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/19/2021] [Accepted: 12/02/2021] [Indexed: 12/29/2022]
Abstract
Clostridioides difficile is classified as an urgent antibiotic resistance threat by the Centers for Disease Control and Prevention (CDC). C. difficile infection (CDI) is mainly caused by the C. difficile exotoxin TcdB, which invades host cells via receptor-mediated endocytosis. However, many natural variants of TcdB have been identified including some from the hypervirulent strains, which pose significant challenges for developing effective CDI therapies. Here, we review the recent research progress on the molecular mechanisms by which TcdB recognizes Frizzed proteins (FZDs) and chondroitin sulfate proteoglycan 4 (CSPG4) as two major host receptors. We suggest that the receptor-binding sites and several previously identified neutralizing epitopes on TcdB are ideal targets for the development of broad-spectrum inhibitors to protect against diverse TcdB variants.
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Affiliation(s)
- Peng Chen
- Department of Physiology and Biophysics, University of California Irvine, Irvine, California, 92697, USA
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California Irvine, Irvine, California, 92697, USA
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Bassotti G, Fruganti A, Stracci F, Marconi P, Fettucciari K. Cytotoxic synergism of Clostridioides difficile toxin B with proinflammatory cytokines in subjects with inflammatory bowel diseases. World J Gastroenterol 2023; 29:582-596. [PMID: 36742168 PMCID: PMC9896618 DOI: 10.3748/wjg.v29.i4.582] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/03/2022] [Accepted: 12/27/2022] [Indexed: 01/20/2023] Open
Abstract
Clostridioides difficile (C. difficile) is progressively colonizing humans and animals living with humans. During this process, hypervirulent strains and mutated toxin A and B of C. difficile (TcdA and TcdB) are originating and developing. While in healthy subjects colonization by C. difficile becomes a risk after the use of antibiotics that alter the microbiome, other categories of people are more susceptible to infection and at risk of relapse, such as those with inflammatory bowel disease (IBD). Recent in vitro studies suggest that this increased susceptibility could be due to the strong cytotoxic synergism between TcdB and proinflammatory cytokines the tumor necrosis factor-alpha and interferon-gamma (CKs). Therefore, in subjects with IBD the presence of an inflammatory state in the colon could be the driver that increases the susceptibility to C. difficile infection and its progression and relapses. TcdB is internalized in the cell via three receptors: chondroitin sulphate proteoglycan 4; poliovirus receptor-like 3; and Wnt receptor frizzled family. Chondroitin sulphate proteoglycan 4 and Wnt receptor frizzled family are involved in cell death by apoptosis or necrosis depending on the concentration of TcdB and cell types, while poliovirus receptor-like 3 induces only necrosis. It is possible that cytokines could also induce a greater expression of receptors for TcdB that are more involved in necrosis than in apoptosis. Therefore, in subjects with IBD there are the conditions: (1) For greater susceptibility to C. difficile infection, such as the inflammatory state, and abnormalities of the microbiome and of the immune system; (2) for the enhancement of the cytotoxic activity of TcdB +Cks; and (3) for a greater expression of TcdB receptors stimulated by cytokines that induce cell death by necrosis rather than apoptosis. The only therapeutic approach currently possible in IBD patients is monitoring of C. difficile colonization for interventions aimed at reducing tumor necrosis factor-alpha and interferon-gamma levels when the infection begins. The future perspective is to generate bacteriophages against C. difficile for targeted therapy.
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Affiliation(s)
- Gabrio Bassotti
- Department of Medicine and Surgery, Gastroenterology, Hepatology & Digestive Endoscopy Section University of Perugia Medical School, Piazza Lucio Severi, Perugia 06132, Italy, and Santa Maria della Misericordia Hospital, Gastroenterology & Hepatology Unit Perugia 06156, Italy
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, Matelica 62024, Italy
| | - Fabrizio Stracci
- Medicine and Surgery, Hygiene and Public Health Section, University of Perugia, Perugia 06123, Italy
| | - Pierfrancesco Marconi
- Medicine and Surgery, Biosciences & Medical Embryology Section, University of Perugia, Perugia 06132, Italy
| | - Katia Fettucciari
- Medicine and Surgery, Biosciences & Medical Embryology Section, University of Perugia, Perugia 06132, Italy
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Heils L, Schneemann M, Gerhard R, Schulzke JD, Bücker R. CDT of Clostridioides difficile Induces MLC-Dependent Intestinal Barrier Dysfunction in HT-29/B6 Epithelial Cell Monolayers. Toxins (Basel) 2023; 15:54. [PMID: 36668874 PMCID: PMC9866553 DOI: 10.3390/toxins15010054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
Background: Clostridioides difficile binary toxin (CDT) defines the hypervirulence of strains in nosocomial antibiotic-induced colitis with the highest mortality. The objective of our study was to investigate the impact of CDT on the intestinal epithelial barrier and to enlighten the underlying molecular mechanisms. Methods: Functional measurements of epithelial barrier function by macromolecular permeability and electrophysiology were performed in human intestinal HT-29/B6 cell monolayers. Molecular analysis of the spatial distribution of tight junction protein and cytoskeleton was performed by super-resolution STED microscopy. Results: Sublethal concentrations of CDT-induced barrier dysfunction with decreased TER and increased permeability for 332 Da fluorescein and 4 kDa FITC-dextran. The molecular correlate to the functional barrier defect by CDT was found to be a tight junction protein subcellular redistribution with tricellulin, occludin, and claudin-4 off the tight junction domain. This redistribution was shown to be MLCK-dependent. Conclusions: CDT compromised epithelial barrier function in a human intestinal colonic cell model, even in sublethal concentrations, pointing to barrier dysfunction in the intestine and leak flux induction as a diarrheal mechanism. However, this cannot be attributed to the appearance of apoptosis and necrosis, but rather to an opening of the paracellular leak pathway as the result of epithelial tight junction alterations.
