Systemic viral interleukin-10 gene delivery prevents cartilage invasion by human rheumatoid synovial tissue engrafted in SCID mice

Association between polymorphisms of interleukin 10 with inflammatory biomarkers in East Chinese Han patients with rheumatoid arthritis

OBJECTIVES

The aim of the present study was to examine the association between polymorphisms of IL-10 with inflammatory biomarkers in East Chinese Han patients with rheumatoid arthritis (RA).

METHODS

We examined IL-10 rs1800872 A/C polymorphisms in 615 RA patients, and 839 controls, in an East Chinese Han population. Genotyping was performed using a custom-by-design 48-Plex SNP scan TM Kit. The blood plasma concentration of IL-10 was measured using an Iodine [(125)I] IL-10 Radioimmunoassay Kit, in 90 RA patients and 90 controls.

RESULTS

IL-10 rs1800872 A/C polymorphisms were associated with risk of RA. Following stratified analysis, an increased risk of RA was associated with the CC genotype among male, older, C-reactive protein-positive, anti-cyclic citrullinated peptide antibody-positive, and rheumatoid factor-positive-patients, and among patients with a DAS28 of≥3.20 or an erythrocyte sedimentation rate of≥25, and in functional class I and II patients. The average plasma concentration of IL-10 was significantly higher in RA patients compared with controls. RA patients positive for the homozygote CC were characterized by significantly higher levels of IL-10 compared with patients with the heterozygote AC. We also found that there were significant relationships between the single nucleotide polymorphisms in the human IL-10 rs1800872 A/C and production of IL-10.

CONCLUSIONS

Our results suggest that the IL-10 rs1800872 A/C allele might increase the risk of RA. The IL-10 rs1800872 A/C allele might also impact the inflammatory reaction of IL-10 in patients with RA.

Association of tumor necrosis factor alpha and IL-10 promoter polymorphisms with rheumatoid arthritis in North Indian population

Rheumatoid arthritis is a chronic autoimmune disorder associated with altered expression of pro- and anti-inflammatory cytokines in the affected tissues. The aim of this study was to investigate the association between promoter polymorphisms of TNFalpha and IL-10 gene with susceptibility, age of disease onset and disease severity in North Indian patients with rheumatoid arthritis (RA). SNPs at position -308 and -863 of TNF gene and -819/-592 and -1082 position of IL-10 gene were determined in 222 patients and 208 healthy controls using RFLP or ARMS method. Polymorphism TNF -308A was less prevalent among the patients (1.7%) than controls (4.9%; p = 0.01, OR: 0.32, 95% CI: 0.13-0.76). Among female patients, IL-10 -592A allele associated with higher baseline disease activity scores (5.77 +/- 1.99) than -592C (5.57 +/- 1.19; p = 0.04). Female patients carrying allele A of TNFalpha -863 had earlier age of onset of RA (33.99 +/- 9.6 years) than those with allele C (36.15 +/- 11.21 years; p = 0.043). In conclusion, allele A at TNFalpha -308 locus provides protection against RA in North Indian population while another TNF allele A at -863 position had weak association with earlier onset of disease in female patients. On the other hand promoter polymorphisms of IL-10 did not affect susceptibility but polymorphism at -819/-592A was associated with higher disease activity scores at baseline.

Biomimetic strategies based on viruses and bacteria for the development of immune evasive biomaterials

The field of biomaterials has begun to focus upon materials strategies for modulating the immune response. While certain approaches appear promising, they are currently limited to isolated facets of inflammation process. It is well documented that both bacteria and viruses have highly developed methods for evading the immune system, providing inspiration for a more biomimetic approach to materials design. This review presents the immune evasive tactics employed by viruses and bacteria, and offers suggestions for future directions that apply these principles to design of immune evasive biomaterials.

