Interleukin-6 Receptor Antibody Research Articles

Targeting interleukin-6 receptor inhibits preterm delivery induced by inflammation

Intrauterine infection is still a common trigger of preterm delivery (PTD) and also a determinant risk factor for the subsequent development of neurodevelopmental abnormalities in neonates. In this study, we examined the expressional pattern of various inflammatory cytokines such as interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) in placentae complicated with severe chorioamnionitis (CAM) and found that IL-6 is mainly expressed in macrophages in villous mesenchyme by immunohistochemical analysis with anti-CD-68 antibody. Using an experimental lipopolysaccharide (LPS)-induced PTD model, the therapeutic potential of targeting this cytokine was investigated. Anti-IL-6 receptor antibody (MR16-1) was delivered 6 h before LPS treatment. Mice in the MR16-1 group had a significantly lower rate of PTD (17%) than in the controls (53%, P = 0.026). As a result, MR16-1 treatment significantly prolonged the gestational period (control; 18.4 ± 1.7d, MR16-1; 19.8 ± 1.5d, P = 0.007) without any apparent adverse events on the mice and their pups. In primary human amniotic epithelial cells, pretreatment with a humanized anti-human IL-6 receptor antibody, tocilizumab, significantly inhibited the production of prostaglandin E2 induced by IL-6. In conclusion, IL-6 was strongly expressed mainly in macrophages in villous mesenchyme in placentae complicated with CAM. Anti-IL-6R antibody significantly decreased the rate of PTD in LPS-induced inflammatory model in mice, and inhibited PGE2 production from human primary amniotic epithelial cells. Targeting IL-6 signaling could be a promising option for the prevention of PTD and needs to be further explored for future clinical application.

Effect of interleukin-6 receptor blockade on feto-maternal outcomes in a rat model of intrauterine inflammation

To study the effect of blocking the inflammatory cascade with interleukin-6 receptor antibody (anti-IL-6R) on feto-maternal outcomes in a rat model. Pregnant Sprague-Dawley rats (n = 38) were injected intraperitoneally (day 22) (control, anti-IL-6R 30 μg/kg, lipopolysaccharide [LPS] 250 μg/kg or 500 μg/kg alone or combined with anti-IL-6R) followed by preterm caesarian performed 12 h later. Resuscitated pups (n = 179) were given to surrogate mothers. Primary outcomes were maternal and pup mortality. Fifty percent of pregnant rats died after LPS 500 μg/kg + anti-IL-6R injection but none in other groups. Neonatal mortality at 24 h was 63% and 86% in LPS 500 μg/kg and LPS 500 μg/kg + anti-IL-6R groups, respectively (P < 0.05). Surviving pups in the latter group presented a severe growth deficit compared to the LPS 500 μg/kg group (P < 0.01) and showed no difference with controls for open field testing. Maternal cytokine analysis after LPS 500 μg/kg + anti-IL-6R injection showed a tendency for increased IL-1 production (P = 0.06). Paradoxically, the association of pregnancy, inflammation and anti-IL-6R increases the inflammatory effects of LPS.

Husten, Atemnot und B-Symptome bei einer 40-jährigen Frau

Multicentric Castleman's disease (MCD) is a rare polyclonal lymphoproliferative disorder that is typically accompanied by an overproduction of circulating cytokines (mainly interleukin-6). We here report the case of a 40-year-old HIV-negative woman with pulmonary manifestation of MCD. There is no standard treatment for MCD. In our patient, various treatment courses with immunomodulatory drugs were unsuccessful. Finally, treatment with the interleukin-6 receptor antibody tocilizumab has resulted in continual clinical improvement over the last 5 years.

SAT0139 Importance of Concomitant MTX Use During Treatment with Tocilizumab in Patients with Rheumatoid Arthritis

BackgroundNow, predictive factors at baseline for the good outcome of treatment with biologics are very important not to waste time to treatment goal “remission”.ObjectivesThe aims of this study are 1)...

