Anti-tumor necrosis factor-alpha therapy of rheumatoid arthritis

Reverse Genetics Applied to Immunobiology of Tumor Necrosis Factor, a Multifunctional Cytokine

Tumor necrosis factor (TNF) is one of many cytokines - protein molecules responsible for communication between the cells of immune system. TNF was discovered and given its grand name because of its striking antitumor effects in experimental systems, but its main physiological functions in the context of whole organism turned out to be completely unrelated to protection against tumors. This short review discusses "man-made" mouse models generated by early genome-editing technologies, which enabled us to establish true functions of TNF in health and certain diseases as well as to unravel potential strategies for improving therapy of TNF-dependent diseases.

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes.

Efficient T-cell priming and activation requires signaling through prostaglandin E2 (EP) receptors

Understanding the regulation of T-cell responses during inflammation and auto-immunity is fundamental for designing efficient therapeutic strategies against immune diseases. In this regard, prostaglandin E2 (PGE2) is mostly considered a myeloid-derived immunosuppressive molecule. We describe for the first time that T cells secrete PGE2 during T-cell receptor stimulation. In addition, we show that autocrine PGE2 signaling through EP receptors is essential for optimal CD4(+) T-cell activation in vitro and in vivo, and for T helper 1 (Th1) and regulatory T cell differentiation. PGE2 was found to provide additive co-stimulatory signaling through AKT activation. Intravital multiphoton microscopy showed that triggering EP receptors in T cells is also essential for the stability of T cell-dendritic cell (DC) interactions and Th-cell accumulation in draining lymph nodes (LNs) during inflammation. We further demonstrated that blocking EP receptors in T cells during the initial phase of collagen-induced arthritis in mice resulted in a reduction of clinical arthritis. This could be attributable to defective T-cell activation, accompanied by a decline in activated and interferon-γ-producing CD4(+) Th1 cells in draining LNs. In conclusion, we prove that T lymphocytes secret picomolar concentrations of PGE2, which in turn provide additive co-stimulatory signaling, enabling T cells to attain a favorable activation threshold. PGE2 signaling in T cells is also required for maintaining long and stable interactions with DCs within LNs. Blockade of EP receptors in vivo impairs T-cell activation and development of T cell-mediated inflammatory responses. This may have implications in various pathophysiological settings.

Efficacy of anti-tumor necrosis factor therapy for extra-articular manifestations in patients with ankylosing spondylitis: a meta-analysis

Background

We performed a meta-analysis to evaluate the effect of anti–tumor necrosis factor (TNF) therapy on the frequency of extra–articular manifestations (EAMs) in patients with ankylosing spondylitis (AS).

Methods

We searched with the terms ‘ankylosing spondylitis’, ‘infliximab’, ‘etanercept’, ‘adalimumab’, ‘golimumab’, ‘certolizumab’, ‘TNF inhibitor/blocker/antagonists’ or ‘anti-TNF’ on MEDLINE, EMBASE and Cochrane Library for randomized controlled trials (RCTs) of ≥12 weeks with parallel or crossover design of TNF inhibitor versus placebo to treat uveitis, inflammatory bowel disease (IBD) and/or psoriasis of AS, published before February 2014.

Results

We found 8 RCTs that fit our criteria. Anti–TNF therapy was associated with less uveitis than placebo in patients with AS (OR: 0.35, 95% CI: 0.15–0.81, P = 0.01). Subgroup analysis showed receptor fusion proteins were more efficacious for uveitis than placebo (OR: 0.30, 95% CI: 0.09–0.94, P = 0.04), but monoclonal antibodies were not (OR: 0.43, 95% CI: 0.12–1.49, P = 0.18). Anti–TNF therapy and placebo group did not significantly differ in treating IBD in AS patients (OR: 0.75, 95% CI: 0.25–2.29, P = 0.61). In subgroup analysis, neither monoclonal antibodies (OR: 0.45, 95% CI: 0.10–1.92, P = 0.28) nor receptor fusion proteins (OR: 1.52, 95% CI: 0.25–9.25, P = 0.65) significantly differed from placebo in treating IBD. We found no suitable reports on psoriasis.

Conclusions

Anti–TNF therapy was preventive for flares or new onset of uveitis in AS patients, and might be an alternative for these patients. However, monoclonal anti–TNF antibodies and TNF receptor fusion proteins were not efficacious for IBD in AS patients.

Gentiolactone, a secoiridoid dilactone from Gentiana triflora, inhibits TNF-α, iNOS and Cox-2 mRNA expression and blocks NF-κB promoter activity in murine macrophages

Background

Gentian roots have been used as a herbal medicine because of their anti-inflammatory activities. However, the molecular mechanisms of these anti-inflammatory effects remain to be completely explained.

Methods and Findings

Here, we investigated anti-inflammatory effects of gentian roots and showed that root extracts from Gentiana triflora inhibited lipopolysaccharide (LPS)-induced expression of TNF-α in RAW264.7 cells. The extracts also contained swertiamarin and gentiopicroside, which are the major active compounds of gentian roots; however, neither compound had any effect on LPS-induced TNF-α production in our test system. We isolated gentiolactone as an inhibitor of TNF-α production from the extracts. Gentiolactone also inhibited LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (Cox-2) expression at the mRNA level. Moreover, gentiolactone suppressed NF-κB transcriptional activity without inhibition of IκB degradation or NF-κB nuclear transport.

Conclusions

Our results indicate that inhibition of TNF-α, iNOS and Cox-2 expression by gentiolactone is one of the mechanisms of the anti-inflammatory properties of gentian roots.

