Ultrasound efficacy of targeted-synthetic disease-modifying anti-rheumatic drug treatment in rheumatoid arthritis: a multicenter prospective cohort study in Japan.

OBJECTIVE: This study investigated the effectiveness of treatment with Janus kinase (JAK) inhibitors in rheumatoid arthritis (RA) assessed by ultrasonography (US) activity, and the influence of patient characteristics and previous treatments. METHOD: This prospective study assessed 60 treatment initiations among 53 Japanese patients diagnosed with RA who underwent treatment with JAK inhibitors during June 2013 to February 2020. Of the 53 patients, seven patients were enrolled in duplicate because they were treated with two different JAK inhibitors at different periods. For each case, the improvement rate on the power Doppler (PD) score was assessed at 6 month follow-up. Median improvement rate of PD score was used to classify cases as either US responders or non-responders, and patient characteristics were compared between the two groups. RESULTS: All indicators of clinical disease activity and US activity showed a significant improvement at 3 months compared with baseline. Although the JAK inhibitor-cycler group and the interleukin-6 (IL-6) inhibitor inadequate response (IR) group tended to show a later improvement for US activity, all indicators of clinical disease activity and US activity showed a significant improvement at 6 months compared with baseline for both groups. Multivariate analysis showed that concomitant methotrexate use and an IR to the previous biologic or targeted-synthetic disease-modifying anti-rheumatic drug (b/tsDMARD) treatment were independently and significantly associated with US responders. CONCLUSION: Use of a JAK inhibitor in combination with methotrexate and an absence of IR to any previous b/tsDMARDs demonstrated superior effectiveness for patients with RA.

Discrepancy between clinical and ultrasound remissions in rheumatoid arthritis: a multicentre ultrasound cohort study in Japan.

Objectives: Using multicentre ultrasound (US) cohort data among patients with rheumatoid arthritis (RA), we aimed to identify baseline factors that permit differentiation between two patient cohorts achieving US remission and clinical remission, and to determine the factors contributing to the discrepancy.Method: We reviewed 248 Japanese patients diagnosed with RA who underwent treatment with biological disease-modifying anti-rheumatic drugs at 13 centres. We performed US assessments of the synovia of 22 joints. We assessed the percentages of patients with clinical remission and US remission, defined as total power Doppler scores of 0 at 12 months.Results: The 87 patients who achieved US remission were divided into a group that achieved both clinical and US remission (n = 53) and a group that achieved US remission only (n = 34). Baseline factors that were significantly and independently associated with clinical remission at 12 months among patients who also achieved US remission included short disease duration, the presence of concomitant methotrexate use, and low patient global assessment score (p < 0.05, p < 0.05, and p < 0.005, respectively).Conclusions: RA patients with baseline high patient global assessment scores and long disease duration at baseline were unlikely to achieve clinical remission even after achieving US remission. Objective joint assessments using US provide additional information of potential importance for the management of RA.

Significance of anti-Ro/SSA antibodies in the response and retention of abatacept in patients with rheumatoid arthritis: a multicentre cohort study.

Objective: To determine whether the positivity of baseline anti-Ro/Sjögren's syndrome antigen A (SSA) antibodies influences the response to abatacept, we compared therapeutic responses between anti-Ro/SSA antibody-negative and -positive patients with rheumatoid arthritis (RA) using a multicentre RA ultrasonography prospective cohort. Method: We reviewed Japanese patients with RA who started abatacept as the first biological disease-modifying anti-rheumatic drug between June 2013 and April 2018. We assessed 28-joint Disease Activity Score-erythrocyte sedimentation rate (DAS28-ESR) change between baseline and 6 or 12 months after treatment in RA patients treated with abatacept, and European League Against Rheumatism (EULAR) response at 6 and 12 months. The Global OMERACT-EULAR Synovitis Score (GLOESS) was calculated at baseline and at 6 and 12 months. Results: Overall, 51 patients were enrolled and divided into anti-Ro/SSA antibody-negative and -positive groups of 35 and 16, respectively. Median age at baseline was significantly higher in the anti-Ro/SSA antibody-negative group (p = 0.04). The retention rate and percentage of EULAR good responders at 12 months were significantly higher in the anti-Ro/SSA antibody-negative group (both p = 0.02). Anti-Ro/SSA antibody-negative patients exhibited larger decreases in both DAS28-ESR and DAS28-C-reactive protein at 12 months than anti-Ro/SSA antibody-positive patients (p = 0.02 and 0.04, respectively). GLOESS decreased significantly at 6 months in anti-Ro/SSA antibody-negative patients (p = 0.03). Multivariate analyses showed that anti-Ro/SSA antibody positivity was an independent factor associated with change in the DAS28-ESR at 6 months (p < 0.05). Conclusion: Anti-Ro/SSA antibody positivity predicts a poor response to abatacept and low retention rate.

