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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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Tubau-Juni N, Bassaganya-Riera J, Leber AJ, Alva SS, Hontecillas R. Oral Omilancor Treatment Ameliorates Clostridioides difficile Infection During IBD Through Novel Immunoregulatory Mechanisms Mediated by LANCL2 Activation. Inflamm Bowel Dis 2024; 30:103-113. [PMID: 37436905 DOI: 10.1093/ibd/izad124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Indexed: 07/14/2023]
Abstract
BACKGROUND Clostridioides difficile infection (CDI) is an opportunistic infection of the gastrointestinal tract, commonly associated with antibiotic administration, that afflicts almost 500 000 people yearly only in the United States. CDI incidence and recurrence is increased in inflammatory bowel disease (IBD) patients. Omilancor is an oral, once daily, first-in-class, gut-restricted, immunoregulatory therapeutic in clinical development for the treatment of IBD. METHODS Acute and recurrent murine models of CDI and the dextran sulfate sodium-induced concomitant model of IBD and CDI were utilized to determine the therapeutic efficacy of oral omilancor. To evaluate the protective effects against C. difficile toxins, in vitro studies with T84 cells were also conducted. 16S sequencing was employed to characterize microbiome composition. RESULTS Activation of the LANCL2 pathway by oral omilancor and its downstream host immunoregulatory changes decreased disease severity and inflammation in the acute and recurrence models of CDI and the concomitant model of IBD/CDI. Immunologically, omilancor treatment increased mucosal regulatory T cell and decreased pathogenic T helper 17 cell responses. These immunological changes resulted in increased abundance and diversity of tolerogenic gut commensal bacterial strains in omilancor-treated mice. Oral omilancor also resulted in accelerated C. difficile clearance in an antimicrobial-free manner. Furthermore, omilancor provided protection from toxin damage, while preventing the metabolic burst observed in intoxicated epithelial cells. CONCLUSIONS These data support the development of omilancor as a novel host-targeted, antimicrobial-free immunoregulatory therapeutic for the treatment of IBD patients with C. difficile-associated disease and pathology with the potential to address the unmet clinical needs of ulcerative colitis and Crohn's disease patients with concomitant CDI.
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Bratkovič T, Zahirović A, Bizjak M, Rupnik M, Štrukelj B, Berlec A. New treatment approaches for Clostridioides difficile infections: alternatives to antibiotics and fecal microbiota transplantation. Gut Microbes 2024; 16:2337312. [PMID: 38591915 PMCID: PMC11005816 DOI: 10.1080/19490976.2024.2337312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 03/27/2024] [Indexed: 04/10/2024] Open
Abstract
Clostridioides difficile causes a range of debilitating intestinal symptoms that may be fatal. It is particularly problematic as a hospital-acquired infection, causing significant costs to the health care system. Antibiotics, such as vancomycin and fidaxomicin, are still the drugs of choice for C. difficile infections, but their effectiveness is limited, and microbial interventions are emerging as a new treatment option. This paper focuses on alternative treatment approaches, which are currently in various stages of development and can be divided into four therapeutic strategies. Direct killing of C. difficile (i) includes beside established antibiotics, less studied bacteriophages, and their derivatives, such as endolysins and tailocins. Restoration of microbiota composition and function (ii) is achieved with fecal microbiota transplantation, which has recently been approved, with standardized defined microbial mixtures, and with probiotics, which have been administered with moderate success. Prevention of deleterious effects of antibiotics on microbiota is achieved with agents for the neutralization of antibiotics that act in the gut and are nearing regulatory approval. Neutralization of C. difficile toxins (iii) which are crucial virulence factors is achieved with antibodies/antibody fragments or alternative binding proteins. Of these, the monoclonal antibody bezlotoxumab is already in clinical use. Immunomodulation (iv) can help eliminate or prevent C. difficile infection by interfering with cytokine signaling. Small-molecule agents without bacteriolytic activity are usually selected by drug repurposing and can act via a variety of mechanisms. The multiple treatment options described in this article provide optimism for the future treatment of C. difficile infection.
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Affiliation(s)
- Tomaž Bratkovič
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Abida Zahirović
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Maruša Bizjak
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Maja Rupnik
- National Laboratory for Health, Environment and Food, Prvomajska 1, Maribor, Slovenia
- Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Borut Štrukelj
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Aleš Berlec
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia
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Zhao H, Li W, Zhou X, Pan L, Feng Y, Gao P, Ji J, Zhang H, Zhao K, Wang C, Lu Z. C-X-C Motif Chemokine Ligand 1 Promotes Colitis by Modulating the Gut Microbiota. J Innate Immun 2023; 16:33-44. [PMID: 38071977 PMCID: PMC10776137 DOI: 10.1159/000535637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 12/01/2023] [Indexed: 01/11/2024] Open
Abstract
INTRODUCTION C-X-C motif chemokine ligand 1 (CXCL1) is a potent neutrophil chemoattractant that plays a pivotal role in recruiting neutrophils during inflammatory conditions. This study explored the role of CXCL1 in modulating the gut microbiota, influencing neutrophil infiltration, and contributing to the development of colitis. METHODS We employed quantitative PCR to assess CXCL1 expression in colon samples. A mouse model of dextran sulfate sodium (DSS)-induced colitis was utilized to explore the progression of colitis in wild-type (WT) and CXCL1-deficient (CXCL1-/-) mice. RESULTS Colitis attenuation was evident in CXCL1-/- mice. Significant alterations were observed in the gut microbiome, as revealed by 16S rRNA gene sequencing. Furthermore, CXCL1-/- mice exhibited reduced gut permeability and diminished endotoxin levels in peripheral blood following DSS treatment compared to WT mice. In response to DSS treatment, WT mice showed a clear increase in neutrophil infiltration, while CXCL1-/- mice exhibited lower levels of infiltration. Fecal microbiota transplantation (FMT) using stools from CXCL1-/- mice alleviated DSS-induced colitis. Interestingly, FMT from patients with colitis increased CXCL1 and Ly6G expression in the colons of gut-sterilized mice. Clinical data analysis revealed elevated CXCL1 and CD15 expression in patients with colitis, with a positive correlation between the severity of colitis and the expression of CXCL1 and CD15. CONCLUSION These findings shed light on the pivotal role of CXCL1 in promoting colitis by modulating the gut microbiota.
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Affiliation(s)
- Hang Zhao
- Department of Gastroenterology, Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai, China
| | - Wenhua Li
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xin Zhou
- Department of Gastroenterology, Jintan Hospital, Jiangsu University, Changzhou, China
| | - Liang Pan
- Department of Gastroenterology, Jintan Hospital, Jiangsu University, Changzhou, China
| | - Yun Feng
- Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Pingyu Gao
- Pathology Center, Jintan Hospital, Jiangsu University, Zhenjiang, China
| | - Jie Ji
- Clinical Laboratory, Jintan Hospital, Jiangsu University, Zhenjiang, China
| | - Huanyan Zhang
- Clinical Laboratory, Jintan Hospital, Jiangsu University, Zhenjiang, China
| | - Kai Zhao
- Department of Gastroenterology, Jintan Hospital, Jiangsu University, Changzhou, China
| | - Chi Wang
- Department of Precision Mechanical Engineering, Shanghai University, Shanghai, China
| | - Zhanjun Lu
- Department of Gastroenterology, Jintan Hospital, Jiangsu University, Changzhou, China
- Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Mavrogeni ME, Asadpoor M, Judernatz JH, van Ark I, Wösten MMSM, Strijbis K, Pieters RJ, Folkerts G, Braber S. Protective Effects of Alginate and Chitosan Oligosaccharides against Clostridioides difficile Bacteria and Toxin. Toxins (Basel) 2023; 15:586. [PMID: 37888617 PMCID: PMC10610568 DOI: 10.3390/toxins15100586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 09/01/2023] [Accepted: 09/12/2023] [Indexed: 10/28/2023] Open
Abstract
Clostridioides difficile infection is expected to become the most common healthcare-associated infection worldwide. C. difficile-induced pathogenicity is significantly attributed to its enterotoxin, TcdA, which primarily targets Rho-GTPases involved in regulating cytoskeletal and tight junction (TJ) dynamics, thus leading to cytoskeleton breakdown and ultimately increased intestinal permeability. This study investigated whether two non-digestible oligosaccharides (NDOs), alginate (AOS) and chitosan (COS) oligosaccharides, possess antipathogenic and barrier-protective properties against C. difficile bacteria and TcdA toxin, respectively. Both NDOs significantly reduced C. difficile growth, while cell cytotoxicity assays demonstrated that neither COS nor AOS significantly attenuated the TcdA-induced cell death 24 h post-exposure. The challenge of Caco-2 monolayers with increasing TcdA concentrations increased paracellular permeability, as measured by TEER and LY flux assays. In this experimental setup, COS completely abolished, and AOS mitigated, the deleterious effects of TcdA on the monolayer's integrity. These events were not accompanied by alterations in ZO-1 and occludin protein levels; however, immunofluorescence microscopy revealed that both AOS and COS prevented the TcdA-induced occludin mislocalization. Finally, both NDOs accelerated TJ reassembly upon a calcium-switch assay. Overall, this study established the antipathogenic and barrier-protective capacity of AOS and COS against C. difficile and its toxin, TcdA, while revealing their ability to promote TJ reassembly in Caco-2 cells.
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Affiliation(s)
- Maria Eleni Mavrogeni
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Mostafa Asadpoor
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Jo H Judernatz
- Structural Biochemistry Group, Bijvoet Centre for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Ingrid van Ark
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Marc M S M Wösten
- Division of Infectious Diseases and Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands
| | - Karin Strijbis
- Division of Infectious Diseases and Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands
| | - Roland J Pieters
- Division of Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Gert Folkerts
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Saskia Braber
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
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Girard M, Bellefeuille SD, Eiselt É, Arguin G, Longpré JM, Sarret P, Gendron FP. Ligand-dependent intracellular trafficking of the G protein-coupled P2Y 6 receptor. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119476. [PMID: 37059189 DOI: 10.1016/j.bbamcr.2023.119476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 03/28/2023] [Accepted: 04/05/2023] [Indexed: 04/16/2023]
Abstract
Endosomal trafficking is intricately linked to G protein-coupled receptors (GPCR) fate and signaling. Extracellular uridine diphosphate (UDP) acts as a signaling molecule by selectively activating the GPCR P2Y6. Despite the recent interest for this receptor in pathologies, such as gastrointestinal and neurological diseases, there is sparse information on the endosomal trafficking of P2Y6 receptors in response to its endogenous agonist UDP and synthetic selective agonist 5-iodo-UDP (MRS2693). Confocal microscopy and cell surface ELISA revealed delayed internalization kinetics in response to MRS2693 vs. UDP stimulation in AD293 and HCT116 cells expressing human P2Y6. Interestingly, UDP induced clathrin-dependent P2Y6 internalization, whereas receptor stimulation by MRS2693 endocytosis appeared to be associated with a caveolin-dependent mechanism. Internalized P2Y6 was associated with Rab4, 5, and 7 positive vesicles independent of the agonist. We have measured a higher frequency of receptor expression co-occurrence with Rab11-vesicles, the trans-Golgi network, and lysosomes in response to MRS2693. Interestingly, a higher agonist concentration reversed the delayed P2Y6 internalization and recycling kinetics in the presence of MRS2693 stimulation without changing its caveolin-dependent internalization. This work showed a ligand-dependent effect affecting the P2Y6 receptor internalization and endosomal trafficking. These findings could guide the development of bias ligands that could influence P2Y6 signaling.