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Affiliation(s)
- Lucas Heils
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Martina Schneemann
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany
| | - Jörg-Dieter Schulzke
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Roland Bücker
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
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Tian S, Xiong X, Zeng J, Wang S, Tremblay BJM, Chen P, Chen B, Liu M, Chen P, Sheng K, Zeve D, Qi W, Breault DT, Rodríguez C, Gerhard R, Jin R, Doxey AC, Dong M. Identification of TFPI as a receptor reveals recombination-driven receptor switching in Clostridioides difficile toxin B variants. Nat Commun 2022; 13:6786. [PMID: 36351897 PMCID: PMC9646764 DOI: 10.1038/s41467-022-33964-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 10/10/2022] [Indexed: 11/11/2022] Open
Abstract
Toxin B (TcdB) is a major exotoxin responsible for diseases associated with Clostridioides difficile infection. Its sequence variations among clinical isolates may contribute to the difficulty in developing effective therapeutics. Here, we investigate receptor-binding specificity of major TcdB subtypes (TcdB1 to TcdB12). We find that representative members of subtypes 2, 4, 7, 10, 11, and 12 do not recognize the established host receptor, frizzled proteins (FZDs). Using a genome-wide CRISPR-Cas9-mediated screen, we identify tissue factor pathway inhibitor (TFPI) as a host receptor for TcdB4. TFPI is recognized by a region in TcdB4 that is homologous to the FZD-binding site in TcdB1. Analysis of 206 TcdB variant sequences reveals a set of six residues within this receptor-binding site that defines a TFPI binding-associated haplotype (designated B4/B7) that is present in all TcdB4 members, a subset of TcdB7, and one member of TcdB2. Intragenic micro-recombination (IR) events have occurred around this receptor-binding region in TcdB7 and TcdB2 members, resulting in either TFPI- or FZD-binding capabilities. Introduction of B4/B7-haplotype residues into TcdB1 enables dual recognition of TFPI and FZDs. Finally, TcdB10 also recognizes TFPI, although it does not belong to the B4/B7 haplotype, and shows species selectivity: it recognizes TFPI of chicken and to a lesser degree mouse, but not human, dog, or cattle versions. These findings identify TFPI as a TcdB receptor and reveal IR-driven changes on receptor-specificity among TcdB variants.
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Affiliation(s)
- Songhai Tian
- Department of Urology, Boston Children's Hospital, Boston, MA, 02115, USA.
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA.
| | - Xiaozhe Xiong
- Department of Urology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
| | - Ji Zeng
- Department of Urology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, 510006, China
| | - Siyu Wang
- Department of Urology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
- Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310016, China
| | - Benjamin Jean-Marie Tremblay
- Department of Biology, Cheriton School of Computer Science, and Waterloo Centre for Microbial Research, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Peng Chen
- Department of Physiology and Biophysics, School of Medicine, University of California Irvine, Irvine, CA, 92697, USA
| | - Baohua Chen
- Department of Physiology and Biophysics, School of Medicine, University of California Irvine, Irvine, CA, 92697, USA
| | - Min Liu
- Department of Urology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
| | - Pengsheng Chen
- Department of Urology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
| | - Kuanwei Sheng
- Wyss Institute for Bioinspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Daniel Zeve
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Wanshu Qi
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - David T Breault
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- Harvard Stem Cell Institute, 7 Divinity Avenue, Cambridge, MA, 02138, USA
| | - César Rodríguez
- Faculty of Microbiology & CIET, University of Costa Rica, San José, Costa Rica
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, 30625, Hannover, Germany
| | - Rongsheng Jin
- Department of Physiology and Biophysics, School of Medicine, University of California Irvine, Irvine, CA, 92697, USA
| | - Andrew C Doxey
- Department of Biology, Cheriton School of Computer Science, and Waterloo Centre for Microbial Research, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Boston, MA, 02115, USA.
- Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA.
