Dissecting the contribution of innate and antigen-specific pathways to the breach of self-tolerance observed in a murine model of arthritis
- M B Nickdel1,
- P Conigliaro1,2,3,
- G Valesini3,
- S Hutchison1,
- R Benson1,
- R V Bundick4,
- A J Leishman4,
- I B McInnes2,
- J M Brewer1,
- P Garside1
- 1Centre for Biophotonics, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
- 2Division of Immunology, Infection and Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, UK
- 3Cattedra di Reumatologia, Dipartimento di Clinica e Terapia Medica Applicata, Università di Roma “La Sapienza”, Rome, Italy
- 4Discovery BioScience, AstraZeneca R&D Charnwood, Loughborough, UK
- Dr P Garside, Centre for Biophotonics Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow G4 0NR, UK; paul.garside{at}strath.ac.uk
- Accepted 10 July 2008
- Published Online First 17 July 2008
Abstract
Background: The relative roles of innate immunity and antigen-specific T cells in rheumatoid arthritis remain controversial. Previous studies demonstrated that T-helper type 1 cells of irrelevant antigen specificity (ovalbumin) induced a transient arthritis in BALB/c mice, which recapitulates many of the pre-articular and articular features of human disease and is associated with the emergence of autoreactive T and B-cell responses to joint-specific antigens. However, the mechanisms underlying this phenomenon were unclear.
Objectives: The aim of this study was to dissect the relative contribution of innate and heterologous antigen-specific pathways to the breach of self-tolerance and pathology observed in this model and how this may result from modified T and B-cell interactions.
Methods: To address this issue, experimental arthritis was elicited either by a non-specific inflammatory stimulus alone, by activation of T cells of an irrelevant specificity or a combination of both.
Results: The non-specific inflammatory response generated by lipopolysaccharide led to articular inflammation and cartilage erosion, but did not break tolerance to joint-specific antigens. In contrast, local activation of T cells of an irrelevant specificity produced a similar pathological picture but, in addition, induced T-cell responses to unrelated joint-specific antigens with associated activation of autoreactive B cells. These effects could be further potentiated by the addition of lipopolysaccharide.
Conclusion: These data demonstrate that non-specific inflammation alone is insufficient to breach self-tolerance. In contrast, T cells of an irrelevant specificity, when triggered locally in an antigen-specific manner, can breach self-tolerance leading to arthritis and autoantibody production, which can then be amplified in a non-specific manner.
Footnotes
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Competing interests: None.
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Funding: This study received grant support from a BBSRC CASE award and AstraZeneca.