FRI0054 IL-6 negatively regulates osteoblast differentiation through ERK pathway in vitro

BackgroundInterleukin-6 (IL-6), a potent inflammatory cytokine, plays a key role in the pathogenesis of rheumatoid arthritis (RA), including osteoporosis not only in inflamed joints but possibly also in whole body....

AB0158 Anti-interleukin-6 receptor antibody suppresses loss of trabecular bone volume in mice with glucose-6-phosphate isomerase-induced arthritis

BackgroundOsteoporosis can lead to increased risk of fractures, which are associated with increased morbidity and mortality. The incidence rate of osteoporosis in patients with RA is several times that in...

AB0330 Long-term administration of tocilizumab increases the structural remission rate year by year and continuously inhibits radiographic progression: 3 year results from michinoku tocilizumab study group

BackgroundThe inhibition of radiographic progression is one of the important therapeutic goals in patients with rheumatoid arthritis (RA). Tocilizumab (TCZ) is a humanized anti-human IL-6 receptor antibody and it has...

THU0079 Anti-IL-6 Receptor Antibody Suppresses Systemic Bone Loss by not Only Normalizing Bone Resorption but also Enhancing Bone Formation in a Mouse Model of Collagen-Induced Arthritis

BackgroundPatients with rheumatoid arthritis (RA) have a high risk of osteoporosis and osteoporotic fracture. In primary osteoporosis (either high bone turnover osteoporosis [type I] or low bone turnover osteoporosis [type...

THU0343 No Upregulation of IL-6 at Different Sites in Facet Joints of Patients with Ankylosing Spondylitis Compared to Controls

BackgroundThe analysis of interleukin-6 serum levels in patients with ankylosing spondylitis (AS) have indicated that IL-6 might be a proinflammatory cytokine in AS patients. However, a placebo-controlled trail using Tocilizumab...

AB0697 Tocilizumab in systemic and polyarticular juvenile idiopathic arthritis: results of a retrospective evaluation in real-life clinical practice

BackgroundInterleukin-6 (IL-6) is a proinflammatory cytokine that is overexpressed in patients with Juvenile Idiopathic Arthritis (JIA). A key role of this cytokine in the pathogenesis of such group of chronic...

FRI0048 Interleukin-6 increases the number of osteoclast precursors in femur bone marrow via up-regulation of sphingosine-1-phosphate receptor 2 in inflammatory arthritic mice

BackgroundRheumatoid arthritis (RA) is associated with an increased risk of osteoporosis and fractures. A number of factors such as menopause, glucocorticoid use, and high RA disease activity are associated with...

AB0308 Optimal timing for tocilizumab administration to patients with rheumatoid arthritis in japan based on a cost-effectiveness analysis using the iorra cohort study

BackgroundRheumatoid arthritis (RA) imposes a considerable economic burden on societies. Early, adequate control of disease activity can prevent permanent disability and decrease the overall costs of treatment. In clinical studies,...

Ramsay Hunt syndrome associated with tocilizumab therapy in rheumatoid arthritis: a case report

Ramsay Hunt syndrome associated with tocilizumab therapy in rheumatoid arthritis: a case report

Chemotherapy Alters Monocyte Differentiation to Favor Generation of Cancer-Supporting M2 Macrophages in the Tumor Microenvironment