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Affiliation(s)
- Mélissa Girard
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada; Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Canada
| | - Steve Dagenais Bellefeuille
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Émilie Eiselt
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Canada; Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Canada
| | - Guillaume Arguin
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jean-Michel Longpré
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Canada; Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Canada
| | - Philippe Sarret
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Canada; Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Canada
| | - Fernand-Pierre Gendron
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada; Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Canada.
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Ok MT, Liu J, Bliton RJ, Hinesley CM, San Pedro EET, Breau KA, Gomez-Martinez I, Burclaff J, Magness ST. A leaky human colon model reveals uncoupled apical/basal cytotoxicity in early Clostridioides difficile toxin exposure. Am J Physiol Gastrointest Liver Physiol 2023; 324:G262-G280. [PMID: 36749911 PMCID: PMC10010926 DOI: 10.1152/ajpgi.00251.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/31/2023] [Accepted: 02/05/2023] [Indexed: 02/09/2023]
Abstract
Clostridioides difficile (C. difficile) toxins A (TcdA) and B (TcdB) cause antibiotic-associated colitis in part by disrupting epithelial barrier function. Accurate in vitro models are necessary to detect early toxicity kinetics, investigate disease etiology, and develop preclinical models for new therapies. Properties of cancer cell lines and organoids inherently limit these efforts. We developed adult stem cell-derived monolayers of differentiated human colonic epithelium (hCE) with barrier function, investigated the impact of toxins on apical/basal aspects of monolayers, and evaluated whether a leaky epithelial barrier enhances toxicity. Single-cell RNA-sequencing (scRNAseq) mapped C. difficile-relevant genes to human lineages. Transcriptomics compared hCE to Caco-2, informed timing of in vitro stem cell differentiation, and revealed transcriptional responses to TcdA. Transepithelial electrical resistance (TEER) and fluorescent permeability assays measured cytotoxicity. Contribution of TcdB toxicity was evaluated in a diclofenac-induced leaky gut model. scRNAseq demonstrated broad and variable toxin receptor expression. Absorptive colonocytes in vivo displayed increased toxin receptor, Rho GTPase, and cell junction gene expression. Advanced TcdA toxicity generally decreased cytokine/chemokine and increased tight junction and death receptor genes. Differentiated Caco-2 cells remained immature whereas hCE monolayers were similar to mature colonocytes in vivo. Basal exposure of TcdA/B caused greater toxicity and apoptosis than apical exposure. Apical exposure to toxins was enhanced by diclofenac. Apical/basal toxicities are uncoupled with more rapid onset and increased magnitude postbasal toxin exposure. Leaky junctions enhance toxicity of apical TcdB exposure. hCE monolayers represent a physiologically relevant and sensitive system to evaluate the impact of microbial toxins on gut epithelium.NEW & NOTEWORTHY Novel human colonocyte monolayer cultures, benchmarked by transcriptomics for physiological relevance, detect early cytopathic impacts of Clostridioides difficile toxins TcdA and TcdB. A fluorescent ZO-1 reporter in primary human colonocytes is used to track epithelial barrier disruption in response to TcdA. Basal TcdA/B exposure generally caused more rapid onset and cytotoxicity than apical exposure. Transcriptomics demonstrate changes in tight junction, chemokine, and cytokine receptor gene expression post-TcdA exposure. Diclofenac-induced leaky epithelium enhanced apical exposure toxicity.
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Affiliation(s)
- Meryem T Ok
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Jintong Liu
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - R Jarrett Bliton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Caroline M Hinesley
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Ekaterina Ellyce T San Pedro
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Keith A Breau
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Ismael Gomez-Martinez
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Joseph Burclaff
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Scott T Magness
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
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Cheng JKJ, Unnikrishnan M. Clostridioides difficile infection: traversing host-pathogen interactions in the gut. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36848200 DOI: 10.1099/mic.0.001306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
C. difficile is the primary cause for nosocomial infective diarrhoea. For a successful infection, C. difficile must navigate between resident gut bacteria and the harsh host environment. The perturbation of the intestinal microbiota by broad-spectrum antibiotics alters the composition and the geography of the gut microbiota, deterring colonization resistance, and enabling C. difficile to colonize. This review will discuss how C. difficile interacts with and exploits the microbiota and the host epithelium to infect and persist. We provide an overview of C. difficile virulence factors and their interactions with the gut to aid adhesion, cause epithelial damage and mediate persistence. Finally, we document the host responses to C. difficile, describing the immune cells and host pathways that are associated and triggered during C. difficile infection.
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Affiliation(s)
- Jeffrey K J Cheng
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| | - Meera Unnikrishnan
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
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9
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Bassotti G, Fruganti A, Stracci F, Marconi P, Fettucciari K. Cytotoxic synergism of Clostridioides difficile toxin B with proinflammatory cytokines in subjects with inflammatory bowel diseases. World J Gastroenterol 2023; 29:582-596. [PMID: 36742168 PMCID: PMC9896618 DOI: 10.3748/wjg.v29.i4.582] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/03/2022] [Accepted: 12/27/2022] [Indexed: 01/20/2023] Open
Abstract
Clostridioides difficile (C. difficile) is progressively colonizing humans and animals living with humans. During this process, hypervirulent strains and mutated toxin A and B of C. difficile (TcdA and TcdB) are originating and developing. While in healthy subjects colonization by C. difficile becomes a risk after the use of antibiotics that alter the microbiome, other categories of people are more susceptible to infection and at risk of relapse, such as those with inflammatory bowel disease (IBD). Recent in vitro studies suggest that this increased susceptibility could be due to the strong cytotoxic synergism between TcdB and proinflammatory cytokines the tumor necrosis factor-alpha and interferon-gamma (CKs). Therefore, in subjects with IBD the presence of an inflammatory state in the colon could be the driver that increases the susceptibility to C. difficile infection and its progression and relapses. TcdB is internalized in the cell via three receptors: chondroitin sulphate proteoglycan 4; poliovirus receptor-like 3; and Wnt receptor frizzled family. Chondroitin sulphate proteoglycan 4 and Wnt receptor frizzled family are involved in cell death by apoptosis or necrosis depending on the concentration of TcdB and cell types, while poliovirus receptor-like 3 induces only necrosis. It is possible that cytokines could also induce a greater expression of receptors for TcdB that are more involved in necrosis than in apoptosis. Therefore, in subjects with IBD there are the conditions: (1) For greater susceptibility to C. difficile infection, such as the inflammatory state, and abnormalities of the microbiome and of the immune system; (2) for the enhancement of the cytotoxic activity of TcdB +Cks; and (3) for a greater expression of TcdB receptors stimulated by cytokines that induce cell death by necrosis rather than apoptosis. The only therapeutic approach currently possible in IBD patients is monitoring of C. difficile colonization for interventions aimed at reducing tumor necrosis factor-alpha and interferon-gamma levels when the infection begins. The future perspective is to generate bacteriophages against C. difficile for targeted therapy.
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Affiliation(s)
- Gabrio Bassotti
- Department of Medicine and Surgery, Gastroenterology, Hepatology & Digestive Endoscopy Section University of Perugia Medical School, Piazza Lucio Severi, Perugia 06132, Italy, and Santa Maria della Misericordia Hospital, Gastroenterology & Hepatology Unit Perugia 06156, Italy
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, Matelica 62024, Italy
| | - Fabrizio Stracci
- Medicine and Surgery, Hygiene and Public Health Section, University of Perugia, Perugia 06123, Italy
| | - Pierfrancesco Marconi
- Medicine and Surgery, Biosciences & Medical Embryology Section, University of Perugia, Perugia 06132, Italy
| | - Katia Fettucciari
- Medicine and Surgery, Biosciences & Medical Embryology Section, University of Perugia, Perugia 06132, Italy
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10
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Chebly H, Marvaud JC, Safa L, Elkak AK, Kobeissy PH, Kansau I, Larrazet C. Clostridioides difficile Flagellin Activates the Intracellular NLRC4 Inflammasome. Int J Mol Sci 2022; 23:ijms232012366. [PMID: 36293218 PMCID: PMC9604438 DOI: 10.3390/ijms232012366] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/06/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022] Open
Abstract
Clostridioides difficile (C. difficile), is a major cause of nosocomial diarrhea and colitis. C. difficile flagellin FliC contributes toxins to gut inflammation by interacting with the immune Toll-like receptor 5 (TLR5) to activate nuclear factor-kappa B (NF-kB) and mitogen-activated protein kinase (MAPK) signaling pathways. Flagella of intracellular pathogens can activate the NLR family CARD domain-containing protein 4 (NLRC4) inflammasome pathway. In this study, we assessed whether flagellin of the extracellular bacterium C. difficile internalizes into epithelial cells and activates the NLRC4 inflammasome. Confocal microscopy showed internalization of recombinant green fluorescent protein (GFP)-FliC into intestinal Caco-2/TC7 cell line. Full-length GFP-FliC activates NLRC4 in Caco-2/TC7 cells in contrast to truncated GFP-FliC lacking the C-terminal region recognized by the inflammasome. FliC induced cleavage of pro-caspase-1 into two subunits, p20 and p10 as well as gasdermin D (GSDMD), suggesting the caspase-1 and NLRC4 inflammasome activation. In addition, colocalization of GFP-FliC and pro-caspase-1 was observed, indicating the FliC-dependent NLRC4 inflammasome activation. Overexpression of the inflammasome-related interleukin (interleukin (IL)-1β, IL-18, and IL-33) encoding genes as well as increasing of the IL-18 synthesis was detected after cell stimulation. Inhibition of I-kappa-B kinase alpha (IKK-α) decreased the FliC-dependent inflammasome interleukin gene expression suggesting a role of the NF-κB pathway in regulating inflammasome. Altogether, these results suggest that FliC internalizes into the Caco-2/TC7 cells and activates the intracellular NLRC4 inflammasome thus contributing to the inflammatory process of C. difficile infection.
