1
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Norman KM, Lang GA, Shadid TM, Honold ST, Reel JM, Cox MA, Ballard JD, Lang ML. Clostridioides difficile toxin B subverts germinal center and antibody recall responses by stimulating a drug-treatable CXCR4-dependent mechanism. Cell Rep 2024; 43:114245. [PMID: 38761377 PMCID: PMC11210377 DOI: 10.1016/j.celrep.2024.114245] [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: 10/19/2023] [Revised: 04/04/2024] [Accepted: 05/02/2024] [Indexed: 05/20/2024] Open
Abstract
Recurrent Clostridioides difficile infection (CDI) results in significant morbidity and mortality. We previously established that CDI in mice does not protect against reinfection and is associated with poor pathogen-specific B cell memory (Bmem), recapitulating our observations with human Bmem. Here, we demonstrate that the secreted toxin TcdB2 is responsible for subversion of Bmem responses. TcdB2 from an endemic C. difficile strain delayed immunoglobulin G (IgG) class switch following vaccination, attenuated IgG recall to a vaccine booster, and prevented germinal center formation. The mechanism of TcdB2 action included increased B cell CXCR4 expression and responsiveness to its ligand CXCL12, accounting for altered cell migration and a failure of germinal center-dependent Bmem. These results were reproduced in a C. difficile infection model, and a US Food and Drug Administration (FDA)-approved CXCR4-blocking drug rescued germinal center formation. We therefore provide mechanistic insights into C. difficile-associated pathogenesis and illuminate a target for clinical intervention to limit recurrent disease.
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Affiliation(s)
- Kaylee M Norman
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences, Oklahoma City, OK 73104, USA
| | - Gillian A Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences, Oklahoma City, OK 73104, USA
| | - Tyler M Shadid
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences, Oklahoma City, OK 73104, USA
| | - Sydney T Honold
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences, Oklahoma City, OK 73104, USA
| | - Jessica M Reel
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences, Oklahoma City, OK 73104, USA
| | - Maureen A Cox
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences, Oklahoma City, OK 73104, USA
| | - Jimmy D Ballard
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences, Oklahoma City, OK 73104, USA
| | - Mark L Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences, Oklahoma City, OK 73104, USA.
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2
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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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3
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Fachi JL, Vinolo MAR, Colonna M. Reviewing the Clostridioides difficile Mouse Model: Insights into Infection Mechanisms. Microorganisms 2024; 12:273. [PMID: 38399676 PMCID: PMC10891951 DOI: 10.3390/microorganisms12020273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 01/16/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
Clostridioides difficile is an anaerobic, spore-forming bacterium associated with intestinal infection, manifesting a broad spectrum of gastrointestinal symptoms, ranging from mild diarrhea to severe colitis. A primary risk factor for the development of C. difficile infection (CDI) is antibiotic exposure. Elderly and immunocompromised individuals are particularly vulnerable to CDI. A pivotal aspect for comprehending the complexities of this infection relies on the utilization of experimental models that mimic human CDI transmission, pathogenesis, and progression. These models offer invaluable insights into host-pathogen interactions and disease dynamics, and serve as essential tools for testing potential therapeutic approaches. In this review, we examine the animal model for CDI and delineate the stages of infection, with a specific focus on mice. Our objective is to offer an updated description of experimental models employed in the study of CDI, emphasizing both their strengths and limitations.
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Affiliation(s)
- José L. Fachi
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA;
| | - Marco A. R. Vinolo
- Department of Genetics and Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas, Campinas 13083-862, SP, Brazil;
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA;
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4
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Barbero AM, Hernández Del Pino RE, Fuentes F, Barrionuevo P, Pasquinelli V. Platelets promote human macrophages-mediated macropinocytosis of Clostridioides difficile. Front Cell Infect Microbiol 2024; 13:1252509. [PMID: 38249298 PMCID: PMC10796631 DOI: 10.3389/fcimb.2023.1252509] [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: 07/04/2023] [Accepted: 12/11/2023] [Indexed: 01/23/2024] Open
Abstract
Clostridioides difficile is the main causative agent of hospital-acquired diarrhea and the potentially lethal disease, C. difficile infection. The cornerstone of the current therapy is the use of antibiotics, which is not fully effective. The molecular mechanisms, inflammatory conditions and host-immune responses that could benefit the persistence or elimination of C. difficile remain unclear. Macrophages perform different ways of endocytosis as part of their immune surveillance functions and platelets, classically known for their coagulatory role, are also important modulators of the immune system. The aim of this study was to evaluate the endocytosis of vegetative C. difficile by human macrophages and the involvement of platelets in this process. Our results showed that both macrophages and platelets interact with live and heat-killed C. difficile. Furthermore, platelets form complexes with human monocytes in healthy donor's fresh blood and the presence of C. difficile increased these cell-cell interactions. Using flow cytometry and confocal microscopy, we show that macrophages can internalize C. difficile and that platelets improve this uptake. By using inhibitors of different endocytic pathways, we demonstrate that macropinocytosis is the route of entry of C. difficile into the cell. Taken together, our findings are the first evidence for the internalization of vegetative non-toxigenic and hypervirulent C. difficile by human macrophages and highlight the role of platelets in innate immunity during C. difficile infection. Deciphering the crosstalk of C. difficile with immune cells could provide new tools for understanding the pathogenesis of C. difficile infection and for the development of host-directed therapies.
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Affiliation(s)
- Angela María Barbero
- Centro de Investigaciones Básicas y Aplicadas (CIBA), Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA), Buenos Aires, Argentina
- Centro de Investigaciones y Transferencias del Noroeste de la Provincia de Buenos Aires (CIT NOBA), UNNOBA-Universidad Nacional de San Antonio de Areco (UNSAdA)- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Rodrigo Emanuel Hernández Del Pino
- Centro de Investigaciones Básicas y Aplicadas (CIBA), Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA), Buenos Aires, Argentina
- Centro de Investigaciones y Transferencias del Noroeste de la Provincia de Buenos Aires (CIT NOBA), UNNOBA-Universidad Nacional de San Antonio de Areco (UNSAdA)- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Federico Fuentes
- Instituto de Medicina Experimental (CONICET-Academia Nacional de Medicina), Buenos Aires, Argentina
| | - Paula Barrionuevo
- Instituto de Medicina Experimental (CONICET-Academia Nacional de Medicina), Buenos Aires, Argentina
| | - Virginia Pasquinelli
- Centro de Investigaciones Básicas y Aplicadas (CIBA), Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA), Buenos Aires, Argentina
- Centro de Investigaciones y Transferencias del Noroeste de la Provincia de Buenos Aires (CIT NOBA), UNNOBA-Universidad Nacional de San Antonio de Areco (UNSAdA)- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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5
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Grześkowiak Ł, Vahjen W, Zentek J. Influence of high- and low-fermentable dietary fibres in sows' diet on the colostrum potential against Clostridioides difficile toxin-induced effects in IPEC-J2 cells. J Anim Physiol Anim Nutr (Berl) 2023; 107:1376-1380. [PMID: 37203280 DOI: 10.1111/jpn.13834] [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: 12/17/2022] [Revised: 03/31/2023] [Accepted: 05/06/2023] [Indexed: 05/20/2023]
Abstract
Sow colostrum has been reported to protect the IPEC-J2 cells and piglet colon tissues from detrimental effect of Clostridioides difficile toxins. Since dietary fibre can influence the colostrum composition in sows, we hypothesised that it can also differentially affect the colostrum potential against C. difficile toxin-induced effects in IPEC-J2. IPEC-J2 were incubated with colostrum from sows fed either high-fermentable sugar beet pulp (SBP) or low-fermentable lignocellulose (LNC) fibres and in combination with the toxins and analysed by trans-epithelial electrical resistance (TEER) and cell viability using propidium iodide in flow cytometry. Toxins drastically decreased the integrity of IPEC-J2. Colostrum from the sows fed either SBP or LNC exerted protective effect against toxins on IPEC-J2 integrity and this effect was numerically superior in the SBP group. Differences in the percentages of TEER between different treatments were noted after 2 h (p = 0.043), 3 h (p = 0.017) and 4 h (p = 0.017) of incubation and a tendency for differences was noted after 5 h of incubation (p = 0.071). Colostrum from either SBP- or LNC-fed sows did not protect the IPEC-J2 from toxin-induced death. Colostrum of the sows fed either high-fermentable or low-fermentable fibres has a potential to protect IPEC-J2 from the loss of integrity, which may be important in protection from C. difficile-infection development in neonatal piglets.
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Affiliation(s)
- Łukasz Grześkowiak
- Department of Veterinary Medicine, Institute of Animal Nutrition, Freie Universität Berlin, Berlin, Germany
| | - Wilfried Vahjen
- Department of Veterinary Medicine, Institute of Animal Nutrition, Freie Universität Berlin, Berlin, Germany
| | - Jürgen Zentek
- Department of Veterinary Medicine, Institute of Animal Nutrition, Freie Universität Berlin, Berlin, Germany
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6
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Rogers AP, Mileto SJ, Lyras D. Impact of enteric bacterial infections at and beyond the epithelial barrier. Nat Rev Microbiol 2023; 21:260-274. [PMID: 36175770 DOI: 10.1038/s41579-022-00794-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2022] [Indexed: 11/09/2022]
Abstract
The mucosal lining of the gut has co-evolved with a diverse microbiota over millions of years, leading to the development of specialized mechanisms to actively limit the invasion of pathogens. However, some enteric microorganisms have adapted against these measures, developing ways to hijack or overcome epithelial micro-integrity mechanisms. This breach of the gut barrier not only enables the leakage of host factors out of circulation but can also initiate a cascade of detrimental systemic events as microbiota, pathogens and their affiliated secretions passively leak into extra-intestinal sites. Under normal circumstances, gut damage is rapidly repaired by intestinal stem cells. However, with substantial and deep perturbation to the gut lining and the systemic dissemination of gut contents, we now know that some enteric infections can cause the impairment of host regenerative processes. Although these local and systemic aspects of enteric disease are often studied in isolation, they heavily impact one another. In this Review, by examining the journey of enteric infections from initial establishment to systemic sequelae and how, or if, the host can successfully repair damage, we will tie together these complex interactions to provide a holistic overview of the impact of enteric infections at and beyond the epithelial barrier.
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Affiliation(s)
- Ashleigh P Rogers
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.,Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Steven J Mileto
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.,Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia. .,Department of Microbiology, Monash University, Melbourne, Victoria, Australia.
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7
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Mileto SJ, Hutton ML, Walton SL, Das A, Ioannidis LJ, Ketagoda D, Quinn KM, Denton KM, Hansen DS, Lyras D. Bezlotoxumab prevents extraintestinal organ damage induced by Clostridioides difficile infection. Gut Microbes 2022; 14:2117504. [PMID: 36045589 PMCID: PMC9450906 DOI: 10.1080/19490976.2022.2117504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Clostridioides difficile is the most common cause of infectious antibiotic-associated diarrhea, with disease mediated by two major toxins TcdA and TcdB. In severe cases, systemic disease complications may arise, resulting in fatal disease. Systemic disease in animal models has been described, with thymic damage an observable consequence of severe disease in mice. Using a mouse model of C. difficile infection, we examined this disease phenotype, focussing on the thymus and serum markers of systemic disease. The efficacy of bezlotoxumab, a monoclonal TcdB therapeutic, to prevent toxin mediated systemic disease complications was also examined. C. difficile infection causes toxin-dependent thymic damage and CD4+CD8+ thymocyte depletion in mice. These systemic complications coincide with changes in biochemical markers of liver and kidney function, including increased serum urea and creatinine, and hypoglycemia. Administration of bezlotoxumab during C. difficile infection prevents systemic disease and thymic atrophy, without blocking gut damage, suggesting the leakage of gut contents into circulation may influence systemic disease. As the thymus has such a crucial role in T cell production and immune system development, these findings may have important implications in relapse of C. difficile disease and impaired immunity during C. difficile infection. The prevention of thymic atrophy and reduced systemic response following bezlotoxumab treatment, without altering colonic damage, highlights the importance of systemic disease in C. difficile infection, and provides new insights into the mechanism of action for this therapeutic.Abbreviations: Acute kidney injury (AKI); Alanine Transaminase (ALT); Aspartate Aminotransferase (AST); C. difficile infection (CDI); chronic kidney disease (CKD); combined repetitive oligo-peptides (CROPS); cardiovascular disease (CVD); Double positive (DP); hematoxylin and eosin (H&E); immunohistochemical (IHC); multiple organ dysfunction syndrome (MODS); phosphate buffered saline (PBS); standard error of the mean (SEM); surface layer proteins (SLP); Single positive (SP); wild-type (WT).
