Rheumatoid Arthritis: Marinova-Mutafchieva L

Staines NA, Derry CJ, Marinova-Mutafchieva L, Ali N, Davies DH, Murphy JJ. · Infection and Immunity Research Group, King's College London, Stamford Street, London, SE1 9NN, UK. · Ann N Y Acad Sci. · Pubmed #15681763 No free full text.

Abstract: Mucosal administration of an autoantigen has been shown to be a powerful way of inducing tolerance in both animal and human arthritis clinical trials. Bovine or chicken type II collagen has been administered orally to rheumatoid arthritis patients, resulting in some, although in many cases rather limited, clinical improvement. Animal studies have revealed that the mechanisms that underlie induction of mucosal tolerance include clonal deletion, suppression of the proinflammatory Th1 cells, and the induction of regulatory T cells. These cells, defined as a persistently CD25-expressing subset of CD4(+) cells, are frequently anergic, may produce anti-inflammatory cytokines such as IL-10 and TGF-beta, and are likely to be agents of bystander suppression. A key feature that may affect the induction of these cells and other suppressive mechanisms is the dose of antigen administered. The results from human clinical trials suggest a daily dose of significantly less than 1 mg is optimal. Similarly data from collagen-induced arthritis studies reveal an optimal dose above and below which there is little or no immune suppression. Indeed, the incorrect dose can prime the immune response and aggravate disease. The timing and frequency of administration is also vital to the level of immune tolerance induced and the control of the pathological process. This and other findings derived from animal studies are discussed here in relation to the results from human clinical trials.

Gabay C, Marinova-Mutafchieva L, Williams RO, Gigley JP, Butler DM, Feldmann M, Arend WP. · Division of Rheumatology, University Hospital of Geneva, Switzerland. · Arthritis Rheum. · Pubmed #11229477 links to  free full text

Abstract: OBJECTIVE: To examine the patterns of production of interleukin-1 receptor antagonist (IL-1Ra) isoforms and of IL-1beta during arthritis in vivo. METHODS: Arthritis was induced in DBA/1 mice by immunization with type II collagen, and the production of IL-1Ra isoforms was examined in whole joints and in dissected synovial tissues by reverse transcription-polymerase chain reaction (RT-PCR), RNase protection assay, Western blotting, immunostaining, and in situ hybridization. Production of IL-1beta also was examined using similar approaches. RESULTS: Production of IL-1Ra increased in the joints during collagen-induced arthritis (CIA). By RT-PCR, secreted IL-1Ra messenger RNA (mRNA) was detected in normal joints, whereas intracellular IL-1Ra type I (icIL-1Ra1) mRNA was only produced in inflamed joints. Western blot studies showed that icIL-1Ra1 protein levels increased in the joints during the course of CIA and that icIL-1Ra3 protein was also present in low amounts. RNase protection assays showed that the IL-1beta:IL-1Ra mRNA ratio was increased in inflamed joints through day 14 of arthritis, whereas a reverse pattern was present at later time points (from day 20 to day 60). Consistent with this finding, immunohistochemistry and in situ hybridization studies confirmed that icIL-1Ra1 was only present in inflamed joints. The histologic evaluation of CIA during the course of the disease indicated a resolution of acute inflammation, since icIL-1Ra1 production increased and the ratio of IL-1beta to total IL-1Ra decreased. CONCLUSION: Production of IL-1Ra isoforms, particularly icIL-1Ra1, is stimulated in inflamed joints during CIA in mice. The combination of decreased production of IL-1beta and elevated levels of icIL-1Ra1 during the course of CIA was associated with a reduction in inflammatory activity. These results suggest that icIL-1Ra1 may play a role in the resolution of murine CIA.

Marinova-Mutafchieva L, Taylor P, Funa K, Maini RN, Zvaifler NJ. · Kennedy Institute of Rheumatology, London, UK. · Arthritis Rheum. · Pubmed #11014356 links to  free full text

Abstract: OBJECTIVE: To evaluate the presence of cells of an early mesenchymal lineage, as judged by the expression of bone morphogenetic protein receptors (BMPRs), in the joints of normal individuals and patients with rheumatoid arthritis (RA). METHODS: Synovial fluids, single cell suspensions of cultured fibroblast-like synoviocytes (FLS), and synovial tissues were examined by immunohistology with antibodies to BMPR type IA (BMPRIA), BMPRIB, and BMPRII and then quantified using computerized image analysis. Other antibodies were evaluated by cytofluorography. RESULTS: In primary cultures of joint effusions from patients with RA and other forms of inflammatory arthritis, there were large adherent cells with the appearance of either fibroblasts or stromal cells that stained with antibodies to mesenchymal elements-CD44, type I collagen, alpha-actin, and vimentin-but not with antibodies to hematopoietic markers. These cells proliferated rapidly, expressed BMPRIA and BMPRII, and soon became the predominant cells in culture. They were retained through multiple passages and persistently displayed surface vascular cell adhesion molecule 1. Immunohistochemical analysis of cultured RA FLS (passages 3, 4, and 6; n = 6) revealed that 11.6% were BMPR-positive, while only 2.0% of osteoarthritis FLS (passage 4; n = 3) were BMPR-positive, and 1 normal synovial culture had no BMPR-positive cells. In all RA synovial membranes examined (n = 9), BMPRI- and BMPRII-expressing cells were identified in the intimal lining and were also scattered in the subintima. These cells constituted approximately 25% and approximately 7% of the cells in each area, respectively. Double immunostaining showed no coexpression of BMPR-positive cells with CD68, CD34, or CD3. Cells expressing BMPR were not seen in any normal synovial samples (n = 4). Strong staining for BMPR was identified on cells at the invasive front of the pannus and at sites of cartilage erosion. CONCLUSION: The inflamed RA joint contains BMPR-positive mesenchymal cells. Their origin is still speculative, but since their counterparts in the bone marrow are essential for osteoclastogenesis, support lymphocyte development and maturation, and protect T cells and B cells from programmed cell death, the BMPR-positive cells may be essential elements in the pathogenesis of RA and other inflammatory forms of chronic synovitis.

