Overview : Destruction of the Extracellular Matrix in Rheumatoid Arthritis

not available Altered T Cell Differentiation in Patients with Early Rheumatoid Arthritis Alla Skapenko, Jörg Wendler, Peter E Lipsky, Joachim R Kalden, and Hendrik Schulze-Koops University of Erlangen-Nuremberg, Erlangen, Germany and University of Texas Southwestern Medical Center, Dallas, Texas, USA Chronic inflammation in rheumatoid arthritis (RA) is likely to be driven by activated Th1 cells without sufficient Th2 cell differentiation to down-modulate inflammation [1,2]. To test whether, in RA, Th cells express an alteration in their ability to differentiate into effector cells, we investigated Th cell differentiation in patients with early untreated RA and in ageand sex-matched controls in vitro. All patients had active RA with symptoms of the disease for 6 weeks to 12 months. A cell culture system was used that permitted the differentiation of Th effectors from resting memory T cells by short-term priming [3]. No difference in the cytokine secretion profile of freshly isolated T cells was detected between patients and controls. However, marked differences were found in the response to priming. Th2 cells could be induced in all healthy individuals by priming with anti-CD28 in the absence of TCR ligation. By contrast, priming under those conditions resulted in Th2 differentiation in only 9/24 RA patients. The addition of exogenous IL-4 could overcome the apparent Th2 differentiation defect in seven patients but was without effect in the remaining eight patients. In all patients, a marked decrease in IL-2 producing cells and a significant increase in well-differentiated Th1 cells that produced IFN-γ but no IL-2 was evident after priming with anti-CD3 and anti-CD28 [4]. The data suggest that CD4+ memory T cells from patients with early untreated RA manifest an intrinsic abnormality in their ability to differentiate into specific cytokine producing effector cells, which might contribute to the characteristic Th1 dominated chronic (auto)immune inflammation in RA. 1. Schulze-Koops H, Lipsky PE, Kavanaugh AF, Davis LS: Elevated Th1or Th0-like cytokine mRNA in peripheral circulation of patients with rheumatoid arthritis: modulation by treatment with AntiICAM-1 correlates with clinical benefit. J Immunol 1995, 155:5029–5037. 2. Simon AK, Seipelt E, Sieper J: Divergent T-cell cytokine patterns in inflammatory arthritis. Proc Natl Acad Sci USA 1994, 91:8562–8566. 3. Schulze-Koops H, Lipsky PE, Davis LS: Human memory T cell differentiation into Th2-like effector cells is dependent on IL-4 and CD28 stimulation and inhibited by TCR ligation. Eur J Immunol 1998, 28:2517–2529. 4. Skapenko A, Wendler J, Lipsky PE, Kalden JR, Schulze-Koops H: Altered memory T cell differentiation in patients with early rheumatoid arthritis. J Immunol 1999, 163:491–499. Arthritis Research Vol 1 Suppl 1 Abstracts 4 B Cells in Rheumatoid Arthritis Evidence for an antigen-driven immune response in the chronically inflamed synovium Claudia Berek and H-J Kim Deutsches Rheuma ForschungsZentrum, Berlin, Germany Recently it has been shown that proinflammatory cytokines, like TNF-alpha and lymphotoxin play a crucial role in the organogenesis of the lymphoid tissue. Thus, during chronic inflammation, in the affected tissue, these cytokines may promote the development of a micro-environment which supports a local immune response. In patients with rheumatoid arthritis large lymphocytic infiltrates are often seen in the synovial tissue. These cell clusters have a characteristic arrangement of T, B and plasma cells. Proliferating B cells are found only centrally in a network of follicular dendritic cells. Using micro-manipulation CD20+ B cells and plasma cells were isolated separately from different parts of single infiltrates. DNA was extracted and the VH/VL gene repertoires determined. The data show that within the network of follicular dendritic cells there is an oligoclonal expansion of B cells. During proliferation V-gene variants are generated by the hypermutation mechanism. The pattern of somatic mutations suggests that both naive and memory B cells become activated in the synovial tissue. Within single infiltrates we did not find identical rearrangements between CD20+ B and plasma cells. Nevertheless, the finding of clonally related plasma cells suggests that these cells underwent terminal differentiation in the synovial tissue. The analysis of individual B cells recovered from synovial tissue opens a new way to determine the specificity of those cells which take part in the local immune reaction. 