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Affiliation(s)
- Steven J. Mileto
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
| | - Melanie L. Hutton
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
| | - Sarah L. Walton
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Australia
| | - Antariksh Das
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
| | - Lisa J. Ioannidis
- Walter and Eliza Hall Insitiute, Infectious Diseases and Immune Defence Division, Parkville, Australia,Department of Medical Biology, the University of Melbourne, Parkville, Australia
| | - Don Ketagoda
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
| | - Kylie M. Quinn
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia,RMIT University School of Biomedical and Health Sciences, Chronic Inflammatory and Infectious Diseases Program, Bundoora, Australia
| | - Kate M. Denton
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Australia
| | - Diana S. Hansen
- Walter and Eliza Hall Insitiute, Infectious Diseases and Immune Defence Division, Parkville, Australia,Department of Medical Biology, the University of Melbourne, Parkville, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia,CONTACT Dena Lyras Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria3800, Australia
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8
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Boeriu A, Roman A, Fofiu C, Dobru D. The Current Knowledge on Clostridioides difficile Infection in Patients with Inflammatory Bowel Diseases. Pathogens 2022; 11:pathogens11070819. [PMID: 35890064 PMCID: PMC9323231 DOI: 10.3390/pathogens11070819] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/17/2022] [Accepted: 07/18/2022] [Indexed: 11/17/2022] Open
Abstract
Clostridioides difficile (C. difficile) represents a major health burden with substantial economic and clinical impact. Patients with inflammatory bowel diseases (IBD) were identified as a risk category for Clostridioides difficile infection (CDI). In addition to traditional risk factors for C. difficile acquisition, IBD-specific risk factors such as immunosuppression, severity and extension of the inflammatory disease were identified. C. difficile virulence factors, represented by both toxins A and B, induce the damage of the intestinal mucosa and vascular changes, and promote the inflammatory host response. Given the potential life-threatening complications, early diagnostic and therapeutic interventions are required. The screening for CDI is recommended in IBD exacerbations, and the diagnostic algorithm consists of clinical evaluation, enzyme immunoassays (EIAs) or nucleic acid amplification tests (NAATs). An increased length of hospitalization, increased colectomy rate and mortality are the consequences of concurrent CDI in IBD patients. Selection of CD strains of higher virulence, antibiotic resistance, and the increasing rate of recurrent infections make the management of CDI in IBD more challenging. An individualized therapeutic approach is recommended to control CDI as well as IBD flare. Novel therapeutic strategies have been developed in recent years in order to manage severe, refractory or recurrent CDI. In this article, we aim to review the current evidence in the field of CDI in patients with underlying IBD, pointing to pathogenic mechanisms, risk factors for infection, diagnostic steps, clinical impact and outcomes, and specific management.
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Affiliation(s)
- Alina Boeriu
- Gastroenterology Department, University of Medicine Pharmacy, Sciences, and Technology “George Emil Palade” Targu Mures, 540142 Targu Mures, Romania; (A.B.); (C.F.); (D.D.)
- Gastroenterology Department, Mures County Clinical Hospital, 540103 Targu Mures, Romania
| | - Adina Roman
- Gastroenterology Department, University of Medicine Pharmacy, Sciences, and Technology “George Emil Palade” Targu Mures, 540142 Targu Mures, Romania; (A.B.); (C.F.); (D.D.)
- Gastroenterology Department, Mures County Clinical Hospital, 540103 Targu Mures, Romania
- Correspondence: ; Tel.: +40-752934465
| | - Crina Fofiu
- Gastroenterology Department, University of Medicine Pharmacy, Sciences, and Technology “George Emil Palade” Targu Mures, 540142 Targu Mures, Romania; (A.B.); (C.F.); (D.D.)
| | - Daniela Dobru
- Gastroenterology Department, University of Medicine Pharmacy, Sciences, and Technology “George Emil Palade” Targu Mures, 540142 Targu Mures, Romania; (A.B.); (C.F.); (D.D.)
- Gastroenterology Department, Mures County Clinical Hospital, 540103 Targu Mures, Romania
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9
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Nyblade C, Parreno V, Zhou P, Hensley C, Oakes V, Mahsoub HM, Kiley K, Frazier M, Frazier A, Zhang Y, Feng H, Yuan L. Establishment of a gnotobiotic pig model of Clostridioides difficile infection and disease. Gut Pathog 2022; 14:22. [PMID: 35668452 PMCID: PMC9169267 DOI: 10.1186/s13099-022-00496-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/11/2022] [Indexed: 11/10/2022] Open
Abstract
AbstractClostridioides difficile (C. difficile) is a gram-positive, spore-forming, anaerobic bacterium known to be the most common cause of hospital-acquired and antibiotic-associated diarrhea. C. difficile infection rates are on the rise worldwide and treatment options are limited, indicating a clear need for novel therapeutics. Gnotobiotic piglets are an excellent model to reproduce the acute pseudomembranous colitis (PMC) caused by C. difficile due to their physiological similarities to humans and high susceptibility to infection. Here, we established a gnotobiotic pig model of C. difficile infection and disease using a hypervirulent strain. C. difficile-infected pigs displayed classic signs of C. difficile infection, including severe diarrhea and weight loss. Inoculated pigs had severe gross and microscopic intestinal lesions. C. difficile infection caused an increase in pro-inflammatory cytokines in samples of serum, large intestinal contents, and pleural effusion. C. difficile spores and toxins were detected in the feces of inoculated animals as tested by anaerobic culture and cytotoxicity assays. Successful establishment of this model is key for future work as therapeutics can be evaluated in an environment that accurately mimics what happens in humans. The model is especially suitable for evaluating potential prophylactics and therapeutics, including vaccines and passive immune strategies.
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10
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Lang GA, Norman K, Amadou Amani S, Shadid TM, Ballard JD, Lang ML. Use of a Clostridioides difficile Murine Immunization and Challenge Model to Evaluate Single and Combination Vaccine Adjuvants Consisting of Alum and NKT Cell-Activating Ligands. Front Immunol 2022; 12:818734. [PMID: 35095921 PMCID: PMC8794951 DOI: 10.3389/fimmu.2021.818734] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/27/2021] [Indexed: 01/14/2023] Open
Abstract
Adjuvant combinations may enhance or broaden the expression of immune responses to vaccine antigens. Information on whether established Alum type adjuvants can be combined with experimental CD1d ligand adjuvants is currently lacking. In this study, we used a murine Clostridioides difficile immunization and challenge model to evaluate Alum (Alhydrogel™), α-galactosylceramide (α-GC), and one of its analogs 7DW8-5 singly and in combination as vaccine adjuvants. We observed that the Alum/α-GC combination caused modest enhancement of vaccine antigen-specific IgG1 and IgG2b responses, and a broadening to include IgG2c that did not significantly impact overall protection. Similar observations were made using the Alum/7DW8-5 combination. Examination of the impact of adjuvants on NKT cells revealed expansion of invariant NKT (iNKT) cells with modest expansion of their iNKTfh subset and little effect on diverse NKT (dNKT) cells. Side effects of the adjuvants was determined and revealed transient hepatotoxicity when Alum/α-GC was used in combination but not singly. In summary these results showed that the Alum/α-GC or the Alum/7DW8-5 combination could exert distinct effects on the NKT cell compartment and on isotype switch to produce Th1-driven IgG subclasses in addition to Alum/Th2-driven subclasses. While Alum alone was efficacious in stimulating IgG-mediated protection, and α-GC offered no apparent additional benefit in the C. difficile challenge model, the work herein reveals immune response features that could be optimized and harnessed in other vaccine contexts.
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11
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Marquardt I, Jakob J, Scheibel J, Hofmann JD, Klawonn F, Neumann-Schaal M, Gerhard R, Bruder D, Jänsch L. Clostridioides difficile Toxin CDT Induces Cytotoxic Responses in Human Mucosal-Associated Invariant T (MAIT) Cells. Front Microbiol 2022; 12:752549. [PMID: 34992584 PMCID: PMC8727052 DOI: 10.3389/fmicb.2021.752549] [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: 08/03/2021] [Accepted: 11/24/2021] [Indexed: 12/31/2022] Open
Abstract
Clostridioides difficile is the major cause of antibiotic-associated colitis (CDAC) with increasing prevalence in morbidity and mortality. Severity of CDAC has been attributed to hypervirulent C. difficile strains, which in addition to toxin A and B (TcdA, TcdB) produce the binary toxin C. difficile transferase (CDT). However, the link between these toxins and host immune responses as potential drivers of immunopathology are still incompletely understood. Here, we provide first experimental evidence that C. difficile toxins efficiently activate human mucosal-associated invariant T (MAIT) cells. Among the tested toxins, CDT and more specifically, the substrate binding and pore-forming subunit CDTb provoked significant MAIT cell activation resulting in selective MAIT cell degranulation of the lytic granule components perforin and granzyme B. CDT-induced MAIT cell responses required accessory immune cells, and we suggest monocytes as a potential CDT target cell population. Within the peripheral blood mononuclear cell fraction, we found increased IL-18 levels following CDT stimulation and MAIT cell response was indeed partly dependent on this cytokine. Surprisingly, CDT-induced MAIT cell activation was found to be partially MR1-dependent, although bacterial-derived metabolite antigens were absent. However, the role of antigen presentation in this process was not analyzed here and needs to be validated in future studies. Thus, MR1-dependent induction of MAIT cell cytotoxicity might be instrumental for hypervirulent C. difficile to overcome cellular barriers and may contribute to pathophysiology of CDAC.
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Affiliation(s)
- Isabel Marquardt
- Cellular Proteomics, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Institute of Medical Microbiology and Hospital Hygiene, Infection Immunology, Health Campus Immunology, Infectiology and Inflammation, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.,Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Josefine Jakob
- Cellular Proteomics, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Institute of Medical Microbiology and Hospital Hygiene, Infection Immunology, Health Campus Immunology, Infectiology and Inflammation, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.,Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Jessica Scheibel
- Cellular Proteomics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Julia Danielle Hofmann
- Braunschweig Integrated Centre of Systems Biology (BRICS), Department of Bioinformatics and Biochemistry, Technical University Braunschweig, Braunschweig, Germany
| | - Frank Klawonn
- Cellular Proteomics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Meina Neumann-Schaal
- Braunschweig Integrated Centre of Systems Biology (BRICS), Department of Bioinformatics and Biochemistry, Technical University Braunschweig, Braunschweig, Germany.,Metabolomics, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Dunja Bruder
- Institute of Medical Microbiology and Hospital Hygiene, Infection Immunology, Health Campus Immunology, Infectiology and Inflammation, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.,Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Lothar Jänsch
- Cellular Proteomics, Helmholtz Centre for Infection Research, Braunschweig, Germany
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12
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Monaghan TM, Duggal NA, Rosati E, Griffin R, Hughes J, Roach B, Yang DY, Wang C, Wong K, Saxinger L, Pučić-Baković M, Vučković F, Klicek F, Lauc G, Tighe P, Mullish BH, Blanco JM, McDonald JAK, Marchesi JR, Xue N, Dottorini T, Acharjee A, Franke A, Li Y, Wong GKS, Polytarchou C, Yau TO, Christodoulou N, Hatziapostolou M, Wang M, Russell LA, Kao DH. A Multi-Factorial Observational Study on Sequential Fecal Microbiota Transplant in Patients with Medically Refractory Clostridioides difficile Infection. Cells 2021; 10:cells10113234. [PMID: 34831456 PMCID: PMC8624539 DOI: 10.3390/cells10113234] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 12/11/2022] Open
Abstract
Fecal microbiota transplantation (FMT) is highly effective in recurrent Clostridioides difficile infection (CDI); increasing evidence supports FMT in severe or fulminant Clostridioides difficile infection (SFCDI). However, the multifactorial mechanisms that underpin the efficacy of FMT are not fully understood. Systems biology approaches using high-throughput technologies may help with mechanistic dissection of host-microbial interactions. Here, we have undertaken a deep phenomics study on four adults receiving sequential FMT for SFCDI, in which we performed a longitudinal, integrative analysis of multiple host factors and intestinal microbiome changes. Stool samples were profiled for changes in gut microbiota and metabolites and blood samples for alterations in targeted epigenomic, metabonomic, glycomic, immune proteomic, immunophenotyping, immune functional assays, and T-cell receptor (TCR) repertoires, respectively. We characterised temporal trajectories in gut microbial and host immunometabolic data sets in three responders and one non-responder to sequential FMT. A total of 562 features were used for analysis, of which 78 features were identified, which differed between the responders and the non-responder. The observed dynamic phenotypic changes may potentially suggest immunosenescent signals in the non-responder and may help to underpin the mechanisms accompanying successful FMT, although our study is limited by a small sample size and significant heterogeneity in patient baseline characteristics. Our multi-omics integrative longitudinal analytical approach extends the knowledge regarding mechanisms of efficacy of FMT and highlights preliminary novel signatures, which should be validated in larger studies.
