The role of IL-12 in inflammatory activity of patients with rheumatoid arthritis (RA)

The long non-coding RNA HOTAIR contributes to joint-specific gene expression in rheumatoid arthritis

Although patients with rheumatoid arthritis (RA) typically exhibit symmetrical joint involvement, some patients develop alternative disease patterns in response to treatment, suggesting that different molecular mechanism may underlie disease progression depending on joint location. Here, we identify joint-specific changes in RA synovium and synovial fibroblasts (SF) between knee and hand joints. We show that the long non-coding RNA HOTAIR, which is only expressed in knee SF, regulates more than 50% of this site-specific gene expression in SF. HOTAIR is downregulated after stimulation with pro-inflammatory cytokines and is expressed at lower levels in knee samples from patients with RA, compared with osteoarthritis. Knockdown of HOTAIR in knee SF increases PI-Akt signalling and IL-6 production, but reduces Wnt signalling. Silencing HOTAIR inhibits the migratory function of SF, decreases SF-mediated osteoclastogenesis, and increases the recruitment of B cells by SF. We propose that HOTAIR is an important epigenetic factor in joint-specific gene expression in RA.

Exosomes derived from mesenchymal stem cells primed with disease-condition-serum improved therapeutic efficacy in a mouse rheumatoid arthritis model via enhanced TGF-β1 production

BACKGROUNDS

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease characterized by synovial inflammation-mediated progressive destruction of the cartilage and bone, resulting in reduced quality of life. We primed human telomerase reverse transcriptase-overexpressing immortalized human adipose tissue-derived mesenchymal stem cells (iMSCs) with serum derived from a non-human primate RA model and studied the immunomodulatory ability of exosomes obtained from primed iMSCs.

METHODS

After immunophenotyping, nanoparticle tracking analysis, and in vitro functional tests, Dulbecco's phosphate-buffered saline (dPBS, Group C), exosomes derived from the supernatant of iMSCs (Exo-FBS, Group E), exosomes derived from the supernatant of iMSCs primed with RA serum (Exo-RA, Group F), and methotrexate (Group M) were administered in collagen-induced arthritis (CIA) model mice. dPBS was administered to the normal (N) group for comparison (n = 10/group).

RESULTS

Exo-RA had a significantly higher number of exosomes compared to Exo-FBS when measured with nanoparticle tracking analysis or exosome marker CD81, and Transforming growth factor-β1 amounts were significantly higher in Exo-RA than in Exo-FBS. When Exo-FBS or Exo-RA was administered to the collagen-induced arthritis model, serum interleukin (IL)-4 and the proportion of Th2 (CD4+CD25+GATA3+) and M2 (CD11c - CD206+ of CD45+CD64+) cells were significantly increased compared to the control group. Furthermore, Exo-RA could alleviate cartilage damage by significantly lowering the concentrations of proinflammatory cytokines such as tumor necrosis factor-α, keratinocyte chemoattractant, and IL-12p70.

CONCLUSION

Exosomes derived from disease-condition-serum-primed iMSCs ameliorated cartilage damage in a RA model by enhancing TGF-β1 production, inducing Th2 and M2 polarization and lowering proinflammatory cytokines, TNF-α, KC, and IL-12p70 in the host. Patient-derived serum can be used as an iMSC priming strategy in iMSC-derived exosome treatment of RA.

IL-15-producing splenic B cells play pathogenic roles in the development of autoimmune hepatitis

Background & Aims

B-cell depletion therapy with an anti-CD20 is an effective treatment strategy for patients with refractory autoimmune hepatitis (AIH). However, the mechanisms underlying B-cell action are unclear.

Methods

Herein, we used the adeno-associated virus IL-12 model, in which hepatic IL-12 expression triggers liver injuries characteristic of AIH. We also analysed the clinical samples of patients with AIH.

Results

B-cell depletion using anti-CD20 or splenectomy was found to improve liver functions and decrease the cytotoxic CD8⁺ T-cell (cytotoxic T lymphocyte [CTL]) count in the liver. This improvement was reversed by the adoptive transfer of splenic B cells derived from AAV IL-12-treated mice to splenectomised mice as it caused the hepatic CTL count to increase. RNA-sequencing analysis identified IL-15 as a key factor in pathogenic B cells, which promotes CTL expansion and subsequent migration to the liver via the CXCL9/CXCR3 axis. Indeed, IL-15 neutralisation ameliorated hepatitis by suppressing splenic and hepatic CTLs in vivo. The close distribution of B220⁺ B cells and CD8⁺ T cells in the spleen of AIH mice suggested mutual interactions. Mechanistically, IFNγ and CD40L/CD40 signalling were indispensable for the expression of IL-15 in B cells, and in vitro co-culture experiments revealed that splenic CD40L⁺CD8⁺ T cells promoted IL-15 production in B cells, which led to CTL expansion. In patients with AIH, high serum IL-15 concentration and IL-15⁺ B-cell counts, positively correlating with serum alanine aminotransferase levels, support translation and potential therapeutic targeting in human AIH.

Conclusions

This investigation elucidated the roles of IL-15-producing splenic B cells that occur in concert with pathogenic CD8⁺ T cells during the development of AIH.

Impact and Implications

IL-15-producing B cells were shown to exacerbate experimental AIH via cytotoxic T lymphocyte expansion. CD40L⁺CD8⁺ T cells promoted IL-15 expression in B cells, indicating the mutual interaction of both cells. High serum IL-15 concentrations, IL-15⁺ B-cell counts, and CD40L⁺IL-15Rα⁺CD8⁺ T-cell counts were confirmed in the blood of patients with AIH.

Methotrexate and Sulforaphane loaded PBA-G5-PAMAM dendrimers as a combination therapy for anti-inflammatory response in an intra-articular joint arthritic animal model

L-sulforaphane (LSF), a natural product developed from cruciferous vegetables, have shown potent anti-inflammatory effect in cancer as well as arthritis. However, the stable delivery of LSF remains a major challenge. Methotrexate (MTX) is currently the first line treatment for managing RA and is most effective in patients when used in combination with other anti-inflammatory or anti-rheumatic drugs. Here we developed phenylboronic acid-PAMAM dendrimer (PBA-G5D) nanoparticles conjugated MTX (MTX-PBA-G5D), and L-sulforaphane (LSF/PBA-G5D) loaded dendrimers. The MTX and LSF drug loading and release kinetics was analyzed using HPLC. The lipopolysaccharide (LPS) stimulated macrophages were treated with the formulations to study the inflammatory response in vitro. For in vivo studies, arthritis was induced in five-week-old female Wistar rats, and the MTX- and LSF/PBA-G5-D were injected via intra-articular injection for treatment and the arthritis reduction was scored by weight, knee diameter, and serum cytokine level measurement. The average size of the drug-nanoparticle conjugates ranged from 135-250 nm, with mostly cationic surface charges. The encapsulation efficiency of the drugs to the modified dendrimer was more than 60% with a slow release of drugs from the nanoparticles within 24 h at pH 7.4. Drugs in the nanoparticle formulation were biocompatible, with promising anti-inflammatory effects in vitro against LPS-activated murine macrophages. Further in vivo studies on arthritis induced female Wistar rats, revealed significant anti-arthritic effects based on the arthritic scoring from the knee diameter reading, and anti-inflammatory effects based on the serum cytokine levels. This study provides a promising strategy for utilizing PAMAM dendrimers as a nanocarrier for LSF delivery for RA therapy.

Pregabalin inhibits proinflammatory cytokine release in patients with fibromyalgia syndrome

Objectives

The main goal of the study was to investigate how pregabalin (PGB) affects proinflammatory cytokine release in patients with fibromyalgia syndrome (FMS).

Patients and methods

This experimental research study was conducted with 85 female participants (mean age: 49.6±10.1 years; range, 30 to 73 years) between April 2020 and November 2020. Of the participants, 30 were FMS patients using PGB 150 mg/day for at least three months, 30 were FMS patients not using PGB, and 25 were healthy individuals. The detection of FMS was carried out according to the 2010 American College of Rheumatology diagnostic criteria. Levels of proinflammatory cytokines (interleukin [IL]-2, IL-6, IL-12, IL-17, interferon-gamma, and tumor necrosis factor-alpha) were measured by enzyme-linked immunosorbent assay.

