Rheumatoid Tissue Research Articles

Inhibitory effect of CD147/HAb18 monoclonal antibody on cartilage erosion and synovitis in the SCID mouse model for rheumatoid arthritis

To explore the therapeutic potential of CD147/HAb18 mAb in the treatment of RA in severe combined immunodeficiency (SCID) mice engrafted with human cartilage and rheumatoid synovium tissue (SCID-HuRAg). SCID-HuRAg mice were treated separately with CD147/HAb18 mAb, anti-TNF-alpha mAb or a combination of both. The mice in control group were treated with anti-Japanese encephalitis virus mAb. The volume of engrafts was measured and the number of inflammatory cells and cartilage erosion score were examined. Expression of MMP-2, -3 and -9 was determined by immunohistochemistry. Human inflammatory cytokine levels in mouse sera were assessed using cytometric bead array kit. The volume of engrafts decreased significantly in SCID-HuRAg mice treated separately with anti-CD147 mAb or anti-TNF-alpha mAb, and in the mice treated with anti-CD147 mAb plus anti-TNF-alpha mAb (P < 0.05). Significant reduction was observed in cartilage erosion score in anti-CD147 treatment group and combined treatment group (P < 0.05). Immunohistochemical analysis showed that expression of MMP-2, -3 and -9 was lower in the anti-CD147 treatment group and combined treatment group than in the control mAb group (P < 0.05). Moreover, the level of TNF-alpha, IL-6 and -8 in CD147 mAb group showed a significant decrease compared with that of the control mAb group (P < 0.05). CD147/HAb18 mAb can reduce cartilage erosion and synovitis by inhibition of the MMPs and reduction of inflammatory cytokines in SCID-HuRAg mice, which suggests that CD147/HAb18 mAb is a promising treatment option for RA patients.

Human rheumatoid arthritis tissue production of IL-17A drives matrix and cartilage degradation: synergy with tumour necrosis factor-alpha, Oncostatin M and response to biologic therapies.

IntroductionThe aim of this study was to examine IL-17A in patients, following anti-TNF-α therapy and the effect of IL-17A on matrix turnover and cartilage degradation.MethodsIL-17A expression was examined by ELISA and immunohistology in the rheumatoid arthritis (RA) joints. RA whole synovial tissue explant (RA ST), primary synovial fibroblasts (RASFC), human cartilage and chondrocyte cultures were stimulated with IL-17A +/- TNF-α and Oncostatin M (OSM). Matrix metalloproteinase (MMP) and tissue inhibitor (TIMP-1) were assessed by ELISA and zymography. Cartilage proteoglycan release was assessed histologically by Safranin-O staining. Clinical parameters, IL-17A, MMP/TIMP were assessed in patients pre/post biologic therapy.ResultsIL-17A levels were higher in RA vs osteoarthritis (OA)/normal joints (P < 0.05). IL-17A up-regulated MMP-1, -2, -9, and -13 in RA ST, RASFC, cartilage and chondrocyte cultures (P < 0.05). In combination with TNF-α and OSM, IL-17A shifted the MMP:TIMP-1 ratio in favor of matrix degradation (all P < 0.05). Cartilage proteoglycan depletion in response to IL-17A was mild; however, in combination with TNF-α or OSM showed almost complete proteoglycan depletion. Serum IL-17A was detected in 28% of patients commencing biologic therapy. IL-17A negative patients demonstrated reductions post therapy in serum MMP1/TIMP4, MMP3/TIMP1 and MMP3/TIMP4 ratios and an increase in CS846 (all P < 0.05). No significant changes were observed in IL-17A positive patients.ConclusionsIL-17A is produced locally in the inflamed RA joint. IL-17A promotes matrix turnover and cartilage destruction, especially in the presence of other cytokines, mimicking the joint environment. IL-17A levels are modulated in vivo, following anti-TNF therapy, and may reflect changes in matrix turnover.