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Affiliation(s)
- Tanya M. Monaghan
- NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham NG7 2UH, UK
- Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham NG7 2UH, UK;
- Correspondence: (T.M.M.); (M.W.); (L.A.R.); (D.H.K.); Tel.: +115-8231090 (T.M.M.)
| | - Niharika A. Duggal
- MRC-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2TT, UK;
| | - Elisa Rosati
- Institute of Clinical Molecular Biology, Universitätsklinikum Schleswig-Holstein, Christian-Albrecht University of Kiel, 24105 Kiel, Germany; (E.R.); (A.F.)
| | - Ruth Griffin
- Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham NG7 2UH, UK;
- Synthetic Biology Research Centre, The University of Nottingham Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, UK;
| | - Jamie Hughes
- Synthetic Biology Research Centre, The University of Nottingham Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, UK;
| | - Brandi Roach
- Division of Gastroenterology, Department of Medicine, University of Alberta; Edmonton, Alberta, AB T6G 2G3, Canada; (B.R.); (D.Y.Y.); (C.W.); (K.W.)
| | - David Y. Yang
- Division of Gastroenterology, Department of Medicine, University of Alberta; Edmonton, Alberta, AB T6G 2G3, Canada; (B.R.); (D.Y.Y.); (C.W.); (K.W.)
| | - Christopher Wang
- Division of Gastroenterology, Department of Medicine, University of Alberta; Edmonton, Alberta, AB T6G 2G3, Canada; (B.R.); (D.Y.Y.); (C.W.); (K.W.)
| | - Karen Wong
- Division of Gastroenterology, Department of Medicine, University of Alberta; Edmonton, Alberta, AB T6G 2G3, Canada; (B.R.); (D.Y.Y.); (C.W.); (K.W.)
| | - Lynora Saxinger
- Division of Infectious Diseases, Department of Medicine, University of Alberta; Edmonton, Alberta, AB T6G 2G3, Canada;
| | - Maja Pučić-Baković
- Glycoscience Research Laboratory, Genos Ltd., Borongajska cesta 83H, 10000 Zagreb, Croatia; (M.P.-B.); (F.V.); (F.K.); (G.L.)
| | - Frano Vučković
- Glycoscience Research Laboratory, Genos Ltd., Borongajska cesta 83H, 10000 Zagreb, Croatia; (M.P.-B.); (F.V.); (F.K.); (G.L.)
| | - Filip Klicek
- Glycoscience Research Laboratory, Genos Ltd., Borongajska cesta 83H, 10000 Zagreb, Croatia; (M.P.-B.); (F.V.); (F.K.); (G.L.)
| | - Gordan Lauc
- Glycoscience Research Laboratory, Genos Ltd., Borongajska cesta 83H, 10000 Zagreb, Croatia; (M.P.-B.); (F.V.); (F.K.); (G.L.)
- Faculty of Pharmacy and Biochemistry, University of Zagreb, 10000 Zagreb, Croatia
| | - Paddy Tighe
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK;
| | - Benjamin H. Mullish
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK; (B.H.M.); (J.M.B.); (J.A.K.M.); (J.R.M.)
| | - Jesus Miguens Blanco
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK; (B.H.M.); (J.M.B.); (J.A.K.M.); (J.R.M.)
| | - Julie A. K. McDonald
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK; (B.H.M.); (J.M.B.); (J.A.K.M.); (J.R.M.)
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Julian R. Marchesi
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK; (B.H.M.); (J.M.B.); (J.A.K.M.); (J.R.M.)
| | - Ning Xue
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham NG7 2UH, UK; (N.X.); (T.D.)
| | - Tania Dottorini
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham NG7 2UH, UK; (N.X.); (T.D.)
| | - Animesh Acharjee
- College of Medical and Dental Sciences, Institute of Cancer and Genomic Sciences, Centre for Computational Biology, University of Birmingham, Birmingham B15 2TT, UK;
| | - Andre Franke
- Institute of Clinical Molecular Biology, Universitätsklinikum Schleswig-Holstein, Christian-Albrecht University of Kiel, 24105 Kiel, Germany; (E.R.); (A.F.)
| | - Yingrui Li
- Shenzhen Digital Life Institute, Shenzhen 518016, China;
| | - Gane Ka-Shu Wong
- Department of Biological Sciences, Department of Medicine, University of Alberta, Edmonton, AB T6G 2E1, Canada;
| | - Christos Polytarchou
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK; (C.P.); (T.O.Y.); (N.C.); (M.H.)
| | - Tung On Yau
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK; (C.P.); (T.O.Y.); (N.C.); (M.H.)
| | - Niki Christodoulou
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK; (C.P.); (T.O.Y.); (N.C.); (M.H.)
| | - Maria Hatziapostolou
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK; (C.P.); (T.O.Y.); (N.C.); (M.H.)
| | - Minkun Wang
- Shenzhen Digital Life Institute, Shenzhen 518016, China;
- Innovation Lab, Innovent Biologics, Inc., Suzhou 215011, China
- Correspondence: (T.M.M.); (M.W.); (L.A.R.); (D.H.K.); Tel.: +115-8231090 (T.M.M.)
| | - Lindsey A. Russell
- Division of Gastroenterology, Department of Medicine, McMaster University, Hamilton, ON L8N 3Z5, Canada
- Correspondence: (T.M.M.); (M.W.); (L.A.R.); (D.H.K.); Tel.: +115-8231090 (T.M.M.)
| | - Dina H. Kao
- Division of Gastroenterology, Department of Medicine, University of Alberta; Edmonton, Alberta, AB T6G 2G3, Canada; (B.R.); (D.Y.Y.); (C.W.); (K.W.)
- Correspondence: (T.M.M.); (M.W.); (L.A.R.); (D.H.K.); Tel.: +115-8231090 (T.M.M.)
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13
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High Serum Levels of Toxin A Correlate with Disease Severity in Patients with Clostridioides difficile Infection. Antibiotics (Basel) 2021; 10:antibiotics10091093. [PMID: 34572675 PMCID: PMC8470527 DOI: 10.3390/antibiotics10091093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/30/2021] [Accepted: 09/07/2021] [Indexed: 12/13/2022] Open
Abstract
Cloistridioides difficile (CD) represents a major public healthcare-associated infection causing significant morbidity and mortality. The pathogenic effects of CD are mainly caused by the release of two exotoxins into the intestine: toxin A (TcdA) and toxin B (TcdB). CD infection (CDI) can also cause toxemia, explaining the systemic complications of life-threatening cases. Currently, there is a lack of sensitive assays to detect exotoxins circulating in the blood. Here, we report a new semi-quantitative diagnostic method to measure CD toxins serum levels. The dot-blot assay was modified to separately detect TcdA and TcdB in human serum with a limit of detection at the pg/mL levels. TcdA and TcdB concentrations in the plasma of 35 CDI patients were measured at the time of CDI diagnosis and at the fourth and tenth day after CDI diagnosis and initiation of anti-CDI treatment. TcdA and TcdB levels were compared to those determined in nine healthy blood donors. Toxemia was detected in the plasma of 33 out of the 35 CDI cases. We also assessed the relationship between TcdA serum levels and CDI severity, reporting that at the time of CDI diagnosis the proportion of severe CDI cases with a TcdA serum level > 60 pg/µL was higher than in mild CDI cases (29.4% versus 66.6%, p = 0.04). In conclusion, data reported here demonstrate for the first time that toxemia is much more frequent than expected in CDI patients, and specifically that high serum levels of TcdA correlate with disease severity in patients with CDI.
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14
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Fettucciari K, Marconi P, Marchegiani A, Fruganti A, Spaterna A, Bassotti G. Invisible steps for a global endemy: molecular strategies adopted by Clostridioides difficile. Therap Adv Gastroenterol 2021; 14:17562848211032797. [PMID: 34413901 PMCID: PMC8369858 DOI: 10.1177/17562848211032797] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 06/26/2021] [Indexed: 02/06/2023] Open
Abstract
Clostridioides difficile infection (CDI) is on the rise worldwide and is associated with an increase in deaths and socio-health burden. C. difficile has become ubiquitous in anthropized environments because of the extreme resistance of its spores. Based on the epidemiological data and knowledge of molecular pathogenesis of C. difficile, it is possible to predict its progressive colonization of the human population for the following reasons: first, its global spread is unstoppable; second, the toxins (Tcds) produced by C. difficile, TcdA and TcdB, mainly cause cell death by apoptosis, but the surviving cells acquire a senescence state that favours persistence of C. difficile in the intestine; third, proinflammatory cytokines, tumour necrosis factor-α and interferon-γ, induced during CDI, enhance the cytotoxicity of Tcds and can increase the survival of senescent cells; fourth, Tcds block mobility and induce apoptosis in immune cells recruited at the infection site; and finally, after remission from primary infection or relapse, C. difficile causes functional abnormalities in the enteric glial cell (EGC) network that can result in irritable bowel syndrome, characterized by a latent inflammatory response that contributes to C. difficile survival and enhances the cytotoxic activity of low doses of TcdB, thus favouring further relapses. Since a 'global endemy' of C. difficile seems inevitable, it is necessary to develop an effective vaccine against Tcds for at-risk individuals, and to perform a prophylaxis/selective therapy with bacteriophages highly specific for C. difficile. We must be aware that CDI will become a global health problem in the forthcoming years, and we must be prepared to face this menace.
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Affiliation(s)
- Katia Fettucciari
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, Medical School -Piazza Lucio Severi 1, Edificio B - IV piano; Sant’Andrea delle Fratte, Perugia, 06132, Italy
| | - Pierfrancesco Marconi
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Andrea Marchegiani
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Andrea Spaterna
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
- Gastroenterology & Hepatology Unit, Santa Maria della Misericordia Hospital, Perugia, Italy
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15
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Chen K, Zhu Y, Zhang Y, Hamza T, Yu H, Saint Fleur A, Galen J, Yang Z, Feng H. A probiotic yeast-based immunotherapy against Clostridioides difficile infection. Sci Transl Med 2021; 12:12/567/eaax4905. [PMID: 33115949 DOI: 10.1126/scitranslmed.aax4905] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 02/12/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022]
Abstract
Antibiotic-resistant Clostridioides difficile is an anaerobic Gram-positive bacterium that colonizes the colon and is responsible for more than 29,000 deaths in the United States each year. Hence, C. difficile infection (CDI) poses an urgent threat to public health. Antibody-mediated neutralization of TcdA and TcdB toxins, the major virulence factors of CDI, represents an effective strategy to combat the disease without invoking antibiotic resistance. However, current antitoxin approaches are mostly based on parenteral infusion of monoclonal antibodies that are costly, narrow spectrum, and not optimized against the intestinal disease. Here, we engineered probiotic Saccharomyces boulardii to constitutively secrete a single tetra-specific antibody that potently and broadly neutralized both toxins and demonstrated protection against primary and recurrent CDI in both prophylactic and therapeutic mouse models of disease. This yeast immunotherapy is orally administered, can be used concurrently with antibiotics, and may have potential as a prophylactic against CDI risk and as a therapeutic for patients with CDI.
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Affiliation(s)
- Kevin Chen
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Yixuan Zhu
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yongrong Zhang
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Therwa Hamza
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Hua Yu
- FZata Inc., Halethorpe, MD 21227, USA
| | - Ashley Saint Fleur
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - James Galen
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201, USA.
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16
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Fettucciari K, Fruganti A, Marchegiani A, Brancorsini S, Marconi P, Bassotti G. Proinflammatory Cytokines: Possible Accomplices for the Systemic Effects of Clostridioides difficile Toxin B. J Inflamm Res 2021; 14:57-62. [PMID: 33469335 PMCID: PMC7810702 DOI: 10.2147/jir.s287096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/01/2020] [Indexed: 12/13/2022] Open
Abstract
Clostridioides difficile infection (CDI) has a serious impact on the healthcare system, and most of its pathogenic effects are mainly due to the activity of toxins A and B (TcdA and TcdB, respectively). The molecular mechanisms of their cytotoxic activity are well known, especially in the colon, where the infection occurs and normally remains localized. However, the mechanisms causing toxic effects on various systemic organs (extraintestinal manifestations) with frequent lethal outcomes in some patients affected by CDI are still poorly understood. Few studies are available that demonstrate low serum levels of Tcds in both experimental animal models and patients with CDI. Until now, it has remained unclear how low levels of circulating Tcds could lead to serious toxic effects. On the basis of our previous in vitro studies, in which the proinflammatory cytokines TNF-alpha and IFN-gamma strongly potentiated the toxic activity of low doses of TcdB, we hypothesize that the presence of both TcdB in the circulation and a systemic proinflammatory cytokine storm may be responsible for the selective severe effects of TcdB in some patients. This may occur in patients with severe CDI and systemic Tcds, in whom proinflammatory cytokines such as TNF-alpha and IFN-gamma reach a significant concentration in the circulation. This hypothesis could identify therapeutic interventions based on the reduction or neutralization of the indirect toxic action of these cytokines.
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Affiliation(s)
- Katia Fettucciari
- Department of Experimental Medicine, University of Perugia Medical School, Perugia, Italy
- Correspondence: Katia Fettucciari Department of Experimental Medicine, University of Perugia Medical School, Piazza Lucio Severi 1, Edificio B IV Piano, Sant’Andrea delle Fratte, Perugia06132, ItalyTel +39755858124 Email
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Andrea Marchegiani
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Stefano Brancorsini
- Department of Experimental Medicine, University of Perugia Medical School, Perugia, Italy
| | - Pierfrancesco Marconi
- Department of Experimental Medicine, University of Perugia Medical School, Perugia, Italy
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine, University of Perugia Medical School, Perugia, Italy
- Gastroenterology & Hepatology Unit, Santa Maria della Misericordia Hospital, Perugia, Italy
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17
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Danz HR, Lee S, Chapman-Bonofiglio SP, Ginese M, Beamer G, Girouard DJ, Tzipori S. The Impact of Actotoxumab Treatment of Gnotobiotic Piglets Infected With Different Clostridium difficile Isogenic Mutants. J Infect Dis 2020; 221:276-284. [PMID: 31495879 DOI: 10.1093/infdis/jiz459] [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: 05/17/2019] [Accepted: 09/06/2019] [Indexed: 11/14/2022] Open
Abstract
Nosocomial infections with Clostridium difficile are on the rise in the Unites States, attributed to emergence of antibiotic-resistant and hypervirulent strains associated with greater likelihood of recurrent infections. In addition to antibiotics, treatment with Merck anti-toxin B (TcdB) antibody bezlotoxumab is reported to reduce recurrent infections. However, treatment with anti-toxin A (TcdA) antibody actotoxumab was associated with dramatically increased disease severity and mortality rates in humans and gnotobiotic piglets. Using isogenic mutants of C. difficile strain NAPI/BI/027 deficient in TcdA (A-B+) or TcdB (A+B-), and the wild type, we investigated how and why treatment of infected animals with anti-TcdA dramatically increased disease severity. Contrary to the hypothesis, among piglets treated with anti-TcdA, those with A+B- infection were disease free, in contrast to the disease enhancement seen in those with wild-type or A-B+ infection. It seems that the lack of TcdA, through either deletion or neutralization with anti-TcdA, reduces a competitive pressure, allowing TcdB to freely exert its profound effect, leading to increased mucosal injury and disease severity.
