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Ramamurthy K, Madesh S, Priya PS, Ayub R, Aljawdah HM, Arokiyaraj S, Guru A, Arockiaraj J. Textile azo dye, Sudan Black B, inducing hepatotoxicity demonstrated in in vivo zebrafish larval model. FISH PHYSIOLOGY AND BIOCHEMISTRY 2024:10.1007/s10695-024-01371-0. [PMID: 38970761 DOI: 10.1007/s10695-024-01371-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 06/19/2024] [Indexed: 07/08/2024]
Abstract
Environmental pollution, particularly from textile industry effluents, raises concerns globally. The aim of this study is to investigate the hepatotoxicity of Sudan Black B (SBB), a commonly used textile azo dye, on embryonic zebrafish. SBB exposure led to concentration-dependent mortality, reaching 100% at 0.8 mM, accompanied by growth retardation and diverse malformations in zebrafish. Biochemical marker analysis indicated adaptive responses to SBB, including increased SOD, CAT, NO, and LDH, alongside decreased GSH levels. Liver morphology analysis unveiled significant alterations, impacting metabolism and detoxification. Also, glucose level was declined and lipid level elevated in SBB-exposed in vivo zebrafish. Inflammatory gene expressions (TNF-α, IL-10, and INOS) showcased a complex regulatory interplay, suggesting an organismal attempt to counteract pro-inflammatory states during SBB exposure. The increased apoptosis revealed a robust hepatic cellular response due to SBB, aligning with observed liver tissue damage and inflammatory events. This multidimensional study highlights the intricate web of responses due to SBB exposure, which is emphasizing the need for comprehensive understanding and targeted mitigation strategies. The findings bear the implications for both aquatic ecosystems and potentially parallels to human health, underscoring the imperative for sustained research in this critical domain.
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Affiliation(s)
- Karthikeyan Ramamurthy
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Chengalpattu District, Kattankulathur, 603203, Tamil Nadu, India
| | - Selvam Madesh
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Chengalpattu District, Kattankulathur, 603203, Tamil Nadu, India
| | - P Snega Priya
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Chengalpattu District, Kattankulathur, 603203, Tamil Nadu, India
| | - Rashid Ayub
- College of Science, King Saud University, P.O. Box 2454, 11451, Riyadh, Saudi Arabia
| | - Hossam M Aljawdah
- Department of Zoology, College of Science, King Saud University, P.O. Box 2455, 11451, Riyadh, Saudi Arabia
| | - Selvaraj Arokiyaraj
- Department of Food Science & Biotechnology, Sejong University, Seoul, 05006, Korea
| | - Ajay Guru
- Department of Cariology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India.
| | - Jesu Arockiaraj
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Chengalpattu District, Kattankulathur, 603203, Tamil Nadu, India.
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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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Saad G, Azrad M, Aias M, Leshem T, Hamo Z, Rahmoun LA, Peretz A. The effect of different C. difficile MLST strains on viability and activity of macrophages. Heliyon 2023; 9:e13846. [PMID: 36873553 PMCID: PMC9982624 DOI: 10.1016/j.heliyon.2023.e13846] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
Objectives Clostridioides difficile is the most common infectious agent of nosocomial diarrhea. C. difficile infection (CDI) pathogenesis and disease severity depend on its toxins (toxins A, B and binary) and on the host's immune response, especially the innate immune system. The current study examined the efficacy of macrophage activity, macrophages viability and cytokine secretion levelsin response to different sequence type (ST) strains of C. difficile. Methods RAW 264.7 macrophages were exposed to six different strains of C. difficile as well as to both toxins A and B and macrophage viability was measured. The levels of four secreted cytokines were determined by RT-PCR and ELISA. Morphological changes to the macrophages were investigated by fluorescent microscopy. Results Strains ST37 and ST42 affected macrophages' vitality the most. Toxins A and B led to a significant reduction in macrophages' vitality at most time points. In addition, starting at 30-min post-exposure to 5 ng/μl of both toxins led to significant differences in macrophage viability versus at lower concentrations. Furthermore, cytokine secretion levels, including IL-12, IL-6 and TNF-α, increased dramatically when macrophages were exposed to strains ST42 or ST104. Finally, gene expression surveys point to increases in IL-12 gene expression in response to both ST42 and ST104. Conclusions C. difficile strains with higher toxins levels induced an increased activation of the innate immune system and may activate macrophages more profoundly resulting in secretion of higher levels of pro-inflammatory cytokines. However, higher toxin levels may also damage macrophages' normal skeletal structure, reducing macrophage viability.
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Affiliation(s)
- Gewa Saad
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, 1311502, Israel
| | - Maya Azrad
- Clinical Microbiology Laboratory, Tzafon Medical Center, Poriya, Tiberias 1528001, Israel
| | - Meral Aias
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, 1311502, Israel
| | - Tamar Leshem
- Clinical Microbiology Laboratory, Tzafon Medical Center, Poriya, Tiberias 1528001, Israel
| | - Zohar Hamo
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, 1311502, Israel
| | - Layan Abu Rahmoun
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, 1311502, Israel
| | - Avi Peretz
- Azrieli Faculty of Medicine, Bar Ilan University, Safed, 1311502, Israel
- Clinical Microbiology Laboratory, Tzafon Medical Center, Poriya, Tiberias 1528001, Israel
- Corresponding author. Hanna Senesh 818/2 Tiberias, Israel.
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Chaves-Cordero C, Quesada-Gómez C, Chaves-Olarte E, Barquero-Calvo E. Human neutrophils are resistant to Clostridioides difficile toxin B. Anaerobe 2022; 74:102553. [DOI: 10.1016/j.anaerobe.2022.102553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 02/08/2023]
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Ke S, Pollock NR, Wang XW, Chen X, Daugherty K, Lin Q, Xu H, Garey KW, Gonzales-Luna AJ, Kelly CP, Liu YY. Integrating gut microbiome and host immune markers to understand the pathogenesis of Clostridioides difficile infection. Gut Microbes 2021; 13:1-18. [PMID: 34132169 PMCID: PMC8210874 DOI: 10.1080/19490976.2021.1935186] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Clostridioides difficile (C.difficile) infection is the most common cause of healthcare-associated infection and an important cause of morbidity and mortality among hospitalized patients. A comprehensive understanding of C.difficile infection (CDI) pathogenesis is crucial for disease diagnosis, treatment, and prevention. Here, we characterized gut microbial compositions and a broad panel of innate and adaptive immunological markers in 243 well-characterized human subjects (including 187 subjects with both microbiota and immune marker data), who were divided into four phenotype groups: CDI, Asymptomatic Carriage, Non-CDI Diarrhea, and Control. We found that the interactions between gut microbiota and host immune markers are very sensitive to the status of C.difficile colonization and infection. We demonstrated that incorporating both gut microbiome and host immune marker data into classification models can better distinguish CDI from other groups than can either type of data alone. Our classification models display robust diagnostic performance to differentiate CDI from Asymptomatic carriage (AUC~0.916), Non-CDI Diarrhea (AUC~0.917), or Non-CDI that combines all other three groups (AUC~0.929). Finally, we performed symbolic classification using selected features to derive simple mathematic formulas that explicitly quantify the interactions between the gut microbiome and host immune markers. These findings support the potential roles of gut microbiota and host immune markers in the pathogenesis of CDI. Our study provides new insights for a microbiome-immune marker-derived signature to diagnose CDI and design therapeutic strategies for CDI.
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Affiliation(s)
- Shanlin Ke
- Channing Division of Network Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MassachusettsUSA,School of Animal Science and Technology, State Key Laboratory of Pig Genetic Improvement and Production Technology, Jiangxi Agricultural University 330045, China
| | - Nira R. Pollock
- Division of Infectious Diseases, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA,Department of Laboratory Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Xu-Wen Wang
- Channing Division of Network Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MassachusettsUSA
| | - Xinhua Chen
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Kaitlyn Daugherty
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Qianyun Lin
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Hua Xu
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Kevin W. Garey
- Department of Pharmacy Practice and Translation Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Anne J. Gonzales-Luna
- Department of Pharmacy Practice and Translation Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Ciarán P. Kelly
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA,Ciarán P. Kelly Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MassachusettsUSA
| | - Yang-Yu Liu
- Channing Division of Network Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MassachusettsUSA,CONTACT Yang-Yu Liu Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MassachusettsUSA
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Abstract
Large clostridial toxins (LCTs) are a family of bacterial exotoxins that infiltrate and destroy target cells. Members of the LCT family include Clostridioides difficile toxins TcdA and TcdB, Paeniclostridium sordellii toxins TcsL and TcsH, Clostridium novyi toxin TcnA, and Clostridium perfringens toxin TpeL. Since the 19th century, LCT-secreting bacteria have been isolated from the blood, organs, and wounds of diseased individuals, and LCTs have been implicated as the primary virulence factors in a variety of infections, including C. difficile infection and some cases of wound-associated gas gangrene. Clostridia express and secrete LCTs in response to various physiological signals. LCTs invade host cells by binding specific cell surface receptors, ultimately leading to internalization into acidified vesicles. Acidic pH promotes conformational changes within LCTs, which culminates in translocation of the N-terminal glycosyltransferase and cysteine protease domain across the endosomal membrane and into the cytosol, leading first to cytopathic effects and later to cytotoxic effects. The focus of this review is on the role of LCTs in infection and disease, the mechanism of LCT intoxication, with emphasis on recent structural work and toxin subtyping analysis, and the genomic discovery and characterization of LCT homologues. We provide a comprehensive review of these topics and offer our perspective on emerging questions and future research directions for this enigmatic family of toxins.