Therapeutic efficacy of three bispecific antibodies on collagen-induced arthritis mouse model

Interleukin-1β (IL-1β) and interleukin-17A (IL-17A) are inducible factors and important cytokines in the pathogenesis of rheumatoid arthritis (RA). In the present study, three bispecific and neutralizing antibodies (BsAB-1, BsAB-2 and BsAB-3) against both hIL-1β and hIL-17A were constructed, their therapeutic efficacy was compared on collagen induced arthritis (CIA) model mice. In vitro assays demonstrated that the three antibodies could simultaneously bind to target both hIL-1β and hIL-17A. Mice with CIA were subcutaneously administered with one of three antibodies every two days for 29 days, we noticed that, compared with the BsAB-2 and BsAB-3, BsAB-1 antibody therapy resulted in more significant effect on alleviating the severity of arthritis by preventing bone damage and cartilage destruction and substantially decreasing production of CII-specific antibodies. In addition, BsAB-1 antibody was more potent in the inhibition of mRNA expression of IL-2, IL-1β, IL-17A, TNF-α and MMP-3 in the spleen of CIA mice compared to the other two. In summary, BsAB-1 is superior over BsAB-2 and BsAB-3 for the treatment of RA model mice, and may be chosen as an ideal candidate for further development of therapeutic drugs for treatment of RA.

High C-reactive protein in Crohn's disease patients predicts nonresponse to infliximab treatment

BACKGROUND

Infliximab (IFX) is effective in treating Crohn's disease (CD) and C-reactive protein (CRP) is a useful biomarker in assessing inflammatory activity.

AIM

Correlate CRP levels before beginning of IFX, at week 14 and CRP delta within the first year of IFX treatment.

METHODS

Retrospective study of CD patients undergoing treatment with IFX. Primary nonresponse (PNR) was defined as no symptomatic improvement and CRP persistently elevated; sustained response (SR) as symptomatic improvement for at least 1 year without therapeutic adjustment; response after therapeutic adjustment (RTA) as analytic and clinical response but requiring IFX dose/frequency adjustment or association with another drug.

RESULTS

Baseline CRP levels were higher in PNR compared with SR (26.2mg/L vs 9.6 mg/L, p=0.015) and RTA (26.2mg/L vs 7.6 mg/L, p=0.007). CRP levels greater than 15 mg/L at baseline predict PNR with 67% sensitivity and 65% specificity. Lower CRP levels at week 14 were more likely to predict SR relative to RTA (3.1mg/L vs 7.6 mg/L p=0.019) and PNR (3.1mg/L vs 9.1mg/L; p=0.013). CRP levels greater than 4.6 mg/L at week 14 predict PNR with 67% sensitivity and 62% specificity. A higher CRP delta between beginning of treatment and week 14 is more likely to predict SR relative to RTA (5.2mg/L vs 0.6 mg/L p=0.027).

CONCLUSION

CRP levels at week 14 were associated with SR in patients treated with IFX, independently of baseline CRP serum levels. High inflammatory burden at beginning of IFX treatment was correlated with a worse response.

TNF inhibitor therapy for rheumatoid arthritis

Immunotherapy has markedly improved treatment outcomes in rheumatoid arthritis (RA). Tumor necrosis factor (TNF)-α antagonists, such as infliximab (IFX), etanercept (ETN), adalimumab (ADA), golimumab (GOLI) and certolizumab pegol (CZP) have been widely used for the treatment of RA. IFX provides significant, clinically relevant improvement in physical function and the quality of life, inhibits progressive joint damage and sustains improvement in the signs and symptoms of patients with RA. ETN is effective and safe for patients with RA. Combination therapy with ETN plus methotrexate (MTX) reduces disease activity, decreases total joint score progression, slows the pace of joint destruction and improves function more effectively compared to any of the monotherapies. ADA with or without MTX also relieves the signs and symptoms of RA. CZP and GOLI expand the therapeutic schedule for patients with RA. The TNF-α inhibitors have similar efficacy, but distinct clinical pharmacokinetic and -dynamic properties. The common adverse events of these TNF-α antagonists include adverse reactions, infections and injection-site reaction. Additionally, these adverse events are mostly mild or moderate and their incidence is low. Certain patients exhibit a lack of response to anti-TNF-α therapies. Some patients may discontinue the initial drug and switch to a second anti-TNF-α agent. The shortage of clinical response to one agent may not predict deficiency of response to another. This review mainly addresses the latest developments of these biological agents in the treatment of RA.

Suicide attempt in ulcerative colitis patient after 4 months of infliximab therapy--a case report

In the summary of product characteristics of infliximab (IFX), psychiatric side effects are reported to be rare, and in literature only limited data exist. This report presents a case of a patient with ulcerative colitis who developed a depression with psychotic symptoms during IFX therapy and made a suicide attempt 4 months after the initiation of therapy. Although the time between start of IFX therapy and onset of symptoms could suggest a correlation, this, of course, does not prove that IFX was the causative factor for his depression and suicide attempt.

Epstein-Barr Virus (EBV) Prevalence and the Risk of Reactivation in Patients with Inflammatory Arthritis Using Anti-TNF Agents and in those who are Biologic Naive

Objective:

Anti-TNF agents (etanercept, infliximab and adalimumab) are widely used in inflammatory conditions, such as rheumatoid arthritis; however, they are not without side effects, potentially including lymphoma. We compared Epstein-Barr virus (EBV) levels in patients with inflammatory arthritis taking biologic agents and controls matched for disease, age, gender and disease duration who were biologic naïve. Secondly, we determined the risk of reactivation of EBV in patients taking biologics.

Methods:

One hundred and twenty-two patients were recruited and blood samples were collected. Immunoglobulin G (IgG) antibody to EBV was analysed using enzyme-linked immunosorbent assay. EBV DNA was analysed using polymerase chain reaction (PCR) on all positive IgG samples. Quantitative measures of viral DNA were made and expressed as copies/reaction volume. Reactivation was defined as the presence of viral DNA in the plasma and PCR activity was evaluated between 6 and 18 months after anti-TNF therapy.