Viral interleukin-10 gene transfer prevents liver ischemia-reperfusion injury: Toll-like receptor-4 and heme oxygenase-1 signaling in innate and adaptive immunity

Ischemia-reperfusion injury (IRI) contributes to early and late dysfunction of liver transplants. We have shown that sentinel Toll-like receptor-4 (TLR4) plays a key role in the activation of T cell immune responses during hepatic IRI. We have also documented that overexpression of heme oxygenase-1 (HO-1) exerts potent cytoprotective effects. This study analyzes how adenovirus (Ad)-based viral interleukin-10 (vIL-10) gene transfer affects TLR4 and HO-1 signaling in host innate and adaptive immunity during liver IRI. Using a partial lobar warm IRI model, groups of wild-type and HO-1(+/-) knockout (KO) mice were assessed for severity of hepatocellular damage after 90 min of warm ischemia followed by 6 hr of reperfusion. Both wild-type and HO-1 (+/-) KO mice treated with Ad-vIL-10 have shown improved hepatic function (serum glutamic-oxaloacetic transaminase levels), ameliorated histological signs of IRI (Suzuki's score), decreased neutrophil accumulation (myeloperoxidase activity), and depressed tumor necrosis factor-alpha/IL-1beta, IL-2/interferon-gamma, E-selectin, and macrophage inflammatory protein-2 expression. These effects were IL-10 dependent as treatment with neutralizing antibody re-created liver IRI. In contrast, untreated wild-type and HO-1 (+/-) KO mice, as well as wild-type and HO-1 (+/-) KO mice treated with Ad-beta-Gal, showed severe hepatocellular damage due to IRI. Unlike in controls, wild-type and HO-1 (+/-) KO mice treated with Ad-vIL-10 revealed markedly depressed TLR4 and NF-kappaB expression, along with increased HO-1 and Bcl-2/Bcl-x(L) expression, as compared with respective controls. Thus, vIL-10 gene transfer prevents hepatic IRI in association with depressed expression of innate TLR4, and adaptive Th1 cytokine/chemokine programs. The induction of antioxidant HO-1 and anti-apoptotic Bcl-2/Bcl-x(L) by vIL-10 exerts synergistic cytoprotective function against antigen-independent hepatic inflammatory response triggered by IRI.

Reversal of the immunosuppressive properties of mesenchymal stem cells by tumor necrosis factor alpha in collagen-induced arthritis

OBJECTIVE

Adult mesenchymal stem cells (MSCs) represent promising tools for therapeutic applications such as tissue engineering and cellular therapy. Recent data suggest that, due to their immunosuppressive nature, MSCs may be of interest to enhance allogeneic hematopoietic engraftment and prevent graft-versus-host disease. Using a murine model of rheumatoid arthritis (RA), this study investigated whether the immunosuppressive properties of MSCs could be of therapeutic value to inhibit reactive T cells in autoimmune diseases such as RA.

METHODS

In mice with collagen-induced arthritis (CIA), we injected various doses of C3 MSCs at the time of immunization or booster injection, and subsequently evaluated the clinical and immunologic parameters. The immunosuppressive properties of MSCs were determined in vitro in mixed lymphocyte reactions with or without the addition of tumor necrosis factor alpha (TNFalpha).

RESULTS

In the CIA model of arthritis, MSCs did not confer any benefit. Both the clinical and the immunologic findings suggested that MSCs were associated with accentuation of the Th1 response. Using luciferase-expressing MSCs, we were unable to detect labeled cells in the articular environment of the knee, suggesting that worsening of the symptoms was unlikely due to the homing of MSCs in the joints. Experiments in vitro showed that the addition of TNFalpha was sufficient to reverse the immunosuppressive effect of MSCs on T cell proliferation, and this observation was associated with an increase in interleukin-6 secretion.

CONCLUSION

Our data suggest that environmental parameters, in particular those related to inflammation, may influence the immunosuppressive properties of MSCs.

CD4+CD25bright Regulatory T Cells Actively Regulate Inflammation in the Joints of Patients with the Remitting Form of Juvenile Idiopathic Arthritis