LILRA5 is expressed by synovial tissue macrophages in rheumatoid arthritis, selectively induces pro‐inflammatory cytokines and IL‐10 and is regulated by TNF‐α, IL‐10 and IFN‐γ

Leukocyte immunoglobulin-like receptor A5 (LILRA5) belongs to a family of receptors known to regulate leukocyte activation. There are two membrane-bound and two soluble forms of LILRA5. The transmembrane LILRA5 contain a short cytoplasmic domain and a charged arginine residue within the transmembrane region. Cross-linking of LILRA5 on monocytes induced production of pro-inflammatory cytokines, suggesting that LILRA5 plays a role in inflammation. However, expression of LILRA5 in diseases with extensive inflammatory component is unknown. Rheumatoid arthritis (RA) is a chronic inflammatory synovitis characterized by unregulated activation of leukocytes leading to joint destruction. Here we demonstrate extensive LILRA5 expression on synovial tissue macrophages and in synovial fluid of patients with active RA but not in patients with osteoarthritis. We also show that LILRA5 associated with the common gamma chain of the FcR and LILRA5 cross-linking induced phosphorylation of Src tyrosine kinases and Spleen tyrosine kinase (Syk). Furthermore, LILRA5 induced selective production of pro-inflammatory cytokines as well as IL-10. LILRA5 mRNA and protein expression was tightly regulated by TNF-alpha, IL-10 and IFN-gamma. Increased expression of LILRA5 in rheumatoid tissue, together with its ability to induce key cytokines involved in RA, suggests that this novel receptor may contribute to disease pathogenesis.

Frequency and significance of anticardiolipin antibodies in Chinese patients with primary Sjögren's syndrome

Materials and methods Patients were consecutively recruited among the patients with pSS seen in our rheumatic department between March 2001 and October 2007. All the included patients met the revised European Community Criteria for pSS. All patients fulfilling the clinical criteria for rheumatoid arthritis (RA), SLE, polymyositis, systemic sclerosis or other diffuse connective tissue diseases were excluded from pSS group. Any patients with sarcoidosis, graft-versus-host disease, acquired immune deficiency syndrome or preexisting lymphoma were also excluded.

Relationship between cryoglobulinemia-associated nephritis and HCV infection

The pathogenetic mechanisms in hepatitis C virus (HCV)-related cryoglobulinemia are sustained by the chronic lymphocyte stimulation of HCV infection, and include the synthesis of IgM rheumatoid factor and tissue deposition of immunocomplexes, characterized by abnormal kinetics and an underlying lymphoproliferative disorder. Based on postulated pathogenetic mechanisms, therapeutic strategies include antiviral, immunosuppressive and immunomodulatory treatments. Combined interferon and ribavirin has shown a better response rate than interferon alone. Pegylated interferons are currently recommended in association with ribavirin. Advances in tolerance might be achieved by tailoring doses and treatment duration according to genotype and individual factors. Conventional immunosuppressive therapy has been widely used in patients with progressive renal involvement or relapsing disease. Rituximab is a promising alternative treatment option for severe cryoglobulinemic vasculitis and nephritis. Although the optimal treatment strategy in HCV-related cryoglobulinemia has not been determined yet, an algorithm based on the clinical severity of disease could be proposed, in which rituximab might be a first-line option in severe cases.

Characterization of the binucleated giant cells generated in the autologous mixed leucocyte reaction from patients with rheumatoid arthritis

Binucleated giant cells several times larger than lymphocytes or monocytes were generated in an autologous mixed leucocyte reaction (AMLR) independent of DNA synthesis in patients with rheumatoid arthritis (RA). The AMLR giant cells with multiple cytoplasmic granules were non-specific esterase-staining positive, phagocytic, non-adherent, HLA-DR+, CD11b+, CD14+, 4F2+, CDW29+, and anti-transferrin receptor positive, but negative for T, B, or NK markers. RA patients aged less than 60 years from more giant cells: 12.6 +/- 13.5% (n = 33) as compared with 0.4 +/- 1.5% in age- and sex-matched normals (n = 38, (P less than 0.001). More giant cells were seen over age 60 in both groups: RA 20.1 +/- 15.5% (n = 5) and healthy controls 3.0 +/- 3.2% (n = 8) (P less than 0.01). Neither disease activity nor treatment appear to influence the result in RA. The giant cells that are probably derived from monocytes in AMLR may explain the formation of the giant cells in rheumatoid granulation tissues.