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Przyklenk M, Heumüller SE, Freiburg C, Lütke S, Sengle G, Koch M, Paulsson M, Schiavinato A, Wagener R. Lack of evidence for a role of anthrax toxin receptors as surface receptors for collagen VI and for its cleaved-off C5 domain/endotrophin. iScience 2022; 25:105116. [PMID: 36185380 PMCID: PMC9515600 DOI: 10.1016/j.isci.2022.105116] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 05/29/2022] [Accepted: 09/08/2022] [Indexed: 11/26/2022] Open
Abstract
The microfibril-forming collagen VI is proteolytically cleaved and it was proposed that the released C-terminal Kunitz domain (C5) of the α3 chain is an adipokine important for tumor progression and fibrosis. Designated “endotrophin,” C5 is a potent biomarker for fibroinflammatory diseases. However, the biochemical mechanisms behind endotrophin activity were not investigated. Earlier, anthrax toxin receptor 1 was found to bind C5, but this potential interaction was not further studied. Given the proposed physiological role of endotrophin, we aimed to determine how the signal is transmitted. Surprisingly, we could not detect any interaction between endotrophin and anthrax toxin receptor 1 or its close relative, anthrax toxin receptor 2. Moreover, we detect no binding of fully assembled collagen VI to either receptor. We also studied the collagen VI receptor NG2 (CSPG4) and confirmed that NG2 binds assembled collagen VI, but not cleaved C5/endotrophin. A cellular receptor for C5/endotrophin, therefore, still remains elusive. ANTXR1 does not support collagen VI or C5/endotrophin binding to the cell surface ANTXR2 does not support collagen VI or C5/endotrophin binding to the cell surface NG2/CSPG4 supports collagen VI, but not C5/endotrophin binding to the cell surface
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Qin Q, Liu H, He W, Guo Y, Zhang J, She J, Zheng F, Zhang S, Muyldermans S, Wen Y. Single Domain Antibody application in bacterial infection diagnosis and neutralization. Front Immunol 2022; 13:1014377. [PMID: 36248787 PMCID: PMC9558170 DOI: 10.3389/fimmu.2022.1014377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 09/15/2022] [Indexed: 11/21/2022] Open
Abstract
Increasing antibiotic resistance to bacterial infections causes a serious threat to human health. Efficient detection and treatment strategies are the keys to preventing and reducing bacterial infections. Due to the high affinity and antigen specificity, antibodies have become an important tool for diagnosis and treatment of various human diseases. In addition to conventional antibodies, a unique class of “heavy-chain-only” antibodies (HCAbs) were found in the serum of camelids and sharks. HCAbs binds to the antigen through only one variable domain Referred to as VHH (variable domain of the heavy chain of HCAbs). The recombinant format of the VHH is also called single domain antibody (sdAb) or nanobody (Nb). Sharks might also have an ancestor HCAb from where SdAbs or V-NAR might be engineered. Compared with traditional Abs, Nbs have several outstanding properties such as small size, high stability, strong antigen-binding affinity, high solubility and low immunogenicity. Furthermore, they are expressed at low cost in microorganisms and amenable to engineering. These superior properties make Nbs a highly desired alternative to conventional antibodies, which are extensively employed in structural biology, unravelling biochemical mechanisms, molecular imaging, diagnosis and treatment of diseases. In this review, we summarized recent progress of nanobody-based approaches in diagnosis and neutralization of bacterial infection and further discussed the challenges of Nbs in these fields.
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Affiliation(s)
- Qian Qin
- Department of General Surgery, Center for Microbiome Research of Med-X Institute, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, Health Science Center, Xi'an Jiaotong University, Xi'an, China
| | - Hao Liu
- Center for Biomedical Research, Institute of Future Agriculture, Northwest A&F University, Yangling, China
| | - Wenbo He
- Department of General Surgery, Center for Microbiome Research of Med-X Institute, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Yucheng Guo
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, Health Science Center, Xi'an Jiaotong University, Xi'an, China
| | - Jiaxin Zhang
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, Health Science Center, Xi'an Jiaotong University, Xi'an, China
| | - Junjun She
- Department of General Surgery, Center for Microbiome Research of Med-X Institute, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Fang Zheng
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, Health Science Center, Xi'an Jiaotong University, Xi'an, China
| | - Sicai Zhang
- Center for Biomedical Research, Institute of Future Agriculture, Northwest A&F University, Yangling, China
| | - Serge Muyldermans
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Yurong Wen
- Department of General Surgery, Center for Microbiome Research of Med-X Institute, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, Health Science Center, Xi'an Jiaotong University, Xi'an, China
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Yan Z, Zhang K, Wang G, Wang L, Zhang J, Qiu Z, Guo Z, Zhang K, Li J. Differential proteomic of plasma provides a new perspective on scientific diagnosis and drug screening for dampness heat diarrhea in calves. Front Vet Sci 2022; 9:986329. [PMID: 36204290 PMCID: PMC9530945 DOI: 10.3389/fvets.2022.986329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 08/23/2022] [Indexed: 11/22/2022] Open
Abstract
Dampness heat diarrhea (DHD) is one of the most common syndromes of calf diarrhea. Its complex etiology and lack of objective diagnostic criteria bring great challenges to the diagnosis and treatment of this disease. This study aims to screen some prospective diagnostic biomarkers or therapeutic targets for calves with DHD by investigating the differential protein profiles of plasma between DHD calves and clinically healthy calves by mass spectrometry-based proteomic. A total of 120 DHD calves and 90 clinically healthy calves were divided into two groups randomly, 30 DHD calves and 30 clinically healthy calves in the test group, and 90 DHD calves and 60 clinically healthy calves in the validation group. In the test group, a total of 52 proteins were differentially expressed between calves with DHD and clinically healthy calves, 13 proteins were significantly increased and 39 proteins were significantly decreased. The differentially expressed proteins were associated with the intestinal immune network of IgA production, caffeine metabolism, purine metabolism, and PI3K signaling pathway. In the validation group, 13 proteins were selected from 52 differential expression proteins for parallel reaction monitoring validation to verify their associations with DHD calves. The targeted proteomic results showed that fibronectin precursor (FN1) and apolipoprotein C-IV precursor (APOC4) were significantly associated with DHD in calves, and they were downregulated in sick calves. In conclusion, the differential expression of plasma proteins was associated with DHD pathogenesis in calves, and the FN1 and APOC4 might be the potential clinical biomarkers for diagnosis of DHD in calves, and the intestinal immune network of IgA production, caffeine metabolism, purine metabolism, and PI3K signaling pathway are the candidate targets to treat DHD in calves. Our finding provides a reference for further investigating the pathogenesis, developing techniques of diagnosis, and screening treatment drugs for DHD in calves.