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Chiu PJ, Rathod J, Hong YP, Tsai PJ, Hung YP, Ko WC, Chen JW, Paredes-Sabja D, Huang IH. Clostridioides difficile spores stimulate inflammatory cytokine responses and induce cytotoxicity in macrophages. Anaerobe 2021; 70:102381. [PMID: 34082120 DOI: 10.1016/j.anaerobe.2021.102381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 03/30/2021] [Accepted: 05/04/2021] [Indexed: 02/08/2023]
Abstract
Clostridioides difficile is a gram-positive, spore-forming anaerobic bacterium, and the leading cause of antibiotic-associated diarrhea worldwide. During C. difficile infection, spores germinate in the presence of bile acids into vegetative cells that subsequently colonize the large intestine and produce toxins. In this study, we demonstrated that C. difficile spores can universally adhere to, and be phagocytosed by, murine macrophages. Only spores from toxigenic strains were able to significantly stimulate the production of inflammatory cytokines by macrophages and subsequently induce significant cytotoxicity. Spores from the isogenic TcdA and TcdB double mutant induced significantly lower inflammatory cytokines and cytotoxicity in macrophages, and these activities were restored by pre-exposure of the spores to either toxins. These findings suggest that during sporulation, spores might be coated with C. difficile toxins from the environment, which could affect C. difficile pathogenesis in vivo.
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Affiliation(s)
- Po-Jung Chiu
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jagat Rathod
- Department of Earth Sciences National Cheng Kung University, Tainan, Taiwan
| | - Yu-Ping Hong
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Pei-Jane Tsai
- Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan, Taiwan; Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
| | - Yuan-Pin Hung
- Department of Internal Medicine, Tainan Hospital, Ministry of Health and Welfare, Tainan, Taiwan
| | - Wen-Chien Ko
- Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Jenn-Wei Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
| | - Daniel Paredes-Sabja
- Department of Biology, Texas A&M University, College Station, TX, 77843, USA; Millennium Nucleus in the Biology of Intestinal Microbiota, Santiago, Chile
| | - I-Hsiu Huang
- Department of Biochemistry and Microbiology, Oklahoma State University Center for Health Sciences, Tulsa, OK, USA; Oklahoma State University College of Osteopathic Medicine at Cherokee Nation, Tahlequah, OK, USA.
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McKee HK, Kajiwara C, Yamaguchi T, Ishii Y, Shimizu N, Ohara A, Tateda K. Clostridioides difficile toxins enhanced the in vitro production of CXC chemokine ligand 2 and tumor necrosis factor-α via Toll-like receptors in macrophages. J Med Microbiol 2021; 70. [PMID: 33830910 DOI: 10.1099/jmm.0.001342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Introduction. Clostridioides difficile infection (CDI) causes toxin-mediated enteropathy, such as antibiotic-associated diarrhoea and pseudomembranous colitis. Rho-glucosylating toxin A (TcdA) and toxin B (TcdB) have been clearly implicated in pathogenesis, whereas the virulence of binary toxin (CDT) is still debated.Hypothesis statement. We hypothesized that CDT is involved in the host immune response and plays a pivotal role in establishing virulence by modulating pro-inflammatory cytokine production; this is achieved through the integral Toll-like receptor (TLR) signalling pathways.Aim. The aim of the present study was to determine whether and how CDT impacts macrophages compared to TcdA or TcdB by examining the induction of CXC chemokine ligand 2 (CXCL2) and tumour necrosis factor-α (TNF-α), both of which are crucial in mediating local and systematic inflammatory responses.Methodology. RAW264.7 cells or transfected human embryonic kidney (HEK) 293 T cells were incubated with TcdA, TcdB, or CDT. In some experiments, a neutralizing antibody against TLR2 or TLR4, or myeloid differentiation 88 inhibitory peptide were added. The amount of CXCL2 and TNF-α secreted was then measured.Results. In RAW264.7 macrophages, CXCL2 and TNF-α were produced via the Toll-like receptor 2 (TLR2) or Toll-like receptor 4 (TLR4) pathway in a TcdA, TcdB, or CDT dose-dependent manner. Interleukin-8 secretion was induced in TLR4/MD2/CD14-transfected, but not in TLR2-transfected, HEK 293 T cells following TcdB or CDT exposure.Conclusion. Our results showed that C. difficile toxins, including CDT, enhanced macrophage-mediated CXCL2 and TNF-α production via TLR2 and TLR4, indicating that CDT affects host immune responses.
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Affiliation(s)
- Hiroe Konishi McKee
- Department of Pediatrics, Toho University Ohashi Medical Center, Tokyo 153-8515, Japan.,Department of Pediatrics, Toho University Graduate School of Medicine, Tokyo 143-8540, Japan
| | - Chiaki Kajiwara
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo 143-8540, Japan
| | - Tetsuo Yamaguchi
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo 143-8540, Japan
| | - Yoshikazu Ishii
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo 143-8540, Japan
| | - Norikazu Shimizu
- Department of Pediatrics, Toho University Ohashi Medical Center, Tokyo 153-8515, Japan.,Department of Pediatrics, Toho University Graduate School of Medicine, Tokyo 143-8540, Japan
| | - Akira Ohara
- Department of Pediatrics, Toho University Graduate School of Medicine, Tokyo 143-8540, Japan
| | - Kazuhiro Tateda
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo 143-8540, Japan
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El-Deeb W, Fayez M, Elsohaby I, Mkrtchyan HV, Alhaider A. Changes in blood biomarkers in Arabian horses with Clostridium difficile-induced enterocolitis. Comp Immunol Microbiol Infect Dis 2020; 73:101525. [PMID: 32877870 DOI: 10.1016/j.cimid.2020.101525] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/21/2020] [Accepted: 08/04/2020] [Indexed: 12/26/2022]
Abstract
Clostridium difficile (CD) is considered a major health care problem both in developing and developed countries; frequently reported to be associated with enterocolitis and diarrhea in horses and other animals. In this study, we examined acute phase response (APR), cytokines response, neopterin (NP) procalcitonin (PCT) production and oxidative stress condition in horses and foals with C. difficile-induced enterocolitis (CDIE) and evaluated the effectiveness of these parameters as biomarkers for the disease. A total of 407 Arabian horses in 35 stables were examined between January 2017 to December 2018. Only 24 out of 407 horses showed two or more signs of CDIE. The blood level of serum amyloid A (SAA), haptoglobin (HP), proinflammatory cytokines (TNF-α, IL-6 and IL1-β), serum malondialdehyde (MDA), PCT and NPT in horses with CDIE were higher than in healthy horses. Nevertheless, the levels of nitric oxide (NO), superoxide dismutase (SOD) and total antioxidant concentration (TAC) were considerably lower in diseased horses compared to those that were healthy. The ROC curves for eleven selected blood parameters, both in healthy horses and horses with CDIE demonstrated that all examined blood markers had significant levels of differentiation between CDIE cases and healthy controls (AUC > 87.5). The data in this study suggest that the evaluation of acute-phase proteins, cytokines, PCT, NPT, and oxidative stress biomarkers may well be used as a tool for diagnosis and assessment of CDIE and in disease pathogenesis in Arabian horses.
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Affiliation(s)
- Wael El-Deeb
- Department of Clinical Sciences, College of Veterinary Medicine, King Faisal University, Al-Ahsa 31982, Al-Hofuf P.O. 400, Saudi Arabia; Department of Veterinary Medicine, Infectious Diseases and Fish Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
| | - Mahmoud Fayez
- Al Ahsa Veterinary Diagnostic Laboratory, Ministry of Environment, Water and Agriculture, Saudi Arabia; Veterinary Serum and Vaccine Research Institute, Ministry of Agriculture, Cairo, Egypt
| | - Ibrahim Elsohaby
- Department of Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt; Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - Hermine V Mkrtchyan
- School of Biomedical Sciences, University of West London, St Mary's Rd, London, W5 5RF, UK
| | - Abdulrahman Alhaider
- Department of Clinical Sciences, College of Veterinary Medicine, King Faisal University, Al-Ahsa 31982, Al-Hofuf P.O. 400, Saudi Arabia
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10
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Abstract
Clostridioides difficile infection is the most common health care-associated infection in the United States with more than 20% patients experiencing symptomatic recurrence. The complex nature of host-bacterium interactions makes it difficult to predict the course of the disease based solely on clinical parameters. In the present study, we built a robust prediction model using representative plasma biomarkers and clinical parameters for 90-day all-cause mortality. Risk prediction based on immune biomarkers and clinical variables may contribute to treatment selection for patients as well as provide insight into the role of immune system in C. difficile pathogenesis. There is a pressing need for biomarker-based models to predict mortality from and recurrence of Clostridioides difficile infection (CDI). Risk stratification would enable targeted interventions such as fecal microbiota transplant, antitoxin antibodies, and colectomy for those at highest risk. Because severity of CDI is associated with the immune response, we immune profiled patients at the time of diagnosis. The levels of 17 cytokines in plasma were measured in 341 CDI inpatients. The primary outcome of interest was 90-day mortality. Increased tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), C-C motif chemokine ligand 5 (CCL-5), suppression of tumorigenicity 2 receptor (sST-2), IL-8, and IL-15 predicted mortality by univariate analysis. After adjusting for demographics and clinical characteristics, the mortality risk (as indicated by the hazard ratio [HR]) was higher for patients in the top 25th percentile for TNF-α (HR = 8.35, P = 0.005) and IL-8 (HR = 4.45, P = 0.01) and lower for CCL-5 (HR = 0.18, P ≤ 0.008). A logistic regression risk prediction model was developed and had an area under the receiver operating characteristic curve (AUC) of 0.91 for 90-day mortality and 0.77 for 90-day recurrence. While limited by being single site and retrospective, our work resulted in a model with a substantially greater predictive ability than white blood cell count. In conclusion, immune profiling demonstrated differences between patients in their response to CDI, offering the promise for precision medicine individualized treatment.