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Affiliation(s)
- Hillary R Danz
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
| | - Sangun Lee
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
| | - Susan P Chapman-Bonofiglio
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
| | - Melanie Ginese
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
| | - Gillian Beamer
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
| | - Donald J Girouard
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
| | - Saul Tzipori
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
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18
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Shah HB, Smith K, Scott EJ, Larabee JL, James JA, Ballard JD, Lang ML. Human C. difficile toxin-specific memory B cell repertoires encode poorly neutralizing antibodies. JCI Insight 2020; 5:138137. [PMID: 32663199 PMCID: PMC7455132 DOI: 10.1172/jci.insight.138137] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/08/2020] [Indexed: 12/18/2022] Open
Abstract
Clostridioides difficile is a leading cause of nosocomial infection responsible for significant morbidity and mortality with limited options for therapy. Secreted C. difficile toxin B (TcdB) is a major contributor to disease pathology, and select TcdB-specific Abs may protect against disease recurrence. However, the high frequency of recurrence suggests that the memory B cell response, essential for new Ab production following C. difficile reexposure, is insufficient. We therefore isolated TcdB-specific memory B cells from individuals with a history of C. difficile infection and performed single-cell deep sequencing of their Ab genes. Herein, we report that TcdB-specific memory B cell–encoded antibodies showed somatic hypermutation but displayed limited isotype class switch. Memory B cell–encoded mAb generated from the gene sequences revealed low to moderate affinity for TcdB and a limited ability to neutralize TcdB. These findings indicate that memory B cells are an important factor in C. difficile disease recurrence. The C. difficile toxin-specific human memory B cell repertoire encodes low-affinity, non-neutralizing antibodies.
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Affiliation(s)
- Hemangi B Shah
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center (OUHSC)
| | - Kenneth Smith
- Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, and
| | - Edgar J Scott
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center (OUHSC)
| | - Jason L Larabee
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center (OUHSC)
| | - Judith A James
- Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, and.,Departments of Medicine and Pathology, OUHSC, University of Oklahoma, Oklahoma City, Oklahoma, USA
| | - Jimmy D Ballard
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center (OUHSC)
| | - Mark L Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center (OUHSC)
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19
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Engevik MA, Danhof HA, Chang-Graham AL, Spinler JK, Engevik KA, Herrmann B, Endres BT, Garey KW, Hyser JM, Britton RA, Versalovic J. Human intestinal enteroids as a model of Clostridioides difficile-induced enteritis. Am J Physiol Gastrointest Liver Physiol 2020; 318:G870-G888. [PMID: 32223302 PMCID: PMC7272722 DOI: 10.1152/ajpgi.00045.2020] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Clostridioides difficile is an important nosocomial pathogen that produces toxins to cause life-threatening diarrhea and colitis. Toxins bind to epithelial receptors and promote the collapse of the actin cytoskeleton. C. difficile toxin activity is commonly studied in cancer-derived and immortalized cell lines. However, the biological relevance of these models is limited. Moreover, no model is available for examining C. difficile-induced enteritis, an understudied health problem. We hypothesized that human intestinal enteroids (HIEs) express toxin receptors and provide a new model to dissect C. difficile cytotoxicity in the small intestine. We generated biopsy-derived jejunal HIE and Vero cells, which stably express LifeAct-Ruby, a fluorescent label of F-actin, to monitor actin cytoskeleton rearrangement by live-cell microscopy. Imaging analysis revealed that toxins from pathogenic C. difficile strains elicited cell rounding in a strain-dependent manner, and HIEs were tenfold more sensitive to toxin A (TcdA) than toxin B (TcdB). By quantitative PCR, we paradoxically found that HIEs expressed greater quantities of toxin receptor mRNA and yet exhibited decreased sensitivity to toxins when compared with traditionally used cell lines. We reasoned that these differences may be explained by components, such as mucins, that are present in HIEs cultures, that are absent in immortalized cell lines. Addition of human-derived mucin 2 (MUC2) to Vero cells delayed cell rounding, indicating that mucus serves as a barrier to toxin-receptor binding. This work highlights that investigation of C. difficile infection in that HIEs can provide important insights into the intricate interactions between toxins and the human intestinal epithelium.NEW & NOTEWORTHY In this article, we developed a novel model of Clostridioides difficile-induced enteritis using jejunal-derived human intestinal enteroids (HIEs) transduced with fluorescently tagged F-actin. Using live-imaging, we identified that jejunal HIEs express high levels of TcdA and CDT receptors, are more sensitive to TcdA than TcdB, and secrete mucus, which delays toxin-epithelial interactions. This work also optimizes optically clear C. difficile-conditioned media suitable for live-cell imaging.
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Affiliation(s)
- Melinda A. Engevik
- 1Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas,2Department of Pathology, Texas Children’s Hospital, Houston, Texas
| | - Heather A. Danhof
- 3Alkek Center for Metagenomic and Microbiome Research, Baylor College of Medicine, Houston, Texas,4Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | | | - Jennifer K. Spinler
- 1Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas,2Department of Pathology, Texas Children’s Hospital, Houston, Texas
| | - Kristen A. Engevik
- 3Alkek Center for Metagenomic and Microbiome Research, Baylor College of Medicine, Houston, Texas,4Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Beatrice Herrmann
- 1Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas,2Department of Pathology, Texas Children’s Hospital, Houston, Texas
| | - Bradley T. Endres
- 5Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas
| | - Kevin W. Garey
- 5Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas
| | - Joseph M. Hyser
- 1Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas,2Department of Pathology, Texas Children’s Hospital, Houston, Texas
| | - Robert A. Britton
- 3Alkek Center for Metagenomic and Microbiome Research, Baylor College of Medicine, Houston, Texas,4Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - James Versalovic
- 1Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas,2Department of Pathology, Texas Children’s Hospital, Houston, Texas
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20
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di Masi A, Leboffe L, Polticelli F, Tonon F, Zennaro C, Caterino M, Stano P, Fischer S, Hägele M, Müller M, Kleger A, Papatheodorou P, Nocca G, Arcovito A, Gori A, Ruoppolo M, Barth H, Petrosillo N, Ascenzi P, Di Bella S. Human Serum Albumin Is an Essential Component of the Host Defense Mechanism Against Clostridium difficile Intoxication. J Infect Dis 2019; 218:1424-1435. [PMID: 29868851 DOI: 10.1093/infdis/jiy338] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 06/01/2018] [Indexed: 01/05/2023] Open
Abstract
Background The pathogenic effects of Clostridium difficile are primarily attributable to the production of the large protein toxins (C difficile toxins [Tcd]) A (TcdA) and B (TcdB). These toxins monoglucosylate Rho GTPases in the cytosol of host cells, causing destruction of the actin cytoskeleton with cytotoxic effects. Low human serum albumin (HSA) levels indicate a higher risk of acquiring and developing a severe C difficile infection (CDI) and are associated with recurrent and fatal disease. Methods We used a combined approach based on docking simulation and biochemical analyses that were performed in vitro on purified proteins and in human epithelial colorectal adenocarcinoma cells (Caco-2), and in vivo on stem cell-derived human intestinal organoids and zebrafish embryos. Results Our results show that HSA specifically binds via its domain II to TcdA and TcdB and thereby induces their autoproteolytic cleavage at physiological concentrations. This process impairs toxin internalization into the host cells and reduces the toxin-dependent glucosylation of Rho proteins. Conclusions Our data provide evidence for a specific HSA-dependent self-defense mechanism against C difficile toxins and provide an explanation for the clinical correlation between CDI severity and hypoalbuminemia.
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Affiliation(s)
| | - Loris Leboffe
- Department of Sciences, Roma Tre University, Roma, Italy
| | - Fabio Polticelli
- Department of Sciences, Roma Tre University, Roma, Italy.,National Institute of Nuclear Physics, Roma Tre Section, Roma, Italy
| | - Federica Tonon
- Department of Medical, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Cristina Zennaro
- Department of Medical, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Marianna Caterino
- Department of Molecular Medicine and Medical Biotechnology, University of Napoli "Federico II", Napoli, Italy.,Associazione Culturale DiSciMuS RCF, Casoria, Napoli, Italy
| | - Pasquale Stano
- Department of Sciences, Roma Tre University, Roma, Italy
| | - Stephan Fischer
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Marlen Hägele
- Department of Internal Medicine I, University of Ulm Medical Center, Germany
| | - Martin Müller
- Department of Internal Medicine I, University of Ulm Medical Center, Germany
| | - Alexander Kleger
- Department of Internal Medicine I, University of Ulm Medical Center, Germany
| | - Panagiotis Papatheodorou
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany.,Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
| | - Giuseppina Nocca
- Institute of Biochemistry and Clinical Biochemistry, Catholic University of Sacred Heart, Roma, Italy.,Institute of Chemistry of Molecular Recognition, CNR, Roma, Italy
| | - Alessandro Arcovito
- Institute of Biochemistry and Clinical Biochemistry, Catholic University of Sacred Heart, Roma, Italy
| | - Andrea Gori
- Clinic of Infectious Diseases, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy
| | - Margherita Ruoppolo
- Department of Molecular Medicine and Medical Biotechnology, University of Napoli "Federico II", Napoli, Italy.,Associazione Culturale DiSciMuS RCF, Casoria, Napoli, Italy.,CEINGE Biotecnologie Avanzate, Napoli, Italy
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Nicola Petrosillo
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Roma, Italy
| | - Paolo Ascenzi
- Department of Sciences, Roma Tre University, Roma, Italy
| | - Stefano Di Bella
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Roma, Italy
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21
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Armstrong AR, Wünschmann A, Rigatti LH, Klein EC. Clostridium difficile Enterocolitis in a Captive Geoffroy's Spider Monkey ( Ateles geoffroyi) and Common Marmosets ( Callithrix jacchus). Vet Pathol 2019; 56:959-963. [PMID: 31382854 DOI: 10.1177/0300985819864307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Clostridium difficile is a well-documented cause of enterocolitis in several species, including humans, with limited documentation in New World nonhuman primates. We report several cases of C. difficile-associated pseudomembranous enterocolitis, including a case in a Geoffroy's spider monkey (Ateles geoffroyi) and several cases in common marmosets (Callithrix jacchus). The histologic lesions included a spectrum of severity, with most cases characterized by the classic "volcano" lesions described in humans and several other animal species. C. difficile was isolated from the colon of the spider monkey, while the presence of toxin A or toxin B or of the genes of toxin A or B by polymerase chain reaction served as corroborative evidence in several affected marmosets. C. difficile should be considered a cause of enterocolitis in these species.
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Affiliation(s)
| | - Arno Wünschmann
- Department of Population Medicine, University of Minnesota, St. Paul, MN, USA
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22
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The Antibiotic Bacitracin Protects Human Intestinal Epithelial Cells and Stem Cell-Derived Intestinal Organoids from Clostridium difficile Toxin TcdB. Stem Cells Int 2019; 2019:4149762. [PMID: 31467562 PMCID: PMC6701344 DOI: 10.1155/2019/4149762] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 06/11/2019] [Indexed: 01/05/2023] Open
Abstract
Bacitracin is an established antibiotic for local application and inhibits the cell wall synthesis of Gram-positive bacteria. Recently, we discovered a completely different mode of action of bacitracin and reported that this drug protects human cells from intoxication by a variety of medically relevant bacterial protein toxins including CDT, the binary actin ADP-ribosylating toxin of Clostridium (C.) difficile. Bacitracin prevents the transport of CDT into the cytosol of target cells, most likely by inhibiting the transport function of the binding subunit of this toxin. Here, we tested the effect of bacitracin towards TcdB, a major virulence factor of C. difficile contributing to severe C. difficile-associated diseases (CDAD) including pseudomembranous colitis. Bacitracin protected stem cell-derived human intestinal organoids as well as human gut epithelial cells from intoxication with TcdB. Moreover, it prevented the TcdB-induced disruption of epithelia formed by gut epithelium cells in vitro and maintained the barrier function as detected by measuring transepithelial electrical resistance (TEER). In the presence of bacitracin, TcdB was not able reach its substrate Rac1 in the cytosol of human epithelial cells, most likely because its pH-dependent transport across cell membranes into the cytosol is decreased by bacitracin. In conclusion, in addition to its direct antibiotic activity against C. difficile and its inhibitory effect towards the toxin CDT, bacitracin neutralizes the exotoxin TcdB of this important pathogenic bacterium.