Key differences in TLR3/poly I:C signaling and cytokine induction by human primary cells: a phenomenon absent from murine cell systems

AbstractTLR3 recognizes double-stranded RNA, a product associated with viral infections. Many details of TLR3-induced mechanisms have emerged from gene-targeted mice or inhibition studies in transformed cell lines. However, the pathways activated in human immune cells or cells from disease tissue are less well understood. We have investigated TLR3-induced mechanisms of human primary cells of the innate immune system, including dendritic cells (DCs), macrophages (MØs), endothelial cells (ECs), and synovial fibroblasts isolated from rheumatoid arthritis joint tissue (RA-SFs). Here, we report that while these cells all express TLR3, they differ substantially in their response to TLR3 stimulation. The key antiviral response chemokine IP-10 was produced by all cell types, while DCs and MØs failed to produce the proinflammatory cytokines TNFα and IL-6. Unexpectedly, TNFα was found secreted by TLR3-stimulated RA-SF. Furthermore, TLR3 stimulation did not activate NFκB, MAPKs, or IRF-3 in DCs and MØs, but was able to do so in ECs and RA-SF. These findings were specific for human cells, thereby revealing a complexity not previously expected. This is the first report of such cell type– and species-specific response for any TLR stimulation and helps to explain important difficulties in correlating murine models of inflammatory diseases and human inflammation.

Could toll-like receptors provide a missing link in chronic inflammation in rheumatoid arthritis? Lessons from a study on human rheumatoid tissue

In the last decade the development of a number of biological therapies has revolutionised the treatment of rheumatic diseases. The first and most widely used of these approaches, tumour necrosis...

Simultaneous analysis of multiple serum proteins adhering to the surface of medical grade polydimethylsiloxane elastomers

Although polydimethylsiloxane (PDMS, silicone) elastomers are presumed to be chemically inert and of negligible toxicity, they induce a prompt acute inflammatory response with subsequent fibrotic reactions. Since local inflammatory and fibrotic side effects are associated with the proteinaceous film on the surface of silicone implants, the process of protein adherence to silicone is of practical medical relevance, and interesting from theoretical, clinical and biotechnological perspectives. It is hypothesized that the systemic side effects resembling rheumatoid and other connective tissue diseases may be triggered by local immunological changes, but this functional relationship has yet to be defined. Because the proteinaceous film on the surface of silicone has been identified as a key player in the activation of host defense mechanisms, we propose a test system based on a proteomics screen to simultaneously identify proteins adsorbed from serum to the surface of silicone. Herein, we describe protein adsorption kinetics on the surface of silicone implants, correlate the adhesion properties of serum proteins with the occurrence of adverse reactions to silicone, and successfully discriminate their signature on the silicone surface in a blinded study of patients suffering from fibrotic reactions (as determined by Baker scale) to silicone implants.

Tetraplegia in rheumatoid arthritis with complete recovery after surgery.

Abstract A patient with tetraplegia caused by subluxation of the lower cervical spine in rheumatoid arthritis is presented. The clinical history, early complication, and delayed diagnosis are described. Compression of the dura mater by rheumatoid granulation tissue and vertebral subluxation are suggested to be responsible for the cord damage. Failure of conservative treatment after a week is a strong indication for surgery. Posterior decompression of the cervical spine and splitting of the dura mater are recommended.