Results:

IgG for EBV was detected in 98% of controls and 90% of cases. Viral reactivation related to EBV was not observed in this study. There was one patient who tested positive for EBV using PCR, but upon confirmatory testing, this sample was actually negative. No samples were positive on PCR at the follow-up time points.

Conclusion:

There was a high rate of EBV IgG in the cases and controls in this study. Given the small sample size and timeframe for this study, treatment with anti-TNF agents does not seem to lead to EBV reactivation, and thus, this is likely not a mechanism for the development of lymphoma in patients taking biologics.

T cell abnormalities in systemic lupus erythematosus

Because of the consensus that T cells play a central role in the pathogenesis of systemic lupus erythematosus (SLE), we explored the molecular basis of the defective function of SLE T cells for expression of signal transduction molecules, as well as surface structures such as adhesion molecules, by extensively testing peripheral blood T cells from SLE patients. Upregulated expression and function of adhesion molecules was observed in T cells from patients with active SLE who had specific clinical manifestations such as vasculitis, epithelitis and arthritis, but proximal signal transduction was defective. Comprehensive analysis to identify the molecules responsible for the defects showed the expression of the TCR zeta chain was attenuated, or absent in more than half of SLE patients. Moreover, the aberrant transcripts of the TCR zeta chain, including spliced variants lacking exon 7 and with a short 3' UTR, were detected in SLE T cells. Although attenuated expression of the TCR zeta chain is also observed in patients with cancers, infections and other autoimmune diseases, sustained attenuation of TCR zeta expression and aberrant transcripts are only observed in SLE. In this review we discuss the unique features of the TCR zeta defects in SLE.

Cytokine signal regulation and autoimmune disorders

Understanding of biological activities of cytokines and exquisite mechanism to regulate their functions has facilitated the therapeutic concept to restore the disequilibrium between pro-inflammatory cytokines and anti-inflammatory cytokines or cytokine inhibitors in some autoimmune inflammatory diseases such as rheumatoid arthritis (RA) and Crohn's disease. The application of molecular biology techniques to design monoclonal antibodies, soluble receptors, or receptor antagonists as therapeutic biologic agents made it possible to regulate the cytokine signals for the treatment of the diseases refractory to conventional therapies. Japanese researchers have contributed considerably to the establishment of cytokine signal regulation in autoimmune diseases. In this article, Japanese studies of cytokine signal regulation, particularly for Interleukin-6 (IL-6) in autoimmune diseases are reviewed.

Inhalation of carbon monoxide ameliorates collagen-induced arthritis in mice and regulates the articular expression of IL-1beta and MCP-1

Carbon monoxide (CO), long considered a toxic gas, has recently been shown to mediate anti-inflammatory effects in various animal models. The aim of this study was to investigate whether the inhalation of CO ameliorated collagen-induced arthritis (CIA) in mice. CIA was induced in female DBA/1 mice by the injection of an anti-type II collagen antibody and lipopolysaccharide. The CO treatment group was exposed to CO gas at a concentration of 200 ppm in a closed cage starting on the day of the injection with an anti-type II collagen antibody and throughout the remaining study period. The clinical arthritis scores was examined daily for swelling of the paws as a sign of arthritis. For histopathology, the sections of the hind legs were evaluated by hematoxylin-eosin staining. Moreover, we evaluated the expression of interleukin (IL)-1beta and monocyte chemoattractant protein-1 (MCP-1) mRNA in the hind paws. Both clinical arthritis scores as well as histological findings of joint inflammation were significantly reduced in mice treated with CO gas inhalation compared to untreated mice. Further, CO significantly inhibited the increased expression of IL-1beta and MCP-1 mRNA in paws at day 3 after the induction of arthritis. In conclusion, the inhalation of CO protected mice from the synovial inflammation of CIA. Based on these data, the beneficial effects of CO in murine RA model may be attributed to its anti-inflammatory properties.

Infliximab for the treatment of ulcerative colitis

Infliximab (IFX), an anti-TNF biologic agent, has been demonstrated to offer benefits for the treatment of autoimmune disorders, such as rheumatoid arthritis and Crohn's disease. Several trials have also investigated the efficacy of IFX for the treatment of ulcerative colitis (UC). IFX was found to be well tolerated. In most trials, IFX treatment was more effective than placebo for patients with moderate, moderate-to-severe or severe UC. However, its place in the treatment algorithms for UC remains to be defined and, to this end, clinical trials comparing IFX treatment to conventional therapies are needed.

In vivo delivery of lentiviral vectors expressing vasoactive intestinal peptide complementary DNA as gene therapy for collagen-induced arthritis

OBJECTIVE

Vasoactive intestinal peptide (VIP) has been shown to exert potent immunomodulatory activity, and the use of lentiviral vectors has been found to be an effective means of gene delivery. The present study was therefore undertaken to investigate the feasibility and efficiency of gene therapy using lentiviral vectors expressing VIP (LentiVIP) for the treatment of rheumatoid arthritis (RA).

METHODS

We evaluated the therapeutic potential of the gene therapy strategy in the collagen-induced arthritis (CIA) mouse model, administering the vectors at different phases of the disease. The inflammatory response was determined by measuring the levels of various inflammatory cytokines and chemokines in the joints and serum. The Th1-mediated response was evaluated by determining the proliferative response and cytokine profile of T cells stimulated with autoantigen.

RESULTS

A single intraperitoneal injection of LentiVIP was highly effective in treating CIA. Mice with established, severe arthritis showed complete regression of the disease. The therapeutic effect of LentiVIP was associated with widespread biodistribution of the vector and increased VIP levels, especially in joints and lymphoid organs, and was mediated through a striking reduction of the 2 deleterious components of the disease, i.e., the autoimmune response (self-reactive Th1 cell activity and autoantibody production) and the inflammatory response. LentiVIP treatment also induced the generation and/or activation of CD4+,CD25+,FoxP3+ Treg cells in arthritic mice.

