Cartilage destruction and bone erosion in arthritis: the role of tumour necrosis factor alpha.
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Animals↗
Biomedical subjects
M Feldmann
Publications and source records attributed to M Feldmann.
Insights into the pathogenesis of rheumatoid arthritis from application of anti-TNF therapy.
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Arthritis, Rheumatoid↗
Effective adenoviral transfer of IkappaBalpha into human fibroblasts and chondrosarcoma cells reveals that the induction of matrix metalloproteinases and proinflammatory cytokines is nuclear factor-kappaB dependent.
OBJECTIVE: To determine whether, in human fibroblasts and chondrosarcoma cells, the regulation of interleukins (IL)-6, 8, and 11 and matrix metalloproteinases (MMP)-1, 3, and 13, and their tissue inhibitor TIMP-1, depends on the transcription factor nuclear factor-kappaB (NF-kappaB). METHODS: Fibroblasts and chondrosarcoma cells were effectively infected with an adenovirus encoding human IkappaBalpha, and inhibition of NF-kappaB function was observed. The induction of MMP and IL-6, 8, and 11 by various stimuli was assessed by ELISA. RESULTS: The induction of IL-6 and IL-8 clearly depended on NF-kappaB in both fibroblasts and chondrosarcoma cells, irrespective of stimulus, but IkappaBalpha overexpression had little effect on IL-11. MMP-1, -3, and -13 were also inhibited, but TIMP-1 was unaffected. CONCLUSION: NF-kappaB appears to play an important and selective role in MMP induction in human fibroblasts and chondrosarcoma cells. This suggests there are NF-kappaB dependent mechanisms of cartilage destruction in rheumatoid arthritis, and supports the concept that there are similarities in the regulation of inflammatory and destructive pathways in that disease.
Arthritis, Rheumatoid↗
Infliximab (chimeric anti-tumour necrosis factor alpha monoclonal antibody) versus placebo in rheumatoid arthritis patients receiving concomitant methotrexate: a randomised phase III trial. ATTRACT Study Group.
BACKGROUND: Not all patients with rheumatoid arthritis can tolerate or respond to methotrexate, a standard treatment for this disease. There is evidence that antitumour necrosis factor alpha (TNFalpha) is efficacious in relief of signs and symptoms. We therefore investigated whether infliximab, a chimeric human-mouse anti-TNFalpha monoclonal antibody would provide additional clinical benefit to patients who had active rheumatoid arthritis despite receiving methotrexate. METHODS: In an international double-blind placebo-controlled phase III clinical trial, 428 patients who had active rheumatoid arthritis, who had received continuous methotrexate for at least 3 months and at a stable dose for at least 4 weeks, were randomised to placebo (n=88) or one of four regimens of infliximab at weeks 0, 2, and 6. Additional infusions of the same dose were given every 4 or 8 weeks thereafter on a background of a stable dose of methotrexate (median 15 mg/week for > or =6 months, range 10-35 mg/wk). Patients were assessed every 4 weeks for 30 weeks. FINDINGS: At 30 weeks, the American College of Rheumatology (20) response criteria, representing a 20% improvement from baseline, were achieved in 53, 50, 58, and 52% of patients receiving 3 mg/kg every 4 or 8 weeks or 10 mg/kg every 4 or 8 weeks, respectively, compared with 20% of patients receiving placebo plus methotrexate (p<0.001 for each of the four infliximab regimens vs placebo). A 50% improvement was achieved in 29, 27, 26, and 31% of infliximab plus methotrexate in the same treatment groups, compared with 5% of patients on placebo plus methotrexate (p<0.001). Infliximab was well-tolerated; withdrawals for adverse events as well as the occurrence of serious adverse events or serious infections did not exceed those in the placebo group. INTERPRETATION: During 30 weeks, treatment with infliximab plus methotrexate was more efficacious than methotrexate alone in patients with active rheumatoid arthritis not previously responding to methotrexate.
Adult↗
Regulation of cytokines, cytokine inhibitors, and acute-phase proteins following anti-TNF-alpha therapy in rheumatoid arthritis.
Treatment with a chimeric mAb to TNF-alpha has been shown to suppress inflammation and improve patient well-being in rheumatoid arthritis (RA), but the mechanisms of action of such treatment have not been fully explored. Here we show that in vivo administration of anti-TNF-alpha Ab, using a longitudinal analysis, results in the rapid down-regulation of a spectrum of cytokines, cytokine inhibitors, and acute-phase proteins. Marked diurnal variation in the serum levels of some of these were detected. These results were consistent with the concept of a cytokine-dependent cytokine cascade, and the degree of clinical benefit noted after anti-TNF-alpha therapy is probably due to the reduction in many proinflammatory mediators apart from TNF-alpha, such as IL-6, which reached normal levels within 24 h. Serum levels of cytokine inhibitors such as soluble p75 and p55 TNFR were reduced as was IL-1 receptor antagonist. Reductions in acute-phase proteins occurred after serum IL-6 fell and included serum amyloid A, haptoglobin, and fibrinogen. The latter reduction could be of importance, as it is a risk factor for atherosclerosis, which is augmented in RA patients.