This study investigates the role of CD4(+)CD25(+) regulatory T cells during the clinical course of juvenile idiopathic arthritis (JIA). Persistent oligoarticular JIA (pers-OA JIA) is a subtype of JIA with a relatively benign, self-remitting course while extended oligoarticular JIA (ext-OA JIA) is a subtype with a much less favorable prognosis. Our data show that patients with pers-OA JIA display a significantly higher frequency of CD4(+)CD25(bright) T cells with concomitant higher levels of mRNA FoxP3 in the peripheral blood than ext-OA JIA patients. Furthermore, while numbers of synovial fluid (SF) CD4(+)CD25(bright) T cells were equal in both patient groups, pers-OA JIA patients displayed a higher frequency of CD4(+)CD25(int) T cells and therefore of CD4(+)CD25(total) in the SF than ext-OA JIA patients. Analysis of FoxP3 mRNA levels revealed a high expression in SF CD4(+)CD25(bright) T cells of both patient groups and also significant expression of FoxP3 mRNA in the CD4(+)CD25(int) T cell population. The CD4(+)CD25(bright) cells of both patient groups and the CD4(+)CD25(int) cells of pers-OA JIA patients were able to suppress responses of CD25(neg) cells in vitro. A markedly higher expression of CTLA-4, glucocorticoid-induced TNFR, and HLA-DR on SF CD4(+)CD25(bright) T regulatory (Treg) cells compared with their peripheral counterparts suggests that the CD4(+)CD25(+) Treg cells may undergo maturation in the joint. In correlation with this mature phenotype, the SF CD4(+)CD25(bright) T cells showed an increased regulatory capacity in vitro compared with peripheral blood CD4(+)CD25(bright) T cells. These data suggest that CD4(+)CD25(bright) Treg cells play a role in determining the patient's fate toward either a favorable or unfavorable clinical course of disease.

Role of gene therapy in tissue engineering procedures in rheumatology: the use of animal models

Tissue engineering is not only the application of cells and scaffolds to generate a new tissue but should also bring into play biological principles to guide cellular behavior. A way to modify cellular behavior is genetic modification of the cells used for tissue engineering (gene therapy). In the field of rheumatic diseases, cellular modification by overexpressing anabolic factors, such as insulin-like growth factor-I or transforming growth factor beta, or inhibitors of catabolic cytokines or proteolytic enzymes can protect tissues form further destruction and stimulate tissue repair. To test the effect of transgenes on tissue engineering adequate test systems have to be available. Initial testing can be done in simple in vitro systems. However, animal models are unavoidable to study the interaction between the environment and tissue engineering. Optimal models to study gene therapy in combination with tissue engineering in the field of rheumatology are not available at this moment. Arthritis models are mainly developed in small animals while high-quality tissue engineering experiments ask for a large animal model. Development of animal models that can be used for tissue engineering experiments and mimic end stage arthritic diseases is needed.

Hydrodynamics-based delivery of the viral interleukin-10 gene suppresses experimental crescentic glomerulonephritis in Wistar-Kyoto rats

Gene therapy is expected to revolutionize the treatment of kidney diseases. Viral interleukin (vIL)-10 has a variety of immunomodulatory properties. We examined the applicability of vIL-10 gene transfer to the treatment of rats with crescentic glomerulonephritis, a T helper 1 (Th 1) predominant disease. To produce the disease, Wistar-Kyoto rats were injected with a rabbit polyclonal anti-rat glomerular basement membrane antibody. After 3 h, a large volume of plasmid DNA expressing vIL-10 (pCAGGS-vIL-10) solution was rapidly injected into the tail vein. pCAGGS solution was similarly injected into control rats (pCAGGS rats). We confirmed the presence of vector-derived vIL-10 mainly in the liver and observed high serum vIL-10 levels in pCAGGS-vIL-10-injected rats. Compared with the pCAGGS rats, the pCAGGS-vIL-10 rats showed significant therapeutic effects: reduced frequency of crescent formation, decrease in the number of total cells, macrophages, and CD4+ T cells in the glomeruli, decrease in urine protein, and attenuation of kidney dysfunction. Using quantitative real-time polymerase chain reaction, we also observed that this model was Th1-predominant in the glomeruli and that the ratio of the transcripts of CD4, interferon-gamma, tumor necrosis factor-alpha, and monocyte chemotactic protein-1 to the transcripts of glucose-6-phosphate dehydrogenase in the glomeruli were all significantly lower in the pCAGGS-vIL-10 rats than in the pCAGGS rats. These results demonstrate that pCAGGS-vIL-10 gene transfer by hydrodynamics-based transfection suppresses crescentic glomerulonephritis.

The spontaneous remission of juvenile idiopathic arthritis is characterized by CD30+ T cells directed to human heat-shock protein 60 capable of producing the regulatory cytokine interleukin-10

OBJECTIVE

To test the hypothesis that T cell reactivity to self heat-shock protein 60 (Hsp60) in patients with remitting juvenile idiopathic arthritis (JIA) is part of an antiinflammatory, regulatory mechanism.

METHODS

Using peripheral blood-derived mononuclear cells (PBMCs) and synovial fluid-derived mononuclear cells (SFMCs) obtained from patients with JIA, we analyzed the expression of CD30 and the induction of regulatory cytokines in response to human and mycobacterial Hsp60.