CONCLUSION

Our findings show that in vivo administration of lentiviral vector expressing VIP produces one of the most potent therapeutic effects described so far in any animal model of RA. We propose that VIP gene transfer should be further investigated as a potential novel, effective treatment of RA and other chronic autoimmune disorders.

Sustained Clinical Response and High Infliximab Survival in Psoriatic Arthritis Patients: A 3-year Long-Term Study

OBJECTIVE

To investigate the efficacy, toxicity, and survival of infliximab in patients with psoriatic arthritis (PsA).

METHODS

Thirty-two patients with PsA, refractory to at least 2 disease-modifying antirheumatic drugs, were included in this prospective, open-label, uncontrolled study. All had active disease, defined as having a tender or swollen joint count > or =6, Psoriasis Area and Severity Index (PASI) scores > or =10, and erythrocyte sedimentation rate > or =28 mm Hg/h, or C-reactive protein > or =10 mg/L. The primary endpoints were the percentage of patients who achieved the Psoriatic Arthritis Response criteria (PsARC) and the improvement of PASI. Patients were treated with infliximab (5 mg/kg) at weeks 0, 2, 6, and every 8 weeks thereafter for a period of 3 years. Data concerning infliximab efficacy, tolerability, concomitant therapy, adverse events, and drug discontinuation were recorded. The clinical response according to the American College of Rheumatology (ACR) criteria as well as the disease activity for 28 joint indices score (DAS-28) were also recorded.

RESULTS

After the third year of treatment, PsARC was achieved by 23/32 of patients, PASI 70 by 24/32, and PASI 90 by 23/32. A significant improvement of ACR and DAS-28 was noted. Clinical improvement was associated with a reduction of acute phase reactants. Eight patients withdrew from the study primarily for acute allergic reactions. After the first year, infliximab survival was 84%, while after the second year, it was 75%, which was maintained throughout the third year of treatment.

CONCLUSION

Infliximab was effective, safe, and well tolerated in patients with PsA. The clinical response was maintained for a period of 3 years with high infliximab survival.

Tumor necrosis factor as a therapeutic target of rheumatologic disease

TNF-alpha is a crucial pro-inflammatory and immunoregulatory cytokine that is central to the pathogenesis of various inflammatory and autoimmune conditions. A number of controlled trials have shown effectiveness for TNF-alpha inhibitors in several diseases, in particular rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis and Crohn's disease. These agents may also be useful in additional autoimmune conditions. The introduction of TNF-alpha inhibitors has revolutionized the therapeutic approach and treatment paradigms especially for patients with rheumatoid arthritis. Despite extensive investigation, the full profile of their mechanisms of action remain incompletely understood. Optimal use of these agents requires consideration of their possible adverse effects. In addition to the presently available TNF-alpha blockers, other agents targeting this key mediator are under study. Recent advances and future directions in anti-TNF-alpha therapy are discussed in this paper.

An extensive phenotypic characterization of the hTNFalpha transgenic mice

BACKGROUND

Tumor necrosis factor alpha (TNFalpha) is implicated in a wide variety of pathological and physiological processes, including chronic inflammatory conditions, coronary artery disease, diabetes, obesity, and cachexia. Transgenic mice expressing human TNFalpha (hTNFalpha) have previously been described as a model for progressive rheumatoid arthritis. In this report, we describe extensive characterization of an hTNFalpha transgenic mouse line.

RESULTS

In addition to arthritis, these hTNFalpha transgenic mice demonstrated major alterations in body composition, metabolic rate, leptin levels, response to a high-fat diet, bone mineral density and content, impaired fertility and male sexual function. Many phenotypes displayed an earlier onset and a higher degree of severity in males, pointing towards a significant degree of sexual dimorphism in response to deregulated expression of TNFalpha.

CONCLUSION

These results highlight the potential usefulness of this transgenic model as a resource for studying the progressive effects of constitutively expressed low levels of circulating TNFalpha, a condition mimicking that observed in a number of human pathological conditions.

[p38 MAP Kinase inhibitor]

FR167653 is a potent inhibitor of p38 MAP Kinase and inhibits TNF-alpha and IL-1beta production in inflammatory cells. In this study we investigated the effect of FR167653 on CIA. CIA rats were subcutaneously injected with FR167653 (32 mg/kg/day) starting on the day of the booster injection and after the onset of arthritis in the prophylactic and therapeutic treatment groups, respectively. The hind paw swelling, radiolographic and histologic scores, and osteoclast number were evaluated. Serum and tissue cytokine levels were assessed by ELISA. Flow cytometric analysis of T-lymphocytes from bone marrow was also performed. The effect of FR167653 on in vitro osteoclast formation induced by sRANKL and TNF-alpha was examined. Hind paw swelling occurred in CIA rats but not in the prophylactic treatment group. Therapeutic treatment also significantly reduced the paw swelling. The mean radiographic, histologic score, and osteoclast number of the treatment group were significantly lower than those of CIA rats without treatment. FR167653 treatment reduced serum TNF-alpha and IL-1beta levels, ankle IL-1beta concentration, and CD4-CD8a+ T-cell population in bone marrow. Furthermore, FR167653 inhibited the osteoclast-like cell differentiation induced by both sRANKL and TNF-alpha in vitro. FR167653 prevented the onset of arthritis in a prophylactic treatment model and suppresses the progression of joint destruction in a therapeutic treatment model, suggesting that p38 MAP Kinase is a potential therapeutic target for rheumatoid arthritis.