Results

Serum concentrations of proinflammatory cytokines were remarkably decreased in FMS patients using PGB (p<0.001) and were higher in patients with FMS not using PGB than in healthy subjects (p<0.001). The highest values of proinflammatory cytokines were found in the group of FMS patients not using PGB (p<0.001).

Conclusion

These results indicate that PGB inhibits the release of proinflammatory cytokines, suggesting that it can be used as an anti-inflammatory agent in inflammatory cases.

Biomarker Approach Towards Rheumatoid Arthritis Treatment

Rheumatoid arthritis is an auto-immune disorder, recognized by cartilage as well as bone destruction, which causes irreversible joint deformities, which further results in functional limitations in the patient. Genes like HLA-DRB1 and PTPN22 are likely implicated in the genetic predisposition of rheumatoid arthritis pathology. The first and foremost clinical manifestation in a person with rheumatoid arthritis is joint destruction followed by cartilage and bone destruction caused by cell-cell interactions. The cell-cell interactions are thought to be initialized through the contact of antigen-presenting cells (APC) with CD4+ cells, leading to the progression of the disease. APC includes a complex of class ІІ major histocompatibility complex molecules along with peptide antigens and binds to the receptors present on the surface of T-cells. Further, the activation of macrophages is followed by the release of various pro-inflammatory cytokines such as IL-1 and TNF-α, which lead to the secretion of enzymes that degrade proteoglycan and collagen, which in turn, increase tissue degradation. Biomarkers like IL-6, IL-12, IL-8 and IL-18, 14-3-3η, RANKL, IFN-γ, IFN-β and TGF-β have been designated as key biomarkers in disease development and progression. The study of these biomarkers is very important as they act as a molecular indicator of pathological processes that aggravate the disease.

Associations between cytokine gene polymorphisms and rheumatoid arthritis in Turkish population

OBJECTIVE:

Various cytokine polymorphisms have been associated with genetic risk factors predisposing to Rheumatoid Arthritis (RA) in different populations. To predict the clinical outcome as well as response to therapy in RA, studies aimed to describe genetic markers. The present study aims to search for polymorphisms of 13 cytokine coding genes in the Eastern Black Sea Region of Turkey.

METHODS:

DNAs of 49 patients and 96 healthy bone marrow and kidney donors were isolated from peripheral blood samples. Genotyping was performed using the Heidelberg Cytokine Typing Tray kit. PCR products were visualized on an agarose gel, and results were analyzed using the interpretation scheme provided with the kit. Arlequin 3.5 software was used for statistical analysis.

RESULTS:

No positive association was found between allele frequencies and the disease. However, a negative association was found for the IL-A -889 C allele (p=0.02, OR=0.533, Wald’s 95% CI=0.318–0.893). IL-12 -1188 CC (p=0.01, OR=3.667, Wald’s 95% CI=1.246–10.786), IL-4 -1098 GT (p=0.02, OR=2.405, Wald’s 95% CI=1.129–5.125) genotypes were found positively associated with the RA, while IL-4 -590 CT (p=0.02, OR=0.422, Wald’s 95% CI=0.201–0.886) was found negatively associated with the disease. In addition, IL-6 GG haplotype was found positively associated with the RA (p=0.02, OR=1.880, Wald’s 95% CI=1.086–3.254).

CONCLUSION:

Our findings suggest that some polymorphisms of the IL-1A, IL-2, IL-4, IL-6 and IL-12 could be responsible for the susceptibility or protective to RA in our study population. Multi-centered and large numbers of subjects containing studies that search for cytokine polymorphisms will gather more information regarding the susceptibility to RA of Turkish patients.

Study of bilateral elbow joint osteoarthritis treatment using conditioned medium from allogeneic adipose tissue-derived MSCs in Labrador retrievers

Canine elbow dysplasia is a common cause of forelimb lameness in dogs and can lead to development of osteoarthritis (OA). A potential alternative to pain management is the use of a safe cell-free based therapy through trophic and paracrine factors of mesenchymal stem cells (MSCs). The aim of study was to identify the profile of selected mediators of potential clinical relevance in synovial fluid (SF) samples of dogs with elbow OA and analyse the range of motion (ROM) before and after cell-free MSCs-based treatment. In this study, conditioned medium from allogeneic canine adipose tissue - derived MSC (CM-AD-MSC) was prepared and administered into both elbow joints with OA in six Labrador retriever dogs (n = 6) on day 0 and 14 without creating a control group with a placebo. The SF of the elbow joints was analysed for the presence of several biomolecules (IL-6, IL-10, IL-8, IL-2, IL-12, TNF-αIFN-γ, MMP-3TIMP-1) before and after intraarticular applications of CM-AD-MSC. Kinematic analysis was used to assess the clinical effect of CM-AD-MSC. Analyses of SF and ROM were performed on days 0, 14 and 42. Concentration levels of MMP-3, TIMP-1, IL-6 and TNF-α in SF showed significant differences before and after the treatment (P < .05). There was a significant improvement in ROM between day 0 and 42 (P < .001). No severe adverse events were observed during the study. Results support the potential supportive effect of CM-AD-MSC as a noninvasive therapeutic tool for pain management of OA elbow joints in dogs.

Bedside to bench: defining the immunopathogenesis of psoriatic arthritis

Psoriatic arthritis (PsA) is an immune-mediated, systemic inflammatory disorder. PsA can present with heterogeneous clinical features. Advances in understanding the immunopathogenesis of PsA have helped to facilitate the development of agents targeting specific components of the dysregulated inflammatory and immune responses relevant to PsA. Interestingly, agents with distinct mechanisms of action have shown differential responses across the various disease domains of PsA, counter to what might have been expected from basic science investigations. Here, we review data utilizing various novel targeted therapies for PsA, focusing on biologic and targeted synthetic therapies. These data might support the idea of a 'bedside to bench' concept, whereby results from clinical trials of specific targeted therapies inform our understanding of the immunopathogenesis of PsA. For example, TNF inhibition confers substantial and comparable benefit for all domains of PsA, supporting the view that TNF is a central pro-inflammatory cytokine across diverse areas of disease involvement. On the other hand, inhibition of IL-12-IL-23, as compared with inhibition of TNF, has greater efficacy for psoriasis, comparable efficacy for peripheral arthritis, but was ineffective in studies of axial spondyloarthritis. Data from studies of agents with distinct mechanisms of action will help to further refine our understanding of the immunopathogenesis of PsA.

Mesenchymal stem cell transplantation ameliorates Sjögren's syndrome via suppressing IL-12 production by dendritic cells

Background

Mesenchymal stem cells (MSCs) have been demonstrated to be effective in treating autoimmune diseases including Sjögren’s syndrome (SS). We aim to compare the effects of MSC transplantation (MSCT) and the role of serum interleukin-12 (IL-12) in SS.

Methods

IL-12 levels were measured by ELISA. IL-12 mRNA transcripts in dendritic cells (DCs) were determined by RT-PCR. After co-culturing with MSCs, IL-12 mRNA transcripts in mouse and human DCs were detected. Non-obese diabetic (NOD) mice received MSCT, recombinant IL-12, or anti-IL-12 mAb treatment, respectively. Then, salivary flow rates, histopathology of salivary glands, and splenic lymphocyte subsets were examined in these mice.

Results

IL-12 levels in the serum were significantly increased in SS patients and positively correlated with the EULAR 2010 Sjögren’s syndrome disease activity index. DCs from SS patients produced more IL-12 than those from the control. Likewise, IL-12 treatment in NOD mice significantly decreased salivary flow rates and promoted lymphocyte infiltration in salivary glands. IL-12 antibodies downregulated Th1, Th17, and Tfh cell. MSCT enhanced salivary flow rates and decreased lymphocyte infiltrations in salivary glands of NOD mice. MSCT downregulated Th17 and Tfh cells but upregulated regulatory T cells. MSCT reduced IL-12 productions in both SS patients and mice.