1. Berek C, Kim H-J: B-cell activation and development within chronically inflamed synovium in rheumatoid and reactive arthritis. Sem Immunol 1997, 9:261–268. 2. Fu Y-X, Chaplin DD: Development and maturation of secondary lymphoid organs. Annu Rev Immunol 1999, 17:399-433. 3. Kim H-J, Krenn V, Steinhauser G, Berek C: Plasma cell development in synovial germinal centers in patients with rheumatoid and reactive arthritis. J Immunol 1999, 162:3053–3062. 4. Randen I, Mellbye J, Forre O, Natvig JB: The identification of germinal centres and follicular dendritic networks in rheumatoid synovial tissue. Scand J Immuol 1995, 41:481–486. 5. Schröder AE, Greiner A, Seyfert C Berek C: Differentiation of B cells in the nonlymphoid tissue of the synovial membrane of patients with rheumatoid arthritis. Proc Natl Acad Sci USA 1996, 93: 221–225. Expression of RAG1, RAG2, and TdT in Rheumatoid Arthritis Synovia: Evidence for Receptor Revision of Immunoglobulin Light Chains S Louis Bridges Jr and Zhixin Zhang University of Alabama at Birmingham and Birmingham VA Medical Center, USA Some rheumatoid arthritis (RA) synovia contain structures similar to germinal centers (GC), the site of affinity maturation of B lymphocytes [1,2]. Previous analyses of immunoglobulin (Ig) kappa and lambda light chains expressed in RA synovia showed clonally related sequences with frequent N region addition and unusually long CDR3s [3,4]. The presence of clonally related Ig heavy chain sequences in GC-like structures from RA synovia suggests in situ antigendependent B cell maturation. RAG1 and 2, enzymes that mediate V(D)J recombination during B cell development, are expressed in a subset of GC B cells in normal peripheral lymphoid organs [5,6]. RAG expression allows secondary Ig rearrangements, which salvages B cells with undesirable specificities or low antigen affinity (receptor revision). We sought to determine whether RAG and TdT (the enzyme responsible for N region addition) are expressed in RA synovia and whether secondary Ig rearrangements occur. Using nested RT-PCR, we detected RAG1, RAG2, and TdT mRNA in 8, 9, and 6 of 12 synovial samples (11 RA, 1 JRA), respectively. RAG1 was expressed in B cells (5/8 samples) and T cells (4/8). RAG2 was expressed in B cells (4/8) more often than in T cells (1/8). TdT was expressed in B cells only (2/8). Immunohistochemical staining indicated that RAG proteins were distributed in lymphoid aggregates. In some synovia, secondary rearrangement products (ds-DNA breaks at recombination signal sequences in the Jkappa region) were detected by ligation-mediated PCR. We speculate that receptor revision in nonlymphoid tissues such as RA synovia may generate autoreactive antibodies, which has important implications for chronic inflammatory diseases. 1. Randen I, Mellbye OJ, Førre O, Natvig JB: The identification of germinal centres and follicular dendritic networks in rheumatoid synovial tissue. Scand J Immunol 1995, 41:481–486. 2. Schröder AE, Greiner A, Seyfert C, Berek C: Differentiation of B cells in the nonlymphoid tissue of the synovial membrane of patients with rheumatoid arthritis. Proc Natl Acad Sci, USA.1996, 93:221–225. 3. Bridges SL, Jr: Frequent N addition and clonal relatedness among immunoglobulin lambda light chains expressed in rheumatoid arthritis synovia and PBL, and the influence of Vlambda gene segment utilization on CDR3 length. Molecular Med 1998, 4:525–553. 4. Bridges SL, Jr, Lee SK, Johnson MJ, et al: Somatic mutation and CDR3 lengths of immunoglobulin kappa light chains expressed in patients with rheumatoid arthritis and normal individuals. J Clin Invest 1995, 96:831–841. 5. Papavasiliou F, Casellas R, Suh H, et al: V(D)J recombination in mature B cells: a mechanism for altering antibody responses. Science 1997, 278:298–301. 6. Han S, Zheng B, Schatz DG, Spanopoulou E, Kelsoe G: Neoteny in lymphocytes: Rag1 and Rag2 expression in germinal center B cells. Science 1996, 274:2094–2097. Role of Rheumatoid Factor B Cells in Normal and Pathologic Antigen Presentation