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Mead TJ, Bhutada S, Martin DR, Apte SS. Proteolysis: a key post-translational modification regulating proteoglycans. Am J Physiol Cell Physiol 2022; 323:C651-C665. [PMID: 35785985 PMCID: PMC9448339 DOI: 10.1152/ajpcell.00215.2022] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/28/2022] [Accepted: 06/28/2022] [Indexed: 11/22/2022]
Abstract
Proteoglycans are composite molecules comprising a protein backbone, i.e., the core protein, with covalently attached glycosaminoglycan chains of distinct chemical types. Most proteoglycans are secreted or attached to the cell membrane. Their specialized structures, binding properties, and biophysical attributes underlie diverse biological roles, which include modulation of tissue mechanics, cell adhesion, and the sequestration and regulated release of morphogens, growth factors, and cytokines. As an irreversible post-translational modification, proteolysis has a profound impact on proteoglycan function, abundance, and localization. Proteolysis is required for molecular maturation of some proteoglycans, clearance of extracellular matrix proteoglycans during tissue remodeling, generation of bioactive fragments from proteoglycans, and ectodomain shedding of cell-surface proteoglycans. Genetic evidence shows that proteoglycan core protein proteolysis is essential for diverse morphogenetic events during embryonic development. In contrast, dysregulated proteoglycan proteolysis contributes to osteoarthritis, cardiovascular disorders, cancer, and inflammation. Proteolytic fragments of perlecan, versican, aggrecan, brevican, collagen XVIII, and other proteoglycans are associated with independent biological activities as so-called matrikines. Yet, proteoglycan proteolysis has been investigated to only a limited extent to date. Here, we review the actions of proteases on proteoglycans and illustrate their functional impact with several examples. We discuss the applications and limitations of strategies used to define cleavage sites in proteoglycans and explain how proteoglycanome-wide proteolytic mapping, which is desirable to fully understand the impact of proteolysis on proteoglycans, can be facilitated by integrating classical proteoglycan isolation methods with mass spectrometry-based proteomics.
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Affiliation(s)
- Timothy J Mead
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio
| | - Sumit Bhutada
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio
| | - Daniel R Martin
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio
| | - Suneel S Apte
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio
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Plakoglobin and High-Mobility Group Box 1 Mediate Intestinal Epithelial Cell Apoptosis Induced by Clostridioides difficile TcdB. mBio 2022; 13:e0184922. [PMID: 36043787 DOI: 10.1128/mbio.01849-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridioides difficile infection (CDI) is the leading cause of antibiotic-associated intestinal disease, resulting in severe diarrhea and fatal pseudomembranous colitis. TcdB, one of the essential virulence factors secreted by this bacterium, induces host cell apoptosis through a poorly understood mechanism. Here, we performed an RNA interference (RNAi) screen customized to Caco-2 cells, a cell line model of the intestinal epithelium, to discover host factors involved in TcdB-induced apoptosis. We identified plakoglobin, also known as junction plakoglobin (JUP) or γ-catenin, a member of the catenin family, as a novel host factor and a previously known cell death-related chromatin factor, high-mobility group box 1 (HMGB1). Disruption of those host factors by RNAi and CRISPR resulted in resistance of cells to TcdB-mediated and mitochondrion-dependent apoptosis. JUP was redistributed from adherens junctions to the mitochondria and colocalized with the antiapoptotic factor Bcl-XL. JUP proteins could permeabilize the mitochondrial membrane, resulting in the release of cytochrome c. Our results reveal a novel role of JUP in targeting the mitochondria to promote the mitochondrial apoptotic pathway. Treatment with glycyrrhizin, an HMGB1 inhibitor, resulted in significantly increased resistance to TcdB-induced epithelial damage in cultured cells and a mouse ligated colon loop model. These findings demonstrate the critical roles of JUP and HMGB1 in TcdB-induced epithelial cell apoptosis. IMPORTANCE Clostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea. Toxins, especially TcdB, cause epithelial cell apoptosis, but the underlying cell death mechanism is less clear. Through an apoptosis-focused RNAi screen using a bacterium-made small interfering (siRNA) library customized to a human colonic epithelial cell model, we found a novel host factor, plakoglobin (γ-catenin), as a key factor required for cell apoptosis induced by TcdB. Plakoglobin targets and permeabilizes mitochondria after stimulation by TcdB, demonstrating a hitherto underappreciated role of this catenin family member in the apoptosis of intestinal epithelial cells. We also found a previously known cell death-related chromatin factor, HMGB1, and explored the inhibition of HMGB1 for CDI therapy in vivo.