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Albarrak AA, Romana BS, Uraz S, Yousef MH, Juboori AA, Tahan V. Clostridium Difficile Infection in Inflammatory Bowel Disease Patients. Endocr Metab Immune Disord Drug Targets 2020; 19:929-935. [PMID: 30827274 DOI: 10.2174/1871530319666190301120558] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 01/04/2023]
Abstract
BACKGROUND The rising incidence of Clostridium difficile infection (CDI) in the general population has been recognized by health care organizations worldwide. The emergence of hypervirulent strains has made CDI more challenging to understand and treat. Inflammatory bowel disease (IBD) patients are at higher risk of infection, including CDI. OBJECTIVE A diagnostic approach for recurrent CDI has yet to be validated, particularly for IBD patients. Enzyme immunoassay (EIA) for toxins A and B, as well as glutamate dehydrogenase EIA, are both rapid testing options for the identification of CDI. Without a high index of suspicion, it is challenging to initially differentiate CDI from an IBD flare based on clinical evaluation alone. METHODS Here, we provide an up-to-date review on CDI in IBD patients. When caring for an IBD patient with suspected CDI, it is appropriate to empirically treat the presumed infection while awaiting further test results. RESULTS Treatment with vancomycin or fidaxomicin, but not oral metronidazole, has been advocated by an expert review from the clinical practice update committee of the American Gastroenterology Association. Recurrent CDI is more common in IBD patients compared to non-IBD patients (32% versus 24%), thus more aggressive treatment is recommended for IBD patients along with early consideration of fecal microbiota transplant. CONCLUSION Although the use of infliximab during CDI has been debated, clinical experience exists supporting its use in an IBD flare, even with active CDI when needed.
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Affiliation(s)
- Abdulmajeed A Albarrak
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, United States
| | - Bhupinder S Romana
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, United States
| | - Suleyman Uraz
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, United States
| | - Mohamad H Yousef
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, United States
| | - Alhareth A Juboori
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, United States
| | - Veysel Tahan
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, United States
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12
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Mileto S, Das A, Lyras D. Enterotoxic Clostridia: Clostridioides difficile Infections. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0015-2018. [PMID: 31124432 PMCID: PMC11026080 DOI: 10.1128/microbiolspec.gpp3-0015-2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Indexed: 12/17/2022] Open
Abstract
Clostridioides difficile is a Gram-positive, anaerobic, spore forming pathogen of both humans and animals and is the most common identifiable infectious agent of nosocomial antibiotic-associated diarrhea. Infection can occur following the ingestion and germination of spores, often concurrently with a disruption to the gastrointestinal microbiota, with the resulting disease presenting as a spectrum, ranging from mild and self-limiting diarrhea to severe diarrhea that may progress to life-threating syndromes that include toxic megacolon and pseudomembranous colitis. Disease is induced through the activity of the C. difficile toxins TcdA and TcdB, both of which disrupt the Rho family of GTPases in host cells, causing cell rounding and death and leading to fluid loss and diarrhea. These toxins, despite their functional and structural similarity, do not contribute to disease equally. C. difficile infection (CDI) is made more complex by a high level of strain diversity and the emergence of epidemic strains, including ribotype 027-strains which induce more severe disease in patients. With the changing epidemiology of CDI, our understanding of C. difficile disease, diagnosis, and pathogenesis continues to evolve. This article provides an overview of the current diagnostic tests available for CDI, strain typing, the major toxins C. difficile produces and their mode of action, the host immune response to each toxin and during infection, animal models of disease, and the current treatment and prevention strategies for CDI.
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Affiliation(s)
- S Mileto
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia, 3800
| | - A Das
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia, 3800
| | - D Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia, 3800
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13
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Tumour Necrosis Factor Alpha in Intestinal Homeostasis and Gut Related Diseases. Int J Mol Sci 2019; 20:ijms20081887. [PMID: 30995806 PMCID: PMC6515381 DOI: 10.3390/ijms20081887] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/05/2019] [Accepted: 04/13/2019] [Indexed: 02/06/2023] Open
Abstract
The intestinal epithelium constitutes an indispensable single-layered barrier to protect the body from invading pathogens, antigens or toxins. At the same time, beneficial nutrients and water have to be absorbed by the epithelium. To prevent development of intestinal inflammation or tumour formation, intestinal homeostasis has to be tightly controlled and therefore a strict balance between cell death and proliferation has to be maintained. The proinflammatory cytokine tumour necrosis factor alpha (TNFα) was shown to play a striking role for the regulation of this balance in the gut. Depending on the cellular conditions, on the one hand TNFα is able to mediate cell survival by activating NFκB signalling. On the other hand, TNFα might trigger cell death, in particular caspase-dependent apoptosis but also caspase-independent programmed necrosis. By regulating these cell death and survival mechanisms, TNFα exerts a variety of beneficial functions in the intestine. However, TNFα signalling is also supposed to play a critical role for the pathogenesis of inflammatory bowel disease (IBD), infectious diseases, intestinal wound healing and tumour formation. Here we review the literature about the physiological and pathophysiological role of TNFα signalling for the maintenance of intestinal homeostasis and the benefits and difficulties of anti-TNFα treatment during IBD.
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14
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Sharma D, Malik A, Guy C, Vogel P, Kanneganti TD. TNF/TNFR axis promotes pyrin inflammasome activation and distinctly modulates pyrin inflammasomopathy. J Clin Invest 2018; 129:150-162. [PMID: 30457980 DOI: 10.1172/jci121372] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 10/09/2018] [Indexed: 12/22/2022] Open
Abstract
Pyrin is an inflammasome sensor that promotes caspase-1-mediated pyroptotic cell death and maturation of proinflammatory cytokines IL-1β and IL-18. Familial Mediterranean fever (FMF), an autoinflammatory disorder, is associated with mutations in the gene encoding pyrin (MEFV). FMF-knockin (FMF-KI) mice that express chimeric pyrin protein with FMF mutation (MefvV726A/V726A) exhibit an autoinflammatory disorder mediated by autoactivation of the pyrin inflammasome. Increase in the levels of TNF are observed in FMF-KI mice, and many features of FMF overlap with the autoinflammatory disorder associated with TNF receptor signaling. In this study, we assessed the contribution of TNF signaling to pyrin inflammasome activation and its consequent role in distinct FMF pathologies. TNF signaling promoted the expression of pyrin in response to multiple stimuli and was required for inflammasome activation in response to canonical pyrin stimuli and in myeloid cells from FMF-KI mice. TNF signaling promoted systemic wasting, anemia, and neutrophilia in the FMF-KI mice. Further, TNF-induced pathology was induced specifically through the TNFR1 receptor, while TNFR2-mediated signaling was distinctly protective in colitis and ankle joint inflammation. Overall, our data show that TNF is a critical modulator of pyrin expression, inflammasome activation, and pyrin-inflammasomopathy. Further, specific blockade of TNFR1 or activation of TNFR2 could provide substantial protection against FMF pathologies.
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Affiliation(s)
| | | | | | - Peter Vogel
- Animal Resources Center and the Veterinary Pathology Core, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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15
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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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16
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Popoff MR. Clostridium difficile and Clostridium sordellii toxins, proinflammatory versus anti-inflammatory response. Toxicon 2018; 149:54-64. [DOI: 10.1016/j.toxicon.2017.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 11/07/2017] [Accepted: 11/09/2017] [Indexed: 12/17/2022]
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17
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Chen X, Kelly CP. On and Off: A Dual Role for Cysteine Protease Autoprocessing of C difficile Toxin B on Cytotoxicity vs Proinflammatory Toxin Actions? Cell Mol Gastroenterol Hepatol 2018; 5:654-655. [PMID: 29713672 PMCID: PMC5924747 DOI: 10.1016/j.jcmgh.2018.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
| | - Ciaran P. Kelly
- Correspondence Address correspondence to: Ciaran P. Kelly, MD, Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Dana 601, Boston, Massachusetts 02215.