Current therapy of gynecologic malignancies consists of platinum-containing chemotherapy. Resistance to therapy is associated with increased levels of interleukin (IL)-6 and prostaglandin E2 (PGE(2)), 2 inflammatory mediators known to skew differentiation of monocytes to tumor-promoting M2 macrophages. We investigated the impact of cisplatin and carboplatin on 10 different cervical and ovarian cancer cell lines as well as on the ability of the tumor cells to affect the differentiation and function of cocultured monocytes in vitro. Treatment with cisplatin or carboplatin increased the potency of tumor cell lines to induce IL-10-producing M2 macrophages, which displayed increased levels of activated STAT3 due to tumor-produced IL-6 as well as decreased levels of activated STAT1 and STAT6 related to the PGE(2) production of tumor cells. Blockade of canonical NF-κB signaling showed that the effect of the chemotherapy was abrogated, preventing the subsequent increased production of PGE(2) and/or IL-6 by the tumor cell lines. Treatment with the COX-inhibitor indomethacin and/or the clinical monoclonal antibody against interleukin-6 receptor (IL-6R), tocilizumab, prevented M2-differentiation. Importantly, no correlation existed between the production of PGE(2) or IL-6 by cancer cells and their resistance to chemotherapy-induced cell death, indicating that other mechanisms underlie the reported chemoresistance of tumors producing these factors. Our data suggest that a chemotherapy-mediated increase in tumor-promoting M2 macrophages may form an indirect mechanism for chemoresistance. Hence, concomitant therapy with COX inhibitors and/or IL-6R antibodies might increase the clinical effect of platinum-based chemotherapy in otherwise resistant tumors.

Abstract 4712: Chemotherapy-enhanced NFkB pathway activation in gynecological cancers increases the differentiation of monocytes to M2 macrophages instead of dendritic cells.

Abstract Current therapy of gynecological malignancies consists of platinum-containing chemotherapy. Resistance to therapy is associated with increased levels of interleukin-6 (IL-6) and prostaglandin E2 (PGE2), two inflammatory mediators known to skew differentiation of monocytes to tumor-promoting M2 macrophages. We investigated the impact of cisplatin and carboplatin on 10 different cervical and ovarian cancer cell lines as well as on the differentiation and function of monocytes cultured in the presence of these tumor cells in vitro. Treatment with cisplatin or carboplatin increased the potency of tumor cell lines to induce IL10-producing M2 macrophages which displayed increased levels of activated signal transducer and activator of transcription-3 (STAT3) due to tumor-produced IL-6 as well as decreased levels of activated STAT1 and STAT6 related to the PGE2-production of tumor cells. Blockade of canonical NFκB signaling showed that the effect of chemotherapy depended on the enhanced activation of the NFκB pathway and subsequent increased production of PGE2 and IL-6 by tumor cell lines originally producing these factors. Treatment with cyclooxygenase (COX)-inhibitor indomethacin and/or the clinical monoclonal antibody against IL-6 receptor (IL-6R), tocilizumab, prevented M2-differentiation. Importantly, no correlation existed between the production of PGE2 or IL-6 by cancer cells and their resistance to chemotherapy induced death, indicating that other mechanisms underlie the reported chemoresistance of tumors producing these factors. Our data suggests that a chemotherapy-mediated increase in tumor-promoting M2 macrophages may form an indirect mechanism for chemoresistance. Hence, concomitant therapy with COX-inhibitors and/or IL-6R antibodies might increase the clinical effect of platinum-based chemotherapy in otherwise resistant tumors. Citation Format: Sjoerd H. Van Der Burg, Eveline M. Dijkgraaf, Marij J.P. Welters, Judith R. Kroep. Chemotherapy-enhanced NFkB pathway activation in gynecological cancers increases the differentiation of monocytes to M2 macrophages instead of dendritic cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4712. doi:10.1158/1538-7445.AM2013-4712

Abstract 3736: IL6 feedback loop regulates breast cancer stem cells which mediate trastuzumab resistance.