RESULTS

In oligoarticular JIA patients, in vitro activation of PBMCs and SFMCs with Hsp60 induced a high expression of CD30 on CD4+, activated (HLA-DR-positive), memory (CD45RO+) T cells. The expression of CD30 induced by human Hsp60 was much higher than that induced by mycobacterial Hsp60. In oligoarticular JIA patients with active disease, the expression of CD30 in response to human Hsp60 was paralleled by a high interleukin-10 (IL-10):interferon-gamma (IFNgamma) ratio. In addition, restimulated human Hsp60-specific T cell lines from oligoarticular JIA patients showed a high production of IL-10 and a low production of IFNgamma. In contrast, PBMCs and SFMCs from polyarticular JIA patients responded to human Hsp60 with virtually no expression of CD30 and a low IL-10:IFNgamma ratio.

CONCLUSION

The results show that T cells responding to human Hsp60 in oligoarticular JIA patients express CD30, and during active phases of the disease, these T cells have a cytokine profile with a high IL-10:IFNgamma ratio. These findings suggest that in oligoarticular JIA patients, human Hsp60-specific CD4+ cells have a regulatory function and contribute to disease remission.

Association of the -2849 interleukin-10 promoter polymorphism with autoantibody production and joint destruction in rheumatoid arthritis

OBJECTIVE

To analyze the -2849 A/G interleukin-10 (IL-10) promoter polymorphism, which is associated with high (AG/GG) and low (AA) IL-10 production, in a cohort of rheumatoid arthritis (RA) patients and controls in order to gain a better understanding of its role in the incidence and progression of RA.

METHODS

Allele frequencies of the promoter polymorphism -2849 A/G and carriage rates were compared in 283 RA patients, 413 patients with other rheumatic diseases, and 1,220 healthy controls. The rate of joint damage and baseline levels of IgG and IgM rheumatoid factors and anti-citrullinated peptide antibodies were measured and were correlated with the IL-10 gene polymorphism. Furthermore, the correlation between the invasiveness of fibroblast-like synoviocytes (FLS) and the -2849 IL-10 genotype was tested.

RESULTS

The IL-10 genotype was not associated with the incidence of RA, but instead, correlated with disease progression, as determined by the extent of joint destruction. A higher rate of joint destruction was observed in patients with the genotype associated with high IL-10 production. Since FLS are thought to be involved in joint destruction, we analyzed IL-10 genotypes in conjunction with FLS invasiveness. Although adenoviral gene transfer of IL-10 to FLS inhibited their invasiveness, no differences were observed in vitro in the FLS from RA patients who were -2849 non-G carriers compared with those who were G carriers. Instead, patients with the -2849 AG/GG genotype, which is associated with high IL-10 production, had higher autoantibody titers at baseline.

CONCLUSION

The -2849 IL-10 promoter polymorphism is associated with autoantibody production and subsequent joint damage in RA.

Efficacy of interleukin-10 gene electrotransfer into skeletal muscle in mice with collagen-induced arthritis

BACKGROUND

Gene therapy is very promising in the treatment of rheumatoid arthritis (RA). Electrotransfer is a recent method reported to enhance in vivo intramuscular DNA transfection. Interleukin-10 (IL-10) has antiinflammatory effects in RA and in collagen-induced arthritis (CIA), a murine model of RA. In order to improve our strategy of gene therapy, we used electrotransfer to enhance penetration into skeletal muscle with CIA of plasmids encoding IL-10.

METHODS

CIA was induced in DBA/1 mice by immunization with bovine type II collagen. Injection into the tibial cranial muscle of low-dose (200 ng) pCOR plasmid encoding murine IL-10 (pCOR-CMV-mIL-10) was immediately followed by application of square-wave electric pulses (8 pulses of 200V/cm, 20 ms duration at 2 Hz). Control groups received empty plasmid or saline before electrotransfer.

RESULTS

When electrotransfer was performed twice on days 10 and 25 postimmunization, CIA was significantly delayed (P < 0.05) and attenuated (P < 0.001) in groups treated by electrotransfer or pCOR-CMV-mIL-10 plasmid vs. control groups. When electrotransfer of pCOR-CMV-mIL-10 plasmid was performed on days 25 and 40 postimmunization, at disease onset, the clinical severity of CIA was reduced (P < 0.05). All groups which had been electrotransferred early or late by pCOR-CMV-mIL-10 plasmid showed suppression of histological signs of arthritis.