Acute-Phase Proteins↗
Paradoxical effects of adenovirus-mediated blockade of TNF activity in murine collagen-induced arthritis.
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.
Abatacept↗
The beta2-adrenergic agonist salbutamol is a potent suppressor of established collagen-induced arthritis: mechanisms of action.
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.
Adrenergic beta-Agonists↗
Defining therapeutic targets by using adenovirus: blocking NF-kappaB inhibits both inflammatory and destructive mechanisms in rheumatoid synovium but spares anti-inflammatory mediators.
The role of the transcription factor NF-kappaB in the pathogenesis of rheumatoid arthritis has long been a subject of controversy. We used an adenoviral technique of blocking NF-kappaB through overexpression of the inhibitory subunit IkappaBalpha, which has the advantage that it can be used in the diseased tissue itself, with >90% of the synovial macrophages, fibroblasts, and T cells infected. We found that the spontaneous production of tumor necrosis factor alpha and other pro-inflammatory cytokines is NF-kappaB-dependent in rheumatoid synovial tissue, in contrast to the main anti-inflammatory mediators, like IL-10 and -11, and the IL-1 receptor antagonist. Of even more interest, IkappaBalpha overexpression inhibited the production of matrix metalloproteinases 1 and 3 while not affecting their tissue inhibitor. Blocking NF-kappaB in the rheumatoid joint thus has a very beneficial profile, reducing both the inflammatory response and the tissue destruction. The adenoviral technique described here has widespread applicability, allowing rapid testing of the effects of blocking a potential therapeutic target in either cultures of normal cells or in the diseased tissue itself.
Adenoviridae↗
Selective regulation of cytokine induction by adenoviral gene transfer of IkappaBalpha into human macrophages: lipopolysaccharide-induced, but not zymosan-induced, proinflammatory cytokines are inhibited, but IL-10 is nuclear factor-kappaB independent.
Macrophages are the major cytokine producers in chronic inflammatory diseases, but the biochemical pathways regulating cytokine production are poorly understood. This is because genetic tools to dissect signaling pathways cannot be used in macrophages because of difficulties in transfection. We have developed an adenoviral technique to achieve high efficiency gene delivery into macrophages and recently showed that spontaneous TNF-alpha production in rheumatoid arthritis joint cells, chiefly from macrophages, is 75% blocked by adenoviral transfer of IkappaBalpha. In this report we use the same adenovirus to investigate whether the production of a number of proinflammatory cytokines (e.g., TNF-alpha, IL-1beta, IL-6, and IL-8) from human macrophages depends on NF-kappaB. While the cytokine response to certain inducers, such as LPS, PMA, and UV light, is blocked by overexpression of IkappaBalpha, the response to zymosan is not. In contrast, anti-inflammatory mediators (IL-10 and IL-1 receptor antagonist) induced by LPS are only marginally inhibited by IkappaBalpha excess. These studies demonstrate several new points about macrophage cytokine production. First, there is heterogeneity of mechanisms regulating both the proinflammatory and anti-inflammatory cytokines within populations of a single cell type. In addition, the results confirm the utility of the adenoviral technique for functional analysis of cytokine induction. The results also confirm that there are autocrine and paracrine interactions regulating cytokine synthesis within a single cell type. The selectivity of NF-kappaB blockade for proinflammatory but not anti-inflammatory mediators indicates that in macrophages, NF-kappaB may be a good target for the treatment of chronic inflammatory diseases.
Adenoviridae↗
Anti-IL-12 and anti-TNF antibodies synergistically suppress the progression of murine collagen-induced arthritis.
The co-ordinate role of the Th1 cytokine IL-12 and the proinflammatory cytokine TNF in arthritis was explored using the DBA/1 mouse model, collagen-induced arthritis (CIA). In this study, mice with established arthritis were treated with anti-IL-12 and/or anti-TNF antibodies for 10 days from the onset of disease. Clinical assessment showed that the combined antibody treatment ameliorated disease severity to a greater extent than anti-TNF alone. Supporting these observations, histological analysis revealed that there was a reduced joint damage in the mice that received combined anti-IL-12 and anti-TNF treatment, compared to the other treatment groups. Anti-IL-12 had no statistically significant effect on the clinical outcome of disease. The combination of anti-IL-12 and anti-TNF treatment was found to reduce collagen type II (CII)-specific lymph node cell IFN-gamma production and proliferation, as well as decrease the anti-CII IgG2a:IgG1 ratio more effectively than either treatment alone. When the antibodies were added to synovial cells from arthritic mice and bone marrow macrophages in vitro, anti-TNF diminished IL-12 production, but anti-IL-12 had no effect on TNF production. These data suggest that, through the partial regulation of IL-12, TNF modulates the immune response in arthritis, as well as the inflammatory response. The synergistic action of anti-TNF and anti-IL-12 on CIA may provide a new therapeutic approach for treating rheumatoid arthritis.