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Kunishima H, Ohge H, Suzuki H, Nakamura A, Matsumoto K, Mikamo H, Mori N, Morinaga Y, Yanagihara K, Yamagishi Y, Yoshizawa S. Japanese Clinical Practice Guidelines for Management of Clostridioides (Clostridium) difficile infection. J Infect Chemother 2022; 28:1045-1083. [PMID: 35618618 DOI: 10.1016/j.jiac.2021.12.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/16/2021] [Accepted: 12/13/2021] [Indexed: 12/19/2022]
Affiliation(s)
- Hiroyuki Kunishima
- Department of Infectious Diseases, St. Marianna University School of Medicine, Japan.
| | - Hiroki Ohge
- Department of Infectious Diseases, Hiroshima University Hospital, Japan
| | - Hiromichi Suzuki
- Division of Infectious Diseases, Department of Medicine, Tsukuba Medical Center Hospital, Japan
| | - Atsushi Nakamura
- Division of Infection Control and Prevention, Nagoya City University Hospital, Japan
| | - Kazuaki Matsumoto
- Division of Pharmacodynamics, Faculty of Pharmacy, Keio University, Japan
| | - Hiroshige Mikamo
- Clinical Infectious Diseases, Graduate School of Medicine, Aichi Medical University, Japan
| | - Nobuaki Mori
- Division of General Internal Medicine and Infectious Diseases, National Hospital Organization Tokyo Medical Center, Japan
| | - Yoshitomo Morinaga
- Department of Microbiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Katsunori Yanagihara
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Japan
| | - Yuka Yamagishi
- Clinical Infectious Diseases, Graduate School of Medicine, Aichi Medical University, Japan
| | - Sadako Yoshizawa
- Department of Clinical Laboratory/Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Japan
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Paeniclostridium sordellii hemorrhagic toxin targets TMPRSS2 to induce colonic epithelial lesions. Nat Commun 2022; 13:4331. [PMID: 35882856 PMCID: PMC9321280 DOI: 10.1038/s41467-022-31994-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 07/12/2022] [Indexed: 12/21/2022] Open
Abstract
Hemorrhagic toxin (TcsH) is an important exotoxin produced by Paeniclostridium sordellii, but the exact role of TcsH in the pathogenesis remains unclear, partly due to the lack of knowledge of host receptor(s). Here, we carried out two genome-wide CRISPR/Cas9 screens parallelly with TcsH and identified cell surface fucosylation and TMPRSS2 as host factors contributing to the binding and entry of TcsH. Genetic deletion of either fucosylation biosynthesis enzymes or TMPRSS2 in the cells confers resistance to TcsH intoxication. Interestingly, TMPRSS2 and fucosylated glycans can mediate the binding/entry of TcsH independently, thus serving as redundant receptors. Both TMPRSS2 and fucosylation recognize TcsH through its CROPs domain. By using Tmprss2‒/‒ mice, we show that Tmprss2 is important for TcsH-induced systematic toxicity and colonic epithelial lesions. These findings reveal the importance of TMPRSS2 and surface fucosylation in TcsH actions and further provide insights into host recognition mechanisms for large clostridial toxins. Paeniclostridium sordellii is an opportunistic pathogen that can occur and be fatal in women undergoing abortion or childbirth. The pathogenesis of a hemorrhagic toxin, TcsH, produced by this bacteria, remains unknown. Here, authors carry out genome-wide screens to identify pathologically relevant host factors of TcsH.
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Kordus SL, Thomas AK, Lacy DB. Clostridioides difficile toxins: mechanisms of action and antitoxin therapeutics. Nat Rev Microbiol 2022; 20:285-298. [PMID: 34837014 PMCID: PMC9018519 DOI: 10.1038/s41579-021-00660-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 01/03/2023]
Abstract
Clostridioides difficile is a Gram-positive anaerobe that can cause a spectrum of disorders that range in severity from mild diarrhoea to fulminant colitis and/or death. The bacterium produces up to three toxins, which are considered the major virulence factors in C. difficile infection. These toxins promote inflammation, tissue damage and diarrhoea. In this Review, we highlight recent biochemical and structural advances in our understanding of the mechanisms that govern host-toxin interactions. Understanding how C. difficile toxins affect the host forms a foundation for developing novel strategies for treatment and prevention of C. difficile infection.
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Affiliation(s)
- Shannon L. Kordus
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA,Center for Structural Biology, Vanderbilt University, Nashville, TN, USA,These authors contributed equally: Shannon L. Kordus, Audrey K. Thomas
| | - Audrey K. Thomas
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA,Center for Structural Biology, Vanderbilt University, Nashville, TN, USA,These authors contributed equally: Shannon L. Kordus, Audrey K. Thomas
| | - D. Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA,Center for Structural Biology, Vanderbilt University, Nashville, TN, USA,The Veterans Affairs, Tennessee Valley Healthcare, System, Nashville, TN, USA,
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Stieglitz F, Gerhard R, Hönig R, Giehl K, Pich A. TcdB of Clostridioides difficile Mediates RAS-Dependent Necrosis in Epithelial Cells. Int J Mol Sci 2022; 23:ijms23084258. [PMID: 35457076 PMCID: PMC9024770 DOI: 10.3390/ijms23084258] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 02/06/2023] Open
Abstract
A Clostridioides difficile infection (CDI) is the most common nosocomial infection worldwide. The main virulence factors of pathogenic C. difficile are TcdA and TcdB, which inhibit small Rho-GTPases. The inhibition of small Rho-GTPases leads to the so-called cytopathic effect, a reorganization of the actin cytoskeleton, an impairment of the colon epithelium barrier function and inflammation. Additionally, TcdB induces a necrotic cell death termed pyknosis in vitro independently from its glucosyltransferases, which are characterized by chromatin condensation and ROS production. To understand the underlying mechanism of this pyknotic effect, we conducted a large-scale phosphoproteomic study. We included the analysis of alterations in the phosphoproteome after treatment with TcdA, which was investigated for the first time. TcdA exhibited no glucosyltransferase-independent necrotic effect and was, thus, a good control to elucidate the underlying mechanism of the glucosyltransferase-independent effect of TcdB. We found RAS to be a central upstream regulator of the glucosyltransferase-independent effect of TcdB. The inhibition of RAS led to a 68% reduction in necrosis. Further analysis revealed apolipoprotein C-III (APOC3) as a possible crucial factor of CDI-induced inflammation in vivo.