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18
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Chandrasekaran R, Lacy DB. The role of toxins in Clostridium difficile infection. FEMS Microbiol Rev 2017; 41:723-750. [PMID: 29048477 PMCID: PMC5812492 DOI: 10.1093/femsre/fux048] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 10/10/2017] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile is a bacterial pathogen that is the leading cause of nosocomial antibiotic-associated diarrhea and pseudomembranous colitis worldwide. The incidence, severity, mortality and healthcare costs associated with C. difficile infection (CDI) are rising, making C. difficile a major threat to public health. Traditional treatments for CDI involve use of antibiotics such as metronidazole and vancomycin, but disease recurrence occurs in about 30% of patients, highlighting the need for new therapies. The pathogenesis of C. difficile is primarily mediated by the actions of two large clostridial glucosylating toxins, toxin A (TcdA) and toxin B (TcdB). Some strains produce a third toxin, the binary toxin C. difficile transferase, which can also contribute to C. difficile virulence and disease. These toxins act on the colonic epithelium and immune cells and induce a complex cascade of cellular events that result in fluid secretion, inflammation and tissue damage, which are the hallmark features of the disease. In this review, we summarize our current understanding of the structure and mechanism of action of the C. difficile toxins and their role in disease.
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Affiliation(s)
- Ramyavardhanee Chandrasekaran
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - D. Borden Lacy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- The Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37232, USA
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19
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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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20
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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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21
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Quesada-Gómez C, López-Ureña D, Chumbler N, Kroh HK, Castro-Peña C, Rodríguez C, Orozco-Aguilar J, González-Camacho S, Rucavado A, Guzmán-Verri C, Lawley TD, Lacy DB, Chaves-Olarte E. Analysis of TcdB Proteins within the Hypervirulent Clade 2 Reveals an Impact of RhoA Glucosylation on Clostridium difficile Proinflammatory Activities. Infect Immun 2016; 84:856-65. [PMID: 26755157 PMCID: PMC4771349 DOI: 10.1128/iai.01291-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 01/04/2016] [Indexed: 02/04/2023] Open
Abstract
Clostridium difficile strains within the hypervirulent clade 2 are responsible for nosocomial outbreaks worldwide. The increased pathogenic potential of these strains has been attributed to several factors but is still poorly understood. During a C. difficile outbreak, a strain from this clade was found to induce a variant cytopathic effect (CPE), different from the canonical arborizing CPE. This strain (NAP1V) belongs to the NAP1 genotype but to a ribotype different from the epidemic NAP1/RT027 strain. NAP1V and NAP1 share some properties, including the overproduction of toxins, the binary toxin, and mutations in tcdC. NAP1V is not resistant to fluoroquinolones, however. A comparative analysis of TcdB proteins from NAP1/RT027 and NAP1V strains indicated that both target Rac, Cdc42, Rap, and R-Ras but only the former glucosylates RhoA. Thus, TcdB from hypervirulent clade 2 strains possesses an extended substrate profile, and RhoA is crucial for the type of CPE induced. Sequence comparison and structural modeling revealed that TcdBNAP1 and TcdBNAP1V share the receptor-binding and autoprocessing activities but vary in the glucosyltransferase domain, consistent with the different substrate profile. Whereas the two toxins displayed identical cytotoxic potencies, TcdBNAP1 induced a stronger proinflammatory response than TcdBNAP1V as determined in ex vivo experiments and animal models. Since immune activation at the level of intestinal mucosa is a hallmark of C. difficile-induced infections, we propose that the panel of substrates targeted by TcdB is a determining factor in the pathogenesis of this pathogen and in the differential virulence potential seen among C. difficile strains.
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Affiliation(s)
- Carlos Quesada-Gómez
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales, Universidad de Costa Rica, San José, Costa Rica
| | - Diana López-Ureña
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales, Universidad de Costa Rica, San José, Costa Rica
| | - Nicole Chumbler
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Heather K Kroh
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Carolina Castro-Peña
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales, Universidad de Costa Rica, San José, Costa Rica
| | - César Rodríguez
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales, Universidad de Costa Rica, San José, Costa Rica
| | - Josué Orozco-Aguilar
- Facultad de Farmacia, Universidad de Costa Rica, San José, Costa Rica Laboratorio de Ensayos Biológicos, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica
| | - Sara González-Camacho
- Laboratorio de Ensayos Biológicos, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica
| | - Alexandra Rucavado
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Caterina Guzmán-Verri
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica
| | - Trevor D Lawley
- Host-Microbiota Interactions Laboratory, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - D Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA The Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
| | - Esteban Chaves-Olarte
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales, Universidad de Costa Rica, San José, Costa Rica
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22
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Chen S, Sun C, Wang H, Wang J. The Role of Rho GTPases in Toxicity of Clostridium difficile Toxins. Toxins (Basel) 2015; 7:5254-67. [PMID: 26633511 PMCID: PMC4690124 DOI: 10.3390/toxins7124874] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/18/2015] [Accepted: 11/18/2015] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea prevailing in hospital settings. In the past decade, the morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Toxin A (TcdA) and toxin B (TcdB), the two exotoxins of C. difficile, are the major virulence factors of CDI. The common mode of action of TcdA and TcdB is elicited by specific glucosylation of Rho-GTPase proteins in the host cytosol using UDP-glucose as a co-substrate, resulting in the inactivation of Rho proteins. Rho proteins are the key members in many biological processes and signaling pathways, inactivation of which leads to cytopathic and cytotoxic effects and immune responses of the host cells. It is supposed that Rho GTPases play an important role in the toxicity of C. difficile toxins. This review focuses on recent progresses in the understanding of functional consequences of Rho GTPases glucosylation induced by C. difficile toxins and the role of Rho GTPases in the toxicity of TcdA and TcdB.
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Affiliation(s)
- Shuyi Chen
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 510006, China.
| | - Chunli Sun
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 510006, China.
| | - Haiying Wang
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 510006, China.
| | - Jufang Wang
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 510006, China.
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23
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Shields K, Araujo-Castillo RV, Theethira TG, Alonso CD, Kelly CP. Recurrent Clostridium difficile infection: From colonization to cure. Anaerobe 2015; 34:59-73. [PMID: 25930686 PMCID: PMC4492812 DOI: 10.1016/j.anaerobe.2015.04.012] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 04/22/2015] [Accepted: 04/23/2015] [Indexed: 12/16/2022]
Abstract
Clostridium difficile infection (CDI) is increasingly prevalent, dangerous and challenging to prevent and manage. Despite intense national and international attention the incidence of primary and of recurrent CDI (PCDI and RCDI, respectively) have risen rapidly throughout the past decade. Of major concern is the increase in cases of RCDI resulting in substantial morbidity, morality and economic burden. RCDI management remains challenging as there is no uniformly effective therapy, no firm consensus on optimal treatment, and reliable data regarding RCDI-specific treatment options is scant. Novel therapeutic strategies are critically needed to rapidly, accurately, and effectively identify and treat patients with, or at-risk for, RCDI. In this review we consider the factors implicated in the epidemiology, pathogenesis and clinical presentation of RCDI, evaluate current management options for RCDI and explore novel and emerging therapies.
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Affiliation(s)
- Kelsey Shields
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave., Boston, MA 02215, United States.
| | - Roger V Araujo-Castillo
- Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Lowry Medical Office Building, Suite GB 110 Francis Street, Boston, MA 02215, United States.
| | - Thimmaiah G Theethira
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave., Boston, MA 02215, United States.
| | - Carolyn D Alonso
- Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Lowry Medical Office Building, Suite GB 110 Francis Street, Boston, MA 02215, United States.
| | - Ciaran P Kelly
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave., Boston, MA 02215, United States.
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24
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McDermott AJ, Higdon KE, Muraglia R, Erb-Downward JR, Falkowski NR, McDonald RA, Young VB, Huffnagle GB. The role of Gr-1(+) cells and tumour necrosis factor-α signalling during Clostridium difficile colitis in mice. Immunology 2015; 144:704-16. [PMID: 25399934 DOI: 10.1111/imm.12425] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 10/27/2014] [Accepted: 11/03/2014] [Indexed: 02/01/2023] Open
Abstract
The host response to Clostridium difficile infection in antibiotic-treated mice is characterized by robust recruitment of Gr-1(+) cells, increased expression of inflammatory cytokines including tumour necrosis factor-α (TNF-α), and the development of severe epithelial damage. To investigate the role of Gr-1(+) cells and TNF-α during C. difficile colitis, we treated infected mice with monoclonal antibodies against Gr-1 or TNF-α. Mice were challenged with vegetative cells of C. difficile strain VPI 10463 following treatment with the third-generation cephalosporin ceftriaxone. Ceftriaxone treatment alone was associated with significant changes in cytokine expression within the colonic mucosa but not overt inflammatory histopathological changes. In comparison, C. difficile infection following ceftriaxone treatment was associated with increased expression of inflammatory cytokines and chemokines including Cxcl1, Cxcl2, Il1b, Il17f and Tnfa, as well as robust recruitment of Ly6C(Mid) Gr-1(High) neutrophils and Ly6C(High) Gr-1(Mid) monocytes and the development of severe colonic histopathology. Anti-Gr-1 antibody treatment resulted in effective depletion of both Ly6C(Mid) Gr-1(High) neutrophils and Ly6C(High) Gr-1(Mid) monocytes: however, we observed no protection from the development of severe pathology or reduction in expression of the pro-inflammatory cytokines Il1b, Il6, Il33 and Tnfa following anti-Gr-1 treatment. By contrast, anti-TNF-α treatment did not affect Gr-1(+) cell recruitment, but was associated with increased expression of Il6 and Il1b. Additionally, Ffar2, Ffar3, Tslp, Tff and Ang4 expression was significantly reduced in anti-TNF-α-treated animals, in association with marked intestinal histopathology. These studies raise the possibility that TNF-α may play a role in restraining inflammation and protecting the epithelium during C. difficile infection.