TNF-alpha drives human CD14+ monocytes to differentiate into CD70+ dendritic cells evoking Th1 and Th17 responses

Many mechanisms involving TNF-alpha, Th1 responses, and Th17 responses are implicated in chronic inflammatory autoimmune disease. Recently, the clinical impact of anti-TNF therapy on disease progression has resulted in re-evaluation of the central role of this cytokine and engendered novel concept of TNF-dependent immunity. However, the overall relationship of TNF-alpha to pathogenesis is unclear. Here, we demonstrate a TNF-dependent differentiation pathway of dendritic cells (DC) evoking Th1 and Th17 responses. CD14(+) monocytes cultured in the presence of TNF-alpha and GM-CSF converted to CD14(+) CD1a(low) adherent cells with little capacity to stimulate T cells. On stimulation by LPS, however, they produced high levels of TNF-alpha, matrix metalloproteinase (MMP)-9, and IL-23 and differentiated either into mature DC or activated macrophages (M phi). The mature DC (CD83(+) CD70(+) HLA-DR (high) CD14(low)) expressed high levels of mRNA for IL-6, IL-15, and IL-23, induced naive CD4 T cells to produce IFN-gamma and TNF-alpha, and stimulated resting CD4 T cells to secret IL-17. Intriguingly, TNF-alpha added to the monocyte culture medium determined the magnitude of LPS-induced maturation and the functions of the derived DC. In contrast, the M phi (CD14(high)CD70(+)CD83(-)HLA-DR(-)) produced large amounts of MMP-9 and TNF-alpha without exogenous TNF stimulation. These results suggest that the TNF priming of monocytes controls Th1 and Th17 responses induced by mature DC, but not inflammation induced by activated M phi. Therefore, additional stimulation of monocytes with TNF-alpha may facilitate TNF-dependent adaptive immunity together with GM-CSF-stimulated M phi-mediated innate immunity.

CRP and the disposal of dying cells: consequences for systemic lupus erythematosus and rheumatoid arthritis

C reactive protein (CRP) levels directly correlate with the disease activity of many inflammatory diseases, e.g. sepsis, infection, and various autoimmunopathies such as rheumatoid arthritis (RA). In contrast, insufficient CRP levels are implicated in the development of systemic lupus erythematosus (SLE). This article reports on the level-depended effects of CRP in various diseases. In detail we show that increased and decreased levels of CRP, as demonstrated in patients with RA and SLE, respectively can contribute to disease progression.

THR0921, a novel peroxisome proliferator-activated receptor gamma agonist, reduces the severity of collagen-induced arthritis

THR0921 is a novel peroxisome proliferator-activated receptor gamma (PPARγ) agonist with potent anti-diabetic properties. Because of the proposed role of PPARγ in inflammation, we investigated the potential of orally active THR0921 to inhibit the pathogenesis of collagen-induced arthritis (CIA). CIA was induced in DBA/1J mice by the injection of bovine type II collagen in complete Freund's adjuvant on days 0 and 21. Mice were treated with THR0921 (50 mg/kg/day) starting on the day of the booster injection and throughout the remaining study period. Both clinical disease activity scores as well as histological scores of joint destruction were significantly reduced in mice treated with THR0921 compared to untreated mice. Proliferation of isolated spleen cells, as well as circulating levels of IgG antibody to type II collagen, was decreased by THR0921. Moreover, spleen cell production of IFN-γ, tumor necrosis factor (TNF)-α and IL-1β in response to exposure to lipopolysaccharide or type II collagen was reduced by in vivo treatment with THR0921. Steady state mRNA levels of TNF-α, IL-1β, monocyte chemotactic protein-1 and receptor activator of nuclear factor κB ligand (RANKL) in isolated joints were all decreased in mice treated with THR0921. Finally, THR0921 inhibited osteoclast differentiation of bone marrow-derived cells stimulated with macrophage colony-stimulating factor and RANKL. In conclusion, THR0921 attenuates collagen-induced arthritis in part by reducing the immune response. As such, PPARγ may be an important therapeutic target for rheumatoid arthritis.

What is after cytokine-blocking therapy, a novel therapeutic target--synovial Epstein-Barr virus for rheumatoid arthritis

There has been significant progress in cytokine-blocking therapy for treatment of rheumatoid arthritis (RA) However, inhibition of cytokines involved in immune defense raises severe side effects. The cost of cytokine-blocking treatment is another major issue. Why are levels of inflammatory cytokines increased in RA patients? We have a large amount of circumstantial and direct evidence for the presence of Epstein-Barr virus (EBV) in RA synovial cells. Here, we provide an overview of the implications for novel approaches to therapy for RA patients, based on the most recent available evidences of anti-viral agents.

Infliximab for the treatment of ankylosing spondylitis

Ankylosing spondylitis (AS) had previously been considered as a chronic disease with little therapeutic options. Non-steroidal anti-inflammatory drugs (NSAIDs) and regular physiotherapy were the only treatment modalities available for patients with AS. The introduction of biologics into clinical practice has substantially broadened the therapeutic armamentarium in AS patients who are refractory to NSAIDs. Remicade (infliximab; Centocor, Inc., USA), a chimeric monoclonal antibody, targets TNF-alpha, and by inhibition of this proinflammatory cytokine, exerts strong clinical improvement of signs and symptoms of AS. In AS, infliximab 5 mg/kg body weight is usually given as an infusion at weeks 0, 2 and 6, and every 6 - 8 weeks thereafter. An improvement of the disease activity by at least 50% is seen in as many as 50% of AS patients treated with infliximab in addition to NSAIDs. Back pain and also peripheral manifestations, such as enthesitic sites and arthritis, improve, and quality of life significantly increases. In addition, elevated acute phase reactants return to normal or low levels, and active inflammatory lesions of the spine as detected by magnetic resonance imaging substantially regress during treatment with infliximab. Clinical improvement occurs during the first 2 weeks of treatment and the clinical response to infliximab, if given continuously, is sustained and long-lasting as follow-up data of ongoing studies show. The short-term benefit/risk ratio of infliximab is clearly in favour of the drug, and it is estimated that at present up to 30% of patients with active AS are in need of this kind of effective treatment.