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Affiliation(s)
- Hiba Chebly
- Institut Micalis, Université Paris-Saclay, INRAE, AgroParisTech, 91400 Orsay, France
- Health Resources and Products Valorization Laboratory, Faculty of Pharmacy, Lebanese University, Beirut 1102-2801, Lebanon
| | | | - Layale Safa
- Health Resources and Products Valorization Laboratory, Faculty of Pharmacy, Lebanese University, Beirut 1102-2801, Lebanon
| | - Assem Khalil Elkak
- Health Resources and Products Valorization Laboratory, Faculty of Pharmacy, Lebanese University, Beirut 1102-2801, Lebanon
| | - Philippe Hussein Kobeissy
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut 1102-2801, Lebanon
| | - Imad Kansau
- Institut Micalis, Université Paris-Saclay, INRAE, AgroParisTech, 91400 Orsay, France
| | - Cécile Larrazet
- Institut Micalis, Université Paris-Saclay, INRAE, AgroParisTech, 91400 Orsay, France
- Correspondence:
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11
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Jeffrey MP, MacPherson CW, Tompkins TA, Green-Johnson JM. Lacticaseibacillus rhamnosus R0011 secretome attenuates Salmonella enterica serovar Typhimurium secretome-induced intestinal epithelial cell monolayer damage and pro-inflammatory mediator production in intestinal epithelial cell and antigen-presenting cell co-cultures. Front Microbiol 2022; 13:980989. [PMID: 36246229 PMCID: PMC9554441 DOI: 10.3389/fmicb.2022.980989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 09/06/2022] [Indexed: 11/13/2022] Open
Abstract
Certain lactic acid bacteria (LAB) are associated with immune modulatory activities including down-regulation of pro-inflammatory gene transcription and expression. While host antigen-presenting cells (APCs) and intestinal epithelial cells (IEC) can interact directly with both pathogenic and commensal bacteria through innate immune pattern recognition receptors, recent evidence indicates indirect communication through secreted molecules is an important inter-domain communication mechanism. This communication route may be especially important in the context of IEC and APC interactions which shape host immune responses within the gut environment. We have previously shown that the Lacticaseibacillus rhamnosus R0011 secretome (LrS) dampens pro-inflammatory gene transcription and mediator production from Tumor Necrosis Factor-α and Salmonella enterica serovar Typhimurium secretome (STS)-challenged HT-29 IECs through the induction of negative regulators of innate immunity. However, many questions remain about interactions mediated through these bacterial-derived soluble components and the resulting host immune outcomes in the context of IEC and APC interactions. In the present study, we examined the ability of the LrS to down-regulate pro-inflammatory gene transcription and cytokine production from STS-challenged T84 human IEC and THP-1 human monocyte co-cultures. Cytokine and chemokine profiling revealed that apically delivered LrS induces apical secretion of macrophage inhibitory factor (MIF) and down-regulates STS-induced pro-inflammatory mediator secretion into the apical and basolateral chambers of the T84/THP-1 co-culture. Transcriptional profiling confirmed these results, as the LrS attenuated STS challenge-induced CXCL8 and NFκB1 expression in T84 IECs and THP-1 APCs. Interestingly, the LrS also reversed STS-induced damage to monolayer transepithelial resistance (TER) and permeability, results which were confirmed by ZO-1 gene expression and immunofluorescence visualization of ZO-1 expression in T84 IEC monolayers. The addition of a MIF-neutralizing antibody abrogated the ability of the LrS to reverse STS-induced damage to T84 IEC monolayer integrity, suggesting a novel role for MIF in maintaining IEC barrier function and integrity in response to soluble components derived from LAB. The results presented here provide mechanistic evidence for indirect communication mechanisms used by LAB to modulate immune responses to pathogen challenge, using in vitro approaches which allow for IEC and APC cell communication in a context which more closely mimics that which occurs in vivo.
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Affiliation(s)
- Michael P. Jeffrey
- Applied Bioscience Graduate Program and the Faculty of Science, Ontario Tech University, Oshawa, ON, Canada
| | | | | | - Julia M. Green-Johnson
- Applied Bioscience Graduate Program and the Faculty of Science, Ontario Tech University, Oshawa, ON, Canada
- *Correspondence: Julia M. Green-Johnson,
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12
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Jiang B, Liu M, Li P, Zhu Y, Liu Y, Zhu K, Zuo Y, Li Y. RNA-seq reveals a novel porcine lncRNA MPHOSPH9-OT1 induces CXCL8/IL-8 expression in ETEC infected IPEC-J2 cells. Front Cell Infect Microbiol 2022; 12:996841. [PMID: 36093177 PMCID: PMC9452961 DOI: 10.3389/fcimb.2022.996841] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/01/2022] [Indexed: 11/30/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major cause of bacterial diarrhea in piglets, leading to economic losses in the pig industry. In past decades, long non-coding RNAs (lncRNAs) have shown to be widely involved in the regulation of host immunity in porcine infection diseases. In this study, we explored the lncRNAs associated with ETEC F41 infection in IPEC-J2 cells by high-throughput sequencing and bioinformatic analysis. A total of 10150 novel porcine lncRNAs were identified. There were 161 differentially expressed (DE) lncRNAs associated with ETEC F41 infection, of which 65 DE lncRNAs were up-regulated and 96 DE lncRNAs were down-regulated. Functional and KEGG enrichment analysis of predicted target genes of DE lncRNAs indicated they are enriched in cell growth and inflammation-related pathways, such as endocytosis, focal adhesion, TGF-β signaling pathway, and adherens junctions. We revealed a novel candidate lncRNA MPHOSPH9-OT1 that was up-regulated after ETEC infection. The qRT-PCR validation and ELISA assessment showed the knockdown and overexpression of MPHOSPH9-OT1 resulted in significantly down- and up-regulation of cellular mRNA levels and secreted cytokine levels of CXCL8/IL-8, respectively. Meanwhile, MPHOSPH9-OT1 equilibrium is important to maintain the transepithelial electric resistance value and tight junction protein expression of IPEC-J2 cells. This study provides insights into the functionality of novel porcine lncRNAs in host immune responses to ETEC infection.
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Affiliation(s)
| | | | | | | | | | | | - Yuzhu Zuo
- *Correspondence: Yan Li, ; Yuzhu Zuo,
| | - Yan Li
- *Correspondence: Yan Li, ; Yuzhu Zuo,
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13
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Xu P, Wang C, Xiang W, Liang Y, Li Y, Zhang X, Guo C, Liu M, Shi Y, Ye X, Dang Y. P2RY6 has a critical role in mouse skin carcinogenesis by regulating the YAP and β-catenin signaling pathways. J Invest Dermatol 2022; 142:2334-2342.e8. [PMID: 35304248 DOI: 10.1016/j.jid.2022.02.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 02/23/2022] [Accepted: 02/23/2022] [Indexed: 01/24/2023]
Abstract
P2Y purinoceptor 6 (P2RY6) is highly expressed in skin keratinocytes, but its function in skin diseases is unclear. We use two-step chemical induction method to induce mouse skin tumor formation. Multiple in vitro and in vivo assays were used to explore the role of P2RY6 in skin tumor. We report that P2ry6-deficient mice exhibit marked resistance to DMBA/TPA-induced skin papilloma formation compared with wild-type mice. Consistent with these findings, epidermal hyperplasia in response to TPA was suppressed in the P2ry6 knockout or MRS2578 (P2RY6 antagonist)-treated mice. The dramatic decrease in hyperplasia and tumorigenesis due to P2ry6 disruption was associated with the suppression of TPA-induced keratinocyte proliferation and inflammatory reactions. Notably, P2ry6 deletion prevented the TPA-induced increase in YAP nuclear accumulation and its downstream gene expression in an MST/LATS1-dependent manner. Upon TPA stimulation, enhanced activation of MEK1 and β-catenin were also impaired in P2ry6 knockout primary keratinocytes, tumor tissues or MRS2578-treated HaCaT cells. Moreover, mutual promotion of the YAP and β-catenin signaling pathways was observed in normal skin cells treated with TPA, while P2ry6 deletion could inhibit their crosstalk by regulating MEK1. Thus, P2RY6 is a critical positive regulator of skin tumorigenesis via modulation of the Hippo/YAP and Wnt/β-catenin signaling pathways.
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Affiliation(s)
- Peng Xu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China; Department of Dermatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Caibing Wang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Wan Xiang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Yiyi Liang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Ying Li
- Psoriasis Treatment Center, Shanghai Dermatology Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xilin Zhang
- Psoriasis Treatment Center, Shanghai Dermatology Hospital, Tongji University School of Medicine, Shanghai, China
| | - Chunyuan Guo
- Psoriasis Treatment Center, Shanghai Dermatology Hospital, Tongji University School of Medicine, Shanghai, China
| | - Mingyao Liu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Yuling Shi
- Psoriasis Treatment Center, Shanghai Dermatology Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xiyun Ye
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Yongyan Dang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China.
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14
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Chandra H, Sharma KK, Tuovinen OH, Sun X, Shukla P. Pathobionts: mechanisms of survival, expansion, and interaction with host with a focus on Clostridioides difficile. Gut Microbes 2022; 13:1979882. [PMID: 34724858 PMCID: PMC8565823 DOI: 10.1080/19490976.2021.1979882] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Pathobionts are opportunistic microbes that emerge as a result of perturbations in the healthy microbiome due to complex interactions of various genetic, exposomal, microbial, and host factors that lead to their selection and expansion. Their proliferations can aggravate inflammatory manifestations, trigger autoimmune diseases, and lead to severe life-threatening conditions. Current surge in microbiome research is unwinding these complex interplays between disease development and protection against pathobionts. This review summarizes the current knowledge of pathobiont emergence with a focus on Clostridioides difficile and the recent findings on the roles of immune cells such as iTreg cells, Th17 cells, innate lymphoid cells, and cytokines in protection against pathobionts. The review calls for adoption of innovative tools and cutting-edge technologies in clinical diagnostics and therapeutics to provide insights in identification and quantification of pathobionts.
