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Ryan A, Lynch M, Smith SM, Amu S, Nel HJ, McCoy CE, Dowling JK, Draper E, O'Reilly V, McCarthy C, O'Brien J, Ní Eidhin D, O'Connell MJ, Keogh B, Morton CO, Rogers TR, Fallon PG, O'Neill LA, Kelleher D, Loscher CE. A role for TLR4 in Clostridium difficile infection and the recognition of surface layer proteins. PLoS Pathog 2011; 7:e1002076. [PMID: 21738466 PMCID: PMC3128122 DOI: 10.1371/journal.ppat.1002076] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 04/07/2011] [Indexed: 11/18/2022] Open
Abstract
Clostridium difficile is the etiological agent of antibiotic-associated diarrhoea (AAD) and pseudomembranous colitis in humans. The role of the surface layer proteins (SLPs) in this disease has not yet been fully explored. The aim of this study was to investigate a role for SLPs in the recognition of C. difficile and the subsequent activation of the immune system. Bone marrow derived dendritic cells (DCs) exposed to SLPs were assessed for production of inflammatory cytokines, expression of cell surface markers and their ability to generate T helper (Th) cell responses. DCs isolated from C3H/HeN and C3H/HeJ mice were used in order to examine whether SLPs are recognised by TLR4. The role of TLR4 in infection was examined in TLR4-deficient mice. SLPs induced maturation of DCs characterised by production of IL-12, TNFα and IL-10 and expression of MHC class II, CD40, CD80 and CD86. Furthermore, SLP-activated DCs generated Th cells producing IFNγ and IL-17. SLPs were unable to activate DCs isolated from TLR4-mutant C3H/HeJ mice and failed to induce a subsequent Th cell response. TLR4⁻/⁻ and Myd88⁻/⁻, but not TRIF⁻/⁻ mice were more susceptible than wild-type mice to C. difficile infection. Furthermore, SLPs activated NFκB, but not IRF3, downstream of TLR4. Our results indicate that SLPs isolated from C. difficile can activate innate and adaptive immunity and that these effects are mediated by TLR4, with TLR4 having a functional role in experimental C. difficile infection. This suggests an important role for SLPs in the recognition of C. difficile by the immune system.
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Affiliation(s)
- Anthony Ryan
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Ireland
| | - Mark Lynch
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Ireland
| | - Sinead M. Smith
- Department of Clinical Medicine and Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James's Hospital, Dublin, Ireland
| | - Sylvie Amu
- Department of Clinical Medicine and Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James's Hospital, Dublin, Ireland
| | - Hendrik J. Nel
- Department of Clinical Medicine and Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James's Hospital, Dublin, Ireland
| | - Claire E. McCoy
- School of Biochemistry and Immunology, Trinity College, Dublin, Ireland
| | - Jennifer K. Dowling
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Ireland
| | - Eve Draper
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Ireland
| | - Vincent O'Reilly
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Ireland
| | - Ciara McCarthy
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Ireland
| | - Julie O'Brien
- Department of Clinical Medicine and Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James's Hospital, Dublin, Ireland
| | - Déirdre Ní Eidhin
- Department of Clinical Medicine and Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James's Hospital, Dublin, Ireland
| | - Mary J. O'Connell
- Molecular Evolution Group, School of Biotechnology, Dublin City University, Ireland
| | - Brian Keogh
- Department of Clinical Medicine and Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James's Hospital, Dublin, Ireland
| | - Charles O. Morton
- Department of Clinical Microbiology, St James Hospital, Trinity College, Dublin, Ireland
| | - Thomas R. Rogers
- Department of Clinical Microbiology, St James Hospital, Trinity College, Dublin, Ireland
| | - Padraic G. Fallon
- Department of Clinical Medicine and Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James's Hospital, Dublin, Ireland
| | - Luke A. O'Neill
- School of Biochemistry and Immunology, Trinity College, Dublin, Ireland
| | - Dermot Kelleher
- Department of Clinical Medicine and Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James's Hospital, Dublin, Ireland
| | - Christine E. Loscher
- Immunomodulation Research Group, School of Biotechnology, Dublin City University, Ireland
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Characterization of Clostridium species utilizing liquid chromatography/mass spectrometry of intact proteins. J Microbiol Methods 2009; 77:152-8. [PMID: 19318054 DOI: 10.1016/j.mimet.2009.01.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 01/09/2009] [Accepted: 01/19/2009] [Indexed: 11/23/2022]
Abstract
A method for biomarker candidate discovery and strain level pathogen characterization using liquid chromatography/mass spectrometry (LC/MS) with electrospray ionization is described. This method was applied to two pathogenic Clostridium species: C. difficile and C. perfringens. Seven marker proteins per species (fourteen total) were successfully implemented to speciate unknowns during a blind study and could enhance serological and genetic approaches by serving as new targets for detection. Two sets of C. perfringens isolates that were 100% similar by pulsed-field gel electrophoresis (PFGE) were distinguished using LC/MS, demonstrating the high specificity of this approach. The use of LC/MS is less labor intensive than PFGE, affords greater specificity than real-time PCR, and requires no primers or antibodies.
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