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Affiliation(s)
- Andrew J McDermott
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
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25
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Huang T, Perez-Cordon G, Shi L, Li G, Sun X, Wang X, Wang J, Feng H. Clostridium difficile toxin B intoxicated mouse colonic epithelial CT26 cells stimulate the activation of dendritic cells. Pathog Dis 2015; 73:ftv008. [PMID: 25743476 DOI: 10.1093/femspd/ftv008] [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] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile causes antibiotic-associated diarrhea and pseudomembranous colitis mainly through two exotoxins TcdA and TcdB that target intestinal epithelial cells. Dendritic cells (DCs) play an important role in regulating intestinal inflammatory responses. In the current study, we explored the interaction of TcdB-intoxicated epithelial cells with mouse bone marrow-derived DCs. TcdB induced cell death and heat shock protein translocation in mouse intestinal epithelial CT26 cells. The intoxicated epithelial cells promoted the phagocytosis and the TNF-α secretion by DCs. Incubation with TcdB-intoxicated CT26 cells stimulated DC maturation. Moreover, TcdB-treated CT26 cells induced DC immigration when they were injected into mice subcutaneously. Taken together, these data demonstrate that TcdB-intoxicated intestinal epithelial cells are able to stimulate DC activation in vitro and attract DCs in vivo, indicating that epithelial cells may be able to regulate DC activation under the exposure of TcdB during C. difficile infection.
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Affiliation(s)
- Tuxiong Huang
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 51006, China Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, MD 21021, USA
| | - Gregorio Perez-Cordon
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, MD 21021, USA
| | - Lianfa Shi
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, MD 21021, USA
| | - Guangchao Li
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 51006, China
| | - Xingmin Sun
- Department of Infectious Disease and Global Health, Tufts Cummings School of Veterinary Medicine, North Grafton, MA 01536, USA
| | - Xiaoning Wang
- Institute of Life Science, General Hospital of the People's Liberation Army, Beijing 100853, China
| | - Jufang Wang
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou 51006, China
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, MD 21021, USA
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26
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Konishi H, Fujiya M, Kohgo Y. Host-microbe interactions via membrane transport systems. Environ Microbiol 2014; 17:931-7. [PMID: 25286963 DOI: 10.1111/1462-2920.12632] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 09/16/2014] [Accepted: 09/19/2014] [Indexed: 12/20/2022]
Abstract
Living organisms take in essential molecules and get rid of wastes effectively through the selective transport of materials. Especially in the digestive tract, advanced transport systems are indispensable for the absorption of nutrients and elimination of waste products. These transport pathways control physiological functions by modulating the ionic environment inside and outside the cells. Moreover, recent studies have shown the importance of the expression of trafficking-related molecules and the population of gut microbiota. We found that the molecules secreted from microorganisms are imported into the cells via transporters or endocytosis and that they activate cell survival pathways of intestinal epithelial cells. These findings indicate that the interactions between the gut microbiota and host cells are mediated, at least partly, by the membrane transport systems. In addition, it is well known that the breakdown of transport systems induces various diseases. This review highlights the significance of the transport systems as the pathogenic molecules and therapeutic targets in gastrointestinal disorders. For example, abnormal expression of the genes encoding membrane transport-related molecules is frequently involved in digestive diseases, such as colorectal cancer and inflammatory bowel disease. We herein review the significance of these molecules as pathogenic and therapeutic targets for digestive diseases.
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Affiliation(s)
- Hiroaki Konishi
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
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27
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Huang T, Li S, Li G, Tian Y, Wang H, Shi L, Perez-Cordon G, Mao L, Wang X, Wang J, Feng H. Utility of Clostridium difficile toxin B for inducing anti-tumor immunity. PLoS One 2014; 9:e110826. [PMID: 25340750 PMCID: PMC4207755 DOI: 10.1371/journal.pone.0110826] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 08/01/2014] [Indexed: 12/22/2022] Open
Abstract
Clostridium difficile toxin B (TcdB) is a key virulence factor of bacterium and induces intestinal inflammatory disease. Because of its potent cytotoxic and proinflammatory activities, we investigated the utility of TcdB in developing anti-tumor immunity. TcdB induced cell death in mouse colorectal cancer CT26 cells, and the intoxicated cells stimulated the activation of mouse bone marrow-derived dendritic cells and subsequent T cell activation in vitro. Immunization of BALB/c mice with toxin-treated CT26 cells elicited potent anti-tumor immunity that protected mice from a lethal challenge of the same tumor cells and rejected pre-injected tumors. The anti-tumor immunity generated was cell-mediated, long-term, and tumor-specific. Further experiments demonstrated that the intact cell bodies were important for the immunogenicity since lysing the toxin-treated tumor cells reduced their ability to induce antitumor immunity. Finally, we showed that TcdB is able to induce potent anti-tumor immunity in B16-F10 melanoma model. Taken together, these data demonstrate the utility of C. difficile toxin B for developing anti-tumor immunity.
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Affiliation(s)
- Tuxiong Huang
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou, China
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Shan Li
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou, China
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Guangchao Li
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou, China
| | - Yuan Tian
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou, China
| | - Haiying Wang
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou, China
| | - Lianfa Shi
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Gregorio Perez-Cordon
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Li Mao
- Department of Oncology and Diagnostics, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Xiaoning Wang
- Institute of Life Science, General Hospital of the People’s Liberation Army, Beijing, China
| | - Jufang Wang
- School of Bioscience and Bioengineering, South China University of Technology (SCUT), Guangzhou, China
- * E-mail: (JW); (HF)
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
- * E-mail: (JW); (HF)
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Sun X, Hirota SA. The roles of host and pathogen factors and the innate immune response in the pathogenesis of Clostridium difficile infection. Mol Immunol 2014; 63:193-202. [PMID: 25242213 DOI: 10.1016/j.molimm.2014.09.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 09/03/2014] [Accepted: 09/03/2014] [Indexed: 02/08/2023]
Abstract
Clostridium difficile (C. difficile) is the most common cause of nosocomial antibiotic-associated diarrhea and the etiologic agent of pseudomembranous colitis. The clinical manifestation of C. difficile infection (CDI) is highly variable, from asymptomatic carriage, to mild self-limiting diarrhea, to the more severe pseudomembranous colitis. Furthermore, in extreme cases, colonic inflammation and tissue damage can lead to toxic megacolon, a condition requiring surgical intervention. C. difficile expresses two key virulence factors; the exotoxins, toxin A (TcdA) and toxin B (TcdB), which are glucosyltransferases that target host-cell monomeric GTPases. In addition, some hypervirulent strains produce a third toxin, binary toxin or C. difficile transferase (CDT), which may contribute to the pathogenesis of CDI. More recently, other factors such as surface layer proteins (SLPs) and flagellin have also been linked to the inflammatory responses observed in CDI. Although the adaptive immune response can influence the severity of CDI, the innate immune responses to C. difficile and its toxins play crucial roles in CDI onset, progression, and overall prognosis. Despite this, the innate immune responses in CDI have drawn relatively little attention from clinical researchers. Targeting these responses may prove useful clinically as adjuvant therapies, especially in refractory and/or recurrent CDI. This review will focus on recent advances in our understanding of how C. difficile and its toxins modulate innate immune responses that contribute to CDI pathogenesis.