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Affiliation(s)
- Harish Chandra
- Department of Environmental Microbiology, School of Earth and Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India,Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Krishna Kant Sharma
- Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Olli H. Tuovinen
- Department of Microbiology, Ohio State University, Columbus, OH, USA
| | - Xingmin Sun
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA,Xingmin Sun Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Pratyoosh Shukla
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India,Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India,CONTACT Pratyoosh Shukla School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi 221005, India
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15
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Salem M, Lecka J, Pelletier J, Gomes Marconato D, Dumas A, Vallières L, Brochu G, Robaye B, Jobin C, Sévigny J. NTPDase8 protects mice from intestinal inflammation by limiting P2Y 6 receptor activation: identification of a new pathway of inflammation for the potential treatment of IBD. Gut 2022; 71:43-54. [PMID: 33452178 DOI: 10.1136/gutjnl-2020-320937] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 12/29/2020] [Accepted: 01/04/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Nucleotides are danger signals that activate inflammatory responses via binding P2 receptors. The nucleoside triphosphate diphosphohydrolase-8 (NTPDase8) is an ectonucleotidase that hydrolyses P2 receptor ligands. We investigated the role of NTPDase8 in intestinal inflammation. DESIGN We generated NTPDase8-deficient (Entpd8-/-) mice to define the role of NTPDase8 in the dextran sodium sulfate (DSS) colitis model. To assess inflammation, colons were collected and analysed by histopathology, reverse transcriptase-quantitative real-time PCR (RT-qPCR) and immunohistochemistry. P2 receptor expression was analysed by RT-qPCR on primary intestinal epithelium and NTPDase8 activity by histochemistry. The role of intestinal P2Y6 receptors was assessed by bone marrow transplantation experiments and with a P2Y6 receptor antagonist. RESULTS NTPDase8 is the dominant enzyme responsible for the hydrolysis of nucleotides in the lumen of the colon. Compared with wild-type (WT) control mice, the colon of Entpd8-/- mice treated with DSS displayed significantly more histological damage, immune cell infiltration, apoptosis and increased expression of several proinflammatory cytokines. P2Y6 was the dominant P2Y receptor expressed at the mRNA level by the colonic epithelia. Irradiated P2ry6-/- mice transplanted with WT bone marrow were fully protected from DSS-induced intestinal inflammation. In agreement, the daily intrarectal injection of a P2Y6 antagonist protected mice from DSS-induced intestinal inflammation in a dose-dependent manner. Finally, human intestinal epithelial cells express NTPDase8 and P2Y6 similarly as in mice. CONCLUSION NTPDase8 protects the intestine from inflammation most probably by limiting the activation of P2Y6 receptors in colonic epithelial cells. This may provide a novel therapeutic strategy for the treatment of inflammatory bowel disease.
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Affiliation(s)
- Mabrouka Salem
- Dép de microbiologie-infectiologie et d'immunologie, fac de médecine, Université Laval, Quebec City, QC, Canada
- Axe Maladies infectieuses et immunitaires, CHU de Québec - Université Laval, Quebec City, QC, Canada
| | - Joanna Lecka
- Axe Maladies infectieuses et immunitaires, CHU de Québec - Université Laval, Quebec City, QC, Canada
| | - Julie Pelletier
- Axe Maladies infectieuses et immunitaires, CHU de Québec - Université Laval, Quebec City, QC, Canada
| | - Danielle Gomes Marconato
- Dép de microbiologie-infectiologie et d'immunologie, fac de médecine, Université Laval, Quebec City, QC, Canada
- Axe Maladies infectieuses et immunitaires, CHU de Québec - Université Laval, Quebec City, QC, Canada
| | - Aline Dumas
- Axe Neurosciences, CHU de Québec - Université Laval, Quebec city, QC, Canada
| | - Luc Vallières
- Axe Neurosciences, CHU de Québec - Université Laval, Quebec city, QC, Canada
- Dép de médecine moléculaire, fac de médecine, Université Laval, Quebec City, QC, Canada
| | - Gaetan Brochu
- CHU de Québec - Université Laval, Quebec City, QC, Canada
- Dept. of Surgery, Université Laval, Quebec City, QC, Canada
| | - Bernard Robaye
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Christian Jobin
- Dept of Infectious Diseases & Pathology, University of Florida, Gainesville, Florida, USA
| | - Jean Sévigny
- Dép de microbiologie-infectiologie et d'immunologie, fac de médecine, Université Laval, Quebec City, QC, Canada
- Axe Maladies infectieuses et immunitaires, CHU de Québec - Université Laval, Quebec City, QC, Canada
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16
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Fettucciari K, Marconi P, Marchegiani A, Fruganti A, Spaterna A, Bassotti G. Invisible steps for a global endemy: molecular strategies adopted by Clostridioides difficile. Therap Adv Gastroenterol 2021; 14:17562848211032797. [PMID: 34413901 PMCID: PMC8369858 DOI: 10.1177/17562848211032797] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 06/26/2021] [Indexed: 02/06/2023] Open
Abstract
Clostridioides difficile infection (CDI) is on the rise worldwide and is associated with an increase in deaths and socio-health burden. C. difficile has become ubiquitous in anthropized environments because of the extreme resistance of its spores. Based on the epidemiological data and knowledge of molecular pathogenesis of C. difficile, it is possible to predict its progressive colonization of the human population for the following reasons: first, its global spread is unstoppable; second, the toxins (Tcds) produced by C. difficile, TcdA and TcdB, mainly cause cell death by apoptosis, but the surviving cells acquire a senescence state that favours persistence of C. difficile in the intestine; third, proinflammatory cytokines, tumour necrosis factor-α and interferon-γ, induced during CDI, enhance the cytotoxicity of Tcds and can increase the survival of senescent cells; fourth, Tcds block mobility and induce apoptosis in immune cells recruited at the infection site; and finally, after remission from primary infection or relapse, C. difficile causes functional abnormalities in the enteric glial cell (EGC) network that can result in irritable bowel syndrome, characterized by a latent inflammatory response that contributes to C. difficile survival and enhances the cytotoxic activity of low doses of TcdB, thus favouring further relapses. Since a 'global endemy' of C. difficile seems inevitable, it is necessary to develop an effective vaccine against Tcds for at-risk individuals, and to perform a prophylaxis/selective therapy with bacteriophages highly specific for C. difficile. We must be aware that CDI will become a global health problem in the forthcoming years, and we must be prepared to face this menace.
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Affiliation(s)
- Katia Fettucciari
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, Medical School -Piazza Lucio Severi 1, Edificio B - IV piano; Sant’Andrea delle Fratte, Perugia, 06132, Italy
| | - Pierfrancesco Marconi
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Andrea Marchegiani
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Andrea Spaterna
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
- Gastroenterology & Hepatology Unit, Santa Maria della Misericordia Hospital, Perugia, Italy
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17
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Placet M, Molle CM, Arguin G, Geha S, Gendron FP. The expression of P2Y 6 receptor promotes the quality of mucus in colitic mice. FEBS J 2021; 288:5459-5473. [PMID: 33713543 DOI: 10.1111/febs.15819] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 03/11/2021] [Indexed: 01/01/2023]
Abstract
In the intestine, mucins are expressed and secreted by goblet cells and enterocytes in a constitutive manner and in response to secretagogues to form a protective mucus layer. This protective barrier is often lost in inflammatory bowel disease (IBD). Interestingly, extracellular nucleotides, through P2Y receptors, were identified as mucin secretagogues in mucinous epithelia. These nucleotides are found in the intestine's extracellular milieu under basal conditions and in higher concentrations in pathologies such as IBD. It was observed that the mucus layer was affected in P2ry6 knockout mice suffering from dextran sodium sulfate (DSS)-induced colitis. P2ry6-/- mice were more sensitive to DSS-induced colitis, resulting in larger ulcers and increased disease activity index. Interestingly, the absence of P2Y6 receptor expression negatively affected the mucus quality, as shown by a reduction in sulfomucin staining and the absence of a dense internal fucosylated mucin layer in P2ry6-/- mice. Hence, we cannot rule out that the absence of P2Y6 receptors in knockout animals could negatively impact mucin secretion. However, we did not measure a reduction in the number of goblet cells, as previously reported. Instead, the results suggest that goblet cells rapidly discharged mucins to compensate for the mucus layer's increased lability, which resulted in empty goblet cells that are less visible to mucin staining. This study's results, along with previous reports, point toward a protective role for the P2Y6 receptor in IBD.
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Affiliation(s)
- Morgane Placet
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, QC, Canada
| | - Caroline M Molle
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, QC, Canada
| | - Guillaume Arguin
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, QC, Canada
| | - Sameh Geha
- Department of Pathology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, QC, Canada
| | - Fernand-Pierre Gendron
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, QC, Canada.,Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, QC, Canada
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18
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Roberts AK, Harris HC, Smith M, Giles J, Polak O, Buckley AM, Clark E, Ewin D, Moura IB, Spitall W, Shone CC, Wilcox M, Chilton C, Donev R. A Novel, Orally Delivered Antibody Therapy and Its Potential to Prevent Clostridioides difficile Infection in Pre-clinical Models. Front Microbiol 2020; 11:578903. [PMID: 33072047 PMCID: PMC7537341 DOI: 10.3389/fmicb.2020.578903] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/31/2020] [Indexed: 12/12/2022] Open
Abstract
Clostridioides difficile infection (CDI) is a toxin-mediated infection in the gut and a major burden on healthcare facilities worldwide. We rationalized that it would be beneficial to design an antibody therapy that is delivered to, and is active at the site of toxin production, rather than neutralizing the circulating and luminal toxins after significant damage of the layers of the intestines has occurred. Here we describe a highly potent therapeutic, OraCAb, with high antibody titers and a formulation that protects the antibodies from digestion/inactivation in the gastrointestinal tract. The potential of OraCAb to prevent CDI in an in vivo hamster model and an in vitro human colon model was assessed. In the hamster model we optimized the ratio of the antibodies against each of the toxins produced by C. difficile (Toxins A and B). The concentration of immunoglobulins that is effective in a hamster model of CDI was determined. A highly significant difference in animal survival for those given an optimized OraCAb formulation versus an untreated control group was observed. This is the first study testing the effect of oral antibodies for treatment of CDI in an in vitro gut model seeded with a human fecal inoculum. Treatment with OraCAb successfully neutralized toxin production and did not interfere with the colonic microbiota in this model. Also, treatment with a combination of vancomycin and OraCAb prevented simulated CDI recurrence, unlike vancomycin therapy alone. These data demonstrate the efficacy of OraCAb formulation for the treatment of CDI in pre-clinical models.
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Affiliation(s)
- April K Roberts
- Toxins Group, National Infection Service, Public Health England, Porton Down, United Kingdom
| | - Hannah C Harris
- Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
| | - Michael Smith
- Toxins Group, National Infection Service, Public Health England, Porton Down, United Kingdom
| | - Joanna Giles
- MicroPharm Ltd., Newcastle Emlyn, United Kingdom
| | | | - Anthony M Buckley
- Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
| | - Emma Clark
- Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
| | - Duncan Ewin
- Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
| | - Ines B Moura
- Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
| | - William Spitall
- Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
| | - Clifford C Shone
- Toxins Group, National Infection Service, Public Health England, Porton Down, United Kingdom
| | - Mark Wilcox
- Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom.,Department of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds General Infirmary, Leeds, United Kingdom
| | - Caroline Chilton
- Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
| | - Rossen Donev
- MicroPharm Ltd., Newcastle Emlyn, United Kingdom
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19
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Girard M, Dagenais Bellefeuille S, Eiselt É, Brouillette R, Placet M, Arguin G, Longpré JM, Sarret P, Gendron FP. The P2Y 6 receptor signals through Gα q /Ca 2+ /PKCα and Gα 13 /ROCK pathways to drive the formation of membrane protrusions and dictate cell migration. J Cell Physiol 2020; 235:9676-9690. [PMID: 32420639 DOI: 10.1002/jcp.29779] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 04/09/2020] [Accepted: 05/01/2020] [Indexed: 12/14/2022]
Abstract
Cell migration is a ubiquitous process necessary to maintain and restore tissue functions. However, in cancer, cell migration leads to metastasis development and thus worsens the prognosis. Although the mechanism of cell migration is well understood, the identification of new targets modulating cell migration and deciphering their signaling events could lead to new therapies to restore tissue functions in diseases, such as inflammatory bowel disease, or to block metastatic development in different forms of cancer. Previous research has identified the G-protein-coupled P2Y6 receptor as an innovative target that could dictate cell migration under normal and pathological conditions. Surprisingly, there is little information on the cellular events triggered by activated P2Y6 during cell migration. Here, we demonstrated that P2Y6 activation stimulated A549 human lung cancer cells and Caco-2 colorectal cancer cell migration. Activated P2Y6 increased the number of filopodia and focal adhesions; two migratory structures required for cell migration. The generation of these structures involved Gαq /calcium/protein kinases C (PKC) and Gα13 /RHO-associated protein kinase-dependent pathways that dictate the formation of the migratory structures. These pathways led to the stabilization of the actin cytoskeleton through a PKC-dependent phosphorylation of cofilin. These results support the idea that the P2Y6 receptor represents a target of interest to modulate cell migration and revealed an intricate dialogue between two Gα-protein signaling pathways.