IL-15 is a biomarker involved in the development of rapidly progressive interstitial lung disease complicated with polymyositis/dermatomyositis.

BACKGROUND: Polymyositis/dermatomyositis (PM/DM) is an autoimmune disease that is sometimes complicated with rapidly progressive interstitial lung disease (RPILD). However, serum and lung biomarkers that can predict RPILD development remain unclear. OBJECTIVES: To determine potential serum and lung biomarkers that can predict RPILD development in patients with PM/DM-ILD. METHODS: In total, 49 patients with PM/DM-ILD were enrolled. We measured the serum levels of 41 cytokines/chemokines, ferritin and anti-MDA5 antibody, compared them between the RPILD (n = 23) and non-RPILD (n = 26) groups, and ranked them by their importance through random forest analysis. To distinguish the two groups, we determined biomarker combinations by logistic regression analysis. We also measured the bronchoalveolar lavage fluid (BALF) levels of 41 cytokines/chemokines. Using immunohistochemistry, we examined IL-15 expression in lung tissues. The IL-15 production was also investigated using A549 and BEAS-2B cells. RESULTS: The RPILD group had significantly higher IL-15, IL-1RA, IL-6, CXCL10, VCAM-1, anti-MDA5 antibody and ferritin serum levels than the non-RPILD group, but it had a significantly low CCL22 level. Meanwhile, anti-MDA5 antibody, IL-15, CXCL8, CCL22, IL-1RA and ferritin were the best combination to distinguish the two groups. IL-15 and CCL22 were also predictive marker for RPILD development in anti-MDA5 antibody-positive patients. Additionally, the RPILD group had significantly high IL-15 levels in BALF. The lung tissues expressed IL-15, which increased after cytokine stimulation in the A549 cells. CONCLUSION: This study identified a combination of biomarkers predicting PM/DM-RPILD progression, and IL-15 is an important cytokine for predicting RPILD development and reflecting ILD severity.

Anti-citrullinated protein antibody titre as a predictor of abatacept treatment persistence in patients with rheumatoid arthritis: a prospective cohort study in Japan.

Objective: Successful rheumatoid arthritis (RA) outcome depends on treatment efficacy in the early stages of the disease and its sustainability. It is thus critical to identify factors predicting treatment persistence with biological agents, such as abatacept. We compared clinical profiles, including early changes in autoantibody titres at 3 months, between patients with RA demonstrating sustained persistence and those discontinuing abatacept treatment.Method: We prospectively enrolled 71 and 78 active RA patients treated with abatacept and tumour necrosis factor inhibitors (TNF-Is), respectively, who had previous disease-modifying anti-rheumatic drug) failure. Clinical characteristics were compared between non-continuation and continuation groups stratified according to abatacept or TNF-I persistence for at least 12 months from treatment initiation.Results: Significantly larger decreases in rheumatoid factor titre and anti-citrullinated protein autoantibody (ACPA) titre were observed in the continuation group of abatacept therapy at 3 months, and early reduction in ACPA titre remained a significant and independent predictor of sustained persistence with abatacept in multivariate analysis. In addition, we obtained the area under the receiver operator characteristics curve of 0.904 from a model including baseline ACPA titre and reduction of ACPA titre at 3 months. Sustained reduction of RA disease activity score at 12 months was significantly and independently associated with reduced ACPA titre at 3 months.Conclusions: Persistence with abatacept and sustained therapeutic response are associated with an early reduction in ACPA titre. Prediction of abatacept continuation and efficacy will facilitate the optimal design of therapy in the early stages of RA.

