Sa.49. Anti-DNA Ig Peptides Promote Regulatory T Cell Activity in SLE Patients

S96 collagen-induced arthritis (CIA). Methods Toxicity model. Twenty one male DBA/1 mice were treated with 100 μl of (a)placebo, (b) Pol-Clg (c) Pol-Clg+matrikines (d) methotrexate (2.5 mg/kg) (e) b+d and (f) c+d weekly/month. Early arthritis. Sixty three age-matched mice were immunized intradermally at the base of the tail with 100 μg of chicken CII emulsified in complete Freund's adjuvant. Mice were then boosted with 100 μg of CII in incomplete Freund's adjuvant at 21 day. Treatments a-f were administered same day, weekly/month. Arthritis model: Artritis was induced to 63 mice. Treatments were administered 2 weeks after boost, weekly/month. Clinimorphometric scores. They were assessed before immunization and thereafter weekly. Weight and temperature were determined. Inflammation of the four paws was scored as follows: 0-3 (no inflammation-severe inflammation of whole paw or ankylosis). Inflammatory infiltrates were evaluated by H&E. Th1, Th2, Treg y Th17 subsets were evaluated by flow cytometry. Results: Incidence of CIA was of 100% by day 28 in CII challenged mice. Clinimorphometric analysis showed a down-regulation of inflammation post administration of b, c, e and f treatments (p b 0.05). Histology analysis showed that CIA-mice group had an extensive bone erosion, pannus and severe focal inflammatory infiltrates vs b, c, e and f treatments. Pol-Clg down-regulated Th17 and upregulated Treg and Th1. Conclusion: Pol-Clg exerts a downregulation of autoimmune inflammation (Th17) on established CIA without side effects. doi:10.1016/j.clim.2008.03.268

Sa.48. Comparison of Multiple Bioplex 2200 Assay with Immunoblot Assay for Detection of Antibodies to Extractable Nuclear Antigens Marina Magrey, Elaine Husni, Soumya Chatterjee, Manjula Gupta. Cleveland Clinic, Cleveland, OH

Objective: 1) Compare the accuracy of BioPlex 2200 to Western blot assay (Innogenetics- IG) in detecting antibodies to extractable nuclear antigens (ENA). 2) Evaluate whether positive results by Bioplex 2200 correlate accurately with clinical diagnosis. Methods: Sera of 113 patients suspected to have rheumatologic diseases were assayed for ENA both by IG and Bioplex 2200. Medical records of patients having discrepant results between the 2 assays were reviewed to verify the clinical diagnosis. Diagnosis was based on American College of Rheumatology classification criteria. Results: The following displays agreement and Cohen's Kappa (CK) between 2 assays:- RNP = 92.0% (86-96) CK .63 (.40-.86); Sm = 95.6% (90- 98) CK .71 (.47- .96); SSA= 92.1% (86 -96) CK .83 (.72 - .94); SSB = 88.5% (81- 93) CK .54 (.30-.77); Jo-1 = 96% (90-98) CK 0 (- .96- .96); Scl70 = 97.3%(93-99) CK .38 (- .30 -.107); centromere = 98.2% (94 -99) CK .90 (.76-.104). Majority of the positive results for ENA with Bioplex 2200 correlated with the clinical diagnosis. Conclusion: Bioplex assay for ENA showed moderate to high agreement with IG assay and with clinical diagnosis. Hence, Bioplex 2200 could replace IG since it enables automatic detection of multiple antibodies in

Abstracts single analysis. This reduces turnaround time resulting in prompt diagnosis and timely treatment. doi:10.1016/j.clim.2008.03.269

Sa.49. Anti-DNA Ig Peptides Promote Regulatory T Cell Activity in SLE Patients Antonio La Cava, Marissa Anderson, Bevra Hahn. UCLA, Los Angeles, CA The number of CD4+CD25highFoxP3+ regulatory T (Treg) cells is reduced in several autoimmune conditions including systemic lupus erythematosus (SLE), suggesting that this immune cell subset can contribute to counteract autoimmune reactivity. Although it is technically challenging to expand functional Treg cells ex vivo (mainly because of an intrinsic inability of Treg cells to proliferate following antigenic stimulation), recent reports have described nonspecific expansion of Tregs cells in cultures that contained high doses of interleukin (IL)-2. A possibly beneficial expansion of antigen-reactive, MHC-tetramer-selected Treg cells, is also currently tested by some groups. We report here that three-day in vitro cultures of peripheral blood mononuclear cells (PBMC) from SLE patients (n = 36) with anti-DNA Ig peptides expands functional CD4+CD25high regulatory T cells that suppress anti-CD3-stimulated CD4+CD25- T cells (p b 0.0001 by ANOVA vs 23 healthy matched controls). Importantly, the expanded Treg cells upregulate their intracellular expression of FoxP3 (p b 0.02), which is the transcription factor these cells require for cell contactmediated suppression of proliferation and IFN-gamma production in target effector T cells. Finally, the induction of FoxP3 in SLE Treg cells only occurs in serologically positive patients, and correlates with anti-DNA and IgG serum titers. These findings identify a new strategy to enhance immune regulatory T cell activity with defined antigenic specificity in SLE patients with positive autoimmune serology, and suggest a new approach to reverse the functional deficit that typically characterizes Treg cells of SLE patients. doi:10.1016/j.clim.2008.03.270

Sa.50. Inhibitory Oligodeoxynucleotide (ODN) Activity in Human B Cells Robert Ashman, Adam Goeken, Petar Lenert. University of Iowa, Iowa City, IA Toll-like-receptor(TLR)9 defects bacterial DNA, but recent evidence suggests endogenous TLR9 ligands play a role in autoantibody production in mouse models of lupus and rheumatoid arthritis. Thus inhibitory (IN-)ODNs active in human cells would be desirable. IN-ODN for mouse B cells were discovered by making critical base substitutions in a strong stimulatory (ST-)ODN with a phosphorothioate backbone, including converting the central CGTT to xGGG. Similar substitutions in ST-ODN for human B cells (2006) did not produce an IN-ODN, as assayed by inhibition of ODN 2006driven CD86 expression in the Namalwa B-lymphocyte line, or