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Affiliation(s)
- Mélissa Girard
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Steve Dagenais Bellefeuille
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Émilie Eiselt
- Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Rebecca Brouillette
- Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Morgane Placet
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Guillaume Arguin
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jean-Michel Longpré
- Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Philippe Sarret
- Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Fernand-Pierre Gendron
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Institut de Pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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20
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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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21
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Coffing H, Priyamvada S, Anbazhagan AN, Salibay C, Engevik M, Versalovic J, Yacyshyn MB, Yacyshyn B, Tyagi S, Saksena S, Gill RK, Alrefai WA, Dudeja PK. Clostridium difficile toxins A and B decrease intestinal SLC26A3 protein expression. Am J Physiol Gastrointest Liver Physiol 2018; 315:G43-G52. [PMID: 29597352 PMCID: PMC6109705 DOI: 10.1152/ajpgi.00307.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 03/06/2018] [Accepted: 03/12/2018] [Indexed: 01/31/2023]
Abstract
Clostridium difficile infection (CDI) is the primary cause of nosocomial diarrhea in the United States. Although C. difficile toxins A and B are the primary mediators of CDI, the overall pathophysiology underlying C. difficile-associated diarrhea remains poorly understood. Studies have shown that a decrease in both NHE3 (Na+/H+ exchanger) and DRA (downregulated in adenoma, Cl-/[Formula: see text] exchanger), resulting in decreased electrolyte absorption, is implicated in infectious and inflammatory diarrhea. Furthermore, studies have shown that NHE3 is depleted at the apical surface of intestinal epithelial cells and downregulated in patients with CDI, but the role of DRA in CDI remains unknown. In the current studies, we examined the effects of C. difficile toxins TcdA and TcdB on DRA protein and mRNA levels in intestinal epithelial cells (IECs). Our data demonstrated that DRA protein levels were significantly reduced in response to TcdA and TcdB in IECs in culture. This effect was also specific to DRA, as NHE3 and PAT-1 (putative anion transporter 1) protein levels were unaffected by TcdA and TcdB. Additionally, purified TcdA and TcdA + TcdB, but not TcdB, resulted in a decrease in colonic DRA protein levels in a toxigenic mouse model of CDI. Finally, patients with recurrent CDI also exhibited significantly reduced expression of colonic DRA protein. Together, these findings indicate that C. difficile toxins markedly downregulate intestinal expression of DRA which may contribute to the diarrheal phenotype of CDI. NEW & NOTEWORTHY Our studies demonstrate, for the first time, that C. difficile toxins reduce DRA protein, but not mRNA, levels in intestinal epithelial cells. These findings suggest that a downregulation of DRA may be a critical factor in C. difficile infection-associated diarrhea.
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Affiliation(s)
- Hayley Coffing
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Shubha Priyamvada
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Arivarasu N Anbazhagan
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Christine Salibay
- Department of Pathology, University of Illinois at Chicago , Chicago, Illinois
| | - Melinda Engevik
- Department of Pathology and Immunology, Baylor College of Medicine and Department of Pathology, Texas Children's Hospital , Houston, Texas
| | - James Versalovic
- Department of Pathology and Immunology, Baylor College of Medicine and Department of Pathology, Texas Children's Hospital , Houston, Texas
| | - Mary Beth Yacyshyn
- Division of Digestive Diseases, Department. of Medicine, University of Cincinnati College of Medicine , Cincinnati, Ohio
| | - Bruce Yacyshyn
- Division of Digestive Diseases, Department. of Medicine, University of Cincinnati College of Medicine , Cincinnati, Ohio
| | - Sangeeta Tyagi
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Seema Saksena
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
- Jesse Brown Veterans Affairs Medical Center , Chicago, Illinois
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
| | - Waddah A Alrefai
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
- Jesse Brown Veterans Affairs Medical Center , Chicago, Illinois
| | - Pradeep K Dudeja
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago , Chicago, Illinois
- Jesse Brown Veterans Affairs Medical Center , Chicago, Illinois
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22
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Abstract
P2Y receptors (P2YRs) are a family of G protein-coupled receptors activated by extracellular nucleotides. Physiological P2YR agonists include purine and pyrimidine nucleoside di- and triphosphates, such as ATP, ADP, UTP, UDP, nucleotide sugars, and dinucleotides. Eight subtypes exist, P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, P2Y12, P2Y13, and P2Y14, which represent current or potential future drug targets. Here we provide a comprehensive overview of ligands for the subgroup of the P2YR family that is activated by uracil nucleotides: P2Y2 (UTP, also ATP and dinucleotides), P2Y4 (UTP), P2Y6 (UDP), and P2Y14 (UDP, UDP-glucose, UDP-galactose). The physiological agonists are metabolically unstable due to their fast hydrolysis by ectonucleotidases. A number of agonists with increased potency, subtype-selectivity and/or enzymatic stability have been developed in recent years. Useful P2Y2R agonists include MRS2698 (6-01, highly selective) and PSB-1114 (6-05, increased metabolic stability). A potent and selective P2Y2R antagonist is AR-C118925 (10-01). For studies of the P2Y4R, MRS4062 (3-15) may be used as a selective agonist, while PSB-16133 (10-06) is a selective antagonist. Several potent P2Y6R agonists have been developed including 5-methoxyuridine 5'-O-((Rp)α-boranodiphosphate) (6-12), PSB-0474 (3-11), and MRS2693 (3-26). The isocyanate MRS2578 (10-08) is used as a selective P2Y6R antagonist, although its reactivity and low water-solubility are limiting. With MRS2905 (6-08), a potent and metabolically stable P2Y14R agonist is available, while PPTN (10-14) represents a potent and selective P2Y14R antagonist. The radioligand [3H]UDP can be used to label P2Y14Rs. In addition, several fluorescent probes have been developed. Uracil nucleotide-activated P2YRs show great potential as drug targets, especially in inflammation, cancer, cardiovascular and neurodegenerative diseases.
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Shi JP, Wang SY, Chen LL, Zhang XY, Zhao YH, Du B, Jiang WZ, Qian M, Ren H. P2Y6 contributes to ovalbumin-induced allergic asthma by enhancing mast cell function in mice. Oncotarget 2018; 7:60906-60918. [PMID: 27590515 PMCID: PMC5308625 DOI: 10.18632/oncotarget.11758] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/25/2016] [Indexed: 11/25/2022] Open
Abstract
Extracelluar nucleotides have been identified as regulatory factors in asthmatic pathogenesis by activating purinergic receptors. This research aimed to investigate the function of the purinergic receptor P2Y6 in mediating airway inflammation in allergic asthma. Wild-type (WT) and P2Y6-deficient mice were stimulated with ovalbumin (OVA) to construct asthmatic mouse models. Overexpression of P2Y6 and uridine 5'-diphosphate (UDP)-releasing were demonstrated in lung tissues in ovalbumin-induced asthmatic mice. The release of the cytokine IL-4, mast cell invasion, and the airway remodeling phenotypes were more severe following the application of UDP in asthmatic mice. However, P2Y6 deficiency reduced these asthmatic pathogeneticsymptoms markedly in a mouse model. In vitro, we found that P2Y6 in purified mast cells enhanced the functions of mast cells in the inflammatory response in the asthmatic process by triggering their capability for migration, cytokine secretion and granule release. Moreover, P2Y6 stimulated the function of mast cells through activation of the AKT signaling pathway. Our data provides evidence that P2Y6 contributes to allergic airway inflammation and remodeling by enhancing the functions of mast cells in ovalbumin-induced asthmatic mice.
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Affiliation(s)
- Jue-Ping Shi
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, P.R.China
| | - Shao-Ying Wang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, P.R.China
| | - Li-Li Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, P.R.China
| | - Xiao-Yu Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, P.R.China
| | - Yi-Han Zhao
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, P.R.China
| | - Bing Du
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, P.R.China
| | - Wen-Zheng Jiang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, P.R.China
| | - Min Qian
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, P.R.China
| | - Hua Ren
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, P.R.China
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24
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Placet M, Arguin G, Molle CM, Babeu JP, Jones C, Carrier JC, Robaye B, Geha S, Boudreau F, Gendron FP. The G protein-coupled P2Y₆ receptor promotes colorectal cancer tumorigenesis by inhibiting apoptosis. Biochim Biophys Acta Mol Basis Dis 2018; 1864:1539-1551. [PMID: 29454075 DOI: 10.1016/j.bbadis.2018.02.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/24/2018] [Accepted: 02/12/2018] [Indexed: 12/19/2022]
Abstract
Colorectal tumors are immersed in an array of tumor-promoting factors including extracellular nucleotides such as uridine 5'‑diphosphate (UDP). UDP is the endogenous agonist of the G protein-coupled P2Y6 receptor (P2Y6R), which may contribute to the formation of a tumor-promoting microenvironment by coordinating resistance to apoptosis. Colorectal cancer (CRC) was chemically induced in P2ry6 knockout (P2ry6-/-) mice using azoxymethane and dextran sulfate sodium challenges. Mice were euthanatized and their tumor load determined. Fixed tissues were stained for histological and immunohistochemistry analysis. Tumoroids were also prepared from CRC tumors resected from P2ry6+/+ mice to determine the role of P2Y6R in resistance to apoptosis, whereas HT29 carcinoma cells were used to elucidate the signaling mechanism involved in P2Y6R anti-apoptotic effect. P2ry6-/- mice developed a reduced number of colorectal tumors with apparent tumors having smaller volumes. Overall dysplastic score was significantly lower in P2ry6-/- animals. Stimulation of P2Y6R with the selective agonist MRS2693 protected HT-29 cells from TNFα-induced apoptosis. This protective effect was mediated by the stabilizing phosphorylation of the X-linked inhibitor of apoptosis protein (XIAP) by AKT. Using CRC-derived tumoroids, P2Y6R activation was found to contribute to chemoresistance since addition of the P2Y6R agonist MRS2693 significantly prevented the cytotoxic effect of 5-fluorouracil. The present study shows that sustained activation of P2Y6R may contribute to intestinal tumorigenesis by blocking the apoptotic process and by contributing to chemoresistance, a substantial concern in the treatment of patients with CRC. These results suggest that P2Y6R may represent a prime target for reducing colorectal carcinogenesis.