CONCLUSIONS

Taken together, these data indicate that administration of an antiinflammatory plasmid-born gene by electrotransfer of naked DNA is effective in vivo in an arthritis model.

Tetracycline-inducible interleukin-10 gene transfer mediated by an adeno-associated virus: application to experimental arthritis

The adeno-associated viruses (AAV) offer new perspectives for cytokine gene transfer in rheumatoid arthritis (RA) because they are nonpathogenic and allow long-term transgene expression in vivo. Moreover, the use of a tetracycline-inducible promoter allows regulation of therapeutic gene expression. This study assessed the potential long-term gene regulation of a recombinant AAV vector expressing viral interleukin-10 (vIL-10) in human rheumatoid synovium and the therapeutic efficiency in a mouse model of RA. We constructed a recombinant AAV vector in which the transcription of vIL-10 cDNA is controlled by the TetON system. Transduction of human primary RA synovial cells with AAV-tetON-vIL10 conferred in vitro controlled vIL-10 expression. After intramuscular injection, both incidence and severity of collagen-induced arthritis were significantly reduced at macroscopic, radiological, and histological levels in the group of DBA1 mice treated with AAV-TetON-vIL10 vector plus doxycycline after immunization and boosting compared to control groups. When coinjecting two separate AAV vectors, one encoding the inducible vIL-10 and the other the transcriptional activator, a 10 times excess of the transactivator vector dose allowed efficient control of vIL-10 secretion by doxycycline administration or withdrawal, over an 8-week period. Our results supported, for the first time, the utility of AAV-tetON-vIL10 as a therapeutic tool for gene therapy in RA.

Statistical presentation and analysis of ordered categorical outcome data in rheumatology journals

OBJECTIVE

To assess the appropriateness of presentation of summary measures and analysis of ordered categorical (ordinal) data in three rheumatology journals in 1999, and to consider differences between basic and clinical science articles.

METHODS

Six hundred forty-four full-length articles from the 1999 editions of 3 rheumatology journals were evaluated for inclusion of an ordinal outcome. Articles were classified as basic or clinical science, and the appropriateness of presentation and analysis of the ordinal outcome were assessed. Chi-square tests were used to evaluate difference in percentages.

RESULTS

Ordinal outcomes were identified in 175 (27.2%) of 644 articles. Only 69 (39.4%) had appropriate data presentation, and 111 (63.4%) had appropriate data analysis. Appropriate presentation was seen less commonly in the basic science rather than the clinical science articles, but differences in the occurrence of appropriate analysis were not seen.

CONCLUSION

Ordinal data are common in rheumatology articles, but presentation usually does not conform to recommended guidelines.

Gene therapy for rheumatoid arthritis. Lessons from animal models, including studies on interleukin-4, interleukin-10, and interleukin-1 receptor antagonist as potential disease modulators

Evidence from animal models convincingly supports the fact that gene therapy can be an advantageous strategy in the treatment of chronic destructive RA. In this article, we review the state of the art in anticytokine gene transfer into the synovial arthritic joint with the emphasis on IL-1Ra, IL-4, and IL-10 effects on CIA in mice. In CIA, only high and continuous release of IL-1Ra protein systemically by mini-osmotic pumps could prevent disease onset and was curative in mice. Local gene transfer seemed to be the obvious way to reach the high local levels that are demanded for protection. It was shown that local IL-1Ra overexpression reduced arthritis incidence and severity as well as tissue destruction. In line with observations about neutralizing antibodies and soluble receptors, gene therapy with TNF soluble receptors provided anti-inflammatory activity in early arthritis but not in advanced arthritis. The limited efficacy at later stages and poor protection against destruction imply that the combination of gene constructs for TNF and IL-1 inhibitors is the obvious direction for future therapy. Apart from targeting of proinflammatory cytokines, adenoviral overexpression of IL-10 and IL-4 may have therapeutic applicability. Local injection of AdIL-10 in the knee joint was effective at the site, but also highly reduced spreading to ipsilateral sites. High local dosages caused suppression in contralateral sites as well. The reports on the anti-inflammatory effect of AdIL-4 are conflicting; however, all present data showed that IL-4 overexpression provides impressive protection against cartilage and bone erosion. Apart from the local effects in the injected joint, it is becoming more and more clear that local treatment also affects arthritis in nearby joints. This is an intriguing general finding, which may enlarge the therapeutic applicability of gene transfer in human arthritis. Proving the feasibility of gene therapy in experimental arthritis, most research efforts are now focused on improving local gene delivery by enhanced viral infection of synovial cells, using RGD-modified adenovirus, or achieving prolonged persistence and regulated expression with AAV. Elegant future alternatives are the application of in vitro engineered T cells as a vehicle capable of specific homing to joint tissues. The feasibility of viral transduction of chondrocytes to obtain a tissue-specific approach to treat articular cartilage damage in arthritis needs further attention.