Complete renal response at 12 months after induction therapy is associated with renal relapse-free rate in lupus nephritis: a single-center, retrospective cohort study.

BACKGROUND: Lupus nephritis (LN) is a major risk factor for overall morbidity and mortality in systemic lupus erythematosus (SLE). METHODS: We retrospectively analyzed cases of proliferative and membranous LN patients who underwent a renal biopsy at our hospital in 1993-2016. We analyzed the association between complete renal response (CR) rates at 12 months after induction therapy and predictive factors for CR and their association with renal flares. RESULTS: Of the 95 cases analyzed, we were able to track the therapeutic responses of 81 patients at 12 months after their induction therapy. The median follow-up duration after renal biopsy was 51 months (interquartile range: 16.5-154.5 months). The Cox proportional hazards model showed that, compared to not attaining CR at 12 months, the attainment of CR at 12 months was correlated with being free from renal flares. The multivariate logistic analysis revealed that the predictive factors for CR at 12 months were the anti-La/SSB antibodies (U/ml) (odds ratio (OR) 1.22, 95% confidence interval (CI) 1.01-1.63, p = 0.0220), blood urea nitrogen (BUN) (OR 0.68, 95% CI 0.44-0.90, p = 0.00048) and serum ß2 microglobulin (MG) (OR 0.26, 95% CI 0.06-0.74, p = 0.00098) levels. CONCLUSIONS: Among LN patients, being free from renal flares was associated with attaining CR at 12 months after induction therapy. Anti-La/SSB antibodies were a positive predictive factor, and BUN and serum ß2MG levels were negative predictive factors of CR at 12 months.

Calcium-dependent antigen binding as a novel modality for antibody recycling by endosomal antigen dissociation.

The pH-dependent antigen binding antibody, termed a recycling antibody, has recently been reported as an attractive type of second-generation engineered therapeutic antibody. A recycling antibody can dissociate antigen in the acidic endosome, and thus bind to its antigen multiple times. As a consequence, a recycling antibody can neutralize large amounts of antigen in plasma. Because this approach relies on histidine residues to achieve pH-dependent antigen binding, which could limit the epitopes that can be targeted and affect the rate of antigen dissociation in the endosome, we explored an alternative approach for generating recycling antibodies. Since calcium ion concentration is known to be lower in endosome than in plasma, we hypothesized that an antibody with antigen-binding properties that are calcium-dependent could be used as recycling antibody. Here, we report a novel anti-interleukin-6 receptor (IL-6R) antibody, identified from a phage library that binds to IL-6R only in the presence of a calcium ion. Thermal dynamics and a crystal structure study revealed that the calcium ion binds to the heavy chain CDR3 region (HCDR3), which changes and possibly stabilizes the structure of HCDR3 to make it bind to antigen calcium dependently (PDB 5AZE). In vitro and in vivo studies confirmed that this calcium-dependent antigen-binding antibody can dissociate its antigen in the endosome and accelerate antigen clearance from plasma, making it a novel approach for generating recycling antibody.

pH-dependent antigen-binding antibodies as a novel therapeutic modality.