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23
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Cimolai N. Are Clostridium difficile toxins nephrotoxic? Med Hypotheses 2019; 126:4-8. [PMID: 31010497 DOI: 10.1016/j.mehy.2019.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 03/04/2019] [Indexed: 12/19/2022]
Abstract
Clostridium difficile-associated disease (CDAD) occurs along a spectrum from simple uncomplicated enteritis to a multi-system disease which may include nephropathy. Pathology is attributed to bacterial toxins, but it is unclear if the latter are directly nephrotoxic. Anecdotes of renal disease from human biopsy findings suggest a variation of histopathologies, but data are relatively limited. Acute renal failure does occur in patients with advanced morbidity. CDAD can complicate chronic renal failure. Kidney tissue culture cytotoxicity has long been known. Kidney function alterations among animal models or diseased humans are relatively uncommon in mild to moderate enteritis. Rare findings of toxinemia are reported. Some have proposed that renal dysfunction arises more from pre-renal compromises. Direct toxin studies on whole kidney are sparse. The role of direct toxin-associated renal disease is worthy of further investigation given the current impetus towards the development of protective and therapeutic passive and active immunity. Hypotheses of toxin-direct or pre-renal toxin compromise of renal function prevail.
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Affiliation(s)
- Nevio Cimolai
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, The University of British Columbia, Canada; Department of Pathology and Laboratory Medicine, Children's and Women's Health Centre of British Columbia, 4480 Oak Street, Vancouver, B.C. V6H3V4, Canada.
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24
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Clostridium difficile toxins induce VEGF-A and vascular permeability to promote disease pathogenesis. Nat Microbiol 2018; 4:269-279. [PMID: 30510170 DOI: 10.1038/s41564-018-0300-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Accepted: 10/22/2018] [Indexed: 01/15/2023]
Abstract
Clostridium difficile infection (CDI) is mediated by two major exotoxins, toxin A (TcdA) and toxin B (TcdB), that damage the colonic epithelial barrier and induce inflammatory responses. The function of the colonic vascular barrier during CDI has been relatively understudied. Here we report increased colonic vascular permeability in CDI mice and elevated vascular endothelial growth factor A (VEGF-A), which was induced in vivo by infection with TcdA- and/or TcdB-producing C. difficile strains but not with a TcdA-TcdB- isogenic mutant. TcdA or TcdB also induced the expression of VEGF-A in human colonic mucosal biopsies. Hypoxia-inducible factor signalling appeared to mediate toxin-induced VEGF production in colonocytes, which can further stimulate human intestinal microvascular endothelial cells. Both neutralization of VEGF-A and inhibition of its signalling pathway attenuated CDI in vivo. Compared to healthy controls, CDI patients had significantly higher serum VEGF-A that subsequently decreased after treatment. Our findings indicate critical roles for toxin-induced VEGF-A and colonic vascular permeability in CDI pathogenesis and may also point to the pathophysiological significance of the gut vascular barrier in response to virulence factors of enteric pathogens. As an alternative to pathogen-targeted therapy, this study may enable new host-directed therapeutic approaches for severe, refractory CDI.
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25
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Koya SK, Brusatori M, Martin JV, Yurgelevic S, Huang C, Liberati DM, Auner GW, Diebel LN. Rapid Detection of Clostridium difficile Toxins in Serum by Raman Spectroscopy. J Surg Res 2018; 232:195-201. [DOI: 10.1016/j.jss.2018.06.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/05/2018] [Accepted: 06/08/2018] [Indexed: 02/04/2023]
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26
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TPL2 Is a Key Regulator of Intestinal Inflammation in Clostridium difficile Infection. Infect Immun 2018; 86:IAI.00095-18. [PMID: 29844241 DOI: 10.1128/iai.00095-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/21/2018] [Indexed: 02/06/2023] Open
Abstract
Tumor progression locus 2 (TPL2), a serine/threonine protein kinase, is a major inflammatory mediator in immune cells. The predominant inflammatory actions of TPL2 depend on the activation of mitogen-activated protein kinases (MAPK) and the upregulated production of the cytokines tumor necrosis factor alpha (TNF-α) and interleukin 1β (IL-1β) in macrophages and dendritic cells in response to lipopolysaccharide (LPS). Significant increases in TNF-α, IL-6, IL-β, and IL-8 levels in patients with Clostridium difficile infection (CDI) have been reported. Both TNF-α and IL-6 have been postulated to play key roles in the systemic inflammatory response in CDI, and IL-8 is essential for the development of local intestinal inflammatory responses in CDI. The objective of this study was to elucidate the role of TPL2 in the pathogenesis of CDI. We found that TPL2 was significantly activated in human and mouse intestinal tissues upon C. difficile toxin exposure or CDI. We further demonstrated that TPL2 knockout (TPL2-KO) mice were significantly more resistant to CDI than wild-type mice, with significantly reduced production of TNF-α, IL-6, IL-1β, KC (a mouse homologue of IL-8), and myeloperoxidase (MPO) in the ceca and colons of TPL2-KO mice. Finally, we found that TPL2 inhibition by a specific inhibitor or TPL2 gene ablation significantly reduced TcdB-induced production of TNF-α, IL-6, IL-β, and KC by inhibiting the activation of p38, extracellular signal-regulated kinase (ERK), and c-Jun NH2-terminal kinase (JNK). Taken together, our data suggest that TPL2 represents a potential therapeutic target for CDI treatment.
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27
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Liu YH, Chang YC, Chen LK, Su PA, Ko WC, Tsai YS, Chen YH, Lai HC, Wu CY, Hung YP, Tsai PJ. The ATP-P2X 7 Signaling Axis Is an Essential Sentinel for Intracellular Clostridium difficile Pathogen-Induced Inflammasome Activation. Front Cell Infect Microbiol 2018; 8:84. [PMID: 29616195 PMCID: PMC5864904 DOI: 10.3389/fcimb.2018.00084] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/28/2018] [Indexed: 12/12/2022] Open
Abstract
Clostridium difficile infection (CDI) is the leading cause of nosocomial infection in hospitalized patients receiving long-term antibiotic treatment. An excessive host inflammatory response is believed to be the major mechanism underlying the pathogenesis of C. difficile infection, and various proinflammatory cytokines such as IL-1β are detected in patients with C. difficile infection. IL-1β is known to be processed by caspase-1, a cysteine protease that is regulated by a protein complex called the inflammasome, which leads to a specialized form of cell death called pyroptosis. The function of inflammasome activation-induced pyroptosis is to clear or limit the spread of invading pathogens via infiltrated neutrophils. Here, we focused on inflammasome activation induced by intact C. difficile to re-evaluate the nature of inflammasome activation in CDI pathogenesis, which could provide information that leads to an alternative therapeutic strategy for the treatment of this condition in humans. First, we found that caspase-1-dependent IL-1β production was induced by C. difficile pathogens in macrophages and increased in a time-dependent manner. Moreover, intracellular toxigenic C. difficile was essential for ATP-P2X7 pathway of inflammasome activation and subsequent caspase-1-dependent pyroptotic cell death, leading to the loss of membrane integrity and release of intracellular contents such as LDH. Notably, we also observed that bacterial components such as surface layer proteins (SLPs) were released from pyroptotic cells. In addition, pro-IL-1β production was completely MyD88 and partially TLR2 dependent. Finally, to investigate the role of the caspase-1-dependent inflammasome in host defense, we found that colonic inflammasome activation was also induced by CDI and that caspase-1 inhibition by Ac-YVAD-CMK led to increased disease progression and C. difficile load. Taken together, the present results suggest that MyD88 and TLR2 are critical component in pro-IL-1β production and intracellular C. difficile following the ATP-P2X7 pathway of inflammasome activation and pyroptosis, which play important roles in host defense through the utilization of inflammation-mediated bacterial clearance mechanisms during C. difficile infection.
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Affiliation(s)
- Ya-Hui Liu
- Department of Medical Laboratory Science and Biotechnology, Medical College, National Cheng Kung University, Tainan, Taiwan.,Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Yung-Chi Chang
- Department of Medical Laboratory Science and Biotechnology, Medical College, National Cheng Kung University, Tainan, Taiwan
| | - Liang-Kuei Chen
- Department of Medical Laboratory Science and Biotechnology, Medical College, National Cheng Kung University, Tainan, Taiwan
| | - Po-An Su
- Division of Infectious Diseases, Chi Mei Medical Center, Tainan, Taiwan.,Department of Pharmacy, Chia Nan University of Pharmacy and Science, Tainan, Taiwan
| | - Wen-Chien Ko
- Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.,Center for Infection Control, National Cheng Kung University Hospital, Tainan, Taiwan.,Department of Medicine, Medical College, National Cheng Kung University, Tainan, Taiwan
| | - Yau-Sheng Tsai
- Institute of Clinical Medicine, Medical College, National Cheng Kung University, Tainan, Taiwan.,Cardiovascular Research Center, Medical College, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Hsuan Chen
- Department of Medical Laboratory Science and Biotechnology, Medical College, National Cheng Kung University, Tainan, Taiwan
| | - Hsin-Chih Lai
- Department of Medical Laboratory Science and Biotechnology, Chang Gung University, Taoyaun, Taiwan.,Research Center for Industry of Human Ecology, College of Human Ecology, Chang Gung University of Science and Technology, Taoyaun, Taiwan.,Graduate Institute of Health Industry and Technology, College of Human Ecology, Chang Gung University of Science and Technology, Taoyaun, Taiwan
| | - Cheng-Yeu Wu
- Center for Molecular and Clinical Immunology, Chang Gung University, Taoyaun, Taiwan.,Research Center of Bacterial Pathogenesis, Chang Gung University, Taoyaun, Taiwan
| | - Yuan-Pin Hung
- Department of Internal Medicine, Tainan Hospital, Ministry of Health and Welfare, Tainan, Taiwan
| | - Pei-Jane Tsai
- Department of Medical Laboratory Science and Biotechnology, Medical College, National Cheng Kung University, Tainan, Taiwan.,Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan.,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
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28
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Zhou F, Hamza T, Fleur AS, Zhang Y, Yu H, Chen K, Heath JE, Chen Y, Huang H, Feng H. Mice with Inflammatory Bowel Disease are Susceptible to Clostridium difficile Infection With Severe Disease Outcomes. Inflamm Bowel Dis 2018; 24:573-582. [PMID: 29462386 PMCID: PMC5936643 DOI: 10.1093/ibd/izx059] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Indexed: 01/05/2023]
Abstract
Background Over the past several decades, there has been a significant increase in the incidence of Clostridium difficile infection (CDI) in patients suffering from inflammatory bowel disease (IBD). However, a wild-type animal model is not available to study these comorbid diseases. Methods We evaluated the susceptibility to CDI of mice with dextran sulfate sodium salt (DSS)-induced colitis (IBD mice) with or without antibiotic exposure; we examined the histopathology and cytokine response in the concomitant diseases after the model was created. Results No CDI occurs in healthy control mice, wherease the incidence of CDI in IBD mice is 40%; however, in IBD mice that received antibiotics, the incidence of CDI is 100% and the disease is accompanied by high levels of toxins in the mouse feces and sera. Compared to IBD and CDI alone, those IBD mice infected with C. difficile have more severe symptoms, toxemia, histopathological damage, and higher mortality. Moreover, several proinflammatory cytokines and chemokines are significantly elevated in the colon tissues from IBD mice infected with C. difficile. Conclusions We, for the first time, demonstrate in an animal model that mice with dextran sulfate sodium induced-inflammatory bowel disease are significantly more susceptible to C. difficile infection, and that the bacterial infection led to more severe disease and death. These findings are consistent with clinical observations, thus, the animal model will permit us to study the pathogenesis of these concurrent diseases and to develop therapeutic strategies against the comorbidity of IBD and CDI.
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Affiliation(s)
- Fenfen Zhou
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Therwa Hamza
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Ashley S Fleur
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Yongrong Zhang
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Hua Yu
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Kevin Chen
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Jonathon E Heath
- Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ye Chen
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Haihui Huang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, USA
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29
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Hutton ML, Cunningham BA, Mackin KE, Lyon SA, James ML, Rood JI, Lyras D. Bovine antibodies targeting primary and recurrent Clostridium difficile disease are a potent antibiotic alternative. Sci Rep 2017. [PMID: 28623367 PMCID: PMC5473923 DOI: 10.1038/s41598-017-03982-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The increased incidence of antibiotic resistant 'superbugs' has amplified the use of broad spectrum antibiotics worldwide. An unintended consequence of antimicrobial treatment is disruption of the gastrointestinal microbiota, resulting in susceptibility to opportunistic pathogens, such as Clostridium difficile. Paradoxically, treatment of C. difficile infections (CDI) also involves antibiotic use, leaving patients susceptible to re-infection. This serious health threat has led to an urgent call for the development of new therapeutics to reduce or replace the use of antibiotics to treat bacterial infections. To address this need, we have developed colostrum-derived antibodies for the prevention and treatment of CDI. Pregnant cows were immunised to generate hyperimmune bovine colostrum (HBC) containing antibodies that target essential C. difficile virulence components, specifically, spores, vegetative cells and toxin B (TcdB). Mouse infection and relapse models were used to compare the capacity of HBC to prevent or treat primary CDI as well as prevent recurrence. Administration of TcdB-specific colostrum alone, or in combination with spore or vegetative cell-targeted colostrum, prevents and treats C. difficile disease in mice and reduces disease recurrence by 67%. C. difficile-specific colostrum should be re-considered as an immunotherapeutic for the prevention or treatment of primary or recurrent CDI.
