RESEARCH ARTICLE
Systemic Administration of Tolerogenic Dendritic Cells Ameliorates Murine Inflammatory Arthritis
Louise J Healy, Helen L Collins, Stephen J Thompson*
Article Information
Identifiers and Pagination:
Year: 2008Volume: 2
First Page: 71
Last Page: 80
Publisher ID: TORJ-2-71
DOI: 10.2174/1874312900802010071
Article History:
Received Date: 2/10/2008Revision Received Date: 10/11/2008
Acceptance Date: 12/11/2008
Electronic publication date: 3/12/2008

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
The expression of various cell surface molecules and the production of certain cytokines are important mechanisms by which dendritic cells (DC) are able to bias immune responses. This paper describes the effects of the inflammatory cytokine tumor necrosis factor (TNF)-αon DC phenotype and function. TNF-αtreatment resulted in upregulation of MHC class II and CD86 in the absence of increased cell surface CD40 and CD80 or the production of IL-12. Additionally TNF-αtreated cells were able to bias T cell responses towards an anti-inflammatory profile. On a note of caution this tolerogenic phenotype of the DC was not stable upon subsequent TLR-4 ligation as a 4 hour pulse of the TNF-α treated DC with lipopolysaccharide (LPS) resulted in the restoration of IL-12 production and an enhancement of their T cell stimulatory capacity which resulted in an increased IFN-γproduction. However, TNF-αtreated DC, when administered in vivo, were shown to ameliorate disease in collagen induced arthritis, an experimental model of inflammatory joint disease. Mice receiving TNF-αtreated DC but not LPS matured DC had a delayed onset, and significantly reduced severity, of arthritis. Disease suppression was associated with reduced levels of collagen specific IgG2a and decreased inflammatory cell infiltration into affected joints. In summary the treatment of DC with TNF-αgenerates an antigen presenting cell with a phenotype that can reduce the pro-inflammatory response and direct the immune system towards a disease modifying, anti-inflammatory state.