Trypsin-2 Degrades Human Type II Collagen and Is Expressed and Activated in Mesenchymally Transformed Rheumatoid Arthritis Synovitis Tissue

It has traditionally been believed that only the human collagenases (matrix metalloproteinase-1, -8, and -13) are capable of initiating the degradation of collagens. Here, we show that human trypsin-2 is also capable of cleaving the triple helix of human cartilage collagen type II. We purified human trypsin-2 and tumor-associated trypsin inhibitor by affinity chromatography whereas collagen type II was purified from cartilage extracts using pepsin digestion and salt precipitation. Degradation of type II collagen and gelatin by trypsin-2 was demonstrated with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, zymography, and mass spectrometry, and tumor-associated trypsin inhibitor specifically inhibited this degradation. Although human trypsin-2 efficiently digested type II collagen, bovine trypsin did not. Furthermore, immunohistochemical staining detected trypsin-2 in the fibroblast-like synovial lining and in stromal cells of human rheumatoid arthritis synovial membrane. These findings were confirmed by reverse transcriptase-polymerase chain reaction and nucleotide sequencing. Trypsin-2 alone and complexed with alpha(1)-proteinase inhibitor were also detected in the synovial fluid of affected joints by time-resolved immunofluorometric assay, suggesting that trypsin-2 is activated locally. These results are the first to assess the ability of human trypsin to cleave human type II collagen. Thus, trypsin-2 and its regulators should be further studied for use as markers of prognosis and disease activity in rheumatoid arthritis.

T cell costimulation by fractalkine‐expressing synoviocytes in rheumatoid arthritis

Patients with rheumatoid arthritis (RA) accumulate prematurely aged T cells that have acquired a new profile of regulatory receptors. Many of the de novo-expressed receptors are typically found on natural killer cells, including CX(3)CR1, the receptor for the chemokine fractalkine (FKN). This study explored whether interactions between CX(3)CR1 and FKN are relevant for T cell functions in rheumatoid synovitis. FKN expression was examined by real-time polymerase chain reaction and immunohistochemistry. CX(3)CR1 expression on peripheral blood T cells was analyzed by flow cytometry. T cell activation was quantified by determining proliferative responses, interferon-gamma (IFNgamma) secretion, and granule release. Fibroblast-like synoviocyte (FLS)/T cell adhesion was measured by the retention of 5-carboxyfluorescein diacetate succinimidyl ester-labeled T cells on FLS monolayers. FKN was expressed on cultured synovial fibroblasts and hyperplastic synoviocytes in the rheumatoid tissue. Among CD4+ T cells, only senescent CD28- T cells were positive for CX(3)CR1 (P < 0.001). Such CD4+,CD28-,CX(3)CR1+ T cells strongly adhered to FLS, with soluble FKN blocking the interaction. FKN expressed on FLS costimulated T cell-activating signals and amplified proliferation, IFNgamma production, and expulsion of cytoplasmic granules. Senescent CD4+ T cells that accumulate in rheumatoid arthritis aberrantly express CX(3)CR1. FKN, which is membrane-anchored on synoviocytes, enhances CD4+ T cell adhesion, provides survival signals, and costimulates the production of proinflammatory cytokines as well as the release of granules. By virtue of their altered receptor profile, senescent CD4+ T cells receive strong stimulatory signals from nonprofessional antigen-presenting cells in the synovial microenvironment.

Molecular typing of synovitis: differences between rheumatoid arthritis, osteoarthritis and normal tissue

Molecular typing of synovitis: differences between rheumatoid arthritis, osteoarthritis and normal tissue

Rheumatoid arthritis is a heterogeneous disease: evidence for differences in the activation of the STAT-1 pathway between rheumatoid tissues.