Conclusion

Our results indicate that MSCs ameliorate SS possibly via suppressing IL-12 production in DCs and that IL-12 could be a potential therapeutic target of SS.

Trial registration

NTC00953485. Registered June 2009.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-1023-x) contains supplementary material, which is available to authorized users.

Emerging role of IL-35 in inflammatory autoimmune diseases

Interleukin 35 (IL-35) is the recently identified member of the IL-12 family of cytokines and provides the possibility to be a target for new therapies for autoimmune, inflammatory diseases. It is composed of an α chain (p35) and a β chain (EBI3). IL-35 mediates signaling by binding to its receptors, activates subsequent signaling pathways, and therefore, regulates the differentiation, function of T, B cells, macrophages, dendritic cells. Recent findings have shown abnormal expression of IL-35 in inflammatory autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, type 1 diabetes, psoriasis, multiple sclerosis, autoimmune hepatitis, experimental autoimmune uveitis. In addition, functional analysis suggested that IL-35 is critical in the onset and development of these diseases. Therefore, the present study will systematically review what had been occurred regarding IL-35 in inflammatory autoimmune disease. The information collected will help to understand the biologic role of IL-35 in immune cells, and give information about the therapeutic potential of IL-35 in these diseases.

Synoviocytes-derived Interleukin 35 Potentiates B Cell Response in Patients with Osteoarthritis and Rheumatoid Arthritis

OBJECTIVE

Elevated expression of interleukin 35 (IL-35) is associated with autoimmune disease, including rheumatoid arthritis (RA). The present study was undertaken to determine the functional interaction among IL-35, B cells, and stromal cells residing in the synovium of patients with RA and osteoarthritis (OA).

METHODS

IL-35 (EBI-3/p35) expression was investigated in RA and OA synovium using quantitative real-time PCR (qRT-PCR) and immunohistochemistry. IL-35 receptor (IL-35R) expression on B cells dissociated from synovium and periphery of patients with RA, OA, and healthy donor controls (HC) was determined by flow cytometry. The degree of B cells activation after IL-4 and/or IL-35 stimulation was measured by flow cytometry and qRT-PCR. Synovial fibroblasts (SF) purified from RA and OA synovium were cocultured with peripheral HC B cells in the presence/absence of tumor necrosis factor-α (TNF-α) and with/without anti-IL-35-blocking antibodies.

RESULTS

EBI-3/p35 transcripts were expressed in close proximity to B cells residing in RA and OA synovium. IL-35R subunits, gp130 and IL-27Rα, but not IL-12Rβ2, were expressed in B cells extracted from the synovium and periphery of patients with RA/OA. Notably, RA synovium expressed the highest level of IL-27Rα on their cell surface. IL-35 induced proliferation and IgG production in HC B cells. Cocultures of HC B cells with RASF, but not OASF, exhibited significantly elevated B cells activation. TNF-α-induced, RASF-dependent secretion of IgG in B cells is partly IL-35-dependent.

CONCLUSION

To our knowledge, for the first time we demonstrated that synovial/peripheral B cells expressed IL-35R and were responsive to IL-35 stimulation. SF residing in RA synovium can be linked to B cell activation and maintenance in RA synovium through IL-35.

Bee Venom and Hesperidin Effectively Mitigate Complete Freund's Adjuvant-Induced Arthritis Via Immunomodulation and Enhancement of Antioxidant Defense System

Objectives

This study aims to assess the antirheumatic activity of bee venom (BV) and/or hesperidin as natural products in complete Freund's adjuvant (CFA)-induced arthritis in male Wistar rats.

Material and methods

Rheumatoid arthritis was induced in 30 male Wistar rats (weight 130 g to 150 g; age 10 to 12 weeks) by subcutaneous injection of CFA into the right hind paw of the rats. The rats were divided into five groups of six rats in each and administered the following regimens for 21 days: Normal group (given the equivalent volume of saline and carboxymethylcellulose), arthritic group (given the equivalent volume of saline and carboxymethylcellulose), arthritic group treated with BV (treated with BV along with carboxymethylcellulose), arthritic group treated with hesperidin (treated with hesperidin along with saline), and arthritic group treated with BV and hesperidin (treated with BV and hesperidin concurrently).

Results

Bee venom and/or hesperidin successfully reversed the CFA-arthritis-induced increases in right hind leg paw swelling, leukocytes' count, liver lipid peroxidation, serum inflammatory cytokine interleukin (IL-2 and IL-12) levels and spleen tumor necrosis factor-alpha messenger ribonucleic acid expression. Moreover, the CFA-induced down-regulation in serum IL-10 level and spleen IL-4 messenger ribonucleic acid expression as well as the deterioration in the antioxidant defense system were significantly improved as a result of BV and hesperidin administration. Both treatments also markedly counteracted the severe inflammatory changes and leukocytic infiltration in the periarticular tissue of the ankle joints. In addition, BV and hesperidin obviously amended the lymphoid hyperplasia in white pulps of spleen as well as the widening of the medulla and mononuclear cell infiltration found in thymus.

Conclusion

Bee venom and hesperidin administration produced their ameliorative effects on rheumatoid arthritis via their antioxidant, antiinflammatory and immunomodulatory potentials. BV plus hesperidin particularly seemed to be the most potent in improving rheumatoid arthritis in Wistar rats.

Attenuation of nociceptive pain and inflammatory disorders by total steroid and terpenoid fraction of Euphorbia tirucalli Linn root in experimental in vitro and in vivo model

The plant Euphorbia tirucalli Linn has been successfully used as a tribal folk medicine in India and Africa for the management of acute inflammatory, arthritic, nociceptive pain and asthmatic symptoms. The present study was conducted to assess the anti-inflammatory, analgesic, anti-asthmatic and anti-arthritic role of the total steroid and terpenoid rich fractions of the hydro-alcoholic extract of E. tirucalli root (STF-HAETR). STF-HAETR fraction demonstrated 71.25 ± 2.5 and 74.25 ± 5.1% protection against acetic acid-induced pain and central neuropathic pain at 75 and 100 mg/kg doses, respectively. It showed 96.97% protection against acute inflammation at 100 mg/kg with 1.6-fold better activity than the standard drug. The fraction exhibited such efficacy via inhibition of proinflammatory cytokines TNF-α, IFN-γ, by 61.12 and 65.18%, respectively, at 100 μg/mL. Inhibition of cyclooxygenase and Nitric oxide synthase in a dose-dependent manner affirms its analgesic and anti-inflammatory activity. The spectrophotometric analysis reveals that STF-HAETR induces ameliorative effect against heat-induced denaturation of Bovine serum albumin (BSA) and exhibits significant anti-proteinase activity. The plant fraction also demonstrated anti-asthmatic activity by displaying 62.45% protection against histamine induced bronchoconstriction or dyspnoea. Our findings suggest that STF-HAETR could be an effective safe therapeutic agent to treat nociceptive pain, acute inflammation, asthma, and arthritis which may authenticate its traditional use.

A randomised phase II study evaluating the efficacy and safety of subcutaneously administered ustekinumab and guselkumab in patients with active rheumatoid arthritis despite treatment with methotrexate

Objective

Interleukin (IL)-12 and IL-23 have been implicated in the pathogenesis of rheumatoid arthritis (RA). The safety and efficacy of ustekinumab, a human monoclonal anti-IL-12/23 p40 antibody, and guselkumab, a human monoclonal anti-IL-23 antibody, were evaluated in adults with active RA despite methotrexate (MTX) therapy.

Methods

Patients were randomly assigned (1:1:1:1:1) to receive placebo at weeks 0, 4 and every 8 weeks (n=55), ustekinumab 90 mg at weeks 0, 4 and every 8 weeks (n=55), ustekinumab 90 mg at weeks 0, 4 and every 12 weeks (n=55), guselkumab 50 mg at weeks 0, 4 and every 8 weeks (n=55), or guselkumab 200 mg at weeks 0, 4 and every 8 weeks (n=54) through week 28; all patients continued a stable dose of MTX (10–25 mg/week). The primary end point was the proportion of patients with at least a 20% improvement in the American College of Rheumatology criteria (ACR 20) at week 28. Safety was monitored through week 48.