NFkappaB decoy oligodeoxynucleotides ameliorates osteoporosis through inhibition of activation and differentiation of osteoclasts

The transcription factor, nuclear factor-kappa B (NFkappaB), is believed to play a pivotal role in osteoclast formation. In this study, we focused on NFkappaB decoy oligodeoxynucleotides (ODN) as a new therapeutic strategy to attenuate osteoporosis. Tartrate-resistant acid phosphatase (TRAP)-positive multinuclear osteoclasts formed in mononuclear cells including osteoclast precursors from neonatal rabbit bone marrow were increased in the presence of 1,25-dihydroxyvitamin D3, whereas transfection of NFkappaB decoy ODN decreased the number of TRAP-positive cells and attenuated RANKL and M-CSF-induced osteoclast formation. NFkappaB decoy ODN also inhibited the activity of osteoclasts, as assessed by pit formation. In rat ovariectomized model of estrogen deficiency, continuous administration of NFkappaB decoy ODN attenuated the increase of TRAP activity, accompanied by a significant increase in calcium concentration in tibia and femur and decrease in urinary deoxypyridinoline. In additional osteoporosis model using vitamin C-deficient rat, inhibition of NFkappaB by decoy ODN dramatically improved the bone length, weight, density as assessed by dual-energy X-ray absorptiometry. Overall, inhibition of NFkappaB by decoy strategy prevented osteoporosis through the inhibition of bone resorption. Targeting of NFkappaB might be potential therapy in various bone metabolic diseases.

Effectiveness of anti-folate receptor beta antibody conjugated with truncated Pseudomonas exotoxin in the targeting of rheumatoid arthritis synovial macrophages

OBJECTIVE

To define the distribution of folate receptor beta (FRbeta)-expressing cells in various tissues, including rheumatoid arthritis (RA) synovial tissues, and to verify the effects of an immunotoxin composed of an anti-FRbeta monoclonal antibody (mAb) and truncated Pseudomonas exotoxin A (PEA) on apoptosis and tumor necrosis factor alpha (TNFalpha) production by adherent synovial mononuclear cells from RA patients.

METHODS

Anti-FRbeta mAb were produced by immunizing mice with FRbeta-transfected murine pre-B cells. The distribution of the FRbeta antigen was examined by immunohistochemical analysis using anti-FRbeta mAb and macrophage-specific anti-CD163 mAb. Anti-FRbeta mAb was chemically crosslinked with truncated PEA. FRbeta-expressing macrophages were produced by the transfection of adenovirus vector containing the FRbeta gene. Apoptotic cells were detected by staining with propidium iodide. TNFalpha was measured by enzyme-linked immunosorbent assay.

RESULTS

FRbeta-expressing cells were not present in peripheral blood leukocytes and their activated cells. In all of the tissues examined, most FRbeta-expressing cells were CD163+. The immunotoxin significantly induced the apoptosis of FRbeta-transfected macrophages and adherent RA synovial mononuclear cells and inhibited TNFalpha production by adherent RA synovial mononuclear cells.

CONCLUSION

We demonstrated the limited distribution of FRbeta-expressing cells in various tissues. The immunotoxin targeting FRbeta-expressing cells will provide a therapeutic tool for rheumatoid synovitis.

The role of cytokines in unstable angina

A growing body of evidence suggests that inflammation plays a major role in the pathogenesis of unstable angina; this evidence is mainly derived from the prognostic role of the acute phase reaction proteins, such as C-reactive protein (CRP) and fibrinogen. Since the production of acute phase protein is under the control of the pro-inflammatory cytokines, it is probable that citokines, such as tumour-necrosis factor (TNF)-alpha, interleukin (IL)-1 and IL-6 are involved in the same process. Indeed, elevated levels of IL-1 and IL-6 have been found by our group and by others, in patients with acute coronary syndromes. Cytokines may have procoagulant effects, directly or via endothelial dysfunction, and may induce plaque vulnerability or rupture. They may also be responsible for the activation of other cells, as neutrophils or mast-cells. Although it is conceivable that activated lymphocytes, via interferon-gamma production, are responsible for macrophage activation and cytokine production in unstable angina, the trigger and the precise mechanism of this event are still unknown. The multiple roles of cytokines in unstable angina suggest that a targeted anti-inflammatory therapy might be a novel approach in the future for the treatment of this syndrome.

The therapeutic potential of anti-cytokine antibodies in the treatment of chronic inflammatory disease

The outcome of inflammatory diseases is likely to be dependent upon the relative balance of pro- versus anti-inflammatory cytokines. Control of this balance through the use of anti-cytokine monoclonal antibodies (mAbs) promises to be an effective means of disease therapy. The treatment of rheumatoid arthritis (RA) or inflammatory bowel disease (IBD) with anti- tumour necrosis factor alpha (TNF-alpha) mAb has dramatically ameliorated disease symptoms, indicating that such a treatment approach can be highly successful. Similarly, based on animal studies, the use of neutralising anti-interleukin (IL)-12 mAb may prove efficacious in a number of inflammatory disorders, particularly for IBD.

The therapeutic utility of Interleukin-11 in the treatment of inflammatory disease

Interleukin-11 (IL-11) is a pleiotropic cytokine that exhibits anti-inflammatory and mucosal protective effects in a variety of animal models of acute and chronic inflammation, such as mucositis, inflammatory bowel disease and autoimmune joint disease. This reduction in inflammation and epithelial damage is mediated in part through effects of recombinant human (rh) IL-11 on macrophage effector function and epithelial cell growth. In vitro studies indicate that rhIL-11 inhibits tumour necrosis factor (TNF)-alpha, IL-1beta, IL-12, IL-6, and nitric oxide production from activated macrophages. Analysis of the effects of rhIL-11 on transcription factors that activate pro-inflammatory cytokines demonstrate that the level of induced nuclear factor kappa B (NF-kappaB) binding activity in the nucleus of rhIL-11-treated peritoneal macrophages is significantly reduced. Studies of normal intestinal epithelial cells indicate that rhIL-11 reduces the rate of cellular proliferation. Analysis of cell-cycle progression demonstrates that growth inhibition of epithelial cells by rhIL-11 correlates with delayed entry into S phase and suppression of pRB phosphorylation. IL-11 also protects intestinal crypt stem cells from radiation- or chemotherapy-induced insults. Such immunomodulatory and epithelial activities may contribute to the protective effects of this cytokine and support the clinical utility of rhIL-11 in the treatment of mucositis, as well as a variety of chronic inflammatory diseases, such as Crohn's disease and rheumatoid arthritis.