Monoclonal antibodies have become a general modality in therapeutic development. However, even with infinite binding affinity to an antigen, a conventional antibody is limited in that it can bind to the antigen only once, and this results in antigen-mediated antibody clearance when the a membrane-bound antigen is targeted, or in antibody-mediated antigen accumulation when a soluble antigen is targeted. Recently, a pH-dependent antigen-binding antibody that binds to an antigen in plasma at neutral pH and dissociates from the antigen in endosome at acidic pH has been reported to overcome this limitation and to reduce antigen-mediated antibody clearance and antibody-mediated antigen accumulation. A pH-dependent binding antibody against a soluble antigen can be further improved by Fc engineering to enhance the Fc receptor binding. Various approaches, including histidine-based engineering, direct cloning from immunized animals, and synthetic and combinatorial libraries, have been successfully applied to generate pH-dependent binding antibodies against various antigens. This review discusses the features, approaches, advantages, and challenges of developing a pH-dependent binding antibody as a novel therapeutic modality. This article is part of a Special Issue entitled: Recent advances in molecular engineering of antibody.

Anti-factor IXa/X bispecific antibody (ACE910): hemostatic potency against ongoing bleeds in a hemophilia A model and the possibility of routine supplementation.

BACKGROUND: We previously reported that a humanized anti-factor IXa/X bispecific antibody, hBS23, mimics the function of FVIII even in the presence of FVIII inhibitors, and has preventive hemostatic activity against bleeding in an animal model of acquired hemophilia A. After further molecular engineering of hBS23, we recently identified an improved humanized bispecific antibody, ACE910, for clinical investigation. OBJECTIVES: To elucidate the in vivo hemostatic potency of ACE910 by examining its effect against ongoing bleeds, and to determine its pharmacokinetic parameters for discussion of its potency for prophylactic use. METHODS: A non-human primate model of acquired hemophilia A was established by injecting anti-primate FVIII neutralizing antibody. When bleeds emerged following an artificial bleed-inducing procedure, either ACE910 or recombinant porcine FVIII (rpoFVIII) was intravenously administered. rpoFVIII was additionally administered twice daily on the following 2 days. Bleeding symptoms were monitored for 3 days. A pharmacokinetic study and multiple-dosing simulations of ACE910 were also performed. RESULTS: A single bolus of 1 or 3 mg kg-1 ACE910 showed hemostatic activity comparable to that of 10 U kg-1 (twice daily) rpoFVIII against ongoing bleeds. The determined ACE910 pharmacokinetic parameters included a long half-life (3 weeks) and high subcutaneous bioavailability (nearly 100%). The simulation results based on pharmacokinetic parameters indicated that the above hemostatic level could be maintained with once-weekly subcutaneous administration of ACE910, suggesting the possibility of more effective prophylaxis. CONCLUSIONS: ACE910 may offer an alternative on-demand treatment option for patients with hemophilia A, as well as user-friendly and aggressive routine supplementation.

Anti-factor IXa/X bispecific antibody (ACE910): hemostatic potency against ongoing bleeds in a hemophilia A model and the possibility of routine supplementation.

BACKGROUND: We previously reported that a humanized anti-factor IXa/X bispecific antibody, hBS23, mimics the function of FVIII even in the presence of FVIII inhibitors, and has preventive hemostatic activity against bleeding in an animal model of acquired hemophilia A. After further molecular engineering of hBS23, we recently identified an improved humanized bispecific antibody, ACE910, for clinical investigation. OBJECTIVES: To elucidate the in vivo hemostatic potency of ACE910 by examining its effect against ongoing bleeds, and to determine its pharmacokinetic parameters for discussion of its potency for prophylactic use. METHODS: A nonhuman primate model of acquired hemophilia A was established by injecting anti-primate FVIII neutralizing antibody. When bleeds emerged following an artificial bleed-inducing procedure, either ACE910 or recombinant porcine FVIII (rpoFVIII) was intravenously administered. rpoFVIII was additionally administered twice daily on the following 2 days. Bleeding symptoms were monitored for 3 days. A pharmacokinetic study and multiple-dosing simulations of ACE910 were also performed. RESULTS: A single bolus of 1 or 3 mg kg⁻¹ ACE910 showed hemostatic activity comparable to that of 10 U kg⁻¹ (twice daily) rpoFVIII against ongoing bleeds. The determined ACE910 pharmacokinetic parameters included a long half-life (3 weeks) and high subcutaneous bioavailability (nearly 100%). The simulation results based on pharmacokinetic parameters indicated that the above hemostatic level could be maintained with once-weekly subcutaneous administration of ACE910, suggesting the possibility of more effective prophylaxis. CONCLUSIONS: ACE910 may offer an alternative on-demand treatment option for patients with hemophilia A, as well as user-friendly and aggressive routine supplementation.