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Affiliation(s)
- Morgane Placet
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Guillaume Arguin
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Caroline M Molle
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jean-Philippe Babeu
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Christine Jones
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Julie C Carrier
- Department of Medicine, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Bernand Robaye
- Institute of Interdisciplinary Research, Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, Gosselies, Belgium
| | - Sameh Geha
- Department of Pathology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Francois Boudreau
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Fernand-Pierre Gendron
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
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25
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Zhang Y, Li S, Yang Z, Shi L, Yu H, Salerno-Goncalves R, Saint Fleur A, Feng H. Cysteine Protease-Mediated Autocleavage of Clostridium difficile Toxins Regulates Their Proinflammatory Activity. Cell Mol Gastroenterol Hepatol 2018; 5:611-625. [PMID: 29930981 PMCID: PMC6009800 DOI: 10.1016/j.jcmgh.2018.01.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/30/2018] [Indexed: 02/04/2023]
Abstract
BACKGROUND & AIMS Clostridium difficile toxin A (TcdA) and C difficile toxin toxin B (TcdB), the major virulence factors of the bacterium, cause intestinal tissue damage and inflammation. Although the 2 toxins are homologous and share a similar domain structure, TcdA is generally more inflammatory whereas TcdB is more cytotoxic. The functional domain of the toxins that govern the proinflammatory activities of the 2 toxins is unknown. METHODS Here, we investigated toxin domain functions that regulate the proinflammatory activity of C difficile toxins. By using a mouse ilea loop model, human tissues, and immune cells, we examined the inflammatory responses to a series of chimeric toxins or toxin mutants deficient in specific domain functions. RESULTS Blocking autoprocessing of TcdB by mutagenesis or chemical inhibition, while reducing cytotoxicity of the toxin, significantly enhanced its proinflammatory activities in the animal model. Furthermore, a noncleavable mutant TcdB was significantly more potent than the wild-type toxin in the induction of proinflammatory cytokines in human colonic tissues and immune cells. CONCLUSIONS In this study, we identified a novel mechanism of regulating the biological activities of C difficile toxins in that cysteine protease-mediated autoprocessing regulates toxins' proinflammatory activities. Our findings provide new insight into the pathogenesis of C difficile infection and the design of therapeutics against the disease.
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Key Words
- 3D, 3-dimensional
- ACPD, CPD domain of TcdA
- Autoprocessing
- Bgt, GTD of TcdB
- Br, RBD of TcdB
- C difficile
- CDI, Clostridium difficile infection
- CPD, cysteine protease domain
- Cysteine Protease
- GT, glucosyltransferase
- GTD, glucosyltransferase domain
- IL, interleukin
- Inflammation
- InsP6, inositol hexakisphosphate
- MPO, myeloperoxidase
- PBMC, peripheral blood mononuclear cell
- PBS, phosphate-buffered saline
- PCR, polymerase chain reaction
- RBD, receptor binding domain
- TER, transepithelial electrical resistance
- TcdA, Clostridium difficile toxin A
- TcdB, Clostridium difficile toxin B
- Toxins
- aTcdA, GTD deficient TcdA
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Affiliation(s)
- Yongrong Zhang
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Shan Li
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Zhiyong Yang
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Lianfa Shi
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Hua Yu
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Rosangela Salerno-Goncalves
- Department of Pediatrics and Center for Vaccine Development, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Ashley Saint Fleur
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Hanping Feng
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland,Correspondence Address correspondence to: Hanping Feng, PhD, 650 W Baltimore Street, Room 7211, Baltimore, Maryland 21201. fax: (410) 706-6511.
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26
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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: 210] [Impact Index Per Article: 30.0] [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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Cytokines Are Markers of the Clostridium difficile-Induced Inflammatory Response and Predict Disease Severity. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00037-17. [PMID: 28592627 DOI: 10.1128/cvi.00037-17] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 05/24/2017] [Indexed: 12/25/2022]
Abstract
The host immune response affects pathogen virulence in Clostridium difficile infection (CDI). Thus, cytokine responses to CDI likely are associated with disease initiation and progression. Understanding the molecular drivers of inflammation and biochemical markers of disease severity is important for developing novel therapies and predicting disease prognosis. In this study, we investigated cytokine production in patients with CDI and evaluated the potential of cytokines to serve as biomarkers for CDI and predictors of disease severity. The systemic cytokine profiles of 36 CDI patients (20 with severe disease) and 8 healthy donors and the toxin-induced cytokine profiles of peripheral blood mononuclear cells (PBMC) were determined. Further, we evaluated glucosyltransferase (GT) activity in regulation of toxin-induced cytokine expression. We found upregulation of the majority of measured cytokines (11/20, 55%) in CDI patients. Interleukin-1β (IL-1β), IL-6, IL-8, IL-17A, and IL-16 were the most upregulated. High serum levels of IL-2 and IL-15 were associated with a poor prognosis in CDI patients, whereas high levels of IL-5 and gamma interferon (IFN-γ) were associated with less severe disease. Both TcdA and TcdB were potent inducers of cytokine responses, as demonstrated by stimulation of a greater number and amount of cytokines. In addition to confirming prior reports on the role of IL-8, IL-1β, and IL-6 in CDI, our data suggest that IL-16 and IL-17A, as well as the IL-1β/Th17 axis, play a key role in driving inflammatory responses in CDI. A functional GT domain of C. difficile toxins was required for the induction of a majority of cytokines investigated.
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28
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Li CW, Su MH, Chen BS. Investigation of the Cross-talk Mechanism in Caco-2 Cells during Clostridium difficile Infection through Genetic-and-Epigenetic Interspecies Networks: Big Data Mining and Genome-Wide Identification. Front Immunol 2017; 8:901. [PMID: 28824629 PMCID: PMC5539260 DOI: 10.3389/fimmu.2017.00901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 07/13/2017] [Indexed: 01/05/2023] Open
Abstract
Clostridium difficile is the leading cause of nosocomial antibiotic-associated diarrhea and the major etiologic agent of pseudomembranous colitis. In severe cases, C. difficile infection (CDI) can cause toxic megacolon, intestinal perforation, and death. The intestinal epithelium is the first tissue encountered in the adhesion and colonization of C. difficile, and serves as a physical defense barrier against infection. Despite the well-characterized cytotoxicity, few studies have investigated the genome-wide interplay between host cells and C. difficile. The aim of this study is to investigate the genetic-and-epigenetic molecular mechanisms between human colorectal epithelial Caco-2 cells and C. difficile during the early (0–60 min) and late stages (30–120 min) of infection. To investigate the cross-talk mechanisms during the progression of infection, we introduced a systems biology approach using big data mining, dynamic network modeling, a genome-wide data identification method, system order detection scheme, and principal network projection method (PNP). We focused on the construction of genome-wide genetic-and-epigenetic interspecies networks (GEINs) and subsequent extraction of host–pathogen core networks (HPNs) to investigate the progression of underlying host/pathogen genetic-and-epigenetic mechanisms from the early to late stages of CDI. Based on our results, we suggest that the cell-wall proteins CD2787 and CD0237, which both play an important role in cell adhesion and pathogen defense mechanisms, can be considered as potential drug targets. In addition, the crucial proteins employed by C. difficile for sporulation, including CD1214, CD2629, and CD2643, can also be considered as potential drug targets since spore-mediated re-infection is a critical issue.
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Affiliation(s)
- Cheng-Wei Li
- Laboratory of Control and Systems Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Ming-He Su
- Laboratory of Control and Systems Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Bor-Sen Chen
- Laboratory of Control and Systems Biology, National Tsing Hua University, Hsinchu, Taiwan
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29
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Le Duc D, Schulz A, Lede V, Schulze A, Thor D, Brüser A, Schöneberg T. P2Y Receptors in Immune Response and Inflammation. Adv Immunol 2017; 136:85-121. [PMID: 28950952 DOI: 10.1016/bs.ai.2017.05.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Metabotropic pyrimidine and purine nucleotide receptors (P2Y receptors) are expressed in virtually all cells with implications in very diverse biological functions, including the well-established platelet aggregation (P2Y12), but also immune regulation and inflammation. The classical P2Y receptors bind nucleotides and are encoded by eight genes with limited sequence homology, while phylogenetically related receptors (e.g., P2Y12-like) recognize lipids and peptides, but also nucleotide derivatives. Growing lines of evidence suggest an important function of P2Y receptors in immune cell differentiation and maturation, migration, and cell apoptosis. Here, we give a perspective on the P2Y receptors' molecular structure and physiological importance in immune cells, as well as the related diseases and P2Y-targeting therapies. Extensive research is being undertaken to find modulators of P2Y receptors and uncover their physiological roles. We anticipate the medical applications of P2Y modulators and their immune relevance.
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Affiliation(s)
- Diana Le Duc
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, University of Leipzig, Leipzig, Germany
| | - Angela Schulz
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, University of Leipzig, Leipzig, Germany
| | - Vera Lede
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, University of Leipzig, Leipzig, Germany
| | - Annelie Schulze
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, University of Leipzig, Leipzig, Germany
| | - Doreen Thor
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, University of Leipzig, Leipzig, Germany
| | - Antje Brüser
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, University of Leipzig, Leipzig, Germany
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30
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Milk Fat Globule Membrane Supplementation in Formula Modulates the Neonatal Gut Microbiome and Normalizes Intestinal Development. Sci Rep 2017; 7:45274. [PMID: 28349941 PMCID: PMC5368573 DOI: 10.1038/srep45274] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 02/23/2017] [Indexed: 12/11/2022] Open
Abstract
Breast milk has many beneficial properties and unusual characteristics including a unique fat component, termed milk fat globule membrane (MFGM). While breast milk yields important developmental benefits, there are situations where it is unavailable resulting in a need for formula feeding. Most formulas do not contain MFGM, but derive their lipids from vegetable sources, which differ greatly in size and composition. Here we tested the effects of MFGM supplementation on intestinal development and the microbiome as well as its potential to protect against Clostridium difficile induced colitis. The pup-in-a-cup model was used to deliver either control or MFGM supplemented formula to rats from 5 to 15 days of age; with mother’s milk (MM) reared animals used as controls. While CTL formula yielded significant deficits in intestinal development as compared to MM littermates, addition of MFGM to formula restored intestinal growth, Paneth and goblet cell numbers, and tight junction protein patterns to that of MM pups. Moreover, the gut microbiota of MFGM and MM pups displayed greater similarities than CTL, and proved protective against C. difficile toxin induced inflammation. Our study thus demonstrates that addition of MFGM to formula promotes development of the intestinal epithelium and microbiome and protects against inflammation.