Altered expression of the T cell receptor-CD3 complex in systemic lupus erythematosus

SLE T cells may play a key role in autoantibody production in SLE B cells. In addition, accumulating evidence has shown that SLE T cells participate in the attack on target cells or tissues through the overproduction of pro-inflammatory cytokines or an increase in cell-to-cell adhesion. Thus, the functional abnormality of SLE T cells appears to be pivotal to an understanding of SLE pathogenesis. Accumulating evidence suggests that potential defects may reside in the proximal signal transduction around the TCR-CD3 complex. We have demonstrated that the expression of TCR zeta chain is significantly decreased in peripheral blood T cells from SLE patients. To explore the mechanism of defective expression of TCR zeta chain, we examined mRNA of TCR zeta, and found that two alternatively spliced variants such as exon 7 (-) and short 3'-UTR are detected in SLE. We review the possible role of the TCR zeta defects in autoimmunity and discuss how the splicing variants lead to downregulated protein expression of TCR zeta chain.

Specific type IV phosphodiesterase inhibitor ameliorates thioacetamide-induced liver injury in rats

BACKGROUND AND AIMS

Rolipram is a specific type IV phosphodiesterase inhibitor that suppresses the activity of immune cells and the production of pro-inflammatory cytokines. In this study, we assessed the effect of rolipram on acute liver injury using thioacetamide (TAA)-induced liver injury in rats as a model.

METHODS

Rats were treated with rolipram (0.5-5 mg/kg, intraperitoneally) or vehicle and injected 30 min later with TAA (100 mg/kg, subcutaneously). Serum transaminase concentrations and tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta) and growth related oncogene/cytokine-induced neutrophil chemoattractant-1 (GRO/CINC-1) levels were measured and livers were examined for microscopic changes. Dose-dependent protection against TAA liver injury was based on transaminase levels and inflammatory cytokine production, and was measured 9 h after TAA when the peak release of cytokines occurred.

RESULT

Rolipram suppressed liver injury based on serum aspartate transaminase (AST), alanine transaminase (ALT) and histology and reduced TNF-alpha, IL-1beta and GRO/CINC-1 levels. Rolipram, at doses of 0.5-5 mg/kg, suppressed serum transaminase and TNF-alpha production in a dose-dependent manner, and these effects were significant at doses of 2.5 and 5 mg/kg.

CONCLUSION

In our rodent model of acute liver injury, rolipram clearly reduced liver damage and inhibited pro-inflammatory cytokine production. These results suggest that specific type IV phosphodiesterase inhibitors, such as rolipram, have potent hepatoprotective effects that are associated with suppressing inflammatory cytokine production.

Biological agents for rheumatoid arthritis: targeting both physical function and structural damage

Rheumatoid arthritis (RA) is a chronic progressive inflammatory disease of multifactorial aetiology. The pivotal role of proinflammatory cytokines in the pathogenesis and perpetuation of synovitis has been demonstrated in basic research since the late 1980s and in clinical research since the early 1990s. Biological agents are monoclonal antibodies or recombinant forms of natural inhibitory molecules which selectively interact with molecules or cell receptors affecting immune or inflammatory processes. In RA, etanercept, infliximab and adalimumab are currently available to target tumour necrosis factor (TNF) and an interleukin (IL)-1 receptor antagonist is available to target IL-1 activity. Trials have shown benefits as monotherapy, although the best results for disease control are seen when biological agents are coadministered with methotrexate. The use of these agents in clinical trials and in practice has resulted in dramatic improvements in RA disease control, and delay and prevention of radiographic damage. The remarkable benefits to patients in well-being, quality of life and function, and the speed of onset of action are reminiscent of the early days of corticosteroid use. Ten years after the first clinical trials of anti-TNF therapies, the adverse effect profile is evolving and includes, for anti-TNF therapy, an increased risk of infections associated with immune suppression, injection and infusion reactions, and a risk of drug induced autoimmune syndromes such as systemic lupus erythematosus. Where these drugs are affordable, the prognosis of individuals for control of severe RA is better than ever before. This manuscript summarises the clinical trial results and post-marketing information regarding the biological agents currently in use for RA.

Autoantibody formation in patients with rheumatoid arthritis treated with anti-TNF alpha

BACKGROUND

Research on autoantibody formation in patients treated with TNF alpha inhibitors has produced contradictory results.

OBJECTIVE

To study the prevalence of autoantibodies in patients with rheumatoid arthritis treated with the TNF alpha inhibitor infliximab.

METHODS

53 patients (48 female, 11 male) treated with infliximab for rheumatoid arthritis were followed for autoantibody production before treatment and after 14, 30, and 54 weeks. Six patients treated with etanercept were studied for comparison. The analyses included antibodies against nuclear antigens (ANA), extractable nuclear antigens, double stranded (ds)DNA (by ELISA, IIF on Crithidia luciliae for IgM and IgG, and Farr assay), nucleosomes, cardiolipin, smooth muscle, mitochondria, proteinase 3, and myeloperoxidase antigens.