Humanization and simultaneous optimization of monoclonal antibody.

Antibody humanization is an essential technology for reducing the potential risk of immunogenicity associated with animal-derived antibodies and has been applied to a majority of the therapeutic antibodies on the market. For developing an antibody molecule as a pharmaceutical at the current biotechnology level, however, other properties also have to be considered in parallel with humanization in antibody generation and optimization. This section describes the critical properties of therapeutic antibodies that should be sufficiently qualified, including immunogenicity, binding affinity, physiochemical stability, expression in host cells and pharmacokinetics, and the basic methodologies of antibody engineering involved. By simultaneously optimizing the antibody molecule in the light of these properties, it should prove possible to shorten the research and development period necessary to identify a highly qualified clinical candidate and consequently accelerate the start of the clinical trial.

Crystal structure of a novel asymmetrically engineered Fc variant with improved affinity for FcγRs.

Enhancing the effector function by optimizing the interaction between Fc and Fcγ receptor (FcγR) is a promising approach to enhance the potency of anticancer monoclonal antibodies (mAbs). To date, a variety of Fc engineering approaches to modulate the interaction have been reported, such as afucosylation in the heavy chain Fc region or symmetrically introducing amino acid substitutions into the region, and there is still room to improve FcγR binding and thermal stability of the CH2 domain with these approaches. Recently, we have reported that asymmetric Fc engineering, which introduces different substitutions into each Fc region of heavy chain, can further improve the FcγR binding while maintaining the thermal stability of the CH2 domain by fine-tuning the asymmetric interface between the Fc domain and FcγR. However, the structural mechanism by which the asymmetrically engineered Fc improved FcγR binding remained unclear. In order to elucidate the mechanism, we solved the crystal structure of a novel asymmetrically engineered Fc, asym-mAb23, in complex with FcγRIIIa. Asym-mAb23 has enhanced binding affinity for both FcγRIIIa and FcγRIIa at the highest level of previously reported Fc variants. The structural analysis reveals the features of the asymmetrically engineered Fc in comparison with symmetric Fc and how each asymmetrically introduced substitution contributes to the improved interaction between asym-mAb23 and FcγRIIIa. This crystal structure could be utilized to enable us to design a more potent asymmetric Fc.

Engineered antibody Fc variant with selectively enhanced FcγRIIb binding over both FcγRIIa(R131) and FcγRIIa(H131).

Engaging inhibitory FcγRIIb by Fc region has been recently reported to be an attractive approach for improving the efficacy of antibody therapeutics. However, the previously reported S267E/L328F variant with enhanced binding affinity to FcγRIIb, also enhances binding affinity to FcγRIIa(R131) allotype to a similar degree because FcγRIIb and FcγRIIa(R131) are structurally similar. In this study, we applied comprehensive mutagenesis and structure-guided design based on the crystal structure of the Fc/FcγRIIb complex to identify a novel Fc variant with selectively enhanced FcγRIIb binding over both FcγRIIa(R131) and FcγRIIa(H131). This novel variant has more than 200-fold stronger binding affinity to FcγRIIb than wild-type IgG1, while binding affinity to FcγRIIa(R131) and FcγRIIa(H131) is comparable with or lower than wild-type IgG1. This selectivity was achieved by conformational change of the C(H)2 domain by mutating Pro to Asp at position 238. Fc variant with increased binding to both FcγRIIb and FcγRIIa induced platelet aggregation and activation in an immune complex form in vitro while our novel variant did not. When applied to agonistic anti-CD137 IgG1 antibody, our variant greatly enhanced the agonistic activity. Thus, the selective enhancement of FcγRIIb binding achieved by our Fc variant provides a novel tool for improving the efficacy of antibody therapeutics.

