Email updates

Keep up to date with the latest news and content from Arthritis Research & Therapy and BioMed Central.

This article is part of the supplement: 25th European Workshop for Rheumatology Research

Poster presentation

NKT cell status and IL-10-dependent therapeutic effect of NKT cell stimulation on collagen-arthritis in DBA/1 mice

N Bessis, A Miellot, A Herbelin, R Zhu and M-C Boissier

Author affiliations

Université Paris 13, France

For all author emails, please log on.

Citation and License

Arthritis Research & Therapy 2005, 7(Suppl 1):P80  doi:10.1186/ar1601

The electronic version of this article is the complete one and can be found online at:


Received:11 January 2005
Published:17 February 2005

© 2005 BioMed Central Ltd

Background and objectives

Defective NKT cell function has been linked with autoimmunity. Both the number of NKT cells and their functional capacity of releasing interferon gamma (IFN-γ) and IL-4 after TCR ligation are for instance impaired in NOD mice developing diabetes, in mice developing a model of multiple sclerosis and also in humans with autoimmune diseases. To investigate the NKT cell role in rheumatoid arthritis, we studied their quantitative and qualitative profile in collagen-induced arthritis (CIA) DBA/1 susceptible mice, and we tested whether NKT stimulation with their synthetic ligand alpha-galactosylceramide (α-GalCer) was therapeutic in CIA.

Methods

The number of NKT cells in the liver was determined by flow cytometry with an anti-TCRαβ or empty or α-GalCer-loaded CD1 tetramer. CIA was induced by immunization of DBA/1 mice with collagen II (CII) in adjuvant, and with a boost 21 days later. α-GalCer (4 μg) was administered at the same time of the first immunization. In one experiment, one group of mice was also treated with an anti-IL-10 receptor antibody. CII-specific CD4+ cells from lymph node (LN) response was monitored by immunizing mice with 75 μg CII in adjuvant in hind paws. Some mice were administered 4 μg α-GalCer in the CII/adjuvant mixture at the same time. Nine days after immunization, CD4+ cells were purified from LN and cultured with CII and antigen-presenting cells. Proliferation was measured after 3 days by measuring BrdU incorporation, and IL-4, IL-10 and IFN-γ levels were assessed by ELISA in the supernatants.

Results

The number of NKT cells among leucocytes in the liver of DBA/1 mice was comparable to what is generally observed in C57Bl/6 and suggest a normal quantitative profile of NKT cells in DBA/1 mice. In contrast, in vivo NKT cell function was altered in DBA/1 mice since stimulation with α-GalCer (4 μg intraperitoneally) led to decreased IL-4 and IFN-γ levels in the serum 2 hours after the injection, as compared with C57Bl/6 mice (693 ± 154 pg/ml versus 1557 ± 137 g/ml IL-4 [P < 0.01] and 2077 ± 378 versus 4005 ± 581 IFN-γ [P < 0.02]). Treatment of CIA with α-GalCer at day 0 induced a clear-cut diminution of clinical (ANOVA test, P = 0.0001) and histological scores (1.19 ± 0.14 versus 1.85 ± 0.24, P < 0.05) of arthritis, as compared with the control group. Importantly, treatment of mice with an anti-IL-10 receptor abrogated the protective effect of α-GalCer. The α-GalCer-induced protection was associated with the ability of LN CD4+ cells from CII-immunized and α-GalCer-treated DBA/1 mice to secrete larger amounts of IL-10 upon in vitro restimulation with CII, while IL-4 and IFN-γ levels were not affected. CII-induced proliferation was slightly reduced in LN CD4 cells from CII-immunized and α-GalCer-treated DBA/1 mice as compared with controls.

Conclusion

These findings raise the possibility that NKT stimulation might induce a shift toward an anti-inflammatory Th2 status and could be used therapeutically to treat chronic autoimmune arthritis.