Cross-talk between IL-1 and IL-6 signaling pathways in rheumatoid arthritis synovial fibroblasts

The balance between pro- and anti-inflammatory cytokines plays an important role in determining the severity of inflammation in rheumatoid arthritis (RA). Antagonism between opposing cytokines at the level of signal transduction plays an important role in many other systems. We have begun to explore the possible contribution of signal transduction cross-talk to cytokine balance in RA by examining the effects of IL-1, a proinflammatory cytokine, on the signaling and action of IL-6, a pleiotropic cytokine that has both pro- and anti-inflammatory actions, in RA synovial fibroblasts. Pretreatment with IL-1 suppressed Janus kinase-STAT signaling by IL-6, modified patterns of gene activation, and blocked IL-6 induction of tissue inhibitor of metalloproteases 1 expression. These results suggest that proinflammatory cytokines may contribute to pathogenesis by modulating or blocking signal transduction by pleiotropic or anti-inflammatory cytokines. The mechanism of inhibition did not require de novo gene activation and did not depend upon tyrosine phosphatase activity, but, instead, was dependent on the p38 stress kinase. These results identify a molecular basis for IL-1 and IL-6 cross-talk in RA synoviocytes and suggest that, in addition to levels of cytokine expression, modulation of signal transduction also plays a role in regulating cytokine balance in RA.

Ex vivo adenovirus mediated gene transfection of human conjunctival epithelium

AIM

To investigate the efficacy of "ex vivo" adenoviral vector mediated gene transfection of human conjunctival epithelial cell as a possible route for gene therapy for the distribution of anti-inflammatory agents for the potential treatment of immune mediated ocular inflammatory disorders.

METHODS

Human conjunctival cells (HCs) were cultured with various concentrations of recombinant adenoviral vectors carrying a reporter gene LacZ, GFP, or an immunomodulating cytokine vIL-10. vIL-10 in culture supernatant was detected by sandwich ELISA and biological activity was assessed by suppression of ConA stimulated splenocyte proliferation. X-gal and GFP expression was assessed by histochemistry.

RESULTS

The extent of adenoviral vector mediated transfer of both reporter genes and vIL-10 was dose dependent. LacZ expression could be detected for at least 50 day after infection with multiple of infection (MOI) 200. Following AdCMVvIL-10 transduction, vIL-10 protein expression occurred between 4-6 days post-transduction, and was maintained at a detectable level for at least 1 month. Secreted vIL-10 showed biological activity, significantly inhibiting Con A induced splenocyte proliferation. Additionally, transfection of HCs with two Adv vectors, one carrying LacZ and the other carrying GFP, resulted in co-expression within a single cell.

CONCLUSION

These results confirm previous successful adenoviral vector mediated gene transfer to HCs and further show that expression can be maintained. Furthermore the data show HCs can secrete biologically active vIL-10 that could be developed as a strategy to suppress immune mediated disorders. The successful co-transduction of HCs as described for other tissues, opens avenues to develop a multiple target gene therapy locally.

Hereditary predisposition to low interleukin-10 production in children with extended oligoarticular juvenile idiopathic arthritis

OBJECTIVE

To determine whether children with extended oligoarticular juvenile idiopathic arthritis (JIA) produce less of the anti-inflammatory cytokine interleukin-10 (IL-10) than those with persistent oligoarticular JIA.

METHODS

We measured IL-10 production in the parents of children with oligoarticular or extended oligoarticular JIA, from whole-blood cultures stimulated with lipopolysaccharide.