Abstract The development of HER2 targeting agents such as trastuzumab and lapatinib represents one of the greatest achievements in clinical oncology demonstrating the effectiveness of molecularly targeted therapeutics (2). Despite the clinical benefits of trastuzumab in improving progression free and overall survival, majority of patients demonstrate “intrinsic” resistance or develop “acquired” resistance within one-to-two years. Although inactivation of the PTEN gene has been implicated in the development of resistance to the HER2 targeting antibody trastuzumab, the mechanisms mediating this resistance remain to be investigated. We generated trastuzumab resistant cells by knocking down PTEN expression in HER2 overexpressing breast cancer cell lines and demonstrated that development of trastuzumab resistance in these cells is mediated by activation of an IL6 inflammatory feedback loop leading to expansion of breast cancer stem cell (CSC) population. We and others previously demonstrated that cytokines including IL6 and IL8 regulates breast cancer stem cell self-renewal. Furthermore, elevated serum levels of these cytokines in breast cancer patients strongly correlated with metastatic disease and therapeutic resistance. We therefore hypothesized that activation of IL6 feedback loop may mediate trastuzumab resistance. Utilizing these models, we demonstrated that long term trastuzumab treatment generates highly enriched CSCs which display an EMT phenotype secreting over 100-fold more IL6 than parental cells. Recombinant IL6 or conditioned medium from high-IL6 secreting cells resulted in trastuzumab resistance in parental PTEN wild type cells expanding CSCs with EMT phenotype characterized by the CD44+/CD24- expression and EMT gene signature. An IL6 receptor antibody interrupted this inflammatory feedback loop reducing the cancer stem cell population resulting in decreased tumor growth and metastasis in mouse xenographs. These studies have important clinical implications demonstrating that trastuzumab resistance may be mediated by an IL-6 inflammatory loop and suggest that blocking this loop represents a novel strategy to overcome trastuzumab resistance. . Citation Format: April L. Davis, Hasan Korkaya, Maria Ouzounova, Fayaz Malik, Gwangil Kim, Ahmed A. Quraishi, Suling Liu, Shawn G. Clouthier, Max S. Wicha. IL6 feedback loop regulates breast cancer stem cells which mediate trastuzumab resistance. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3736. doi:10.1158/1538-7445.AM2013-3736

The Effects of Interleukin‐6 Signal Blockade on Immune System, Reproductive and Skeletal Development in Juvenile Mice

Interleukin-6 (IL-6) is involved in the pathogenesis of multiple disorders, including juvenile autoimmune diseases. IL-6 participates in a broad spectrum of physiological events, and the IL-6 receptor (IL-6R) is widely distributed across multiple organs. The interrelationship of development phases in juveniles together with organs involved in IL-6 signaling called for evaluations of anti-IL-6R antibody induced effects in a juvenile mouse model to assess the safety of such an approach in human juvenile arthritis. Here we show that naive mice in which IL-6 signals have been transiently blocked during the juvenile period develop normally. The fatal immunogenic reactions recorded earlier by repeated administration of the chosen rat anti-mouse IL-6R antibody, MR16-1, to mice were avoided successfully by application of a high loading dose followed by lower maintenance doses, with the support of modeling data. The high loading-dose regimen enabled us to conduct assessments without any major interference due to immunogenicity. Transient and complete inhibition of IL-6 signals from postnatal days 22 to 79 in mice exhibited no biologically important changes in sexual maturation or development of immune and skeletal systems. Although tendencies toward reductions of peripheral blood T-cell counts were observed, normal levels of antigen-specific IgG/IgM antibody productions indicating sufficient immunological functions were confirmed. Our results demonstrate that blockage of IL-6R by the neutralizing antibody does not affect juvenile development. This may be in part due to the generation or existence of compensatory pathways in the whole body system.

Inhibition of IL-6 signaling: A novel therapeutic approach to treating spinal cord injury pain