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Affiliation(s)
- Xingmin Sun
- Tufts University Cummings School of Veterinary Medicine, Department of Infectious Diseases and Global Health, North Grafton, MA 01536, USA; Tufts University, Clinical and Translational Science Institute, Boston, MA 02111, USA.
| | - Simon A Hirota
- University of Calgary, Snyder Institute for Chronic Diseases, Departments of Physiology & Pharmacology and Microbiology, Immunology & Infectious Diseases, Calgary, AB T2N4N1, Canada
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Abstract
Clostridium difficile infection (CDI) is the most common infectious cause of healthcare-acquired diarrhoea. Outcomes of C. difficile colonization are varied, from asymptomatic carriage to fulminant colitis and death, due in part to the interplay between the pathogenic virulence factors of the bacterium and the counteractive immune responses of the host. Secreted toxins A and B are the major virulence factors of C. difficile and induce a profound inflammatory response by intoxicating intestinal epithelial cells causing proinflammatory cytokine release. Host cell necrosis, vascular permeability and neutrophil infiltration lead to an elevated white cell count, profuse diarrhoea and in severe cases, dehydration, hypoalbuminaemia and toxic megacolon. Other bacterial virulence factors, including surface layer proteins and flagella proteins, are detected by host cell surface signal molecules that trigger downstream cell-mediated immune pathways. Human studies have identified a role for serum and faecal immunoglobulin levels in protection from disease, but the recent development of a mouse model of CDI has enabled studies into the precise molecular interactions that trigger the immune response during infection. Key effector molecules have been identified that can drive towards a protective anti-inflammatory response or a damaging proinflammatory response. The limitations of current antimicrobial therapies for CDI have led to the development of both active and passive immunotherapies, none of which have, as yet been formally approved for CDI. However, recent advances in our understanding of the molecular basis of host immune protection against CDI may provide an exciting opportunity for novel therapeutic developments in the future.
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Affiliation(s)
- Katie Solomon
- School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Republic of Ireland
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McDermott AJ, Frank CR, Falkowski NR, McDonald RA, Young VB, Huffnagle GB. Role of GM-CSF in the inflammatory cytokine network that regulates neutrophil influx into the colonic mucosa during Clostridium difficile infection in mice. Gut Microbes 2014; 5:476-84. [PMID: 25045999 PMCID: PMC5915364 DOI: 10.4161/gmic.29964] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Clostridium difficile infection in antibiotic-treated mice results in acute colitis characterized by severe intestinal histopathology, robust neutrophil influx, and increased expression of numerous inflammatory cytokines, including GM-CSF. We utilized a neutralizing monoclonal antibody (mAb) against GM-CSF in a murine model to study the role of GM-CSF during acute C. difficile colitis. Cefoperazone-treated mice were challenged with C. difficile (strain 630) spores. Expression of GM-CSF was significantly increased in animals challenged with C. difficile. Treatment with an anti-GM-CSF mAb did not alter C. difficile colonization levels, weight loss, or expression of IL-22 and RegIIIγ. However, expression of the inflammatory cytokines TNFα and IL-1β, as well as iNOS, was significantly reduced following anti-GM-CSF treatment. Expression of the neutrophil chemokines CXCL1 and CXCL2, but not the chemokines CCL2, CCL4, CXCL9, and CXCL10, was significantly reduced by anti-GM-CSF treatment. Consistent with a decrease in neutrophil-attractant chemokine expression, there were fewer neutrophils in histology sections and a reduction in the expression of secretory leukocyte protease inhibitor (SLPI), a tissue anti-protease that protects against damage by secreted neutrophil elastase. These data indicate that GM-CSF plays a role in the inflammatory signaling network that drives neutrophil recruitment in response to C. difficile infection but does not appear to play a role in clearance of the infection.
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Affiliation(s)
- Andrew J McDermott
- Department of Microbiology and Immunology; University of Michigan Medical School; Ann Arbor, MI USA
| | - Charles R Frank
- Division of Pulmonary and Critical Care Medicine; Department of Internal Medicine; University of Michigan Medical School; Ann Arbor, MI USA
| | - Nicole R Falkowski
- Division of Pulmonary and Critical Care Medicine; Department of Internal Medicine; University of Michigan Medical School; Ann Arbor, MI USA
| | - Roderick A McDonald
- Division of Pulmonary and Critical Care Medicine; Department of Internal Medicine; University of Michigan Medical School; Ann Arbor, MI USA
| | - Vincent B Young
- Department of Microbiology and Immunology; University of Michigan Medical School; Ann Arbor, MI USA,Division of Infectious Diseases; Department of Internal Medicine; University of Michigan Medical School; Ann Arbor, MI USA
| | - Gary B Huffnagle
- Department of Microbiology and Immunology; University of Michigan Medical School; Ann Arbor, MI USA,Division of Pulmonary and Critical Care Medicine; Department of Internal Medicine; University of Michigan Medical School; Ann Arbor, MI USA,Correspondence to: Gary B Huffnagle;
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31
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Hing TC, Ho S, Shih DQ, Ichikawa R, Cheng M, Chen J, Chen X, Law I, Najarian R, Kelly CP, Gallo RL, Targan SR, Pothoulakis C, Koon HW. The antimicrobial peptide cathelicidin modulates Clostridium difficile-associated colitis and toxin A-mediated enteritis in mice. Gut 2013; 62:1295-305. [PMID: 22760006 PMCID: PMC3737259 DOI: 10.1136/gutjnl-2012-302180] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Clostridium difficile mediates intestinal inflammation by releasing toxin A (TxA), a potent enterotoxin. Cathelicidins (Camp as gene name, LL-37 peptide in humans and mCRAMP peptide in mice) are antibacterial peptides that also posses anti-inflammatory properties. OBJECTIVES To determine the role of cathelicidins in models of Clostridium difficile infection and TxA-mediated ileal inflammation and cultured human primary monocytes. DESIGN Wild-type (WT) and mCRAMP-deficient (Camp(-/-)) mice were treated with an antibiotic mixture and infected orally with C difficile. Some mice were intracolonically given mCRAMP daily for 3 days. Ileal loops were also prepared in WT mice and treated with either saline or TxA and incubated for 4 h, while some TxA-treated loops were injected with mCRAMP. RESULTS Intracolonic mCRAMP administration to C difficile-infected WT mice showed significantly reduced colonic histology damage, apoptosis, tissue myeloperoxidase (MPO) and tumour necrosis factor (TNF)α levels. Ileal mCRAMP treatment also significantly reduced histology damage, tissue apoptosis, MPO and TNFα levels in TxA-exposed ileal loops. WT and Camp(-/-) mice exhibited similar intestinal responses in both models, implying that C difficile/TxA-induced endogenous cathelicidin may be insufficient to modulate C difficile/TxA-mediated intestinal inflammation. Both LL-37 and mCRAMP also significantly reduced TxA-induced TNFα secretion via inhibition of NF-κB phosphorylation. Endogenous cathelicidin failed to control C difficile and/or toxin A-mediated inflammation and even intestinal cathelicidin expression was increased in humans and mice. CONCLUSION Exogenous cathelicidin modulates C difficile colitis by inhibiting TxA-associated intestinal inflammation. Cathelicidin administration may be a new anti-inflammatory treatment for C difficile toxin-associated disease.
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Affiliation(s)
- Tressia C Hing
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, the University of California Los Angeles, Los Angeles, California, USA
| | - Samantha Ho
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, the University of California Los Angeles, Los Angeles, California, USA
| | - David Q Shih
- Inflammatory Bowel and Immunobiology Research Institute, Cedars Sinai Medical Center, Los Angeles, California, USA
| | - Ryan Ichikawa
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, the University of California Los Angeles, Los Angeles, California, USA
| | - Michelle Cheng
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, the University of California Los Angeles, Los Angeles, California, USA
| | - Jeremy Chen
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, the University of California Los Angeles, Los Angeles, California, USA
| | - Xinhua Chen
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Ivy Law
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, the University of California Los Angeles, Los Angeles, California, USA
| | - Robert Najarian
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Ciaran P Kelly
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Richard L Gallo
- Division of Dermatology, the University of California San Diego, San Diego, California, USA
| | - Stephan R Targan
- Inflammatory Bowel and Immunobiology Research Institute, Cedars Sinai Medical Center, Los Angeles, California, USA
| | - Charalabos Pothoulakis
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, the University of California Los Angeles, Los Angeles, California, USA
| | - Hon Wai Koon
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, the University of California Los Angeles, Los Angeles, California, USA
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32
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Caspase activation as a versatile assay platform for detection of cytotoxic bacterial toxins. J Clin Microbiol 2013; 51:2970-6. [PMID: 23824772 DOI: 10.1128/jcm.01161-13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Pathogenic bacteria produce several virulence factors that help them establish infection in permissive hosts. Bacterial toxins are a major class of virulence factors and hence are attractive therapeutic targets for vaccine development. Here, we describe the development of a rapid, sensitive, and high-throughput assay that can be used as a versatile platform to measure the activities of bacterial toxins. We have exploited the ability of these toxins to cause cell death via apoptosis of sensitive cultured cell lines as a readout for measuring toxin activity. Caspases (cysteine-aspartic proteases) are induced early in the apoptotic pathway, and so we used their induction to measure the activities of Clostridium difficile toxins A (TcdA) and B (TcdB) and binary toxin (CDTa-CDTb), Corynebacterium diphtheriae toxin (DT), and Pseudomonas aeruginosa exotoxin A (PEA). Caspase induction in the cell lines, upon exposure to toxins, was optimized by toxin concentration and intoxication time, and the specificity of caspase activity was established using a genetically mutated toxin and a pan-caspase inhibitor. In addition, we demonstrate the utility of the caspase assay for measuring toxin potency, as well as neutralizing antibody (NAb) activity against C. difficile toxins. Furthermore, the caspase assay showed excellent correlation with the filamentous actin (F-actin) polymerization assay for measuring TcdA and TcdB neutralization titers upon vaccination of hamsters. These results demonstrate that the detection of caspase induction due to toxin exposure using a chemiluminescence readout can support potency and clinical immunogenicity testing for bacterial toxin vaccine candidates in development.