Animals↗
CD44 involvement in experimental collagen-induced arthritis (CIA).
CD44 is a pro-inflammatory cell surface molecule that supports cell migration and cell lodgment in target organs. Therefore, CD44 targeting with specific monoclonal antibodies (mAbs) should be useful for the inhibition of collagen-induced arthritis (CIA) as well as other autoimmune diseases that are dependent on inflammatory cells. In the present paper, we confirm and expand previous reports showing the anti-arthritogenic effect of anti-CD44 mAbs directed against constant epitopes of the CD44 receptor. We demonstrate that such anti-CD44 mAbs can induce resistance to CIA after disease onset. Even accelerated disease developed after two injections of type II collagen was markedly inhibited by IM7.8.1 anti-CD44 mAb. Although KM81 anti-CD44 mAb is a less efficient anti-arthritogenic reagent than IM7.8.1, its Fab' fragments partially inhibit CIA. This finding implies that the antibody blocks CD44 function rather than modulating CD44 cell surface expression or mediating Fc-dependent activities. Histopathological analysis revealed that the anti-CD44 mAb markedly reduces the synovial inflammatory cellular response and the consequent damage to the joint. As CD44 is an alternatively spliced multistructural molecule, similar anti-arthritogenic effects may be achieved by mAbs directed against CD44 isoforms expressed on the pathological cells in question, but not on normal cells, thus leaving the physiological functions intact.
Animals↗
The murine p75 TNF receptor promoter region: DNA sequence and characterization of a cis-acting silencer.
The promoter region of the murine p75 TNF receptor (TNF-R) was isolated from a mouse genomic DNA cosmid library. The promoter region is devoid of TATA box and has the characteristics of a house keeping gene since it contains multiple SP1 binding sites. Its mRNA has different initiation sites in different lymphoid cell lines. This promoter confers transcriptional activity to heterologous reporter genes. Deletion analysis showed that there is a silencer element located upstream from position -841. This inhibitory sequence is active both in fibroblasts and T-cell lines transiently or permanently transfected. A fragment from -929 to -841 is capable of transferring this 'silencer' activity to the early SV40 promoter. This activity could be blocked in trans- when a plasmid containing the same sequence was co-transfected with the reporter plasmid indicating that a protein binds to this region of the promoter.
Animals↗
Therapeutic antibodies elicited by immunization against TNF-alpha.
Tumor necrosis factor-alpha (TNF-alpha) is critically involved in the pathogenesis of several chronic inflammatory diseases. Monoclonal antibodies against TNF-alpha are currently used for the treatment of rheumatoid arthritis and Crohn's disease. This report describes a simple and effective method for active immunization against self TNF-alpha. This vaccination approach leads to a T-cell-dependent polyclonal and sustainable anti-TNF-alpha autoantibody response that declines upon discontinuation of booster injections. The autoantibodies are elicited by injecting modified recombinant TNF-alpha molecules containing foreign immunodominant T-helper epitopes. In mice immunized with such molecules, the symptoms of experimental cachexia and type II collagen-induced arthritis are ameliorated. These results suggest that vaccination against TNF-alpha may be a useful approach for the treatment of rheumatoid arthritis and other chronic inflammatory diseases.
Animals↗
Putative role for interleukin-7 in the maintenance of the recirculating naive CD4+ T-cell pool.
The capacity of the immune system to respond efficiently to new antigens depends upon a continuous source of naive CD4+ T cells. Such cells exit from the thymus and join the recirculated T-cell pool. Factors present at the sites of naive CD4+ T-cell circulation must be responsible for their survival, since upon removal from their host, naive CD4+ T cells die. However, such factors remain unknown. The presence of the cytokine interleukin-7 (IL-7) in secondary lymphoid organs and the continuous expression of its receptor on naive CD4+ T cells prompted us to examine the possibility that IL-7 might be a survival factor for naive CD4+ T cells. Using naive CD4+ T cells isolated from cord blood we show that IL-7, but not IL-2, can maintain naive CD4+ T-cell viability in vitro for at least 15 days. In addition, we find that IL-7 can induce modest proliferation of naive CD4+ T cells without affecting either their cell surface phenotype or their ability to respond to antigenic stimulation. We also find that after anti-CD3 stimulation, naive CD4+ T cells lose that ability to respond to IL-7. However, if cells are primed with IL-7 prior to antigenic stimulation, their proliferative responses are enhanced. Together, these data suggest a novel and important role for IL-7 in the maintenance and maturation of naive CD4+ T cells, ensuring that they can respond maximally when they first meet antigen in secondary lymphoid tissue.