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Affiliation(s)
- Florian Stieglitz
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; (F.S.); (R.G.)
- Core Facility Proteomics, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; (F.S.); (R.G.)
| | - Rabea Hönig
- Signal Transduction of Cellular Motility, Internal Medicine V, Justus Liebig University Giessen, Aulweg 128, 35392 Giessen, Germany; (R.H.); (K.G.)
| | - Klaudia Giehl
- Signal Transduction of Cellular Motility, Internal Medicine V, Justus Liebig University Giessen, Aulweg 128, 35392 Giessen, Germany; (R.H.); (K.G.)
| | - Andreas Pich
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; (F.S.); (R.G.)
- Core Facility Proteomics, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
- Correspondence: ; Tel.: +49-511-532-2808; Fax: +49-511-532-2879
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43
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Liu J, Kothe M, Zhang J, Oloo E, Stegalkina S, Mundle ST, Li L, Zhang J, Cole LE, Barone L, Biemann HP, Kleanthous H, Anosova NG, Anderson SF. Novel structural insights for a pair of monoclonal antibodies recognizing non-overlapping epitopes of the glucosyltransferase domain of Clostridium difficile toxin B. Curr Res Struct Biol 2022; 4:96-105. [PMID: 35469152 PMCID: PMC9034018 DOI: 10.1016/j.crstbi.2022.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/11/2022] [Accepted: 03/24/2022] [Indexed: 11/06/2022] Open
Abstract
Clostridium difficile toxins are the primary causative agents for hospital-acquired diarrhea and pseudomembranous colitis. Numerous monoclonal antibodies (mAbs) targeting different domains of Clostridium difficile toxin have been reported. Here we report the crystal structures of two mAbs, B1 and B2, in complex with the glycosyltransferase domain (GTD) of the Clostridium difficile toxin B (TcdB). B2 bound to the N-terminal 4 helix bundle of the GTD, a conserved membrane localization domain (MLD) found in the large clostridial glycosylating toxin family implicated in targeting plasma membrane. B1 bound to a distinct epitope at the hinge region between the MLD and the catalytic subdomain of the GTD. Functional studies revealed the potency of these mAbs in vitro and in vivo to be synergistic when given in combination. Identified 2 novel potent mAbs B1 and B2 targeting the TcdB GTD domain and synergistic effects were observed when combined. Novel non-overlapped epitopes were identified for B1 and B2 through X-ray crystallography. B2 epitope belongs to a conserved MLD (membrane localization domain) in the large clostridial glycosylating toxin family. B2 was shown to target the key regions (Loop 1 and Loop 3) of MLD proposed to be essential for membrane localization. B1 epitope was found to be at the hinge region between the GTD catalytic domain and the MLD of GTD.
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Luo J, Yang Q, Zhang X, Zhang Y, Wan L, Zhan X, Zhou Y, He L, Li D, Jin D, Zhen Y, Huang J, Li Y, Tao L. TFPI is a colonic crypt receptor for TcdB from hypervirulent clade 2 C. difficile. Cell 2022; 185:980-994.e15. [PMID: 35303428 DOI: 10.1016/j.cell.2022.02.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 01/11/2022] [Accepted: 02/08/2022] [Indexed: 12/14/2022]
Abstract
The emergence of hypervirulent clade 2 Clostridioides difficile is associated with severe symptoms and accounts for >20% of global infections. TcdB is a dominant virulence factor of C. difficile, and clade 2 strains exclusively express two TcdB variants (TcdB2 and TcdB4) that use unknown receptors distinct from the classic TcdB. Here, we performed CRISPR/Cas9 screens for TcdB4 and identified tissue factor pathway inhibitor (TFPI) as its receptor. Using cryo-EM, we determined a complex structure of the full-length TcdB4 with TFPI, defining a common receptor-binding region for TcdB. Residue variations within this region divide major TcdB variants into 2 classes: one recognizes Frizzled (FZD), and the other recognizes TFPI. TFPI is highly expressed in the intestinal glands, and recombinant TFPI protects the colonic epithelium from TcdB2/4. These findings establish TFPI as a colonic crypt receptor for TcdB from clade 2 C. difficile and reveal new mechanisms for CDI pathogenesis.