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Zhang Y, Shi L, Li S, Yang Z, Standley C, Yang Z, ZhuGe R, Savidge T, Wang X, Feng H. A segment of 97 amino acids within the translocation domain of Clostridium difficile toxin B is essential for toxicity. PLoS One 2013; 8:e58634. [PMID: 23484044 PMCID: PMC3590123 DOI: 10.1371/journal.pone.0058634] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 02/05/2013] [Indexed: 01/27/2023] Open
Abstract
Clostridium difficile toxin B (TcdB) intoxicates target cells by glucosylating Rho GTPases. TcdB (269 kDa) consists of at least 4 functional domains including a glucosyltransferase domain (GTD), a cysteine protease domain (CPD), a translocation domain (TD), and a receptor binding domain (RBD). The function and molecular mode of action of the TD, which is the largest segment of TcdB and comprises nearly 50% of the protein, remain largely unknown. Here we show that a 97-amino-acid segment (AA1756 – 1852, designated as ?97 or D97), located in the C-terminus of the TD and adjacent to the RBD, is essential for the cellular activity of TcdB. Deletion of this segment in TcdB (designated as TxB-D97), did not adversely alter toxin enzymatic activities or its cellular binding and uptake capacity. TxB-D97 bound to and entered cells in a manner similar to TcdB holotoxin. Both wild type and mutant toxins released their GTDs similarly in the presence of inositol hexakisphosphate (InsP6), and showed a similar glucosyltransferase activity in a cell-free glucosylating assay. Despite these similarities, the cytotoxic activity of TxB-D97 was reduced by more than 5 logs compared to wild type toxin, supported by the inability of TxB-D97 to glucosylate Rac1 of target cells. Moreover, the mutant toxin failed to elicit tumor necrosis factor alpha (TNF-α) in macrophages, a process dependent on the glucosyltransferase activity of the toxin. Cellular fractionation of toxin-exposed cells revealed that TxB-D97 was unable to efficiently release the GTD into cytosol. Thereby, we conclude the 97-amino-acid region of the TD C-terminus of TcdB adjacent to the RBD, is essential for the toxicity of TcdB.
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Affiliation(s)
- Yongrong Zhang
- School of Bioengineering, East China University of Science and Technology, Shanghai, China
| | - Lianfa Shi
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Shan Li
- 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
| | - Clive Standley
- University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Zhong Yang
- School of Bioengineering, East China University of Science and Technology, Shanghai, China
| | - Ronghua ZhuGe
- University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Tor Savidge
- Baylor College of Medicine, Houston, Texas, United States of America
| | - Xiaoning Wang
- School of Bioengineering, East China University of Science and Technology, Shanghai, China
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
- * E-mail:
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Zeiser J, Gerhard R, Just I, Pich A. Substrate specificity of clostridial glucosylating toxins and their function on colonocytes analyzed by proteomics techniques. J Proteome Res 2013; 12:1604-18. [PMID: 23387933 DOI: 10.1021/pr300973q] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Clostridium difficile is the major cause of intestinal infections in hospitals. The major virulence factors are toxin A (TcdA) and toxin B (TcdB), which belong to the group of clostridial glucosylating toxins (CGT) that inactivate small GTPases. After a 24 h incubation period with TcdA or a glucosyltransferase-deficient mutant TcdA (gdTcdA), quantitative changes in the proteome of colonic cells (Caco-2) were analyzed using high-resolution LC-MS/MS and the SILAC technique. The changes in abundance of more than 5100 proteins were quantified. Nearly 800 toxin-responsive proteins were identified that were involved in cell cycle, cell structure, and adhesion as well as metabolic processes. Several proteins localized to mitochondria or involved in lipid metabolism were consistently of higher abundance after TcdA treatment. All changes of protein abundance depended on the glucosyltransferase activity of TcdA. Glucosylation of the known targets of TcdA such as RhoA, RhoC, RhoG was detected by LC-MS/MS. In addition, an almost complete glucosylation of Rap1(A/B), Rap2(A/B/C) and a partial glucosylation of Ral(A/B) and (H/K/N)Ras were detected. The glucosylation pattern of TcdA was compared to that of other CGT like TcdB, the variant TcdB from C. difficile strain VPI 1470 (TcdBF), and lethal toxin from C. sordellii (TcsL).
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Affiliation(s)
- Johannes Zeiser
- Hannover Medical School, Institute of Toxicology , Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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35
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Madan R, Petri WA. Immune responses to Clostridium difficile infection. Trends Mol Med 2012; 18:658-66. [PMID: 23084763 PMCID: PMC3500589 DOI: 10.1016/j.molmed.2012.09.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 08/30/2012] [Accepted: 09/14/2012] [Indexed: 01/24/2023]
Abstract
Clostridium difficile is the causal agent of antibiotic-associated diarrhea and is a leading cause of hospital-acquired infections in the US. C. difficile has been known to cause severe diarrhea and colitis for more than 30 years, but the emergence of a newer, hypervirulent strain of C. difficile (BI/NAP1) has further compounded the problem, and recently both the number of cases and mortality associated with C. difficile-associated diarrhea have been increasing. One of the major drivers of disease pathogenesis is believed to be an excessive host inflammatory response. A better understanding of the host inflammation and immune mechanisms that modulate the course of disease and control host susceptibility to C. difficile could lead to novel (host-targeted) strategies for combating the challenges posed by this deadly infection. This review summarizes our current knowledge of the host inflammatory response during C. difficile infection.
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Affiliation(s)
- Rajat Madan
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA 22908-1337, USA
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36
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Tomar N, De RK. Modeling host-pathogen interactions: H. sapiens as a host and C. difficile as a pathogen. J Mol Recognit 2012; 25:474-85. [DOI: 10.1002/jmr.2211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Namrata Tomar
- Machine Intelligence Unit; Indian Statistical Institute; 203 B.T. Road; Kolkata; 700108; India
| | - Rajat K. De
- Machine Intelligence Unit; Indian Statistical Institute; 203 B.T. Road; Kolkata; 700108; India
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37
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Abstract
Clostridium difficile is the most common cause of nosocomial bacterial diarrhoea in the Western world. Diarrhoea and colitis are caused by the actions of toxins A and B released by pathogenic strains of C. difficile. Adaptive immune responses to these toxins influence the outcomes of C. difficile infection (CDI). Symptomless carriers of toxinogenic C. difficile and those with a single episode of CDI without recurrence show more robust antitoxin immune responses than those with symptomatic and recurrent disease. Immune-based approaches to CDI therapy and prevention have been developed using active vaccination or passive immunotherapy targeting C. difficile toxins. Innate immune responses to C. difficile and its toxins are also central to the pathophysiology of CDI. An acute intestinal inflammatory response with prominent neutrophil infiltration and associated tissue injury is characteristic of CDI. Furthermore, inhibiting this acute inflammatory response can protect against the intestinal injury that results from exposure to C. difficile toxins in animal models. Studies examining host risk factors for CDI have led to validated clinical prediction tools for risk of primary and of recurrent disease. Risk factors associated with severe CDI with poor clinical outcomes have also been identified and include marked elevation of the peripheral white blood cell count and elevated creatinine. However, further work is needed in this area to guide the clinical application of new approaches to disease prevention and treatment including new antimicrobials as well as passive and active immunization.
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Affiliation(s)
- Ciarán P Kelly
- Gastroenterology Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, USA
| | - Lorraine Kyne
- Department of Medicine for the Older Person, Mater Misericordiae University Hospital and University College, Dublin, Ireland
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Kuo CL, Oyler GA, Shoemaker CB. Accelerated neuronal cell recovery from Botulinum neurotoxin intoxication by targeted ubiquitination. PLoS One 2011; 6:e20352. [PMID: 21629663 PMCID: PMC3101245 DOI: 10.1371/journal.pone.0020352] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 04/19/2011] [Indexed: 11/19/2022] Open
Abstract
Botulinum neurotoxin (BoNT), a Category A biodefense agent, delivers a protease to motor neuron cytosol that cleaves one or more soluble NSF attachment protein receptors (SNARE) proteins involved in neurotransmission to cause a flaccid paralysis. No antidotes exist to reverse symptoms of BoNT intoxication so severely affected patients require artificial respiration with prolonged intensive care. Time to recovery depends on toxin serotype because the intraneuronal persistence of the seven known BoNT serotypes varies widely from days to many months. Our therapeutic antidote strategy is to develop ‘targeted F-box’ (TFB) agents that target the different intraneuronal BoNT proteases for accelerated degradation by the ubiquitin proteasome system (UPS), thus promoting rapid recovery from all serotypes. These agents consist of a camelid heavy chain-only VH (VHH) domain specific for a BoNT protease fused to an F-box domain recognized by an intraneuronal E3-ligase. A fusion protein containing the 14 kDa anti-BoNT/A protease VHH, ALcB8, joined to a 15 kDa F-box domain region of TrCP (D5) was sufficient to cause increased ubiquitination and accelerate turnover of the targeted BoNT/A protease within neurons. Neuronal cells expressing this TFB, called D5-B8, were also substantially resistant to BoNT/A intoxication and recovered from intoxication at least 2.5 fold quicker than control neurons. Fusion of D5 to a VHH specific for BoNT/B protease (BLcB10) led to accelerated turnover of the targeted protease within neurons, thus demonstrating the modular nature of these therapeutic agents and suggesting that development of similar therapeutic agents specific to all botulinum serotypes should be readily achievable.