To generate a molecular description of synovial tissue from rheumatoid arthritis (RA) patients that would allow us to unravel novel aspects of pathogenesis and to identify different forms of disease. We applied complementary DNA microarray analysis to profile gene expression, with a focus on immune-related genes, in affected joint tissues from RA patients and in tissues from osteoarthritis (OA) patients as a control. To validate microarray data, real-time polymerase chain reaction was performed on genes of interest. The gene expression signatures of synovial tissues from RA patients showed considerable variability, resulting in the identification of at least two molecularly distinct forms of RA tissues. One class of tissues revealed abundant expression of clusters of genes indicative of an involvement of the adaptive immune response. Detailed analysis of the expression profile provided evidence for a prominent role of an activated signal transducer and activator of transcription 1 pathway in these tissues. The expression profiles of another group of RA tissues revealed an increased tissue remodeling activity and a low inflammatory gene expression signature. The gene expression pattern in the latter tissues was reminiscent of that observed in the majority of OA tissues. The differences in the gene expression profiles provide a unique perspective for distinguishing different pathogenetic RA subsets based on molecular criteria. These data reflect important aspects of molecular variation that are relevant for understanding the biologic dysregulation underlying these subsets of RA. This approach may also help to define homogeneous groups for clinical studies and evaluation of targeted therapies.

Expression of focal adhesion kinase, Akt/PKB, Elk-1 and p90RSK in rheumatoid arthritis tissues but not at sites of cartilage invasion

Expression of focal adhesion kinase, Akt/PKB, Elk-1 and p90RSK in rheumatoid arthritis tissues but not at sites of cartilage invasion

Development of large pseudocysts adjacent to the knee joint in rheumatoid arthritis. Assessment of radiological and histopathological approaches

This study examined the pathogenesis of large pseudocysts adjacent to knee joints in rheumatoid arthritis (RA). The radiological and histopathological features of 17 large subarticular pseudocysts in 12 knee joints of 10 patients were analyzed. Nine of the 10 patients were classified as class 2 according to Steinbrocker's functional class. Eight large pseudocysts were located at the lateral femoral condyle, seven were at the proximal part of the tibia, one was at the medial femoral condyle, and one was at the patella. The large pseudocysts were divided into two groups according to whether they did or did not connect with the joint cavity. Serial radiographs revealed that all large pseudocysts in communication with the joint cavity had enlarged gradually over the past several months. They extended from the subarticular area toward the bone marrow. Histopathological findings confirmed that holes allowing communication were located at a transitional zone between the ligament and the hyaline cartilage, and that rheumatoid granulation tissue invaded the large pseudocyst through these holes. The results of this study indicate that large pseudocysts are formed by the extension of articular inflammation. Moreover, repeated extrinsic mechanical stress due to walking and the aggressive inflammatory nature of rheumatoid arthritis play important roles in the formation of large pseudocysts.

Development of large pseudocysts adjacent to the knee joint in rheumatoid arthritis. Assessment of radiological and histopathological approaches

This study examined the pathogenesis of large pseudocysts adjacent to knee joints in rheumatoid arthritis (RA). The radiological and histopathological features of 17 large subarticular pseudocysts in 12 knee joints of 10 patients were analyzed. Nine of the 10 patients were classified as class 2 according to Steinbrocker's functional class. Eight large pseudocysts were located at the lateral femoral condyle, seven were at the proximal part of the tibia, one was at the medial femoral condyle, and one was at the patella. The large pseudocysts were divided into two groups according to whether they did or did not connect with the joint cavity. Serial radiographs revealed that all large pseudocysts in communication with the joint cavity had enlarged gradually over the past several months. They extended from the subarticular area toward the bone marrow. Histopathological findings confirmed that holes allowing communication were located at a transitional zone between the ligament and the hyaline cartilage, and that rheumatoid granulation tissue invaded the large pseudocyst through these holes. The results of this study indicate that large pseudocysts are formed by the extension of articular inflammation. Moreover, repeated extrinsic mechanical stress due to walking and the aggressive inflammatory nature of rheumatoid arthritis play important roles in the formation of large pseudocysts.