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Sil P, Hayes CP, Reaves BJ, Breen P, Quinn S, Sokolove J, Rada B. P2Y6 Receptor Antagonist MRS2578 Inhibits Neutrophil Activation and Aggregated Neutrophil Extracellular Trap Formation Induced by Gout-Associated Monosodium Urate Crystals. THE JOURNAL OF IMMUNOLOGY 2016; 198:428-442. [PMID: 27903742 DOI: 10.4049/jimmunol.1600766] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 10/23/2016] [Indexed: 12/27/2022]
Abstract
Human neutrophils (polymorphonuclear leukocytes [PMNs]) generate inflammatory responses within the joints of gout patients upon encountering monosodium urate (MSU) crystals. Neutrophil extracellular traps (NETs) are found abundantly in the synovial fluid of gout patients. The detailed mechanism of MSU crystal-induced NET formation remains unknown. Our goal was to shed light on possible roles of purinergic signaling and neutrophil migration in mediating NET formation induced by MSU crystals. Interaction of human neutrophils with MSU crystals was evaluated by high-throughput live imaging using confocal microscopy. We quantitated NET levels in gout synovial fluid supernatants and detected enzymatically active neutrophil primary granule enzymes, myeloperoxidase, and human neutrophil elastase. Suramin and PPADS, general P2Y receptor blockers, and MRS2578, an inhibitor of the purinergic P2Y6 receptor, blocked NET formation triggered by MSU crystals. AR-C25118925XX (P2Y2 antagonist) did not inhibit MSU crystal-stimulated NET release. Live imaging of PMNs showed that MRS2578 represses neutrophil migration and blocked characteristic formation of MSU crystal-NET aggregates called aggregated NETs. Interestingly, the store-operated calcium entry channel inhibitor (SK&F96365) also reduced MSU crystal-induced NET release. Our results indicate that the P2Y6/store-operated calcium entry/IL-8 axis is involved in MSU crystal-induced aggregated NET formation, but MRS2578 could have additional effects affecting PMN migration. The work presented in the present study could lead to a better understanding of gouty joint inflammation and help improve the treatment and care of gout patients.
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Affiliation(s)
- Payel Sil
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Craig P Hayes
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Barbara J Reaves
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - Patrick Breen
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602
| | - Shannon Quinn
- Department of Computer Science, Franklin College of Arts and Sciences, University of Georgia, Athens, 30602 GA
| | - Jeremy Sokolove
- Stanford University School of Medicine, Stanford, CA 94305; and.,Internal Medicine and Rheumatology, VA Palo Alto Health Care System, Palo Alto, CA 94034
| | - Balázs Rada
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602;
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32
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Péchiné S, Collignon A. Immune responses induced by Clostridium difficile. Anaerobe 2016; 41:68-78. [PMID: 27108093 DOI: 10.1016/j.anaerobe.2016.04.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/18/2016] [Accepted: 04/19/2016] [Indexed: 02/06/2023]
Abstract
The spectrum of Clostridium difficile infections is highly variable, ranging from asymptomatic carriage to fatal colitis depending on the strain virulence and on the host, its gut microbiota and its immune response. After disruption of the gut microbiota, C. difficile pathogenesis can be divided into three steps: 1) contamination by spores and their germination; 2) multiplication of vegetative cells and intestinal colonization using colonization factors; 3) production of the toxins TcdA and TcdB, and for some strains, the binary toxin, which are responsible for the clinical signs. Three lines of defense counteract C. difficile. The first line is the epithelial barrier, which is breached by the toxins. Then, a rapid innate immune response follows, which forms the second line of defense. It provides very quick defense reactions against C. difficile but is non-specific and does not confer memory. C. difficile and its virulence factors, the toxins and colonization factors, induce a highly pro-inflammatory response, which can be either beneficial or harmful, but triggers the adaptive immunity as the third line of defense required to control the infectious process. Adaptive immunity provides a highly specific immune response against C. difficile with memory and long lasting immunity. The innate and adaptive immune responses against the toxins and surface components are analyzed as well as their role in disease susceptibility, severity and recurrences.
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Affiliation(s)
- Séverine Péchiné
- Faculté de pharmacie, EA 4043 "Unité Bactéries Pathogènes et Santé", Univ. Paris-Sud, Université Paris-Saclay, 5 Rue Jean Baptiste Clément, 92296 Châtenay-Malabry Cedex, France
| | - Anne Collignon
- Faculté de pharmacie, EA 4043 "Unité Bactéries Pathogènes et Santé", Univ. Paris-Sud, Université Paris-Saclay, 5 Rue Jean Baptiste Clément, 92296 Châtenay-Malabry Cedex, France.
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33
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Conroy S, Kindon N, Kellam B, Stocks MJ. Drug-like Antagonists of P2Y Receptors-From Lead Identification to Drug Development. J Med Chem 2016; 59:9981-10005. [PMID: 27413802 DOI: 10.1021/acs.jmedchem.5b01972] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
P2Y receptors are expressed in virtually all cells and tissue types and mediate an astonishing array of biological functions, including platelet aggregation, smooth muscle cell proliferation, and immune regulation. The P2Y receptors belong to the G protein-coupled receptor superfamily and are composed of eight members encoded by distinct genes that can be subdivided into two groups on the basis of their coupling to specific G-proteins. Extensive research has been undertaken to find modulators of P2Y receptors, although to date only a limited number of small-molecule P2Y receptor antagonists have been approved by drug/medicines agencies. This Perspective reviews the known P2Y receptor antagonists, highlighting oral drug-like receptor antagonists, and considers future opportunities for the development of small molecules for clinical evaluation.
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Affiliation(s)
- Sean Conroy
- Centre for Biomolecular Sciences, University of Nottingham , University Park, Nottingham NG7 2RD, U.K
| | - Nicholas Kindon
- Centre for Biomolecular Sciences, University of Nottingham , University Park, Nottingham NG7 2RD, U.K
| | - Barrie Kellam
- Centre for Biomolecular Sciences, University of Nottingham , University Park, Nottingham NG7 2RD, U.K
| | - Michael J Stocks
- Centre for Biomolecular Sciences, University of Nottingham , University Park, Nottingham NG7 2RD, U.K
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34
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Garg A, Zhao A, Erickson SL, Mukherjee S, Lau AJ, Alston L, Chang TKH, Mani S, Hirota SA. Pregnane X Receptor Activation Attenuates Inflammation-Associated Intestinal Epithelial Barrier Dysfunction by Inhibiting Cytokine-Induced Myosin Light-Chain Kinase Expression and c-Jun N-Terminal Kinase 1/2 Activation. J Pharmacol Exp Ther 2016; 359:91-101. [PMID: 27440420 DOI: 10.1124/jpet.116.234096] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/19/2016] [Indexed: 02/06/2023] Open
Abstract
The inflammatory bowel diseases (IBDs) are chronic inflammatory disorders with a complex etiology. IBD is thought to arise in genetically susceptible individuals in the context of aberrant interactions with the intestinal microbiota and other environmental risk factors. Recently, the pregnane X receptor (PXR) was identified as a sensor for microbial metabolites, whose activation can regulate the intestinal epithelial barrier. Mutations in NR1I2, the gene that encodes the PXR, have been linked to IBD, and in animal models, PXR deletion leads to barrier dysfunction. In the current study, we sought to assess the mechanism(s) through which the PXR regulates barrier function during inflammation. In Caco-2 intestinal epithelial cell monolayers, tumor necrosis factor-α/interferon-γ exposure disrupted the barrier and triggered zonula occludens-1 relocalization, increased expression of myosin light-chain kinase (MLCK), and activation of c-Jun N-terminal kinase 1/2 (JNK1/2). Activation of the PXR [rifaximin and [[3,5-Bis(1,1-dimethylethyl)-4-hydroxyphenyl]ethenylidene]bis-phosphonic acid tetraethyl ester (SR12813); 10 μM] protected the barrier, an effect that was associated with attenuated MLCK expression and JNK1/2 activation. In vivo, activation of the PXR [pregnenolone 16α-carbonitrile (PCN)] attenuated barrier disruption induced by toll-like receptor 4 activation in wild-type, but not Pxr-/-, mice. Furthermore, PCN treatment protected the barrier in the dextran-sulfate sodium model of experimental colitis, an effect that was associated with reduced expression of mucosal MLCK and phosphorylated JNK1/2. Together, our data suggest that the PXR regulates the intestinal epithelial barrier during inflammation by modulating cytokine-induced MLCK expression and JNK1/2 activation. Thus, targeting the PXR may prove beneficial for the treatment of inflammation-associated barrier disruption in the context of IBD.
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Affiliation(s)
- Aditya Garg
- Department of Physiology and Pharmacology (A.G., A.Z., S.L.E., L.A., S.A.H.), and Department of Microbiology, Immunology and Infectious Diseases (S.A.H.), University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (Su.M., Sr.M.); and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.J.L., T.K.H.C.)
| | - Angela Zhao
- Department of Physiology and Pharmacology (A.G., A.Z., S.L.E., L.A., S.A.H.), and Department of Microbiology, Immunology and Infectious Diseases (S.A.H.), University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (Su.M., Sr.M.); and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.J.L., T.K.H.C.)
| | - Sarah L Erickson
- Department of Physiology and Pharmacology (A.G., A.Z., S.L.E., L.A., S.A.H.), and Department of Microbiology, Immunology and Infectious Diseases (S.A.H.), University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (Su.M., Sr.M.); and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.J.L., T.K.H.C.)
| | - Subhajit Mukherjee
- Department of Physiology and Pharmacology (A.G., A.Z., S.L.E., L.A., S.A.H.), and Department of Microbiology, Immunology and Infectious Diseases (S.A.H.), University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (Su.M., Sr.M.); and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.J.L., T.K.H.C.)
| | - Aik Jiang Lau
- Department of Physiology and Pharmacology (A.G., A.Z., S.L.E., L.A., S.A.H.), and Department of Microbiology, Immunology and Infectious Diseases (S.A.H.), University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (Su.M., Sr.M.); and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.J.L., T.K.H.C.)
| | - Laurie Alston
- Department of Physiology and Pharmacology (A.G., A.Z., S.L.E., L.A., S.A.H.), and Department of Microbiology, Immunology and Infectious Diseases (S.A.H.), University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (Su.M., Sr.M.); and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.J.L., T.K.H.C.)
| | - Thomas K H Chang
- Department of Physiology and Pharmacology (A.G., A.Z., S.L.E., L.A., S.A.H.), and Department of Microbiology, Immunology and Infectious Diseases (S.A.H.), University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (Su.M., Sr.M.); and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.J.L., T.K.H.C.)
| | - Sridhar Mani
- Department of Physiology and Pharmacology (A.G., A.Z., S.L.E., L.A., S.A.H.), and Department of Microbiology, Immunology and Infectious Diseases (S.A.H.), University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (Su.M., Sr.M.); and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.J.L., T.K.H.C.)
| | - Simon A Hirota
- Department of Physiology and Pharmacology (A.G., A.Z., S.L.E., L.A., S.A.H.), and Department of Microbiology, Immunology and Infectious Diseases (S.A.H.), University of Calgary, Calgary, Alberta, Canada; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (Su.M., Sr.M.); and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.J.L., T.K.H.C.)