Results

At week 28, there were no statistically significant differences in the proportions of patients achieving an ACR 20 response between the combined ustekinumab group (53.6%) or the combined guselkumab group (41.3%) compared with placebo (40.0%) (p=0.101 and p=0.877, respectively). Through week 48, the proportions of patients with at least one adverse event (AE) were comparable among the treatment groups. Infections were the most common type of AE.

Conclusions

Treatment with ustekinumab or guselkumab did not significantly reduce the signs and symptoms of RA. No new safety findings were observed with either treatment.

Trial registration number

NCT01645280.

Rheumatoid Arthritis, Immunosenescence and the Hallmarks of Aging

Age is the most important risk factor for the development of infectious diseases, cancer and chronic inflammatory diseases including rheumatoid arthritis (RA). The very act of living causes damage to cells. A network of molecular, cellular and physiological maintenance and repair systems creates a buffering capacity against these damages. Aging leads to progressive shrinkage of the buffering capacity and increases vulnerability. In order to better understand the complex mammalian aging processes, nine hallmarks of aging and their interrelatedness were recently put forward.

RA is a chronic autoimmune disease affecting the joints. Although RA may develop at a young age, the incidence of RA increases with age. It has been suggested that RA may develop as a consequence of premature aging (immunosenescence) of the immune system. Alternatively, premature aging may be the consequence of the inflammatory state in RA. In an effort to answer this chicken and egg conundrum, we here outline and discuss the nine hallmarks of aging, their contribution to the pre-aged phenotype and the effects of treatment on the reversibility of immunosenescence in RA.

Interleukin 12B gene polymorphisms and susceptibility to rheumatoid arthritis: a data synthesis

The aim of this study was to investigate the association of two common interleukin 12B (IL-12B) polymorphisms (rs3212227 and rs6887695) with rheumatoid arthritis (RA) susceptibility through meta-analyses. A systematic literature search of PubMed, Web of Science, Cochrane Library, and Embase databases was conducted on articles published before 28 February 2016. Then odds ratio (OR) with 95 % confidence interval (CI) was used to quantify the strength of association for homozygote, heterozygote, dominant, and recessive genetic models. Nine articles with a total of 17 case-control studies (12 for IL-12B rs3212227 polymorphism and 5 for IL-12B rs6887695 polymorphism) met our inclusion criteria. The pooled results demonstrated that IL-12B rs3212227 (homozygote model: OR = 0.96, 95 % CI = 0.81-1.15; heterozygote model: OR = 1.07, 95 % CI = 0.93-1.23; dominant model: OR = 1.05, 95 % CI = 0.91-1.20; recessive model: OR = 0.93, 95 % CI = 0.79-1.10) and rs6887695 (homozygote model: OR = 1.01, 95 % CI = 0.84-1.21; heterozygote model: OR = 1.14, 95 % CI = 0.86-1.51; dominant model: OR = 1.14, 95 % CI = 0.87-1.48; recessive model: OR = 1.01, 95 % CI = 0.85-1.21) polymorphisms may not be associated with RA risk. Our meta-analyses demonstrated that IL-12B rs3212227 and rs6887695 polymorphisms do not confer susceptibility to RA.

(p40)2-Fc reduces immune-inflammatory response through the activation of T cells in collagen induced arthritis mice

IL-12p40 homodimer, a natural antagonist of IL-12 and IL-23, performs an important role in the expression of proinflammatory cytokines that is essential for Th1 and Th17 immune responses. Here, we reveal the therapeutic and immunosuppressive effect of the IL-12p40 subunit ((p40)2-Fc) in an experimental autoimmune arthritis model. We hypothesized that (p40)2-Fc may reduce the inflammatory response and the activation of T cells. In this study, we intraperitoneally injected (p40)2-Fc into collagen induced arthritis (CIA) mice to identify whether (p40)2-Fc attenuates CIA severity. (p40)2-Fc reduced the development of CIA, joint inflammation and cartilage destruction. (p40)2-Fc also significantly decreased the concentration of serum immunoglobulin as well as the number of T cells and C II specific T cells. In addition, osteoclastogenesis in (p40)2-Fc treated mice was down-regulated compared to the mice treated with (p40)2-Fc control. We observed that (p40)2-Fc treatment alleviates arthritis in mice with CIA, reducing inflammation and osteoclast differentiation. These findings suggest that (p40)2-Fc can be a potential therapeutic approach for autoimmune arthritis.

Association of IL12B Gene Polymorphisms with Rheumatoid Arthritis: A Meta-analysis

BACKGROUND AND AIMS

Currently published papers regarding the relationship between interleukin (IL)-12B gene polymorphisms and rheumatoid arthritis (RA) are contradictory. The aim of this meta-analysis was to evaluate the associations between the IL-12B gene polymorphisms (rs3122227 and rs6887695) and RA risk.

METHODS

We searched PubMed, Embase, the Cochrane Library and the China Knowledge Resource Integrated Database. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to assess associations between IL12B gene polymorphisms and RA.

RESULTS

A total of eight publications (4,409 cases and 5,591 controls) were included in this meta-analysis. The results demonstrated that rs3122227 and rs6887695 were not associated with RA risk based on current included studies. However, stratification analyses indicated rs6887695 was associated with RA in Asian patients. Rs3122227 was not related with RA in Asian or Caucasian patients.

CONCLUSIONS

Our data indicated that IL-12B gene polymorphisms were not related with RA. However, rs6887695 was associated with RA in Asian patients. Further larger-scale studies are urgently needed to identify the association between IL-12B gene polymorphisms and RA in Asian populations.

Peptide motif analysis predicts alphaviruses as triggers for rheumatoid arthritis

Rheumatoid arthritis (RA) develops in response to both genetic and environmental factors. The strongest genetic determinant is HLA-DR, where polymorphisms within the P4 and P6 binding pockets confer elevated risk. However, low disease concordance across monozygotic twin pairs underscores the importance of an environmental factor, probably infectious. The goal of this investigation was to predict the microorganism most likely to interact with HLA-DR to trigger RA under the molecular mimicry hypothesis. A set of 185 structural proteins from viruses or intracellular bacteria was scanned for regions of sequence homology with a collagen peptide that binds preferentially to DR4; candidates were then evaluated against a motif required for T cell cross-reactivity. The plausibility of the predicted agent was evaluated by comparison of microbial prevalence patterns to epidemiological characteristics of RA. Peptides from alphavirus capsid proteins provided the closest fit. Variations in the P6 position suggest that the HLA binding preference may vary by species, with Ross River virus, Chikungunya virus, and Mayaro virus peptides binding preferentially to DR4, and peptides from Sindbis/Ockelbo virus showing stronger affinity to DR1. The predicted HLA preference is supported by epidemiological studies of post-infection chronic arthralgia. Parallels between the cytokine profiles of RA and chronic alphavirus infection are discussed.

Interleukin 35 Synovial Fluid Levels Are Associated with Disease Activity of Rheumatoid Arthritis

Objectives

To study the association of systemic and local interleukin-35 (IL-35) levels in rheumatoid arthritis.

Methods

37 patients with treatment naïve early RA, 49 with established RA and 29 control patients with osteoarthritis (OA) were studied. Serum and paired synovial fluid samples were analysed for IL-35. Disease activity of RA patients was assessed according to the 28-Joint Count Disease Activity Score (DAS28).

Results

The levels of serum IL-35 were significantly higher in patients with treatment naïve early RA compared to those with established disease and control OA subjects. In addition, serum levels of IL-35 significantly decreased 12 weeks after initiation of glucocorticoids and conventional synthetic disease modifying antirheumatic drugs in patients with treatment naïve early RA. Synovial fluid IL-35 levels were significantly higher in RA compared to OA patients, were significantly elevated compared to serum counterparts and correlated with synovial fluid leukocyte count (r=0.412; p<0.01), serum CRP levels (r=0.362; p<0.05) and DAS28 (r=0.430, p<0.01).