RESULTS

The number of patients treated with infliximab who developed antibodies against dsDNA of both IgG and IgM class (tested by IIF) increased significantly. The prevalence of patients positive for IgG class increased to 66% at 30 weeks and 45% at 54 weeks, and of IgM class to 85% and 70%, respectively. The titre and number of patients expressing antibodies against nucleosomes and ANA also increased significantly. The number of rheumatoid factor or anticardiolipin positive patients was stable and there was no increase in antibodies against the other antigens. A lupus-like syndrome was seen in one patient. No patient treated with etanercept developed any of these autoantibodies.

CONCLUSIONS

Patients treated with infliximab may develop anti-dsDNA antibodies of both IgM and IgG class, anti-nucleosome antibodies, and ANA, with a gradual increase until 30 weeks.

P-selectin glycoprotein ligand 1 therapy ameliorates established collagen-induced arthritis in DBA/1 mice partly through the suppression of tumour necrosis factor

We investigated the therapeutic potential of P-selectin glycoprotein ligand (PSGL)-1 in established collagen-induced arthritis (CIA) in DBA/1 mice. PSGL-1 is the high-affinity specific ligand for P-selectin and is thus important in cell recruitment to inflammatory sites. I-316 PSGL-1 or rPSGL-1Ig fusion protein were administered to mice after the onset of clinical arthritis for 10 days, and the effect of treatment on both clinical and histopathological progression of disease was studied. It was found that both PSGL-1 biologicals effectively suppressed progression of clinical arthritis, and this was accompanied by protection against damage of joint tissues. We sought to investigate a mechanism underlying the effect of rPSGL-1Ig on the reduction of clinical arthritis. Blockade of PSGL-1/P-selectin interaction blocks recruitment of leucocytes, thus we observed a notable reduction in viable cell numbers of synoviocytes from rPSGL-1Ig treated mice. In view of this finding we suspected an effect of treatment on the production of pro-inflammatory mediators such as bioactive tumour necrosis factor-alpha (TNF) in synovial membrane ex vivo cell cultures. Production of TNF was reduced in arthritic mice that had been treated with rPSGL-1Ig. To further investigate the mechanism of rPSGL-1Ig, we explored the possibility that PSGL-1 might also have a direct signalling effect on TNF release from inflammatory cells. Thus synoviocyte cultures from arthritic mice were incubated with rPSGL-1Ig. A significant reduction in the spontaneous bioactive TNF release from these cultures was noted. We therefore confirmed these surprising findings using cultures of a mouse macrophage like cell line RAW 264.7, stimulated by LPS. Our results indicate that both forms of PSGL-1 have significant therapeutic effects in CIA murine model of RA. The mechanism of action involves reduced cellularity of synovium as anticipated, along with a reduction in TNF production from inflammatory cells in the synovium. The latter mechanism needs further mechanistic analysis.

In situ FTIR ATR spectroscopic study of the interaction of immobilized human tumor necrosis factor-alpha with a monoclonal antibody in aqueous environment

By in situ FTIR ATR measurements, the antibody (AB) recognition of human tumor necrosis factor-alpha (TNFalpha) immobilized on the Ge surface of a multiple internal reflection element (MIRE) was investigated. The experiments were performed in aqueous environment in a flow-through cell. After immobilization of TNFalpha on the Ge-MIRE by direct adsorption from aqueous solution, the immobilisate reached stability after about 1 h under flow-through conditions. The remaining sites of the Ge surface were saturated by bovine serum albumin (BSA) in order to prevent unspecific binding of anti-TNFalpha AB which was then added. The obtained FTIR ATR spectra were shown to result exclusively from AB specifically interacting with TNFalpha, since the absence of immunoglobulin binding to BSA adsorbed to the Ge MIRE was verified by a reference experiment. Finally, the stability of all adsorbed protein immobilisates was monitored under flow-through conditions for 10.5 h. The TNFalpha-AB complex showed a decrease of 7.4%, whereas the BSA adsorbate remained stable. IR measurements were performed with polarized light in order to study orientational effects of the immobilized proteins. The dichroic ratios and surface concentrations of all used proteins are available after quantitative analysis of the amide II bands.

Worsening of obstructive sleep apnoeas in a patient with rheumatoid arthritis treated with anti-tumor necrosis factor

We report on a case of an adult patient treated for rheumatoid arthritis with infliximab, a chimerical monoclonal antibody to TNFalpha. Apart from this, the patient also showed clinical signs of obstructive sleep apnea syndrome that was confirmed by polysomnographic study. After infliximab treatment, additional sleep studies revealed an increase in the number of apneic events and SaO2 dips suggesting that TNFalpha plays an important role in the pathophysiology of sleep apnea. Thus, clinical recognition of sleep disordered breathing should be taken into account when rheumatoid arthritis patients are to be treated with infliximab.

Plasmid encoding interleukin-4 in the amelioration of murine collagen-induced arthritis

OBJECTIVE

To evaluate the therapeutic effect of the administration of plasmid encoding interleukin-4 (IL-4) via gene-gun delivery and via intradermal injection on collagen-induced arthritis (CIA).

METHODS

IL-4 plasmid was administered by gene-gun delivery and intradermal injection to DBA/1 mice immunized with type II collagen (CII). The therapeutic effect on the development of CIA was evaluated clinically with a visual scoring method for arthritis and serologically by enzyme-linked immunosorbent assays and polymerase chain reaction.

RESULTS

Treatment with IL-4-expressing plasmid significantly reduced the incidence and severity of CIA, including a reduction in the anti-CII antibody level. In particular, gene-gun delivery had a higher immunosuppressive effect on CIA compared with intradermal injection. As shown by in vitro stimulation assay, the spleen cells from mice immunized with CII and treated with IL-4 plasmid via gene gun exhibited higher Th2 cytokine responses compared with cells treated with control plasmid after in vitro stimulation with CII.

CONCLUSION

The results of this study suggest that treatment with IL-4 plasmid may constitute a new clinical use of cytokine gene therapy for rheumatoid arthritis.