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Affiliation(s)
- Melanie L Hutton
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Bliss A Cunningham
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Kate E Mackin
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Shelley A Lyon
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Meagan L James
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Julian I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia.
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30
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Fettucciari K, Ponsini P, Gioè D, Macchioni L, Palumbo C, Antonelli E, Coaccioli S, Villanacci V, Corazzi L, Marconi P, Bassotti G. Enteric glial cells are susceptible to Clostridium difficile toxin B. Cell Mol Life Sci 2017; 74:1527-1551. [PMID: 27891552 PMCID: PMC11107567 DOI: 10.1007/s00018-016-2426-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 10/27/2016] [Accepted: 11/21/2016] [Indexed: 02/06/2023]
Abstract
Clostridium difficile causes nosocomial/antibiotic-associated diarrhoea and pseudomembranous colitis. The major virulence factors are toxin A and toxin B (TcdB), which inactivate GTPases by monoglucosylation, leading to cytopathic (cytoskeleton alteration, cell rounding) and cytotoxic effects (cell-cycle arrest, apoptosis). C. difficile toxins breaching the intestinal epithelial barrier can act on underlying cells, enterocytes, colonocytes, and enteric neurons, as described in vitro and in vivo, but until now no data have been available on enteric glial cell (EGC) susceptibility. EGCs are crucial for regulating the enteric nervous system, gut homeostasis, the immune and inflammatory responses, and digestive and extradigestive diseases. Therefore, we evaluated the effects of C. difficile TcdB in EGCs. Rat-transformed EGCs were treated with TcdB at 0.1-10 ng/ml for 1.5-48 h, and several parameters were analysed. TcdB induces the following in EGCs: (1) early cell rounding with Rac1 glucosylation; (2) early G2/M cell-cycle arrest by cyclin B1/Cdc2 complex inactivation caused by p27 upregulation, the downregulation of cyclin B1 and Cdc2 phosphorylated at Thr161 and Tyr15; and (3) apoptosis by a caspase-dependent but mitochondria-independent pathway. Most importantly, the stimulation of EGCs with TNF-α plus IFN-γ before, concomitantly or after TcdB treatment strongly increased TcdB-induced apoptosis. Furthermore, EGCs that survived the cytotoxic effect of TcdB did not recover completely and showed not only persistent Rac1 glucosylation, cell-cycle arrest and low apoptosis but also increased production of glial cell-derived neurotrophic factor, suggesting self-rescuing mechanisms. In conclusion, the high susceptibility of EGCs to TcdB in vitro, the increased sensitivity to inflammatory cytokines related to apoptosis and the persistence of altered functions in surviving cells suggest an important in vivo role of EGCs in the pathogenesis of C. difficile infection.
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Affiliation(s)
- Katia Fettucciari
- Department of Experimental Medicine, Histology and Medical Embryology Section, Perugia University, Piazza Lucio Severi 1, Edificio B IV piano, Sant'Andrea delle Fratte, 06132, Perugia, Italy.
| | - Pamela Ponsini
- Department of Experimental Medicine, Histology and Medical Embryology Section, Perugia University, Piazza Lucio Severi 1, Edificio B IV piano, Sant'Andrea delle Fratte, 06132, Perugia, Italy
| | - Davide Gioè
- Department of Experimental Medicine, Histology and Medical Embryology Section, Perugia University, Piazza Lucio Severi 1, Edificio B IV piano, Sant'Andrea delle Fratte, 06132, Perugia, Italy
| | - Lara Macchioni
- Department of Experimental Medicine, Physiology and Biochemistry Section, Perugia University, Perugia, Italy
| | - Camilla Palumbo
- Department of Clinical Sciences and Translational Medicine, Tor Vergata University, Rome, Italy
| | | | - Stefano Coaccioli
- Department of Medicine, Internal Medicine, Rheumatology and Medical Therapy of Pain Section, Perugia University, District of Terni, Perugia, Italy
| | | | - Lanfranco Corazzi
- Department of Experimental Medicine, Physiology and Biochemistry Section, Perugia University, Perugia, Italy
| | - Pierfrancesco Marconi
- Department of Experimental Medicine, Histology and Medical Embryology Section, Perugia University, Piazza Lucio Severi 1, Edificio B IV piano, Sant'Andrea delle Fratte, 06132, Perugia, Italy
| | - Gabrio Bassotti
- Department of Medicine, Gastroenterology, Hepatology and Digestive Endoscopy Section, Perugia University, Perugia, Italy
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Mehta KK, Paskaleva EE, Wu X, Grover N, Mundra RV, Chen K, Zhang Y, Yang Z, Feng H, Dordick JS, Kane RS. Newly identified bacteriolytic enzymes that target a wide range of clinical isolates of Clostridium difficile. Biotechnol Bioeng 2016; 113:2568-2576. [PMID: 27260850 PMCID: PMC5367918 DOI: 10.1002/bit.26029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/23/2016] [Accepted: 05/29/2016] [Indexed: 12/18/2022]
Abstract
Clostridium difficile has emerged as a major cause of infectious diarrhea in hospitalized patients, with increasing mortality rate and annual healthcare costs exceeding $3 billion. Since C. difficile infections are associated with the use of antibiotics, there is an urgent need to develop treatments that can inactivate the bacterium selectively without affecting commensal microflora. Lytic enzymes from bacteria and bacteriophages show promise as highly selective and effective antimicrobial agents. These enzymes often have a modular structure, consisting of a catalytic domain and a binding domain. In the current work, using consensus catalytic domain and cell-wall binding domain sequences as probes, we analyzed in silico the genome of C. difficile, as well as phages infecting C. difficile. We identified two genes encoding cell lytic enzymes with possible activity against C. difficile. We cloned the genes in a suitable expression vector, expressed and purified the protein products, and tested enzyme activity in vitro. These newly identified enzymes were found to be active against C. difficile cells in a dose-dependent manner. We achieved a more than 4-log reduction in the number of viable bacteria within 5 h of application. Moreover, we found that the enzymes were active against a wide range of C. difficile clinical isolates. We also characterized the biocatalytic mechanism by identifying the specific bonds cleaved by these enzymes within the cell wall peptidoglycan. These results suggest a new approach to combating the growing healthcare problem associated with C. difficile infections. Biotechnol. Bioeng. 2016;113: 2568-2576. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Krunal K Mehta
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, 12180, New York
| | - Elena E Paskaleva
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, 12180, New York
| | - Xia Wu
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, 12180, New York
| | - Navdeep Grover
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, 12180, New York
| | - Ruchir V Mundra
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, 12180, New York
| | - Kevin Chen
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland
| | - Yongrong Zhang
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland
| | - Zhiyong Yang
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland
| | - Jonathan S Dordick
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York.
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, 12180, New York.
| | - Ravi S Kane
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 950 Atlantic Drive, Atlanta, 30332, Georgia.
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A Tetraspecific VHH-Based Neutralizing Antibody Modifies Disease Outcome in Three Animal Models of Clostridium difficile Infection. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2016; 23:774-84. [PMID: 27413067 PMCID: PMC5014919 DOI: 10.1128/cvi.00730-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 07/01/2016] [Indexed: 12/17/2022]
Abstract
Clostridium difficile infection (CDI), a leading cause of nosocomial infection, is a serious disease in North America, Europe, and Asia. CDI varies greatly from asymptomatic carriage to life-threatening diarrhea, toxic megacolon, and toxemia. The incidence of community-acquired infection has increased due to the emergence of hypervirulent antibiotic-resistant strains. These new strains contribute to the frequent occurrence of disease relapse, complicating treatment, increasing hospital stays, and increasing morbidity and mortality among patients. Therefore, it is critical to develop new therapeutic approaches that bypass the development of antimicrobial resistance and avoid disruption of gut microflora. Here, we describe the construction of a single heteromultimeric VHH-based neutralizing agent (VNA) that targets the two primary virulence factors of Clostridium difficile, toxins A (TcdA) and B (TcdB). Designated VNA2-Tcd, this agent has subnanomolar toxin neutralization potencies for both C. difficile toxins in cell assays. When given systemically by parenteral administration, VNA2-Tcd protected against CDI in gnotobiotic piglets and mice and to a lesser extent in hamsters. Protection from CDI was also observed in gnotobiotic piglets treated by gene therapy with an adenovirus that promoted the expression of VNA2-Tcd.
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Rampuria P, Lang GA, Devera TS, Gilmore C, Ballard JD, Lang ML. Coordination between T helper cells, iNKT cells, and their follicular helper subsets in the humoral immune response against Clostridium difficile toxin B. J Leukoc Biol 2016; 101:567-576. [PMID: 27566831 DOI: 10.1189/jlb.4a0616-271r] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/02/2016] [Accepted: 08/05/2016] [Indexed: 01/28/2023] Open
Abstract
Activation of iNKT cells with the CD1d-binding glycolipid adjuvant α-galactosylceramide (α-GC) enhances humoral immunity specific for coadministered T-dependent Ag. However, the relationship between the iNKT cell and the classic T helper (Th) or T follicular helper (Tfh) function following this immunization modality remains unclear. We show that immunization with the C-terminal domain (CTD) of Clostridium difficile toxin B (TcdB), accompanied by activation of iNKT cells with α-GC, led to enhanced production of CTD-specific IgG, which was CD1d- and iNKT cell-dependent and associated with increased neutralization of active TcdB. Immunization with CTD plus α-GC followed by NP hapten-linked CTD increased NP-specific IgG1 titers in an NKT-dependent manner, suggesting that iNKT activation could enhance Th or Tfh function or that iNKT and iNKTfh cells could provide supplemental, yet independent, B cell help. Th, Tfh, iNKT, and iNKTfh cells were, therefore, examined quantitatively, phenotypically, and functionally following immunization with CTD or with CTD plus α-GC. Our results demonstrated that α-GC-activated iNKT cells had no direct effect on the numbers, phenotype, or function of Th or Tfh cells. However, CD4+ T cell-specific ablation of the Bcl6 transcription factor demonstrated that Tfh and iNKTfh cells both contributed to B cell help. This work extends our understanding of the immune response to vaccination and demonstrates an important contribution by NKTfh cells to humoral immunity.
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Affiliation(s)
- Pragya Rampuria
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Gillian A Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - T Scott Devera
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Casey Gilmore
- 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
| | - Mark L Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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Abstract
Clostridium difficile continues to be one of the most prevalent hospital-acquired bacterial infections in the developed world, despite the recent introduction of a novel and effective antibiotic agent (fidaxomicin). Alternative approaches under investigation to combat the anaerobic Gram-positive bacteria include fecal transplantation therapy, vaccines, and antibody-based immunotherapies. In this review, we catalog the recent advances in antibody-based approaches under development and in the clinic for the treatment of C. difficile infection. By and large, inhibitory antibodies that recognize the primary C. difficile virulence factors, toxin A and toxin B, are the most popular passive immunotherapies under investigation. We provide a detailed summary of the toxin epitopes recognized by various antitoxin antibodies and discuss general trends on toxin inhibition efficacy. In addition, antibodies to other C. difficile targets, such as surface-layer proteins, binary toxin, motility factors, and adherence and colonization factors, are introduced in this review.
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Affiliation(s)
- Greg Hussack
- Human Health Therapeutics Portfolio, National Research Council Canada, Ottawa
| | - Jamshid Tanha
- Human Health Therapeutics Portfolio, National Research Council Canada, Ottawa; School of Environmental Sciences, University of Guelph, Guelph; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
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Glucosylation Drives the Innate Inflammatory Response to Clostridium difficile Toxin A. Infect Immun 2016; 84:2317-2323. [PMID: 27271747 DOI: 10.1128/iai.00327-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 05/25/2016] [Indexed: 02/04/2023] Open
Abstract
Clostridium difficile is a major, life-threatening hospital-acquired pathogen that causes mild to severe colitis in infected individuals. The tissue destruction and inflammation which characterize C. difficile infection (CDI) are primarily due to the Rho-glucosylating toxins A and B. These toxins cause epithelial cell death and induce robust inflammatory signaling by activating the transcription factor NF-κB, leading to chemokine and cytokine secretion. The toxins also activate the inflammasome complex, which leads to secretion of the pyrogenic cytokine IL-1β. In this study, we utilized glucosylation-deficient toxin A to show that activation of the inflammasome by this toxin is dependent on Rho glucosylation, confirming similar findings reported for toxin B. We also demonstrated that tissue destruction and in vivo inflammatory cytokine production are critically dependent on the enzymatic activity of toxin A, suggesting that inhibiting toxin glucosyltransferase activity may be effective in combating this refractory disease.
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Di Bella S, Ascenzi P, Siarakas S, Petrosillo N, di Masi A. Clostridium difficile Toxins A and B: Insights into Pathogenic Properties and Extraintestinal Effects. Toxins (Basel) 2016; 8:E134. [PMID: 27153087 PMCID: PMC4885049 DOI: 10.3390/toxins8050134] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile infection (CDI) has significant clinical impact especially on the elderly and/or immunocompromised patients. The pathogenicity of Clostridium difficile is mainly mediated by two exotoxins: toxin A (TcdA) and toxin B (TcdB). These toxins primarily disrupt the cytoskeletal structure and the tight junctions of target cells causing cell rounding and ultimately cell death. Detectable C. difficile toxemia is strongly associated with fulminant disease. However, besides the well-known intestinal damage, recent animal and in vitro studies have suggested a more far-reaching role for these toxins activity including cardiac, renal, and neurologic impairment. The creation of C. difficile strains with mutations in the genes encoding toxin A and B indicate that toxin B plays a major role in overall CDI pathogenesis. Novel insights, such as the role of a regulator protein (TcdE) on toxin production and binding interactions between albumin and C. difficile toxins, have recently been discovered and will be described. Our review focuses on the toxin-mediated pathogenic processes of CDI with an emphasis on recent studies.