Conclusion

This is the first study showing elevated circulating levels of IL-35 in treatment naïve early RA, its significant decrease after treatment initiation and positive association between increased synovial fluid IL-35 and disease activity in patients with long-lasting RA.

Effects of Transplantation of CTLA4Ig-Overexpressing Adipose Tissue-Derived Mesenchymal Stem Cells in Mice With Sustained Severe Rheumatoid Arthritis

CTLA4Ig has therapeutic potential for rheumatoid arthritis patients unresponsive to methotrexate (MTX) or TNF-α blockers. However, recombinant CTLA4Ig proteins are short acting and expensive. Adipose tissue-derived mesenchymal stem cells (ASCs) present an ideal stem cell source for practical regenerative medicine due to their abundant availability and their beneficial properties including immunomodulation, homing activity, paracrine effects, and differentiation ability. Therefore, we aimed to determine whether CTLA4Ig and human ASCs show synergistic effects on immunomodulation and clinical improvement of sustained severe rheumatoid arthritis in a mouse model. hASCs overexpressing CTLA4Ig (CTLA4Ig-hASC) were serially transplanted into mice with collagen-induced arthritis. Arthritic mice were subjected to four treatments based on their arthritis score on day 62 postimmunization: control (C group), hASC (H group), CTLA4Ig-hASC (CT group), and MTX (MTX group). A group of healthy mice was used as a normal control (N). Mice in the N and C groups were infused with 150 µl saline, and 2 × 10(6) hASCs or CTLA4Ig-hASCs in 150 µl of saline were intravenously administered to those in the H and CT groups, respectively, on days 63, 70, 77, and 84 after CII immunization. About 1 mg/kg of methotrexate was intraperitoneally administered to the MTX group three times a week for 4 weeks. Serial hASC and CTLA4Ig-hASC transplantation modulated various cytokines and chemokines related to the development of rheumatoid arthritis. Both treatments protected against destruction of cartilage, with CTLA4Ig-hASCs being most effective. Serum levels of CII autoantibodies and C-telopeptide of type II collagen were significantly low in the group transplanted with CTLA4Ig-hASCs. In vitro, ASC and CTLA4Ig-hASC treatment significantly decreased T-bet and GATA-3 expression in splenocytes from arthritic mice, and CTLA4Ig-hASC treatment significantly increased the ratio of Treg/Th17 (CD4(+)CD25(+)FoxP3(+)/CD4(+)CD25(+)RORγt) cells. Serial hASC and CTLA4Ig-hASC transplantation offers promising treatment for rheumatoid arthritis, and CTLA4Ig-hASCs showed stronger therapeutic effects than nontransduced hASCs.

Synovial CD4+ T-cell-derived GM-CSF supports the differentiation of an inflammatory dendritic cell population in rheumatoid arthritis

OBJECTIVE

A population of synovial inflammatory dendritic cells (infDCs) has recently been identified in rheumatoid arthritis (RA) and is thought to be monocyte-derived. Here, we investigated the role and source of granulocyte macrophage-colony-stimulating factor (GM-CSF) in the differentiation of synovial infDC in RA.

METHODS

Production of GM-CSF by peripheral blood (PB) and synovial fluid (SF) CD4+ T cells was assessed by ELISA and flow cytometry. In vitro CD4+ T-cell polarisation experiments were performed with T-cell activating CD2/CD3/CD28-coated beads in the absence or presence of pro-Th1 or pro-Th17 cytokines. CD1c+ DC and CD16+ macrophage subsets were flow-sorted and analysed morphologically and functionally (T-cell stimulatory/polarising capacity).

RESULTS

RA-SF CD4+ T cells produced abundant GM-CSF upon stimulation and significantly more than RA-SF mononuclear cells depleted of CD4+ T cells. GM-CSF-producing T cells were significantly increased in RA-SF compared with non-RA inflammatory arthritis SF, active RA PB and healthy donor PB. GM-CSF-producing CD4+ T cells were expanded by Th1-promoting but not Th17-promoting conditions. Following coculture with RA-SF CD4+ T cells, but not healthy donor PB CD4+ T cells, a subpopulation of monocytes differentiated into CD1c+ infDC; a process dependent on GM-CSF. These infDC displayed potent alloproliferative capacity and enhanced GM-CSF, interleukin-17 and interferon-γ production by CD4+ T cells. InfDC with an identical phenotype to in vitro generated cells were significantly enriched in RA-SF compared with non-RA-SF/tissue/PB.

CONCLUSIONS

We demonstrate a therapeutically tractable feedback loop of GM-CSF secreted by RA synovial CD4+ T cells promoting the differentiation of infDC with potent capacity to induce GM-CSF-producing CD4+ T cells.

Modulation of T-helper cytokines and inflammatory mediators by Atropa accuminata. Royle in adjuvant induced arthritic tissues

ETHNOPHARMACOLOGICAL RELEVANCE

Atropa acuminata has been widely used in traditional medicine against arthritis and several associated inflammatory disorders.

AIM OF THE STUDY

The present study was undertaken to investigate the anti-arthritic activities of ethanolic extract of Atropa accuminata (AAEE) and to explore the probable mechanism of action.

MATERIALS AND METHODS

The anti-arthritic activity of AAEE was evaluated within a dose range of 125-500 mg/kg b.w. in adjuvant induced-arthritis in male wistar rats. An array of pro-inflammatory mediators (PGE2 NO, IL-1β and LTB4) and T-cell-mediated cytokines (IL-2, TNF-a, IFN-c, IL-4, IL-10, IL-12, IL-17, IL-6) were assayed in arthritic paw tissue homogenate of the treated animals. In addition the effects on arthritic lesions, changes in body weight; haematological (Hb, ESR, WBC and RBC) and biochemical parameters (SOD, GSH, GR) and the serum markers (CRP, RF) were also observed.

RESULTS

Significant anti-arthritic activity was observed for AAEE in the polyarthiritis test both in the developing and developed phase of the disease. This was associated with dose dependant suppression of pro-inflammatory mediators (PGE2, NO, IL-1β and LTB4)., Th1-Th17 cytokines (IL-2, TNF-α, IFN-γ, IL-12, IL-17, IL-6) and upregulation of Th2 cytokines (IL-4 and IL-10). AAEE was also observed to protect rats against the primary and secondary arthritic lesions, body weight changes and haematological perturbations. In addition, inhibitory effects of AAEE on biochemical parameters and the serum markers further confirmed that it reduced signs on chronic inflammatory responses.

CONCLUSION

The present investigation therefore suggested that AAEE is a potent anti-arthritic agent. The multipronged attack on the inflammatory mediators and T-helper cytokines and strong potency of AAEE may have relevance for inhibition of the chronic inflammatory responses in arthritis.

Rheumatoid arthritis pathophysiology: update on emerging cytokine and cytokine-associated cell targets

Biologic therapies that target pathogenic cytokines such as TNF, IL-1β or IL-6 have greatly improved the treatment of RA. Unfortunately, not all RA patients respond to current biologic therapies and responses are not always maintained, suggesting that there are alternative drivers of RA pathogenesis that might serve as promising therapeutic targets. Discovery of the new Th17 subset of Th cells, and their role in autoimmune disease development, has implicated the proinflammatory IL-12 and IL-17 families of cytokines in RA disease pathogenesis. Members of these cytokine families are elevated in the blood and joints of RA patients and have been shown to remain elevated in patients who do not respond to current biologics. In addition, these cytokines have been shown to play roles in joint destruction and erosion. A new subclass of biologics that target the IL-12 and/or IL-17 signalling pathways are under development. Here we review evidence for a role of Th17 cells as well as IL-12 and IL-17 cytokines in RA pathogenesis as the rationale for a subsequent discussion of the ongoing and completed clinical trials of newly emerging biologic therapies directed at IL-12 or IL-17 pathway inhibition.