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Affiliation(s)
- Chueh-Ling Kuo
- Department of Biomedical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts, United States of America
| | - George A. Oyler
- Synaptic Research LLC, Baltimore, Maryland, United States of America
| | - Charles B. Shoemaker
- Department of Biomedical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts, United States of America
- * E-mail:
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Kachrimanidou M, Malisiovas N. Clostridium difficile infection: a comprehensive review. Crit Rev Microbiol 2011; 37:178-87. [PMID: 21609252 DOI: 10.3109/1040841x.2011.556598] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Clostridium difficile is one of the most important causes of healthcare acquired diarrhea. The disease spectrum caused by C. difficile infection ranges from mild, self-limited, illness to a severe, life-threatening colitis. The incidence of C. difficile associated disease has risen dramatically over the last decade, leading to increased research interest aiming at the discovery of new virulence factors and the development of new treatment and prevention regimens. This review summarizes the pathogenesis and changing epidemiology of C. difficile associated disease, the clinical spectrum and laboratory methods to diagnose C. difficile infection, and current treatment strategies.
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Affiliation(s)
- Melina Kachrimanidou
- Nuffield Department of Clinical Medicine, Oxford University, John Radcliffe Hospital Oxford, UK, OX3 9DU.
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40
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Toll-like receptor 5 stimulation protects mice from acute Clostridium difficile colitis. Infect Immun 2011; 79:1498-503. [PMID: 21245274 DOI: 10.1128/iai.01196-10] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Clostridium difficile is a spore-forming bacterium that infects the lower intestinal tract of humans and is the most common known cause of diarrhea among hospitalized patients. Clostridium difficile colitis is mediated by toxins and develops during or following antibiotic administration. We have used a murine model of C. difficile infection, which reproduces the major features of the human disease, to study the effect of innate immune activation on resistance to C. difficile infection. We found that administration of purified Salmonella-derived flagellin, a Toll-like receptor 5 (TLR5) agonist, protects mice from C. difficile colitis by delaying C. difficile growth and toxin production in the colon and cecum. TLR5 stimulation significantly improves pathological changes in the cecum and colon of C. difficile-infected mice and reduces epithelial cell loss. Flagellin treatment reduces epithelial apoptosis in the large intestine, thereby protecting the integrity of the intestinal epithelial barrier during C. difficile infection. We demonstrate that restoring intestinal innate immune tone by TLR stimulation in antibiotic-treated mice ameliorates intestinal inflammation and prevents death from C. difficile colitis, potentially providing an approach to prevent C. difficile-induced pathology.
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Ng J, Hirota SA, Gross O, Li Y, Ulke-Lemee A, Potentier MS, Schenck LP, Vilaysane A, Seamone ME, Feng H, Armstrong GD, Tschopp J, Macdonald JA, Muruve DA, Beck PL. Clostridium difficile toxin-induced inflammation and intestinal injury are mediated by the inflammasome. Gastroenterology 2010; 139:542-52, 552.e1-3. [PMID: 20398664 DOI: 10.1053/j.gastro.2010.04.005] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 03/23/2010] [Accepted: 04/08/2010] [Indexed: 01/05/2023]
Abstract
BACKGROUND & AIMS Clostridium difficile-associated disease (CDAD) is the leading cause of nosocomial diarrhea in the United States. C difficile toxins TcdA and TcdB breach the intestinal barrier and trigger mucosal inflammation and intestinal damage. The inflammasome is an intracellular danger sensor of the innate immune system. In the present study, we hypothesize that TcdA and TcdB trigger inflammasome-dependent interleukin (IL)-1beta production, which contributes to the pathogenesis of CDAD. METHODS Macrophages exposed to TcdA and TcdB were assessed for IL-1beta production, an indication of inflammasome activation. Macrophages deficient in components of the inflammasome were also assessed. Truncated/mutated forms of TcdB were assessed for their ability to activate the inflammasome. The role of inflammasome signaling in vivo was assessed in ASC-deficient and IL-1 receptor antagonist-treated mice. RESULTS TcdA and TcdB triggered inflammasome activation and IL-1beta secretion in macrophages and human mucosal biopsy specimens. Deletion of Nlrp3 decreased, whereas deletion of ASC completely abolished, toxin-induced IL-1beta release. TcdB-induced IL-1beta release required recognition of the full-length toxin but not its enzymatic function. In vivo, deletion of ASC significantly reduced toxin-induced inflammation and damage, an effect that was mimicked by pretreatment with the IL-1 receptor antagonist anakinra. CONCLUSIONS TcdA and TcdB trigger IL-1beta release by activating an ASC-containing inflammasome, a response that contributes to toxin-induced inflammation and damage in vivo. Pretreating mice with the IL-1 receptor antagonist anakinra afforded the same level of protection that was observed in ASC-/- mice. These data suggest that targeting inflammasome or IL-1beta signaling may represent new therapeutic targets in the treatment of CDAD.
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Affiliation(s)
- Jeffrey Ng
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
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Sun X, Savidge T, Feng H. The enterotoxicity of Clostridium difficile toxins. Toxins (Basel) 2010; 2:1848-80. [PMID: 22069662 PMCID: PMC3153265 DOI: 10.3390/toxins2071848] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 06/23/2010] [Accepted: 07/09/2010] [Indexed: 02/06/2023] Open
Abstract
The major virulence factors of Clostridium difficile infection (CDI) are two large exotoxins A (TcdA) and B (TcdB). However, our understanding of the specific roles of these toxins in CDI is still evolving. It is now accepted that both toxins are enterotoxic and proinflammatory in the human intestine. Both purified TcdA and TcdB are capable of inducing the pathophysiology of CDI, although most studies have focused on TcdA. C. difficile toxins exert a wide array of biological activities by acting directly on intestinal epithelial cells. Alternatively, the toxins may target immune cells and neurons once the intestinal epithelial barrier is disrupted. The toxins may also act indirectly by stimulating cells to produce chemokines, proinflammatory cytokines, neuropeptides and other neuroimmune signals. This review considers the mechanisms of TcdA- and TcdB-induced enterotoxicity, and recent developments in this field.
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Affiliation(s)
- Xingmin Sun
- Tufts Cummings School of Veterinary Medicine, North Grafton, MA, 01536, USA;
| | - Tor Savidge
- The University of Texas Medical Branch, Galveston, TX, 77555, USA;
| | - Hanping Feng
- Tufts Cummings School of Veterinary Medicine, North Grafton, MA, 01536, USA;
- Author to whom correspondence should be addressed; ; Tel.: +1-508-887-4252; Fax: +1-508-839-7911
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Antibody-enhanced, Fc gamma receptor-mediated endocytosis of Clostridium difficile toxin A. Infect Immun 2009; 77:2294-303. [PMID: 19307220 DOI: 10.1128/iai.01577-08] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Toxin A (TcdA) and toxin B (TcdB) are major virulence factors of Clostridium difficile. These two toxins intoxicate cultured cells by similar mechanisms, and TcdB generally is more potent than TcdA in cultured cells. The exact reason for this difference is unclear. Here, we report that the cellular effects of TcdA can be substantially enhanced via an opsonizing antibody through Fc gamma receptor I (FcgammaRI)-mediated endocytosis. A TcdA-specific monoclonal antibody, A1H3, was found to significantly enhance the cytotoxicity of TcdA to macrophages and monocytes. The A1H3-dependent enhancement of glucosyltransferase activity, cytoskeleton disruption, and tumor necrosis factor alpha production induced by TcdA was further demonstrated using RAW 264.7 cells. Subsequent experiments indicated that the interaction of FcgammaRI with A1H3 underlays the antibody-dependent enhancement of the cellular effects of TcdA. While blocking FcgammaRII and FcgammaRIII with anti-CD16/32 antibodies did not affect the TcdA-mediated glucosylation of Rac1 in RAW 264.7 cells, presaturation of FcgammaRI with anti-CD64 antibodies in THP1 cells significantly reduced this activity. Incubation of a TcdA-A1H3 immune complex with recombinant mouse CD64 completely abrogated the A1H3-mediated enhancement of the glucosyltransferase activity of TcdA in RAW 264.7 cells. Moreover, expression of FcgammaRI in CHO cells strikingly enhanced the sensitivity of these cells to TcdA complexed with A1H3. We showed that the presence of A1H3 facilitated cell surface recruitment of TcdA, contributing to the antibody-dependent, FcgammaRI-mediated enhancement of TcdA activity. Finally, studies using chlorpromazine and endosomal acidification inhibitors revealed an important role of the endocytic pathway in the A1H3-dependent enhancement of TcdA activity.
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