RESULTS

IL-10 production was lower in the parents of children with extended oligoarticular JIA compared with those of children with oligoarticular JIA (P=0.034). There was an increase in the percentage of ATA-containing genotypes (i.e. genotypes ATA/ATA, ATA/ACC or ATA/GCC) in the parents of children with extended oligoarticular JIA compared with healthy controls (P<0.02) but not in the parents of children with oligoarticular JIA.

CONCLUSIONS

As approximately 84% of the variation in IL-10 production is thought to be genetically regulated, these results suggest that stimulated IL-10 production would be lower in children with extended oligoarticular JIA. Because IL-10 is an anti-inflammatory cytokine, this may partly explain why this group of children has more severe disease.

Paradoxical effects of tissue inhibitor of metalloproteinases 1 gene transfer in collagen-induced arthritis

OBJECTIVE

The imbalance between matrix metalloproteinases (MMPs) 1, 3, and 9 and their specific inhibitor, tissue inhibitor of metalloproteinases 1 (TIMP-1), is a critical step in cartilage injury and angiogenesis in arthritis. To explore the therapeutic potential of TIMP-1 gene transfer in erosive arthritis, the effects of an adenoviral vector (Ad-TIMP-1) were assessed in DBA/1 mice with collagen-induced arthritis (CIA).

METHODS

DBA/1 mice with CIA received an intravenous injection of replication-deficient adenovirus containing the human TIMP-1 gene or a control LacZ gene on day 28 postimmunization. The efficiency of gene transfer was determined by serum TIMP-1 detection, measurements of paw swelling, as well as radiologic and histologic examination of the paws.

RESULTS

A single administration of Ad-TIMP-1 resulted in detectable serum levels of the exogenous protein for at least 13 days. The incidence and onset of arthritis were not statistically modified after human TIMP-1 gene transfer in DBA/1 mice compared with control mice. However, the severity of inflammation was statistically significantly increased in Ad-TIMP-1-treated mice and a similar trend was observed in the histologic and radiologic scores. With regard to the mechanisms of the worsened effect in the Ad-TIMP-1-treated mice, we observed 1) higher serum levels of anti-type II collagen IgG2a, 2) a significant increase in endogenous soluble tumor necrosis factor receptor I (TNFRI) in sera, and 3) increased labeling of mouse tumor necrosis factor alpha and TNFRI within arthritic joints.

CONCLUSION

These findings show that overexpression of TIMP-1 does not prevent osteochondral injury in a mouse model of arthritis. Since MMPs have overlapping properties in terms of their roles in extracellular matrix degradation, angiogenesis, and shedding of cell surface adhesion molecules, cytokines, and cytokine receptors, the paradoxical results obtained suggest that TIMP-1 is probably not the main inhibitor to target.

Potential biologic agents for treating rheumatoid arthritis

The encouraging clinical results observed in trials using anti-TNF therapy clearly warrant further studies to determine whether TNF inhibitors are capable of modifying the destructive component of this disease in long-term follow-up studies as well as to assess the safety of long-term use (see the article by Keystone in this issue). It is also reasonable to propose that interfering with the cytokine cascade earlier in the course of disease may be of even greater therapeutic benefit. As the pathogenetic mechanisms in RA are more clearly defined, especially in early disease and in those individuals destined to develop severe disease, the potential of other biologic agents to specifically inhibit these critical pathways may provide better treatments for our patients. Many potential targets in the immune-mediated process of RA are currently being rigorously evaluated in clinical trials. Use of combinations of biologic therapies, perhaps in human patients with RA, should be of considerable interest in future trials.

Direct gene delivery strategies for the treatment of rheumatoid arthritis

Gene therapy offers a novel and innovative approach to the delivery of therapeutic proteins to the joints of patients with arthritis. Several viral vectors, including adenovirus, adeno-associated virus, retrovirus and herpes simplex virus, are capable of delivering exogenous cDNAs to the synovial lining, enabling effective levels of intra-articular transgene expression following direct injection to the joint. The expression of certain gene products has proven to be sufficient to inhibit the progression of disease in animals with experimental arthritis. Non-viral methods of gene transfer, however, are less satisfactory, and are limited by toxicity and transience of expression. Although the principle of direct gene delivery to the joint has been demonstrated, maintaining persistent intra-articular transgene expression remains a challenge.