Human secreted stabilin-1-interacting chitinase-like protein aggravates the inflammation associated with rheumatoid arthritis and is a potential macrophage inflammatory regulator in rodents

OBJECTIVE

To study the relationship between the human secreted protein stabilin-1-interacting chitinase-like protein (SI-CLP) and rheumatoid arthritis (RA).

METHODS

The expression of SI-CLP in peripheral blood mononuclear cells (PBMCs) and synovial fluid from patients with RA and the effects of cytokines on SI-CLP expression were examined by Western blotting. Fluorescence-activated cell sorting analysis was performed to investigate the binding between SI-CLP and cells. Bone marrow-derived macrophages were isolated from wild-type and SI-CLP(-/-) mice, and real-time quantitative polymerase chain reaction was performed to detect the levels of messenger RNA for cytokines or SI-CLP in SI-CLP- or cytokine-treated macrophages. Histologic studies were conducted to evaluate inflammation and the expression of interleukin-12 (IL-12), IL-13, and SI-CLP in lesions. Enzyme-linked immunosorbent assays were used to detect the cytokine levels in bone marrow-derived macrophages. Rats or mice with collagen-induced arthritis (CIA) and SI-CLP(-/-) mice were used to study the function of SI-CLP in RA.

RESULTS

SI-CLP expression was increased in PBMCs and detectable in synovial fluid from patients with RA. Administration of SI-CLP to rats with CIA aggravated arthritis-associated inflammation. SI-CLP was specifically attached to the surface protein of macrophages, which elevated the expression of IL-1β, IL-6, IL-12, and IL-13 in macrophages and mouse bone marrow-derived macrophages, up-regulating ERK phosphorylation. Moreover, SI-CLP was up-regulated by both IL-12 and IL-13 through JNK and JAK/STAT signaling, respectively. Knockout of SI-CLP resulted in a decrease in the expression of IL-1β, IL-6, IL-12, and IL-13 and lower susceptibility to CIA compared with wild-type mice. SI-CLP treatment also aggravated arthritis-related inflammation in wild-type and SI-CLP(-/-) mice.

CONCLUSION

SI-CLP functions as a regulator of the inflammatory response by macrophages. The decrease in inflammation-associated cytokine levels resulting from SI-CLP knockout may explain the lower susceptibility to CIA in SI-CLP(-/-) mice.

Inflammatory mediators alter interleukin-17 receptor, interleukin-12 and -23 expression in human osteoarthritic and rheumatoid arthritis synovial fibroblasts: immunomodulation by vasoactive intestinal Peptide

AIMS

To assess the contribution of fibroblast-like synoviocytes (FLS) to the inflammatory joint microenvironment under different pathogenic stimuli and their potential to respond to interleukin (IL)-17 and to determine whether the neuroimmunomodulatory vasoactive intestinal peptide (VIP) is able to modulate IL-17 receptor (IL-17R) and related cytokines.

METHODS

The effect of proinflammatory cytokines [tumor necrosis factor α (TNFα) and IL-17] and Toll-like receptor (TLR) ligands [poly(I:C) and lipopolysaccharide (LPS)] on IL-17R expression and IL-12 and IL-23 production was studied in osteoarthritis (OA)- and rheumatoid arthritis (RA)-FLS, involved in Th1/Th17 differentiation. The effect of VIP was also determined. IL-17RA, IL-17RC, IL-12p35 and IL-23p19 expression was measured by real-time polymerase chain reaction. IL-12 and IL-23 protein levels were measured by ELISA in supernatant cultures.

RESULTS

TNFα, LPS and poly(I:C) induced an increase in IL-17RA in RA-FLS, whereas TNFα, TNFα plus IL-17 and poly(I:C) enhanced IL-17RC transcripts in FLS. VIP diminished the upregulated expression of IL-17RA in RA-FLS following TNFα and poly(I:C). TNFα, LPS and poly(I:C) increased IL-12 and IL-23 levels in cells derived from patients presenting both pathologies. However, IL-17A DECREASED IL-12 AND AUGMENTED IL-23. VIP DECREASED IL-12P35 MRNA UPREGULATION BY POLY(I:C) AND IL-23P19 TRANSCRIPTS IN LPS-TREATED FLS.

CONCLUSIONS

Inflammatory cytokines and TLR ligands modulate IL-17R, IL-12 and IL-23 possibly favoring the cross talk between FLS and Th1/Th17 cells. The ability of VIP to counteract the enhancing effect of proinflammatory molecules on IL-17R and the IL-12 family of cytokines corroborates and amplifies the beneficial effect of this endogenous neuroimmunopeptide in rheumatic diseases.

Differential effects of chlorogenic acid on various immunological parameters relevant to rheumatoid arthritis

Despite chlorogenic acid (CGA) being widely present in nature, particularly in the human diet, there is very little information regarding its pharmacological activities. The present investigation was carried out to investigate the antiarthritic activities of this compound in adjuvant induced-arthritis in male Wistar rats, and to explore the underlying mechanisms of actions in view of immunological responses. We observed that CGA effectively controlled the total (CD3) and differentiated (CD4 and CD8) T cells count at the dose of 40 mg/kg. We also assessed the effect on co-stimulatory molecules (CD28, CD80/86) and found that CGA efficiently suppressed CD80/86 but failed to bring any changes in the CD28 count, whereas ibuprofen (standard drug) resulted in highly significant inhibition of both. We next examined the effect on CD4⁺ T cells specific Th1/Th2 cytokines by flow cytometry and observed that CGA suppressed the Th1 cytokines in a highly significant manner but elevated Th2 cytokines with dose dependence. Results of the present investigation suggest that CGA is a potent antiarthritic agent.

Circulating cytokine profiles and their relationships with autoantibodies, acute phase reactants, and disease activity in patients with rheumatoid arthritis

Our objective was to analyse the relationship between circulating cytokines, autoantibodies, acute phase reactants, and disease activity in DMARDs-naïve rheumatoid arthritis (RA) patients (n = 140). All cytokines were significantly higher in the RA cohort than in healthy controls. Moderate-to-strong positive intercorrelations were observed between Th1/Th2/macrophage/fibroblast-derived cytokines. RF correlated significantly with IL-1β, IL-2, IL-4, IL-10, IL-12, G-CSF, GM-CSF, IFN-γ, and TNF (P < .0001), and aCCP and aMCV with IL-1β, IL-2, IL-4, and IL-10 (P < .0002), while IL-6 correlated best with the acute phase reactants, CRP, and SAA (P < .0001). In patients with a DAS28 score of ≥5.1, IFN-γ, IL-1β, IL-1Ra, TNF, GM-CSF, and VEGF were significantly correlated (P < .04–.001) with high disease activity (HDA). Circulating cytokines in RA reflect a multifaceted increase in immune reactivity encompassing Th1 and Th2 cells, monocytes/macrophages, and synovial fibroblasts, underscored by strong correlations between these cytokines, as well as their relationships with RF, aCCP, and aMCV, with some cytokines showing promise as biomarkers of HDA.

Antiinflammatory effects of Epimedium brevicornum water extract on lipopolysaccharide-activated RAW264.7 macrophages

Epimedium brevicornum Maxim (Berberidaceae) possesses estrogenic properties. It is one of the most widespread herbal remedies used in Oriental medicine. The present study investigated the effects of Epimedium brevicornum water extract (EB) on proinflammatory mediators secreted from lipopolysaccharide (LPS)-induced RAW264.7 macrophages. EB significantly inhibited the production of nitric oxide (NO), interleukin (IL)-3, IL-10, IL-12p40, interferon-inducible protein-10, keratinocyte-derived chemokine, vascular endothelial growth factor, monocyte chemotactic protein-1 and granulocyte macrophage-colony stimulating factor in LPS-induced RAW264.7 cells at concentrations of 25, 50, 100 and 200 μg/mL (p < 0.05). These results suggest that EB has antiinflammatory activity related to its inhibition of NO, cytokine, chemokine and growth factor production in macrophages.