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Affiliation(s)
- Stefano Di Bella
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Rome 00149, Italy.
| | - Paolo Ascenzi
- Department of Science, Roma Tre University, Rome 00154, Italy.
| | - Steven Siarakas
- Department of Microbiology and Infectious Diseases, Concord Repatriation General Hospital, Sydney 2139, Australia.
| | - Nicola Petrosillo
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Rome 00149, Italy.
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Bassères E, Endres BT, Khaleduzzaman M, Miraftabi F, Alam MJ, Vickers RJ, Garey KW. Impact on toxin production and cell morphology in Clostridium difficile by ridinilazole (SMT19969), a novel treatment for C. difficile infection. J Antimicrob Chemother 2016; 71:1245-51. [PMID: 26895772 PMCID: PMC4830417 DOI: 10.1093/jac/dkv498] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/15/2015] [Accepted: 12/21/2015] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES Ridinilazole (SMT19969) is a narrow-spectrum, non-absorbable antimicrobial with activity against Clostridium difficile undergoing clinical trials. The purpose of this study was to assess the pharmacological activity of ridinilazole and assess the effects on cell morphology. METHODS Antibiotic killing curves were performed using the epidemic C. difficile ribotype 027 strain, R20291, using supra-MIC (4× and 40×) and sub-MIC (0.125×, 0.25× and 0.5×) concentrations of ridinilazole. Following exposure, C. difficile cells were collected for cfu counts, toxin A and B production, and morphological changes using scanning electron and fluorescence microscopy. Human intestinal cells (Caco-2) were co-incubated with ridinilazole-treated C. difficile growth medium to determine the effects on host inflammatory response (IL-8). RESULTS Treatment at supra-MIC concentrations (4× and 40× MIC) of ridinilazole resulted in a significant reduction in vegetative cells over 72 h (4 log difference, P < 0.01) compared with controls without inducing spore formation. These results correlated with a 75% decrease in toxin A production (P < 0.05) and a 96% decrease in toxin B production (P < 0.05). At sub-MIC levels (0.5× MIC), toxin A production was reduced by 91% (P < 0.01) and toxin B production was reduced by 100% (P < 0.001), which resulted in a 74% reduction in IL-8 release compared with controls (P < 0.05). Sub-MIC (0.5×)-treated cells formed filamentous structures ∼10-fold longer than control cells. Following fluorescence labelling, the cell septum was not forming in sub-MIC-treated cells, yet the DNA was dividing. CONCLUSIONS Ridinilazole had robust killing effects on C. difficile that significantly reduced toxin production and attenuated the inflammatory response. Ridinilazole also elicited significant cell division effects suggesting a potential mechanism of action.
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Affiliation(s)
- Eugénie Bassères
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
| | - Bradley T Endres
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
| | | | - Faranak Miraftabi
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
| | - M Jahangir Alam
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
| | - Richard J Vickers
- Summit Therapeutics, 85b Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK
| | - Kevin W Garey
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
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Zhang Y, Feng H. Pathogenic effects of glucosyltransferase from Clostridium difficile toxins. Pathog Dis 2016; 74:ftw024. [PMID: 27044305 DOI: 10.1093/femspd/ftw024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2016] [Indexed: 01/13/2023] Open
Abstract
The glucosyltransferase domain ofClostridium difficiletoxins modifies guanine nucleotide-binding proteins of Rho family. It is the major virulent domain of the holotoxins. Various pathogenic effects ofC. difficiletoxins in response to Rho glucosylation have been investigated including cytoskeleton damage, cell death and inflammation. The most recent studies have revealed some significant characteristics of the holotoxins that are independent of glucosylating activity. These findings arouse discussion about the role of glucosyltransferase activity in toxin pathogenesis and open up new insights for toxin mechanism study. In this review, we summarize the pathogenic effects of glucosyltransferase domain of the toxins in the past years.
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Affiliation(s)
- Yongrong Zhang
- Department of Microbial Pathogenesis, University of Maryland Baltimore, 650 W. Baltimore Street, Baltimore, MD 21201, USA
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Baltimore, 650 W. Baltimore Street, Baltimore, MD 21201, USA
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Devera TS, Lang GA, Lanis JM, Rampuria P, Gilmore CL, James JA, Ballard JD, Lang ML. Memory B Cells Encode Neutralizing Antibody Specific for Toxin B from the Clostridium difficile Strains VPI 10463 and NAP1/BI/027 but with Superior Neutralization of VPI 10463 Toxin B. Infect Immun 2016; 84:194-204. [PMID: 26502913 PMCID: PMC4693989 DOI: 10.1128/iai.00011-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 10/19/2015] [Indexed: 02/07/2023] Open
Abstract
Secreted toxin B (TcdB) substantially contributes to the pathology observed during Clostridium difficile infection. To be successfully incorporated into a vaccine, TcdB-based immunogens must stimulate the production of neutralizing antibody (Ab)-encoding memory B cells (Bmem cells). Despite numerous investigations, a clear analysis of Bmem cellular responses following vaccination against TcdB is lacking. B6 mice were therefore used to test the ability of a nontoxigenic C-terminal domain (CTD) fragment of TcdB to induce Bmem cells that encode TcdB-neutralizing antibody. CTD was produced from the historical VPI 10463 strain (CTD1) and from the hypervirulent strain NAP1/BI/027 (CTD2). It was then demonstrated that CTD1 induced strong recall IgG antibody titers, and this led to the development of functional Bmem cells that could be adoptively transferred to naive recipients. Bmem cell-driven neutralizing Ab responses conferred protection against lethal challenge with TcdB1. Further experiments revealed that an experimental adjuvant (Imject) and a clinical adjuvant (Alhydrogel) were compatible with Bmem cell induction. Reactivity of human Bmem cells to CTD1 was also evident in human peripheral blood mononuclear cells (PBMCs), suggesting that CTD1 could be a good vaccine immunogen. However, CTD2 induced strong Bmem cell-driven antibody titers, and the CTD2 antibody was neutralizing in vitro, but its protection against lethal challenge with TcdB2 was limited to delaying time to death. Therefore, CTD from different C. difficile strains may be a good immunogen for stimulating B cell memory that encodes in vitro neutralizing Ab but may be limited by variable protection against intoxication in vivo.
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Affiliation(s)
- T Scott Devera
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Gillian A Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Jordi M Lanis
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Pragya Rampuria
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Casey L Gilmore
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Judith A James
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA Oklahoma Clinical and Translational Science Institute, Oklahoma City, Oklahoma, USA
| | - Jimmy D Ballard
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Mark L Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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Hamza T, Zhang Z, Melnyk RA, Feng H. Defective mutations within the translocation domain of Clostridium difficile toxin B impair disease pathogenesis. Pathog Dis 2015; 74:ftv098. [PMID: 26507679 DOI: 10.1093/femspd/ftv098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2015] [Indexed: 12/12/2022] Open
Abstract
The Clostridium difficile toxin B is one of the main virulence factors and plays an important role in the pathogenesis of C. difficile infection (CDI). We recently revealed crucial residues in the translocation domain of TcdB for the pore formation and toxin translocation. In this study, we investigated the effects of mutating a critical site involved in pore formation, Leu-1106, to residues that differ in size and polarity (Phe, Ala, Cys, Asp). We observed a broad range of effects on TcdB function in vitro consistent with the role of this site in pore formation and translocation. We show that mice challenged systemically with a lethal dose (LD100) of the most defective mutant (L1106K) showed no symptoms of disease highlighting the importance of this residue and the translocation domain in disease pathogenesis. These findings offer insights into the structure function of the toxin translocation pore, and inform novel therapeutic strategies against CDI.
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Affiliation(s)
- Therwa Hamza
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, MD 21201, USA
| | - Zhifen Zhang
- Program in Molecular Structure & Function, The Hospital for Sick Children, M5G 0A4, Canada
| | - Roman A Melnyk
- Program in Molecular Structure & Function, The Hospital for Sick Children, M5G 0A4, Canada Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, MD 21201, USA
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Monitoring in real time the cytotoxic effect of Clostridium difficile upon the intestinal epithelial cell line HT29. J Microbiol Methods 2015; 119:66-73. [PMID: 26436983 DOI: 10.1016/j.mimet.2015.09.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 09/29/2015] [Accepted: 09/29/2015] [Indexed: 01/05/2023]
Abstract
The incidence and severity of Clostridium difficile infections (CDI) has been increased not only among hospitalized patients, but also in healthy individuals traditionally considered as low risk population. Current treatment of CDI involves the use of antibiotics to eliminate the pathogen, although recurrent relapses have also been reported. For this reason, the search of new antimicrobials is a very active area of research. The strategy to use inhibitors of toxin's activity has however been less explored in spite of being a promising option. In this regard, the lack of fast and reliable in vitro screening methods to search for novel anti-toxin drugs has hampered this approach. The aim of the current study was to develop a method to monitor in real time the cytotoxicity of C. difficile upon the human colonocyte-like HT29 line, since epithelial intestinal cells are the primary targets of the toxins. The label-free, impedance based RCTA (real time cell analyser) technology was used to follow overtime the behaviour of HT29 in response to C. difficile LMG21717 producing both A and B toxins. Results obtained showed that the selection of the medium to grow the pathogen had a great influence in obtaining toxigenic supernatants, given that some culture media avoided the release of the toxins. A cytotoxic dose- and time-dependent effect of the supernatant obtained from GAM medium upon HT29 and Caco2 cells was detected. The sigmoid-curve fit of data obtained with HT29 allowed the calculation of different toxicological parameters, such as EC50 and LOAEL values. Finally, the modification in the behaviour of HT29 reordered in the RTCA was correlated with the cell rounding effect, typically induced by these toxins, visualized by time-lapsed captures using an optical microscope. Therefore, this RTCA method developed to test cytotoxicity kinetics of C. difficile supernatants upon IEC could be a valuable in vitro model for the screening of new anti-CDI agents.
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Defining the Roles of TcdA and TcdB in Localized Gastrointestinal Disease, Systemic Organ Damage, and the Host Response during Clostridium difficile Infections. mBio 2015; 6:e00551. [PMID: 26037121 PMCID: PMC4453007 DOI: 10.1128/mbio.00551-15] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Clostridium difficile is a leading cause of antibiotic-associated diarrhea, a significant animal pathogen, and a worldwide public health burden. Most disease-causing strains secrete two exotoxins, TcdA and TcdB, which are considered to be the primary virulence factors. Understanding the role that these toxins play in disease is essential for the rational design of urgently needed new therapeutics. However, their relative contributions to disease remain contentious. Using three different animal models, we show that TcdA+ TcdB− mutants are attenuated in virulence in comparison to the wild-type (TcdA+ TcdB+) strain, whereas TcdA− TcdB+ mutants are fully virulent. We also show for the first time that TcdB alone is associated with both severe localized intestinal damage and systemic organ damage, suggesting that this toxin might be responsible for the onset of multiple organ dysfunction syndrome (MODS), a poorly characterized but often fatal complication of C. difficile infection (CDI). Finally, we show that TcdB is the primary factor responsible for inducing the in vivo host innate immune and inflammatory responses. Surprisingly, the animal infection model used was found to profoundly influence disease outcomes, a finding which has important ramifications for the validation of new therapeutics and future disease pathogenesis studies. Overall, our results show unequivocally that TcdB is the major virulence factor of C. difficile and provide new insights into the host response to C. difficile during infection. The results also highlight the critical nature of using appropriate and, when possible, multiple animal infection models when studying bacterial virulence mechanisms. Clostridium difficile is a leading cause of antibiotic-associated diarrhea and an important hospital pathogen. TcdA and TcdB are thought to be the primary virulence factors responsible for disease symptoms of C. difficile infections (CDI). However, the individual contributions of these toxins to disease remain contentious. Using three different animal models of infection, we show for the first time that TcdB alone causes severe damage to the gut, as well as systemic organ damage, suggesting that this toxin might be responsible for MODS, a serious but poorly understood complication of CDI. These findings provide important new insights into the host response to C. difficile during infection and should guide the rational development of urgently required nonantibiotic therapeutics for the treatment of CDI.