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Affiliation(s)
- Jianhua Luo
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Qi Yang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Xiaofeng Zhang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Yuanyuan Zhang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China; School of Food Science and Biotechnology Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China
| | - Li Wan
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Xiechao Zhan
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Yao Zhou
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Liuqing He
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Danyang Li
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Dazhi Jin
- Center of Laboratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, China; School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310014, China
| | - Ying Zhen
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Jing Huang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Yanyan Li
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China.
| | - Liang Tao
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China; Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China.
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Chaves-Cordero C, Quesada-Gómez C, Chaves-Olarte E, Barquero-Calvo E. Human neutrophils are resistant to Clostridioides difficile toxin B. Anaerobe 2022; 74:102553. [DOI: 10.1016/j.anaerobe.2022.102553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 02/08/2023]
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Jiang M, Shin J, Simeon R, Chang JY, Meng R, Wang Y, Shinde O, Li P, Chen Z, Zhang J. Structural dynamics of receptor recognition and pH-induced dissociation of full-length Clostridioides difficile Toxin B. PLoS Biol 2022; 20:e3001589. [PMID: 35324891 PMCID: PMC8982864 DOI: 10.1371/journal.pbio.3001589] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 04/05/2022] [Accepted: 03/02/2022] [Indexed: 12/14/2022] Open
Abstract
Clostridioides difficile secretes Toxin B (TcdB) as one of its major virulence factors, which binds to intestinal epithelial and subepithelial receptors, including frizzled proteins and chondroitin sulfate proteoglycan 4 (CSPG4). Here, we present cryo-EM structures of full-length TcdB in complex with the CSPG4 domain 1 fragment (D1401-560) at cytosolic pH and the cysteine-rich domain of frizzled-2 (CRD2) at both cytosolic and acidic pHs. CSPG4 specifically binds to the autoprocessing and delivery domains of TcdB via networks of salt bridges, hydrophobic and aromatic/proline interactions, which are disrupted upon acidification eventually leading to CSPG4 drastically dissociating from TcdB. In contrast, FZD2 moderately dissociates from TcdB under acidic pH, most likely due to its partial unfolding. These results reveal structural dynamics of TcdB during its preentry step upon endosomal acidification, which provide a basis for developing therapeutics against C. difficile infections.
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Affiliation(s)
- Mengqiu Jiang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Joonyoung Shin
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Rudo Simeon
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Jeng-Yih Chang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Ran Meng
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Yuhang Wang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Omkar Shinde
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Pingwei Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Zhilei Chen
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Junjie Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
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47
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Heber S, Barthold L, Baier J, Papatheodorou P, Fois G, Frick M, Barth H, Fischer S. Inhibition of Clostridioides difficile Toxins TcdA and TcdB by Ambroxol. Front Pharmacol 2022; 12:809595. [PMID: 35058787 PMCID: PMC8764291 DOI: 10.3389/fphar.2021.809595] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/10/2021] [Indexed: 02/04/2023] Open
Abstract
Clostridioides (C.) difficile produces the exotoxins TcdA and TcdB, which are the predominant virulence factors causing C. difficile associated disease (CDAD). TcdA and TcdB bind to target cells and are internalized via receptor-mediated endocytosis. Translocation of the toxins’ enzyme subunits from early endosomes into the cytosol depends on acidification of endosomal vesicles, which is a prerequisite for the formation of transmembrane channels. The enzyme subunits of the toxins translocate into the cytosol via these channels where they are released after auto-proteolytic cleavage. Once in the cytosol, both toxins target small GTPases of the Rho/Ras-family and inactivate them by mono-glucosylation. This in turn interferes with actin-dependent processes and ultimately leads to the breakdown of the intestinal epithelial barrier and inflammation. So far, therapeutic approaches to treat CDAD are insufficient, since conventional antibiotic therapy does not target the bacterial protein toxins, which are the causative agents for the clinical symptoms. Thus, directly targeting the exotoxins represents a promising approach for the treatment of CDAD. Lately, it was shown that ambroxol (Ax) prevents acidification of intracellular organelles. Therefore, we investigated the effect of Ax on the cytotoxic activities of TcdA and TcdB. Ax significantly reduced toxin-induced morphological changes as well as the glucosylation of Rac1 upon intoxication with TcdA and TcdB. Most surprisingly, Ax, independent of its effects on endosomal acidification, decreased the toxins’ intracellular enzyme activity, which is mediated by a catalytic glucosyltransferase domain. Considering its undoubted safety profile, Ax might be taken into account as therapeutic option in the context of CDAD.
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Affiliation(s)
- Sebastian Heber
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm, Germany
| | - Lara Barthold
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm, Germany
| | - Jan Baier
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm, Germany
| | | | - Giorgio Fois
- Institute of General Physiology, Ulm University, Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, Ulm University, Ulm, Germany
| | - Holger Barth
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm, Germany
| | - Stephan Fischer
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, Ulm, Germany
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Aminzadeh A, Larsen CE, Boesen T, Jørgensen R. High-resolution structure of native toxin A from Clostridioides difficile. EMBO Rep 2022; 23:e53597. [PMID: 34817920 PMCID: PMC8728606 DOI: 10.15252/embr.202153597] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 01/07/2023] Open
Abstract
Clostridioides difficile infections have emerged as the leading cause of healthcare-associated infectious diarrhea. Disease symptoms are mainly caused by the virulence factors, TcdA and TcdB, which are large homologous multidomain proteins. Here, we report a 2.8 Å resolution cryo-EM structure of native TcdA, unveiling its conformation at neutral pH. The structure uncovers the dynamic movement of the CROPs domain which is induced in response to environmental acidification. Furthermore, the structure reveals detailed information about the interaction area between the CROPs domain and the tip of the delivery and receptor-binding domain, which likely serves to shield the C-terminal part of the hydrophobic pore-forming region from solvent exposure. Similarly, extensive interactions between the globular subdomain and the N-terminal part of the pore-forming region suggest that the globular subdomain shields the upper part of the pore-forming region from exposure to the surrounding solvent. Hence, the TcdA structure provides insights into the mechanism of preventing premature unfolding of the pore-forming region at neutral pH, as well as the pH-induced inter-domain dynamics.