Ustekinumab: an evidence-based review of its effectiveness in the treatment of psoriasis

Introduction:

Psoriasis is a chronic inflammatory skin disease affecting approximately 2% to 3% of the population worldwide. Discoveries over the past 3 to 5 years have significantly altered our view of psoriasis as primarily a T-cell mediated condition. The most recent research has demonstrated the essential role of specific cytokines in the development of this complex disease, including TNF-α, interleukin-23 (IL-23), and potentially, IL-22. These are all part of a newly defined autoimmune pathway directed by specialized T cells called Th17 helper T cells. Ustekinumab is a fully human monoclonal antibody that targets IL-12 and IL-23, thus targeting both Th1 and Th17 arms of immunity. It has a promising efficacy and safety profile that not only represents a valuable treatment alternative, but also a continuation in our constantly evolving understanding of this disorder.

Aims:

To review the emerging evidence supporting the use of ustekinumab in the management of moderate to severe plaque psoriasis.

Evidence review:

There is clear evidence that ustekinumab is effective in the treatment of moderate to severe psoriasis. Phase III trials (PHOENIX 1 and 2) demonstrated a statistically significant difference between Psoriasis Area and Severity Index (PASI) 75 responses achieved by patients receiving ustekinumab, given as a 45 mg or 90 mg subcutaneous injection every 12 weeks, than their placebo counterparts. Treatment with this novel agent resulted in a rapid onset of action, with over 60% of treated patients attaining Physician’s Global Assessment (PGA) scores of “cleared” or “minimal” by week 12. Quality of life assessments paralleled clinical improvements.

Clinical potential:

Ustekinumab is an effective and efficient therapeutic option for patients with moderate to severe psoriasis. Although further studies are required to establish ustekinumab’s place in the therapy of psoriasis, with its convenient dosing schedule and rapid onset of action, this drug could provide a great addition to the current therapeutic armamentarium available for psoriatic patients.

The IL-12 Role in Donor Cell Engraftment in a Murine Model of Semiallogenic GVH Disease with Signs of Autoimmune Disease

We analyzed the IL-12 effect in an autoimmune disease induced in a semiallogenic murine model of graft-vs-host disease (GVHD) Balb/c semiallogenic lymphoid cells i.v. infected in hybrid mice (Balb/c x A/J) F1 (CAF). IL-12 was administered 1 h before cell transplantation following two different protocols: (a) injecting 2 microg of mrIL-12 (murine recombinant IL-12) per mouse before the first semiallogenic cell injection; or (b) injecting the 2 microg of mrIL-12 fractionated in 5 days. ATh1 response was produced but an acute GVHD did not appear although differences in class I and II major histocompatibility complex (MHC) antigens were present. Four days after the semiallogenic cell transfer, IL-12 treated mice showed a marked reduction in the percent of spleen B cells compared with CAF1 control and CAF1 + Balb/c GVHD mice. After 5-6 months of follow-up, the donor cell chimerism increased significantly in spleen (70 +/- 31 vs. 43 +/- 31%) and in thymus. Flow cytometry of spleen lymphocytes demonstrated that donor chimerism was made up of TCD4, TCD8 and B lymphocytes and was higher in animals injected with IL-12. Moreover, CD8 T lymphocytes were 100% donor origin in the IL-12-injected group of GVHD animals and 50% origin in the IL-12-non-injected CAF1 + Balb/c group of animals. This paper shows that: (1) IL- 12 may play a role in the mechanisms of donor cell engraftment, probably produced by a CTL donor anti-host mechanism; (2) no acute GVHD was induced in spite of class I and II MHC differences; (3) IL-12 did not show any effect on the AR-like clinical signs of disease developed in this model of GVHD although histological subclinical signs were less frequent, and no glomerulonephritis was detected in the IL-12-treated GVHD mice.

Signal transducer and activation of transcription (STAT) 4beta, a shorter isoform of interleukin-12-induced STAT4, is preferentially activated by estrogen

Estrogen, a natural immunomodulatory compound, has been shown to promote the induction of a prototype T helper 1 cytokine, interferon (IFN)-gamma, as well as to up-regulate IFNgamma-mediated proinflammatory molecules (nitric oxide, cyclooxygenase 2, monocyte chemoattractant protein 1). Because IL-12 is a major IFNgamma-inducing cytokine, in this study we investigated whether estrogen treatment of wild-type C57BL/6 mice alters IL-12-mediated signaling pathways. A recent study has shown that IL-12 activates two isoforms of signal transducer and activation of transcription (STAT) 4, a normal-sized (full-length STAT4alpha) and a truncated form (STAT4beta). Interestingly, we found that estrogen treatment preferentially up-regulates the phosphorylation of STAT4beta in splenic lymphoid cells. Time kinetic data showed the differential activation of STAT4beta in splenic lymphoid cells from estrogen-treated mice, but not in cells from placebo controls. The activation of STAT4beta was mediated by IL-12 and not IFNgamma because deliberate addition or neutralization of IL-12, but not IFNgamma, affected the activation of STAT4beta. In contrast to IL-12-induced activation of STAT4beta in cells from estrogen-treated mice, STAT4alpha was not increased, rather it tended to be decreased. In this context, STAT4alpha-induced p27(kip1) protein was decreased in concanavalin A + IL-12-activated lymphocytes from estrogen-treated mice only. By using the in vitro DNA binding assay, we confirmed the ability of pSTAT4beta to bind to the IFNgamma-activated sites (IFNgamma activation sequences)/STAT4-binding sites in estrogen-treated mice. Our data are the first to show that estrogen apparently has selective effects on IL-12-mediated signaling by preferentially activating STAT4beta. These novel findings are likely to provide new knowledge with regard to estrogen regulation of inflammation.

Ustekinumab, a human interleukin 12/23 monoclonal antibody, for psoriatic arthritis: randomised, double-blind, placebo-controlled, crossover trial

BACKGROUND

Since some patients with psoriatic arthritis do not respond to typical drug treatments, alternatives are needed. Findings suggest that interleukins 12 and 23 might affect clinical symptoms and pathological joint changes of psoriatic arthritis. Ustekinumab is a human monoclonal antibody that inhibits receptor-binding of these cytokines. We aimed to assess the efficacy and safety of ustekinumab for psoriatic arthritis in this phase II study.

METHODS

We undertook a double-blind, randomised, placebo-controlled, crossover study at 24 sites in North America and Europe. Patients with active psoriatic arthritis were randomly allocated via interactive voice response system to either ustekinumab (90 mg or 63 mg) every week for 4 weeks (weeks 0-3) followed by placebo at weeks 12 and 16 (n=76; Group 1) or placebo (weeks 0-3) and ustekinumab (63 mg) at weeks 12 and 16 (n=70; Group 2). The first 12 weeks of the study were placebo-controlled. Masking was maintained to week 16, and patients were followed up to week 36 [corrected]. The primary endpoint was ACR20 response at week 12. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00267956.

FINDINGS

At week 12, 32 (42%) patients in Group 1 and ten (14%) in Group 2 achieved the primary endpoint (difference 28% [95% CI 14.0-41.6]; p=0.0002). Of 124 (85%) participants with psoriasis affecting 3% or more body surface area, 33 of 63 (52%) in Group 1 and three of 55 (5%) in Group 2 had a 75% or greater improvement in psoriasis area and severity index score at week 12 (47% [33.2-60.6]; p<0.0001). During the placebo-controlled period (weeks 0-12), adverse events arose in 46 (61%) patients in Group 1 and 44 (63%) in Group 2; serious adverse events were recorded in three (4%) Group 2 patients (none in Group 1).

INTERPRETATION

Ustekinumab significantly reduced signs and symptoms of psoriatic arthritis and diminished skin lesions compared with placebo, and the drug was well tolerated. Larger and longer term studies are needed to further characterise ustekinumab efficacy and safety for treatment of psoriatic arthritis.

Evidence that cytokines play a role in rheumatoid arthritis

A large number of cytokines are active in the joints of patients with rheumatoid arthritis (RA). It is now clear that these cytokines play a fundamental role in the processes that cause inflammation, articular destruction, and the comorbidities associated with RA. Following the success of TNF-alpha blockade as a treatment for RA, other cytokines now offer alternative targets for therapeutic intervention or might be useful as predictive biomarkers of disease. In this Review, we discuss the biologic contribution and therapeutic potential of the major cytokine families to RA pathology, focusing on molecules contained within the TNF-alpha, IL-1, IL-6, IL-23, and IL-2 families.