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35
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Ferrari D, McNamee EN, Idzko M, Gambari R, Eltzschig HK. Purinergic Signaling During Immune Cell Trafficking. Trends Immunol 2016; 37:399-411. [PMID: 27142306 DOI: 10.1016/j.it.2016.04.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/05/2016] [Accepted: 04/07/2016] [Indexed: 12/24/2022]
Abstract
Migration and positioning of immune cells is fundamental for their differentiation and recruitment at sites of infection. Besides the fundamental role played by chemokines and their receptors, recent studies demonstrate that a complex network of purinergic signaling events plays a key role in these trafficking events. This process includes the release of nucleotides (such as ATP and ADP) and subsequent autocrine and paracrine signaling events through nucleotide receptors. At the same time, surface-expressed ectoapyrases and nucleotidases convert extracellular nucleotides to adenosine, and adenosine signaling events play additional functional roles in leucocyte trafficking. In this review we revisit classical paradigms of inflammatory cell trafficking in the context of recent studies implicating purinergic signaling events in this process.
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Affiliation(s)
- Davide Ferrari
- Department of Life Science and Biotechnology, University of Ferrara, I-44100 Ferrara, Italy.
| | - Eóin N McNamee
- Organ Protection Program, Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Marco Idzko
- Department of Pulmonary Medicine, University Hospital Freiburg, Freiburg, Germany
| | - Roberto Gambari
- Department of Life Science and Biotechnology, University of Ferrara, I-44100 Ferrara, Italy
| | - Holger K Eltzschig
- Organ Protection Program, Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
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36
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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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37
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Jose S, Madan R. Neutrophil-mediated inflammation in the pathogenesis of Clostridium difficile infections. Anaerobe 2016; 41:85-90. [PMID: 27063896 DOI: 10.1016/j.anaerobe.2016.04.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 04/04/2016] [Indexed: 12/19/2022]
Abstract
Clostridium difficile is the most important cause of nosocomial infectious diarrhea in the western world. C. difficile infections are a major healthcare burden with approximately 500,000 new cases every year and an estimated annual cost of nearly $1 billion in the U.S. Furthermore, the infections are no longer restricted to health care facilities, and recent studies indicate spread of C. difficile infection to the community as well. The clinical spectrum of C. difficile infection ranges from asymptomatic colonization to severe diarrhea, fulminant colitis and death. This spectrum results from a complex interplay between bacterial virulence factors, the colonic microbiome and the host inflammatory response. The overall vigor of host inflammatory response is believed to be an important determinant of C. difficile disease severity, and a more robust immune response is associated with worse outcomes. Neutrophils are the primary cells that respond to C. difficile invasion and neutrophilic inflammation is the hallmark of C. difficile-associated disease. In this review, we will focus on the role of neutrophils (infiltration to infected tissue, pathogen clearance and resolution of inflammation) in the immuno-pathogenesis of C. difficile-associated disease (CDAD).
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Affiliation(s)
- Shinsmon Jose
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati, OH 45267, USA
| | - Rajat Madan
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati, OH 45267, USA.
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38
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Hamers AAJ, van Dam L, Teixeira Duarte JM, Vos M, Marinković G, van Tiel CM, Meijer SL, van Stalborch AM, Huveneers S, te Velde AA, de Jonge WJ, de Vries CJM. Deficiency of Nuclear Receptor Nur77 Aggravates Mouse Experimental Colitis by Increased NFκB Activity in Macrophages. PLoS One 2015; 10:e0133598. [PMID: 26241646 PMCID: PMC4524678 DOI: 10.1371/journal.pone.0133598] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 06/29/2015] [Indexed: 02/07/2023] Open
Abstract
Nuclear receptor Nur77, also referred to as NR4A1 or TR3, plays an important role in innate and adaptive immunity. Nur77 is crucial in regulating the T helper 1/regulatory T-cell balance, is expressed in macrophages and drives M2 macrophage polarization. In this study we aimed to define the function of Nur77 in inflammatory bowel disease. In wild-type and Nur77-/- mice, colitis development was studied in dextran sodium sulphate (DSS)- and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced models. To understand the underlying mechanism, Nur77 was overexpressed in macrophages and gut epithelial cells. Nur77 protein is expressed in colon tissues from Crohn's disease and Ulcerative colitis patients and colons from colitic mice in inflammatory cells and epithelium. In both mouse colitis models inflammation was increased in Nur77-/- mice. A higher neutrophil influx and enhanced IL-6, MCP-1 and KC production was observed in Nur77-deficient colons after DSS-treatment. TNBS-induced influx of T-cells and inflammatory monocytes into the colon was higher in Nur77-/- mice, along with increased expression of MCP-1, TNFα and IL-6, and decreased Foxp3 RNA expression, compared to wild-type mice. Overexpression of Nur77 in lipopolysaccharide activated RAW macrophages resulted in up-regulated IL-10 and downregulated TNFα, MIF-1 and MCP-1 mRNA expression through NFκB repression. Nur77 also strongly decreased expression of MCP-1, CXCL1, IL-8, MIP-1α and TNFα in gut epithelial Caco-2 cells. Nur77 overexpression suppresses the inflammatory status of both macrophages and gut epithelial cells and together with the in vivo mouse data this supports that Nur77 has a protective function in experimental colitis. These findings may have implications for development of novel targeted treatment strategies regarding inflammatory bowel disease and other inflammatory diseases.
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MESH Headings
- Animals
- Cell Line
- Colitis/chemically induced
- Colitis/immunology
- Colitis/metabolism
- Colitis, Ulcerative/metabolism
- Colitis, Ulcerative/pathology
- Colon/metabolism
- Colon/pathology
- Crohn Disease/metabolism
- Crohn Disease/pathology
- Cytokines/biosynthesis
- Cytokines/genetics
- Dextran Sulfate/toxicity
- Disease Models, Animal
- Epithelial Cells/metabolism
- Epithelial Cells/pathology
- Female
- Forkhead Transcription Factors/biosynthesis
- Forkhead Transcription Factors/genetics
- Gene Expression Regulation
- Humans
- Intestinal Mucosa/metabolism
- Intestinal Mucosa/pathology
- Macrophages/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- NF-kappa B/metabolism
- Nuclear Receptor Subfamily 4, Group A, Member 1/deficiency
- Nuclear Receptor Subfamily 4, Group A, Member 1/genetics
- Nuclear Receptor Subfamily 4, Group A, Member 1/immunology
- RAW 264.7 Cells
- Trinitrobenzenesulfonic Acid/toxicity
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Affiliation(s)
- Anouk A. J. Hamers
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Laura van Dam
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - José M. Teixeira Duarte
- Tytgat Institute, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Mariska Vos
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Goran Marinković
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Claudia M. van Tiel
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Sybren L. Meijer
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Anne-Marieke van Stalborch
- Department of Molecular Cell Biology, Sanquin Research and Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Stephan Huveneers
- Department of Molecular Cell Biology, Sanquin Research and Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Anje A. te Velde
- Tytgat Institute, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Wouter J. de Jonge
- Tytgat Institute, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Carlie J. M. de Vries
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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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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40
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Host recognition of Clostridium difficile and the innate immune response. Anaerobe 2014; 30:205-9. [PMID: 25223264 DOI: 10.1016/j.anaerobe.2014.08.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 08/12/2014] [Accepted: 08/28/2014] [Indexed: 02/08/2023]
Abstract
Clostridium difficile is a Gram-positive, spore forming bacillus and the most common cause of antibiotic-associated diarrhea in the United States. Clinical outcomes of C. difficile infection (CDI) range from asymptomatic colonization to pseudomembranous colitis, sepsis and death. Disease is primarily mediated by the action of the Rho-glucosylating toxins A and B, which induce potent pro-inflammatory signaling within the host. The role of this inflammatory response during infection is just beginning to be appreciated, with recent data suggesting inflammatory markers correlate closely with disease severity. In addition to the toxins, multiple innate immune signaling pathways have been implicated in establishing an inflammatory response during infection. In intoxication-based models of disease, inflammation typically enhances pathogenesis, while protection from infection seems to require some level of inflammatory response. Thus, the host immune response plays a key role in shaping the course of infection and a balanced inflammatory response which eradicates infection without damaging host tissues is likely required for successful resolution of disease.
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41
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Evaluation of therapeutic properties of fermented vegetables extract (OM-X®) in the model of colitis induced by Citrobacter rodentium in mice. J Funct Foods 2014. [DOI: 10.1016/j.jff.2014.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Giardia duodenalis cathepsin B proteases degrade intestinal epithelial interleukin-8 and attenuate interleukin-8-induced neutrophil chemotaxis. Infect Immun 2014; 82:2772-87. [PMID: 24733096 DOI: 10.1128/iai.01771-14] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Giardia duodenalis (syn. G. intestinalis, G. lamblia) infections are a leading cause of waterborne diarrheal disease that can also result in the development of postinfectious functional gastrointestinal disorders via mechanisms that remain unclear. Parasite numbers exceed 10(6) trophozoites per centimeter of gut at the height of an infection. Yet the intestinal mucosa of G. duodenalis-infected individuals is devoid of signs of overt inflammation. G. duodenalis infections can also occur concurrently with infections with other proinflammatory gastrointestinal pathogens. Little is known of whether and how this parasite can attenuate host inflammatory responses induced by other proinflammatory stimuli, such as a gastrointestinal pathogen. Identifying hitherto-unrecognized parasitic immunomodulatory pathways, the present studies demonstrated that G. duodenalis trophozoites attenuate secretion of the potent neutrophil chemoattractant interleukin-8 (CXCL8); these effects were observed in human small intestinal mucosal tissues and from intestinal epithelial monolayers, activated through administration of proinflammatory interleukin-1β or Salmonella enterica serovar Typhimurium. This attenuation is caused by the secretion of G. duodenalis cathepsin B cysteine proteases that degrade CXCL8 posttranscriptionally. Furthermore, the degradation of CXCL8 via G. duodenalis cathepsin B cysteine proteases attenuates CXCL8-induced chemotaxis of human neutrophils. Taken together, these data demonstrate for the first time that G. duodenalis trophozoite cathepsins are capable of attenuating a component of their host's proinflammatory response induced by a separate proinflammatory stimulus.
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