Population structure and landscape genetics of two endangered frog species of genus Odorrana: different scenarios on two islands.

Isolation by distance and landscape connectivity are fundamental factors underlying speciation and evolution. To understand how landscapes affect gene flow and shape population structures, island species provide intrinsic study objects. We investigated the effects of landscapes on the population structure of the endangered frog species, Odorrana ishikawae and O. splendida, which each inhabit an island in southwest Japan. This was done by examining population structure, gene flow and demographic history of each species by analyzing 12 microsatellite loci and exploring causal environmental factors through ecological niche modeling (ENM) and the cost-distance approach. Our results revealed that the limited gene flow and multiple-population structure in O. splendida and the single-population structure in O. ishikawae were maintained after divergence of the species through ancient vicariance between islands. We found that genetic distance correlated with geographic distance between populations of both species. Our landscape genetic analysis revealed that the connectivity of suitable habitats influences gene flow and leads to the formation of specific population structures. In particular, different degrees of topographical complexity between islands are the major determining factor for shaping contrasting population structures of two species. In conclusion, our results illustrate the diversification mechanism of organisms through the interaction with space and environment. Our results also present an ENM approach for identifying the key factors affecting demographic history and population structures of target species, especially endangered species.

Changes of concentrations, shipment amounts and ecological risk of pesticides in river water flowing into Lake Biwa.

A survey of various pesticide contaminations was performed for water in Yanamune River flowing into Lake Biwa from 1988 to 2009. Ten pesticides (diazinon and fenitrothion as insecticides, iprobenfos and isoprothiolane as fungicides and chlornitrofen, thiobencarb, molinate, bromobutide, simetryne and pretilachlor as herbicides) were selected and concentration changes of the pesticides were evaluated based on their shipment amounts. Yearly maximum concentrations of eight of the pesticides in Yanamune River water were compared with their no observed effect concentration and their predicted no effect concentration values and initial ecological risk assessment was conducted for five pesticides (diazinon, fenitrothion, iprobenfos, isoprothiolane and thiobencarb) by their predicted no effect concentration values. All of the diazinon (0.01-0.28 µg/L) and fenitrothion (0.005-0.31 µg/L) concentrations from 1988 to 2007, the iprobenfos (2.7 and 2.4 µg/L) concentrations in 1988 and 1990 and the thiobencarb (0.24-2.7 µg/L) concentrations in 1988, 1992, 1993 and 1995 exceeded their predicted no effect concentration (PNEC) (0.00026, 0.00021, 1.0 and 0.17 µg/L) values.

Seasonal changes of PFOS and PFOA concentrations in Lake Biwa water.

A survey on seasonal concentration changes of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) was performed for surface water in Lake Biwa (14 sites) from February to November in 2009. The concentrations of PFOS and PFOA were 0.8-1.6 and 7.0-10 ng/L in northern basin of Lake Biwa (eight sites), 0.9-1.7 and 8.3-13 ng/L in southern basin of Lake Biwa except Akanoi Bay (four sites), 1.4-2.8 and 9.1-17 ng/L in Akanoi Bay (8C) and 2.4-5.3 and 12-26 ng/L in Akanoi Bay (168), respectively. Seasonal changes were recognized for both of PFOS and PFOA in the two sites of Akanoi Bay but not in the other sites of the southern and northern basins of Lake Biwa. Monthly detailed surveys in the surface water were performed on the changes of PFOS and PFOA concentrations from June in 2009 to May in 2010 and further on the changes of conductivity values. The changes of PFOS and PFOA concentrations were well consistent with those of conductivity values.

Reduced elimination of IgG antibodies by engineering the variable region.