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Yu H, Chen K, Wu J, Yang Z, Shi L, Barlow LL, Aronoff DM, Garey KW, Savidge TC, von Rosenvinge EC, Kelly CP, Feng H. Identification of toxemia in patients with Clostridium difficile infection. PLoS One 2015; 10:e0124235. [PMID: 25885671 PMCID: PMC4401762 DOI: 10.1371/journal.pone.0124235] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/27/2015] [Indexed: 01/05/2023] Open
Abstract
Toxemia can develop in Clostridium difficile-infected animals, and correlates with severe and fulminant disease outcomes. Circumstantial evidence suggests that toxemia may occur in patients with C. difficile infection (CDI), but positive diagnosis is extremely rare. We analyzed the potential for C. difficile toxemia in patients, determined its characteristics, and assessed challenges. C. difficile toxins in serum from patients were tested using an ultrasensitive cell-based assay and further confirmed by Rac1 glucosylation assay. The factors that hinder a diagnosis of toxemia were assessed, including investigation of toxin stability, the level of toxins-specific neutralizing antibodies in sera and its effect on diagnosis limits. CDI patients develop detectable toxemia in some cases (2.3%). Toxins were relatively stable in stored sera. Neutralizing anti-toxin antibodies were present during infection and positively correlated with the diagnosis limits. Thus, the masking effect of toxin-specific neutralizing antibodies is the major obstacle in diagnosing C. difficile toxemia using cell-based bioassays.
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Affiliation(s)
- Hua Yu
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Kevin Chen
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Jianguo Wu
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Zhiyong Yang
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Lianfa Shi
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Lydia L. Barlow
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - David M. Aronoff
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America; Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Kevin W. Garey
- University of Houston College of Pharmacy, Houston, Texas, United States of America; Baylor St. Luke's Medical Center, Houston, Texas, United States of America; University of Texas School of Public Health, Houston, Texas, United States of America
| | - Tor C. Savidge
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, United States of America; Texas Children's Microbiome Center, Texas Children's Hospital, Houston, Texas, United States of America
| | - Erik C. von Rosenvinge
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Maryland, Baltimore, Maryland, United States of America; VA Maryland Health Care System, Baltimore, Maryland, United States of America
| | - Ciaran P. Kelly
- Department of Medicine, Harvard Medical School and Celiac Center, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America; Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
- * E-mail:
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44
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Inflammasome activation contributes to interleukin-23 production in response to Clostridium difficile. mBio 2015; 6:mBio.02386-14. [PMID: 25626905 PMCID: PMC4324312 DOI: 10.1128/mbio.02386-14] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Clostridium difficile is the most common hospital-acquired pathogen, causing antibiotic-associated diarrhea in over 250,000 patients annually in the United States. Disease is primarily mediated by toxins A and B, which induce potent proinflammatory signaling in host cells and can activate an ASC-containing inflammasome. Recent findings suggest that the intensity of the host response to infection correlates with disease severity. Our lab has identified the proinflammatory cytokine interleukin-23 (IL-23) as a pathogenic mediator during C. difficile infection (CDI). The mechanisms by which C. difficile induces IL-23, however, are not well understood, and the role of toxins A and B in this process is unclear. Here, we show that toxins A and B alone are not sufficient for IL-23 production but synergistically increase the amount of IL-23 produced in response to MyD88-dependent danger signals, including pathogen-associated molecular patterns (PAMPs) and host-derived damage associated molecular patterns (DAMPs). Danger signals also enhanced the secretion of IL-1β in response to toxins A and B, and subsequent IL-1 receptor signaling accounted for the majority of the increase in IL-23 that occurred in the presence of the toxins. Inhibition of inflammasome activation in the presence of extracellular K+ likewise decreased IL-23 production. Finally, we found that IL-1β was increased in the serum of patients with CDI, suggesting that this systemic response could influence downstream production of pathogenic IL-23. Identification of the synergy of danger signals with toxins A and B via inflammasome signaling represents a novel finding in the mechanistic understanding of C. difficile-induced inflammation. Clostridium difficile is among the leading causes of death due to health care-associated infection, and factors determining disease severity are not well understood. C. difficile secretes toxins A and B, which cause inflammation and tissue damage, and recent findings suggest that some of this tissue damage may be due to an inappropriate host immune response. We have found that toxins A and B, in combination with both bacterium- and host-derived danger signals, can induce expression of the proinflammatory cytokines IL-1β and IL-23. Our results demonstrate that IL-1β signaling enhances IL-23 production and could lead to increased pathogenic inflammation during CDI.
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45
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Abstract
Clostridium difficile is associated with a spectrum of clinical manifestations ranging from asymptomatic carriage to severe life-threatening pseudomembranous colitis. Current perspectives indicate that C difficile pathogenesis is a multifactorial disease process dictated by pathogenic toxin production, gut microbial dysbiosis, and altered host inflammatory responses. This article summarizes recent findings underpinning the cellular and molecular mechanisms regulating bacterial virulence and sheds new light on the critical roles of the host immune response, intestinal microbiota, and metabolome in mediating disease pathogenesis.
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Affiliation(s)
- Tanya M Monaghan
- Biomedical Research Unit, NIHR Nottingham Digestive Diseases Centre, Nottingham University Hospitals NHS Trust, Derby Road, Nottingham NG7 2UH, UK.
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46
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Yuan P, Zhang H, Cai C, Zhu S, Zhou Y, Yang X, He R, Li C, Guo S, Li S, Huang T, Perez-Cordon G, Feng H, Wei W. Chondroitin sulfate proteoglycan 4 functions as the cellular receptor for Clostridium difficile toxin B. Cell Res 2014; 25:157-68. [PMID: 25547119 PMCID: PMC4650570 DOI: 10.1038/cr.2014.169] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 11/06/2014] [Accepted: 11/19/2014] [Indexed: 02/06/2023] Open
Abstract
As a gram-positive, spore-forming anaerobic bacillus, Clostridium difficile (C. difficile) is responsible for severe and fatal pseudomembranous colitis, and poses the most urgent antibiotic resistance threat worldwide. Epidemic C. difficile is the leading cause of antibiotic-associated diarrhoea globally, especially diarrhoea due to the emergence of hypervirulent strains associated with high mortality and morbidity. TcdB, one of the key virulence factors secreted by this bacterium, enters host cells through a poorly understood mechanism to elicit its pathogenic effect. Here we report the first identification of the TcdB cellular receptor, chondroitin sulfate proteoglycan 4 (CSPG4). CSPG4 was initially isolated from a whole-genome human shRNAmir library screening, and its role was confirmed by both TALEN- and CRISPR/Cas9-mediated gene knockout in human cells. CSPG4 is critical for TcdB binding to the cell surface, inducing cytoskeleton disruption and cell death. A direct interaction between the N-terminus of CSPG4 and the C-terminus of TcdB was confirmed, and the soluble peptide of the toxin-binding domain of CSPG4 could protect cells from the action of TcdB. Notably, the complete loss of CSPG4/NG2 decreased TcdB-triggered interleukin-8 induction in mice without significantly affecting animal mortality. Based on both the in vitro and in vivo studies, we propose a dual-receptor model for TcdB endocytosis. The discovery of the first TcdB receptor reveals a previously unsuspected role for CSPG4 and provides a new therapeutic target for the treatment of C. difficile infection.
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Affiliation(s)
- Pengfei Yuan
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Hongmin Zhang
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Changzu Cai
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Shiyou Zhu
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Yuexin Zhou
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Xiaozhou Yang
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Ruina He
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Chan Li
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Shengjie Guo
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Shan Li
- School of Bioscience and Biotechnology, South China University of Technology, Guangzhou, Guangdong 510006, China
| | - Tuxiong Huang
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland 21201, USA
| | - Gregorio Perez-Cordon
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland 21201, USA
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland 21201, USA
| | - Wensheng Wei
- Biodynamic Optical Imaging Center (BIOPIC), State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
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47
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Ivarsson ME, Leroux JC, Castagner B. Investigational new treatments for Clostridium difficile infection. Drug Discov Today 2014; 20:602-8. [PMID: 25499664 DOI: 10.1016/j.drudis.2014.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 11/20/2014] [Accepted: 12/02/2014] [Indexed: 12/21/2022]
Abstract
Significant progress has been made by industry and academia in the past two years to address the medical threats posed by Clostridium difficile infection. These developments provide an excellent example of how patient need has driven a surge of innovation in drug discovery. Indeed, only two drugs were approved for the infection in the past 30 years but there are 13 treatment candidates in clinical trials today. What makes the latter number even more remarkable is the diversity in the strategies represented (antibiotics, microbiota supplements, vaccines, antibiotic quenchers and passive immunization). In this review, we provide a snapshot of the current stage of these breakthroughs and argue that there is still room for further innovation in treating C. difficile infection.
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Affiliation(s)
- Mattias E Ivarsson
- Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH Zurich), Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland
| | - Jean-Christophe Leroux
- Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH Zurich), Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland
| | - Bastien Castagner
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir-William-Osler, H3G1Y6 Montreal, Quebec, Canada.
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48
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Mechanisms of protection against Clostridium difficile infection by the monoclonal antitoxin antibodies actoxumab and bezlotoxumab. Infect Immun 2014; 83:822-31. [PMID: 25486992 DOI: 10.1128/iai.02897-14] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Clostridium difficile infection (CDI) represents the most prevalent cause of antibiotic-associated gastrointestinal infections in health care facilities in the developed world. Disease symptoms are caused by the two homologous exotoxins, TcdA and TcdB. Standard therapy for CDI involves administration of antibiotics that are associated with a high rate of disease recurrence, highlighting the need for novel treatment paradigms that target the toxins rather than the organism itself. A combination of human monoclonal antibodies, actoxumab and bezlotoxumab, directed against TcdA and TcdB, respectively, has been shown to decrease the rate of recurrence in patients treated with standard-of-care antibiotics. However, the exact mechanism of antibody-mediated protection is poorly understood. In this study, we show that the antitoxin antibodies are protective in multiple murine models of CDI, including systemic and local (gut) toxin challenge models, as well as primary and recurrent models of infection in mice. Systemically administered actoxumab-bezlotoxumab prevents both the damage to the gut wall and the inflammatory response, which are associated with C. difficile in these models, including in mice challenged with a strain of the hypervirulent ribotype 027. Furthermore, mutant antibodies (N297Q) that do not bind to Fcγ receptors provide a level of protection similar to that of wild-type antibodies, demonstrating that the mechanism of protection is through direct neutralization of the toxins and does not involve host effector functions. These data provide a mechanistic basis for the prevention of recurrent disease observed in CDI patients in clinical trials.
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49
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Critical roles of Clostridium difficile toxin B enzymatic activities in pathogenesis. Infect Immun 2014; 83:502-13. [PMID: 25404023 DOI: 10.1128/iai.02316-14] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
TcdB is one of the key virulence factors of Clostridium difficile that is responsible for causing serious and potentially fatal colitis. The toxin contains at least two enzymatic domains: an effector glucosyltransferase domain for inactivating host Rho GTPases and a cysteine protease domain for the delivery of the effector domain into host cytosol. Here, we describe a novel intrabody approach to examine the role of these enzymes of TcdB in cellular intoxication. By screening a single-domain heavy chain (V(H)H) library raised against TcdB, we identified two V(H)H antibodies, 7F and E3, that specifically inhibit TcdB cysteine protease and glucosyltransferase activities, respectively. Cytoplasmic expression of 7F intrabody in Vero cells inhibited TcdB autoprocessing and delayed cellular intoxication, whereas E3 intrabody completely blocked the cytopathic effects of TcdB holotoxin. These data also demonstrate for the first time that toxin autoprocessing occurs after cysteine protease and glucosyltransferase domains translocate into the cytosol of target cells. We further determined the role of the enzymatic activities of TcdB in in vivo toxicity using a sensitive systemic challenge model in mice. Consistent with these in vitro results, a cysteine protease noncleavable mutant, TcdB-L543A, delayed toxicity in mice, whereas glycosyltransferase-deficient TcdB demonstrated no toxicity up to 500-fold of the 50% lethal dose (LD50) when it was injected systemically. Thus, glucosyltransferase but not cysteine protease activity is critical for TcdB-mediated cytopathic effects and TcdB systemic toxicity, highlighting the importance of targeting toxin glucosyltransferase activity for future therapy.
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50
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Toxin-mediated paracellular transport of antitoxin antibodies facilitates protection against Clostridium difficile infection. Infect Immun 2014; 83:405-16. [PMID: 25385797 DOI: 10.1128/iai.02550-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The exotoxins TcdA and TcdB are the major virulence factors of Clostridium difficile. Circulating neutralizing antitoxin antibodies are protective in C. difficile infection (CDI), as demonstrated, in part, by the protective effects of actoxumab and bezlotoxumab, which bind to and neutralize TcdA and TcdB, respectively. The question of how systemic IgG antibodies neutralize toxins in the gut lumen remains unresolved, although it has been suggested that the Fc receptor FcRn may be involved in active antibody transport across the gut epithelium. In this study, we demonstrated that genetic ablation of FcRn and excess irrelevant human IgG have no impact on actoxumab-bezlotoxumab-mediated protection in murine and hamster models of CDI, suggesting that Fc-dependent transport of antibodies across the gut wall is not required for efficacy. Tissue distribution studies in hamsters suggest, rather, that the transport of antibodies depends on toxin-induced damage to the gut lining. In an in vitro two-dimensional culture system that mimics the architecture of the intestinal mucosal epithelium, toxins on the apical side of epithelial cell monolayers are neutralized by basolateral antibodies, and antibody transport across the cell layer is dramatically increased upon addition of toxin to the apical side. Similar data were obtained with F(ab')2 fragments, which lack an Fc domain, consistent with FcRn-independent paracellular, rather than transcellular, transport of antibodies. Kinetic studies show that initial damage caused by apical toxin is required for efficient neutralization by basolateral antibodies. These data may represent a general mechanism of humoral response-mediated protection against enteric pathogens.
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