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Affiliation(s)
- Aria Aminzadeh
- Department of Bacteria, Parasites and FungiStatens Serum InstitutCopenhagenDenmark
| | - Christian Engelbrecht Larsen
- Interdisciplinary Nanoscience Center (iNANO)Aarhus UniversityAarhusDenmark
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - Thomas Boesen
- Interdisciplinary Nanoscience Center (iNANO)Aarhus UniversityAarhusDenmark
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - René Jørgensen
- Department of Bacteria, Parasites and FungiStatens Serum InstitutCopenhagenDenmark
- Department of Science and EnvironmentUniversity of RoskildeRoskildeDenmark
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49
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Klepka C, Sandmann M, Tatge H, Mangan M, Arens A, Henkel D, Gerhard R. Impairment of lysosomal function by Clostridioides difficile TcdB. Mol Microbiol 2021; 117:493-507. [PMID: 34931374 DOI: 10.1111/mmi.14864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 12/11/2021] [Indexed: 11/30/2022]
Abstract
TcdB is a potent cytotoxin produced by pathogenic Clostridioides difficile that inhibits Rho GTPases by mono-glucosylation. TcdB enters cells via receptor-mediated endocytosis. The pathogenic glucosyltransferase domain (GTD) egresses endosomes by pH-mediated conformational changes, and is subsequently released in an autoproteolytic manner. We here investigated the uptake, localization and degradation of TcdB. TcdB colocalized with lysosomal marker protein LAMP1, verifying the endosomal-lysosomal route of the toxin. In pulse assays endocytosed TcdB declined to a limit of detection within 2 hr, whereas the released GTD accumulated for up to 8 hr. We observed that autoproteolytic deficient TcdB NXN C698S was degraded significantly faster than wildtype TcdB, suggesting interference of TcdB with lysosomal degradation process. In fact, TcdB reduced lysosomal degradation of endosome cargo as tested with DQ-Green BSA. Lysosomal dysfunction was accompanied by perinuclear accumulation of LAMP1 and a weaker detection in immunoblots. Galectin-8 or galectin-3 was not recruited to lysosomes speaking against lysosome membrane damage. Changes in the autophagosomal marker LC3B suggested additional indirect effect of lysosomal dysfunction on the autophagic flux. In contrast to necrotic signaling induced in by TcdB, lysosomal dysfunction was not abolished by calcium channel blocker nifedipin, indicating separate cytopathogenic effects induced by TcdB during endo-lysosomal trafficking.
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Affiliation(s)
- Carmen Klepka
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Moritz Sandmann
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Helma Tatge
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Matthew Mangan
- Institute of Innate Immunology, Biomedical Center, University of Bonn, Bonn, Germany.,German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Annabel Arens
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Daniel Henkel
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
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50
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Liu Z, Zhang S, Chen P, Tian S, Zeng J, Perry K, Dong M, Jin R. Structural basis for selective modification of Rho and Ras GTPases by Clostridioides difficile toxin B. SCIENCE ADVANCES 2021; 7:eabi4582. [PMID: 34678063 PMCID: PMC8535798 DOI: 10.1126/sciadv.abi4582] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 09/02/2021] [Indexed: 05/15/2023]
Abstract
Toxin B (TcdB) is a primary cause of Clostridioides difficile infection (CDI). This toxin acts by glucosylating small GTPases in the Rho/Ras families, but the structural basis for TcdB recognition and selectivity of specific GTPase substrates remain unsolved. Here, we report the cocrystal structures of the glucosyltransferase domain (GTD) of two distinct TcdB variants in complex with human Cdc42 and R-Ras, respectively. These structures reveal a common structural mechanism by which TcdB recognizes Rho and R-Ras. Furthermore, we find selective clustering of adaptive residue changes in GTDs that determine their substrate preferences, which helps partition all known TcdB variants into two groups that display distinct specificities toward Rho or R-Ras. Mutations that selectively disrupt GTPases binding reduce the glucosyltransferase activity of the GTD and the toxicity of TcdB holotoxin. These findings establish the structural basis for TcdB recognition of small GTPases and reveal strategies for therapeutic interventions for CDI.
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Affiliation(s)
- Zheng Liu
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
| | - Sicai Zhang
- Department of Urology, Boston Children’s Hospital, and Departments of Microbiology and Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Peng Chen
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
| | - Songhai Tian
- Department of Urology, Boston Children’s Hospital, and Departments of Microbiology and Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Ji Zeng
- Department of Urology, Boston Children’s Hospital, and Departments of Microbiology and Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Min Dong
- Department of Urology, Boston Children’s Hospital, and Departments of Microbiology and Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
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