Fc engineering to increase the binding affinity of IgG antibodies to FcRn has been reported to reduce the elimination of IgG antibodies. Herein, we present a novel non-FcRn-dependent approach to reduce the elimination of IgG antibodies. Pharmacokinetic studies conducted in normal mice of various humanized IgG4 antibodies, which had identical constant regions but different variable region sequences, revealed that an antibody with a lower isoelectric point (pI) has a longer half-life. These antibodies exhibited comparable binding affinity to FcRn, and with the antibodies with lower pIs, a longer half-life was also observed in beta2-microglobulin knockout mice, suggesting that differences in the pharmacokinetics were due to a non-FcRn-dependent mechanism. On the basis of our findings, we attempted to engineer the pharmacokinetic properties of a humanized anti-IL6 receptor IgG1 antibody. Selected substitutions in the variable region, without substitution in the Fc region, lowered the pI but did not reduce the biological activity and showed a significant reduction in the clearance of the antibody in cynomolgus monkey. These results suggest that lowering the pI by engineering the variable region could reduce the elimination of IgG antibodies and could provide an alternative to Fc engineering of IgG antibodies.

Isolation and characterization of the plant glsA promoter from Alstroemeria.

The differentiation of a vegetative cell and a generative cell is a critical event during pollen development. The Lilium GlsA is known to localize in pollen and is considered to be involved in development of the generative cell. Here, we cloned a glsA ortholog from Alstroemeria, a commercially important cut flower. The expression of AaglsA (Alstroemeria aurea glsA) transcripts increased gradually after pollen mitosis I (PMI) and reached a significant level when the generative cell started to elongate. Analysis of the promoter of AaglsA suggests that AaglsA expression is controlled by several cis-regulatory elements during pollen development. This is the first investigation of reproductive factors regulating male gametogenesis in Alstroemeria.

Amelioration of human lupus-like phenotypes in MRL/lpr mice by overexpression of interleukin 27 receptor alpha (WSX-1).

OBJECTIVE: In the present work, we investigate the role of interleukin (IL)27/IL27 receptor alpha (Ralpha) (WSX-1) in the development of autoimmune disorders in the MRL/lpr mouse, which is considered as an experimental model of systemic lupus erythaematosus (SLE) in humans. METHODS: We generated two strains of WSX-1 transgenic mice in the MRL/lpr background with different expression levels of WSX-1, and investigated the effect of WSX-1 overexpression on survival, glomerulonephritis and immunological properties. RESULTS: In comparison with wild type (WT) MRL/lpr and transgenic (Tg) low (TgL) mice, Tg high (TgH) mice exhibited a prolonged lifespan and no apparent development of autoimmune nephritis. Production of anti-dsDNA antibody and total IgG and IgG2a were significantly lower in TgH mice than those of TgL and WT mice. The expressed amounts of interferon (IFN)gamma and IL4 mRNA by CD4+ T cells from Tg mice decreased in a dose-dependent fashion. CD4+ splenic lymphocytes in TgH mice were more subject to the IL27-mediated suppression of cytokine production. In vitro stimulation of CD4+ T cells by IL27 resulted in over phosphorylation of STAT3 in TgH cells than in WT cells. CONCLUSION: WSX-1 overexpression in the MRL/lpr background rendered the autoimmune prone mice protected from the development of autoimmune diseases. Our results suggest that IL27 signalling may be a therapeutic target against autoimmune diseases, including human SLE.

Absence of association between the MCP-1 gene polymorphism and histological phenotype of lupus nephritis.

Lupus nephritis presents two polar histological patterns, diffuse proliferative glomerulonephritis (DPGN) and membranous glomerulonephritis (MGN). In the kidney tissue of DPGN, numerous mononuclear cells were seen in the interstitium and glomeruli; on the other hand in MGN, infiltrating cells were less frequent. Monocyte chemoattractant protein-1 (MCP-1) is a potent chemoattractant for monocytes, T-cells, and natural killer cells. In this study we assessed the significance of the MCP-1 gene in determination of the histological phenotype in lupus nephritis. There was no association between the risk of DPGN and the MCP-1 gene genotype.