To characterize the contribution of interleukin-6 (IL-6) to spinal cord injury pain (SCIP), we employed a clinically relevant rat contusion model of SCIP. Using Western blots, we measured IL-6 levels in lumbar segments (L1-L5), at the lesion site (T10), and in the corresponding lumbar and thoracic dorsal root ganglia (DRG) in 2 groups of similarly injured rats: (a) SCI rats that developed hind-limb mechanical allodynia (SCIP), and (b) SCI rats that did not develop SCIP. Only in SCIP rats did we find significantly increased IL-6 levels. Immunocytochemistry showed elevated IL-6 predominantly in reactive astrocytes. Our data also showed that increased production of IL-6 in hyperreactive astrocytes in SCIP rats may explain still-poorly understood astrocytic contribution to SCIP. To test the hypothesis that IL-6 contributes to mechanical allodynia, we treated SCIP rats with neutralizing IL-6 receptor antibody (IL-6-R Ab), and found that one systemic injection abolished allodynia and associated weight loss; in contrast to gabapentin, the analgesic effect lasted for at least 2weeks after the injection, despite the shorter presence of the Ab in the circulation. We also showed that IL-6-R Ab partially reversed SCI-induced decreases in the protein levels of the glutamate transporter GLT-1 12hours and 8days after Ab injection, which may explain the lasting analgesic effect of the Ab in SCIP rats. A link between reactive astrocytes IL-6-GLT-1 has not been previously shown. Given that the humanized IL-6-R Ab tocilizumab is Food and Drug Administration-approved for rheumatoid arthritis, we are proposing tocilizumab as a novel and potentially effective treatment for SCIP.

IL-6 attenuates trimethyltin-induced cognitive dysfunction via activation of JAK2/STAT3, M1 mAChR and ERK signaling network

We previously reported that interleukin (IL)-6 deficiency potentiates trimethyltin (TMT)-induced convulsive neurotoxicity. The purpose in this study was to investigate the molecular mechanism by which cytokines affect TMT-induced cognitive impairment. To accomplish this, we examined hippocampal changes in Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling in relation to cholinergic parameters after TMT treatment in mice genetically deficient in IL-6 (IL-6−/−), tumor necrosis factor-α (TNF-α−/−), or interferon-γ (IFN-γ−/−). The IL-6−/− mice were the most susceptible to TMT-induced cognitive dysfunction and exhibited significant decreases in JAK2/STAT3 signaling and M1 muscarinic acetylcholine receptor (mAChR) expression, as well as other cholinergic parameters, compared with wild-type (WT) animals. Recombinant IL-6 protein (rIL-6) significantly attenuated these impairments in TMT-treated IL-6−/− mice, whereas an IL-6 receptor antibody potentiated these impairments in TMT-treated WT animals. Inhibition of JAK2 with AG490 or inhibition of cholinergic signaling with the M1 mAChR antagonist dicyclomine counteracted the attenuating effects of rIL-6 on phosphorylated extracellular signal-regulated kinase (ERK) expression, or on cognitive impairment in TMT-treated IL-6−/− mice. However, neither AG490 nor dicyclomine significantly attenuated effects of rIL-6 on acetylcholinesterase values. Our results suggest that activation of JAK2/STAT3 signaling and upregulation of the M1 mAChR are essential components of IL-6-mediated memory improvement against TMT toxicity.

Tocilizumab for the Treatment of Patients With Refractory Takayasu Arteritis

Treatment of refractory Takayasu arteritis (TA) remains an unresolved clinical issue. Patients usually respond to glucocorticoid (GC) therapy, but often relapse on tapering of the GC dose. The aim of the present study was to assess the safety and efficacy of the interleukin-6 (IL-6) receptor antibody tocilizumab (TCZ) in patients with TA refractory to conventional therapies including GC. Four patients with TA who had shown GC resistance received TCZ infusions (8 mg/kg) every 4 weeks a total of at least 24 times (range, 24 to 51). Clinical symptoms, the serum levels of acute phase proteins and IL-6, GC dosage necessary to maintain remission, and cross-sectional imaging by enhanced CT and MRI were assessed. All patients achieved good clinical response and rapid normalization of the acute phase proteins such as C-reactive protein and serum amyloid A during the therapy with TCZ. The mean dosage of prednisolone could be reduced from 21.3 mg/day to 1.5 mg/day. Although the serum IL-6 level was transiently elevated in all patients after several TCZ infusions, it gradually recovered to the initial level. Along with the decrease of serum IL-6, two patients exhibited significant reduction in thickened arterial lesions. No drug-related adverse effects were noted. In this small group of patients with refractory TA, TCZ therapy was effective and well-tolerated. Further larger studies should be conducted to confirm this finding.