Antigen Presentation↗
The rationale for the current boom in anti-TNFalpha treatment. Is there an effective means to define therapeutic targets for drugs that provide all the benefits of anti-TNFalpha and minimise hazards?
Progress in understanding mechanisms of disease are necessary to usher in major changes in treatment. A new era in rheumatoid arthritis (RA) and related chronic autoimmune/inflammatory diseases is now beginning, with a variety of anti-TNFalpha treatments licensed for use in both RA and Crohn's disease. The rationale for this new treatment lies in an understanding that cytokines are critical, rate limiting molecules lying at the heart of the chronic autoimmune/inflammatory disease process. This understanding was developed from the critical evaluation of a hypothesis that was proposed linking cytokines, antigen presentation and autoimmunity in 1983. Detailed analysis focusing on the major site of the disease, the rheumatoid synovium was essential to developing indications that blockade of TNFalpha might be efficacious. This clue was validated using anti-TNFalpha treatment of an animal model of RA, murine collagen induced arthritis, and by immunohistochemical demonstration of upregulated TNF and TNF-R expression in the synovium. With this three pronged rationale, the authors were able to convince Centocor, Inc, which had developed a chimaeric anti-TNFalpha antibody for use in sepsis, to work with them to test the concept that TNFalpha blockade would be beneficial in RA. With the success of that first trial, other companies have subsequently tested their anti-TNF strategies successfully. Current interests extend to understanding the processes that regulate TNF production in the rheumatoid joint. Progress in this area is discussed, using adenoviruses to infect normal macrophages and rheumatoid synovium.
Antirheumatic Agents↗
Anti-tumour necrosis factor specific antibody (infliximab) treatment provides insights into the pathophysiology of rheumatoid arthritis.
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Antibodies, Monoclonal↗
Increased urinary nitric oxide metabolites in patients with multiple sclerosis correlates with early and relapsing disease.
Nitric oxide (NO) has been implicated in the immunopathogenesis of MS as a potential mediator of neuronal loss. To investigate the role of.NO in the development of progressive disease we measured the NO metabolites (nitrate and nitrite) and neopterin, in the urine of 129 patients with demyelinating disease (DD): 23 with clinically isolated syndromes compatible with demyelination and in 46 relapsing remitting (RR) and 60 patients with progressive MS. Eighty-nine of these 129 patients underwent Gd-enhanced MRI. In addition 58 normal control subjects (NC), 19 AIDS and 35 rheumatoid arthritis (RA) patients were studied. Patients with DD, AIDS and RA had significantly elevated urinary nitrate plus nitrite (nit : creat. urine) and neopterin (neopt : creat.urine) to creatinine ratios compared to NC subjects. (Median[25th - 75th%] nit : creat.urine: NC=1183[962 - 1365] vs DD=1245[875 - 2403], AIDS=1686[1231 - 2531], and RA=1950[1214 - 2726] mumol/mol, P<0.001 and median[25th - 75th%] neopt : creat.urine: NC=99[76 - 151] vs DD=163[119 - 266], AIDS=972[653 - 1456], and RA=389[257 - 623] mu mol/mol, P<0.001). Patients with early DD and RR MS had significantly elevated nit : creat.urine compared to patients with progressive MS (nit : creat. urine: 1612[1020 - 2733] vs 1159[790 - 1641] mu mol/mol, P=0.006). The nit : creat.urine and neopt : creat.urine did not correlate with clinical relapse or MRI activity. Excretion of.NO metabolites is increased in patients with early or relapsing-remitting disease.NO appears to be a double-edged sword, mediating tissue damage and modulating complex immunological functions which may be protective in MS.
Acquired Immunodeficiency Syndrome↗
The role of cytokines in the pathogenesis of rheumatoid arthritis.
Recombinant DNA technology has made it possible to identify the cytokines expressed in the joints of people with active rheumatoid arthritis (RA). Because a large number of cytokines are expressed in the rheumatoid synovium and many of these cytokines may have redundant biological functions, it was necessary to study cytokine regulation to identify potential therapeutic targets. The regulation of interleukin 1, a proven inducer of bone and cartilage destruction in the rheumatoid synovium, was thus studied and anti-tumour necrosis factor alpha (anti-TNF-alpha) antibody was found to reduce its synthesis markedly, as well as that of other cytokines, leading to our proposal of TNF-alpha as a therapeutic target. The further study of clinical trials in RA verified that the mechanism of action of anti-TNF-alpha includes the down-regulation of several pro-inflammatory agents, diminished leucocyte recruitment and possibly regulation of angiogenesis.
Arthritis, Rheumatoid↗