Marinova-Mutafchieva L, Williams RO, Mauri C, Mason LJ, Walmsley MJ, Taylor PC, Feldmann M, Maini RN. · Kennedy Institute of Rheumatology, London, UK. · Arthritis Rheum. · Pubmed #10728758 links to  free full text

Abstract: OBJECTIVE: Anti-tumor necrosis factor alpha (anti-TNFalpha) therapy is very effective in rheumatoid arthritis (RA), whereas depleting anti-CD4 therapy is relatively ineffective. To explain the differences in efficacy between these 2 therapies, we used an animal model of RA to compare their effects on different aspects of the disease process. METHODS: Mice with collagen-induced arthritis were treated with depleting anti-CD4 monoclonal antibodies (mAb), anti-TNFalpha mAb, or phosphate buffered saline. Another group was given a combination of anti-TNFalpha plus anti-CD4. The treatments were compared for their ability to down-regulate the expression of proinflammatory cytokines and adhesion molecules, reduce the cellularity of the joint, and inhibit Th1 activity. RESULTS: Anti-TNFalpha significantly reduced the numbers of cells expressing TNFalpha, interleukin-1beta (IL-1beta), very late activation antigen 4 (VLA-4), vascular cell adhesion molecule 1 (VCAM-1), and numbers of CD4+ T cells and macrophages in the joint. Anti-CD4 treatment led to a small reduction in the expression of TNFalpha, IL-1beta, VLA-4, and VCAM-1, but this did not reach statistical significance. Depleting anti-CD4 was also surprisingly ineffective in eliminating CD4+ T cells from the joint. Anti-TNFalpha therapy was also more effective than anti-CD4 in reducing Thl activity, as assessed by the production of interferon-gamma in lymph node cell cultures. There was a synergistic relationship between anti-TNFalpha and anti-CD4 in the reduction of histologic score and inhibition of TNFalpha/IL-1beta expression in the joints. CONCLUSION: The efficacy of the 3 treatments correlated with their ability to modulate the expression of inflammatory cytokines and adhesion molecules in the joint, reduce the cellularity of the joint, and inhibit Th1 activity. This kind of analysis may prove useful in the testing of novel therapies for RA.

Quattrocchi E, Walmsley M, Browne K, Williams RO, Marinova-Mutafchieva L, Buurman W, Butler DM, Feldmann M. · Kennedy Institute of Rheumatology, London, United Kingdom. · J Immunol. · Pubmed #10395698 links to  free full text

Abstract: Collagen-induced arthritis (CIA) is an experimental model of arthritis widely used to dissect the pathogenesis of human rheumatoid arthritis and to identify potential therapeutic targets. Among these, TNF-alpha has been recognized to play an important role. Here we investigate the feasibility and therapeutic efficacy of prolonged blockade of TNF-alpha activity through the adenovirus-mediated gene delivery of a dimeric chimeric human p55 TNFR-IgG fusion protein and compare it to protein therapy in established CIA. A single i.v. administration of the replication-deficient adenovirus yielded microgram serum levels of the chimeric fusion protein and ameliorated CIA for 10 days. Subsequently, benefit was lost and a rebound to greater inflammatory activity was observed despite the continual presence of bioactive TNFR fusion protein. A similar trend was also observed in mice injected directly with comparable amounts of a human TNFR-IgG fusion protein, whereas the administration of a control adenovirus-encoding beta-galactosidase or of a control human IgG1 protein did not significantly affect the disease course. The mechanisms of the rebound of CIA were investigated, and augmented Ab response to collagen type II and TNFR were identified as potential causes. Our results confirm the feasibility of adenovirus-mediated gene delivery of cytokine inhibitors in animal models of autoimmune diseases for investigational purposes and highlight the importance of prolonged studies. Further investigations are needed to optimize ways of exploiting the potential of adenoviral gene therapy in RA.

Malfait AM, Malik AS, Marinova-Mutafchieva L, Butler DM, Maini RN, Feldmann M. · Kennedy Institute of Rheumatology, Hammersmith, London, United Kingdom. · J Immunol. · Pubmed #10229875 links to  free full text

Abstract: The therapeutic potential of salbutamol, a beta2-adrenergic agonist, was explored in collagen-induced arthritis. This study was based on a report that salbutamol, by elevating intracellular cAMP, inhibits IL-12 production by macrophages and dendritic cells, thus preventing Th1 development. Ten-week-old male DBA/1 mice were immunized by intradermal injection of type II collagen in CFA. Arthritis developed 15-30 days later and the mice were treated after onset of disease with salbutamol, 200 microgram i.p. After 10 days, the mice were sacrificed, and the hind paws were evaluated histologically. Salbutamol, 200 microgram daily or every other day, had a profound therapeutic effect on the clinical progression of arthritis, as assessed by clinical score and paw thickness. The therapeutic effect was dose dependent. Daily administration of 200 microgram of salbutamol offered the best protection against joint damage, as assessed by histology. In vitro, salbutamol reduced IL-12 and TNF-alpha release by peritoneal macrophages in a dose-dependent manner, as well as TNF release by synovial cells from arthritic mice. Ex vivo, draining lymph node cells of the salbutamol-treated arthritic mice showed a diminished CII-specific IFN-gamma production and proliferation. In vivo, salbutamol specifically blocked mast cell degranulation in joint tissues. In conclusion, salbutamol has important effects on the immunoinflammatory response and a significant therapeutic action in collagen-induced arthritis.