Cytokine-induced human IFN-gamma-secreting effector-memory Th cells in chronic autoimmune inflammation

T-helper (Th) cells activated by cytokines in the absence of T-cell receptor ligation are suspected to participate in inflammatory processes by production of interferon-gamma (IFN-gamma). Still, the relevance of such a mechanism has not been addressed in humans. Here we demonstrate that a subset of human effector-memory Th cells expressing functional interleukin-12R (IL-12R), IL-18Ralpha, and CCR5 ex vivo can be induced to secrete IFN-gamma by cytokines signaling via the IL-2R common gamma-chain in combination with IL-12 and IL-18. Cytokine-driven IFN-gamma production depends on JAK3- and p38 mitogen-activated kinase signals and is sensitive to suppression by CD25(++) regulatory T cells. Contrary to IFN-gamma(+) Th cells induced upon antigen-specific stimulation, their cytokine-activated counterparts characteristically lack expression of costimulator 4-1BB (CD137). Strikingly, the majority of Th cells infiltrating inflamed joints of rheumatoid arthritis patients is equipped with receptors prerequisite for cytokine-induced IFN-gamma secretion. Among these cells, we detected a substantial fraction that secretes IFN-gamma directly ex vivo but lacks 4-1BB expression, indicating that cytokine-induced IFN-gamma(+) Th cells operate in autoimmune inflammation. Our data provide a rationale for how human effector-memory Thcells can participate in perpetuating inflammatory processes in autoimmunity even in the absence of T-cell receptor ligation.

The clinical role of IL-23p19 in patients with rheumatoid arthritis

OBJECTIVE

To determine the clinical implications of the over-expression of synovial and circulating interleukin (IL)-23p19 and the correlation between IL-23p19 and other cytokines such as IL-17, tumour necrosis factor (TNF)alpha, and IL-1beta in rheumatoid arthritis (RA).

METHODS

Synovial fluid (SF) and sera of 22 patients with RA were obtained during knee arthrocentesis and stored at -20 degrees C. Tender/swollen joint counts, 100-mm visual analogue scale (VAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), and antibodies to cyclic citrullinated peptide (anti-CCP Ab) were measured. Bony erosions were determined by X-rays. Serum and SF IL-23p19, IL-17, TNFalpha, and IL-1beta concentrations were measured by sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

The concentration of IL-23p19 correlated with the concentration of IL-17 in SF and sera, and with the concentrations of TNFalpha and IL-1beta in sera. SF IL-23p19 concentration was higher in patients who had bony erosions than those who had not. However, there was no correlation between IL-23p19 concentrations and other clinical parameters of RA.

CONCLUSION

Upregulated IL-23p19 in SF might be involved in joint destruction in RA through interplay with other cytokines such as IL-17, TNFalpha, and IL-1beta.

Emerging cytokine targets in rheumatoid arthritis

PURPOSE OF REVIEW

The utility of cytokines as therapeutic targets in rheumatoid arthritis has been unequivocally demonstrated by the success of tumour necrosis factor blockade in clinical practice. Partial and non-responses to tumour necrosis factor blocking agents, however, together with the increasing clinical drive to remission induction, requires that further therapeutic targets be identified.

RECENT FINDINGS

Numerous cytokine activities with pathogenetic potential have now been demonstrated in rheumatoid arthritis synovial membrane, including members of the IL-1 superfamily and the IL-12 superfamily. Continued efforts are ongoing to target IL-6 and IL-15 in clinical trials with promising data emerging. There is particular interest in the biology of IL-17 and of the recently described IL-32 as critical effector mediators.

SUMMARY

Novel cytokine activities are emerging on an ongoing basis. There remain difficulties in ascribing the optimal regulatory hierarchy for given moieties on the basis of existing preclinical model systems. This in turn poses novel challenges in determining which cytokines represent the best therapeutic targets.

Serum Amyloid A Binding to Formyl Peptide Receptor-Like 1 Induces Synovial Hyperplasia and Angiogenesis

Serum amyloid A (SAA) is a major acute-phase reactant, and has been demonstrated to mediate proinflammatory cellular responses. Although SAA has been used as an indicator for a variety of inflammatory diseases, the role of SAA in synovial hyperplasia and proliferation of endothelial cells, a pathological hallmark of rheumatoid arthritis (RA), has yet to be elucidated. In this study, we have demonstrated that SAA promotes the proliferation of human fibroblast-like synoviocytes (FLS). In addition, SAA protects RA FLS against the apoptotic death induced by serum starvation, anti-Fas IgM, and sodium nitroprusside. The activity of SAA appears to be mediated by the formyl peptide receptor-like 1 (FPRL1) receptor, as it was mimicked by the WKYMVm peptide, a specific ligand for FPRL1, but completely abrogated by down-regulating the FPRL1 transcripts with short interfering RNA. The effect of SAA on FLS hyperplasia was shown to be caused by an increase in the levels of intracellular calcium, as well as the activation of ERK and Akt, which resulted in an elevation in the expression of cyclin D1 and Bcl-2. Moreover, SAA stimulated the proliferation, migration, and tube formation of endothelial cells in vitro, and enhanced the sprouting activity of endothelial cells ex vivo and neovascularization in vivo. These observations indicate that the binding of SAA to FPRL1 may contribute to the destruction of bone and cartilage via the promotion of synoviocyte hyperplasia and angiogenesis, thus providing a potential target for the control of RA.

Plasma interleukin-10 and interleukin-12 levels in patients with familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent attacks of fever, polyserositis and arthritis. A vast array of cytokines were analysed in these patients, however, little is known about the pro-inflammatory cytokine interleukin (IL)-12. Plasma IL-12 and IL-10 were measured in 24 patients with FMF (19 active, 5 inactive) and 18 healthy controls by ELISA. From 15 active patients blood was also drawn in attack-free period. Mean plasma IL-12 levels of the FMF patients (mean +/- SEM, 6.84+/-3.59 pg/ml) were higher than the controls (0.13+/-0.09 pg/ml, P < 0.001). Mean IL-12 levels of active (7.02+/-5.23 pg/ml) and inactive patients (6.89+/-5.61 pg/ml) were comparable, and they were higher compared to controls (P < or = 0.001). Mean plasma IL-10 levels of the total FMF patients (3.01+/-1.53 pg/ml) were also higher than the controls (P = 0.024). Patients had higher IL-10 levels in attacks (3.83+/-2.02 pg/ml) compared to levels when they were in remission (1.86+/-1.59 pg/ml, P = 0.046). Significantly elevated IL-12 levels in FMF patients regardless of activity may suggest the presence of a pro-inflammatory state also in the inactive period of FMF. Significant increase in IL-10 levels in FMF group may point to the compensatory suppression of inflammation in active periods of the disease.

Pathophysiological roles for IL-18 in inflammatory arthritis

IL-18 is a unique cytokine with prominently wide spectrum biological actions. Among these, its IFN-gamma/TNF-alpha-inducing activity primarily contributes to the development of various inflammatory diseases including inflammatory arthritis. IL-18 levels correlate with the disease activity of rheumatoid arthritis (RA) and osteoarthritis (OA). IL-18 is spontaneously released from RA synovial cells and OA chondrocytes and seems to participate in the development of the inflammatory and destructive alterations of joints via induction of TNF-alpha, a potent effector molecule. TNF-alpha, in turn, increases IL-18 expression in RA synovial cells. Recent clinical trials have revealed the efficacy of TNF-alpha in RA with a reduction in circulatory IL-18 levels. These may implicate the positive circuit between IL-18 and TNF-alpha for development of RA. As IL-18-deficient mice evade collagen-induced arthritis in a mouse RA model, therapeutics targeting IL-18 may be beneficial against RA/OA. Here, the authors review the possible roles of IL-18 in inflammatory arthritis.