[Gene transfer immunotherapy in rheumatoid arthritis: perspectives]

INTRODUCTION

Tumor necrosis factor (TNF) blocking agents have changed the therapeutic approach in rheumatoid arthritis, but a true clinical remission remains rare. Gene therapy opens new perspectives in immunotherapy in rheumatoid arthritis. This review focuses on the research, data and clinical development in rheumatoid arthritis using this strategy.

CURRENT KNOWLEDGE AND KEY POINTS

New therapeutical targets have been described besides the cytokine inhibitors: apoptosis inducers, angiogenesis inhibitors and metalloprotease inhibitors, cell activation and signalization have been used in experimental models to inhibit arthritis. Gene therapy makes it possible to better understand the physiopathology of rheumatoid arthritis and offers the opportunity to induce true remissions of experimental arthritis.

FUTURE PROSPECTS AND PROJECTS

Biotechnology allows the development of new safer vectors which permit long-term expression. However, the difficulties to produce high titers and safe vectors limit the use of this strategy. The previous clinical data on gene therapy in rheumatoid arthritis are limited to feasibility studies. We believe that the efficiency of gene therapy will be obtained by combining two or more complementary targets.

Are differences in interleukin 10 production associated with joint damage?

OBJECTIVE

Constitutive differences between individuals in cytokine production may determine the variation in the course of inflammatory arthritis.

METHODS

The association between interleukin 10 (IL-10) production and joint destruction was studied by comparing IL-10 mRNA content in synovial biopsies from seven patients with destructive joint disease and six patients with non-destructive joint disease. The IL-10 mRNA content was 0.4 +/- 0.6 arbitrary units in erosive joints compared with 2.3 +/- 1.2 arbitrary units in non-erosive joints (P: < 0.03, Mann-Whitney U:-test). As this difference suggested that IL-10 production was associated with joint destruction, we tested whether the IL-10 locus determined the extent of joint damage.

RESULTS

Innate differences in IL-10 production are locus-dependent. In line with these data, we showed that innate differences in IL-10 protein production were also present as differences in IL-10 mRNA levels. We tested if polymorphisms in the promoter of IL-10 were associated with the extent of joint damage.

DISCUSSION

In a cohort study of female rheumatoid arthritis patients followed for 12 yr, the extent of joint destruction differed significantly between patients with different IL-10 genotypes. In patients with the -1082AA genotype who were studied prospectively, the mean increase in radiographic damage score (modified Sharp score of X-rays of hands and feet) during the first 6 yr was 9 +/- 9 per yr vs 19 +/- 16 per yr for patients with the genotype -1082GG (P: < 0.02). In line with these data, cultures of endotoxin-stimulated whole blood from 158 donors showed that the presence of the allele associated with less joint destruction correlated with slightly higher IL-10 production.

CONCLUSIONS

Both the immunogenetic and the synovial biopsies suggest that a variation in IL-10 production is associated with joint destruction.

Viral IL-10 and soluble TNF receptor act synergistically to inhibit collagen-induced arthritis following adenovirus-mediated gene transfer

Viral IL-10 (vIL-10) and soluble TNF receptor (sTNFR) are anti-inflammatory proteins that can suppress collagen-induced arthritis (CIA). These and related proteins have shown efficacy in the treatment of human rheumatoid arthritis; however, neither alone is able to completely suppress disease. Furthermore, they have short half-lives, necessitating frequent administration. To determine the ability of these proteins to act synergistically following gene transfer, arthritis was induced in DBA/1 male mice by immunization with type II collagen on days 0 and 21. Mice were injected i.v. either before disease onset (day 20) or after disease onset (day 28) with 1010 particles of adenovirus encoding vIL-10, a soluble TNF receptor-IgG1 fusion protein (sTNFR-Ig), a combination of both vectors, or a control vector lacking a transgene. Significant synergism was observed with the combination of vIL-10 and sTNFR-Ig, with a substantial reduction in both the incidence and severity of disease as well as inhibition of progression of established disease. sTNFR-Ig alone had no effect on CIA. vIL-10 alone inhibited disease when given before disease onset, but had minimal effect on established disease. Both proteins inhibited spleen cell proliferation and IFN-gamma secretion in response to stimulation with type II collagen, but only vIL-10 reduced the synovial mRNA levels of the proinflammatory cytokines IL-1beta, TNF-alpha, and IL-6. These findings demonstrate that vIL-10 and sTNFR-Ig act synergistically in suppressing CIA and suggest that gene transfer offers a potential therapeutic modality for the treatment of arthritis.