Evidence that rheumatoid arthritis synovial T cells are similar to cytokine-activated T cells: involvement of phosphatidylinositol 3-kinase and nuclear factor kappaB pathways in tumor necrosis factor alpha production in rheumatoid arthritis.

To investigate the mechanism that leads to the spontaneous production of tumor necrosis factor alpha (TNFalpha) in rheumatoid arthritis (RA) synovial tissue. Normal blood monocytes were cocultured either with fixed activated T cells generated from normal blood or RA synovial T cells purified from synovium. TNFalpha production was measured in supernatants from these cocultures following blockade of the transcription factor nuclear factor kappaB (NF-kappaB) using adenoviral transfer of the inhibitor of NF-kappaB kinase alpha into the responding monocytes, or blockade of phosphatidylinositol 3-kinase (PI 3-kinase) using the inhibitory drugs wortmannin or LY294002. TNFalpha production was measured by enzyme-linked immunosorbent assay. TNFalpha production in synovial tissue from patients with RA but not osteoarthritis was found to be T cell dependent. The RA synovial joint T cells resembled normal T cells that had been activated for 8 days using a cocktail of cytokines. These T cells, designated Tck (cytokine-activated T cells), and RA synovial T cells both induced TNFalpha production in resting monocytes in a cell-contact-dependent manner, which was abrogated by blockage of the transcription factor NF-kappaB but augmented if PI 3-kinase was inhibited. Normal blood T cells activated conventionally via the T cell receptor with crosslinked anti-CD3 antibody resulted in TNFalpha production from monocytes; this was unaffected by NF-kappaB blockade, but was inhibited in the presence of PI 3-kinase-blocking drugs. These data provide strong evidence for the importance of T cells in inducing TNFalpha in chronic inflammatory rheumatoid tissue, and give insight into the mechanism whereby these T cells are activated in vivo. Furthermore, they indicate that production of TNFalpha in pathologic tissue is regulated differently from physiologic antigen-dependent TNFalpha production, which raises the possibility that selective inhibitors of TNFalpha in disease may be developed.

NF-kappaB-inducing kinase is dispensable for activation of NF-kappaB in inflammatory settings but essential for lymphotoxin beta receptor activation of NF-kappaB in primary human fibroblasts.

The transcription factor NF-kappaB is of major importance in the biology of pro-inflammatory cytokines, such as TNF-alpha and IL-1alpha, and thereby is intimately involved in the process of inflammation. Understanding the mechanisms by which NF-kappaB is activated in response to inflammatory stimuli has become a major goal of inflammation research. The discovery of NF-kappaB-inducing kinase (NIK) as a TNFR-associated factor-interacting enzyme and a potential activator of the IkappaBalpha-kinase complex appeared to have identified an important element of the NF-kappaB activation pathway, a view that was supported by several subsequent studies. However, recent experiments in the alymphoplasia (aly/aly) mouse, which has missense point mutation (G885R) in NIK, has challenged that view. The reasons for the discrepancy between the different studies is unclear and could be due to multiple factors, such as cell type, species of cell, or primary vs transformed cell lines. One system that has not been investigated is primary human cells. Using an adenoviral vector encoding kinase-deficient NIK, we have investigated the role of NIK in LPS, IL-1, TNF-alpha, and lymphotoxin (LT) betaR signaling in primary human cells and TNF-alpha expression from rheumatoid tissue. These data show that, in the primary systems tested, NIK has a restricted role in LTbetaR signaling and is not required by the other stimuli tested. Also, there is no apparent role for NIK in the process of TNF-alpha production in human rheumatoid arthritis. These data also highlight the potential problems in extrapolating the function of signaling pathways between primary and transfected cell lines.

Expression of rank, rankl and OPG is associated with rheumatoid arthritic, periodontal and periprosthetic tissues

Expression of rank, rankl and OPG is associated with rheumatoid arthritic, periodontal and periprosthetic tissues