Modern anti-cytokine therapy of autoimmune diseases

The 12-Membered TNFR1 Peptide, as Well as the 16-Membered and 6-Membered TNF Peptides, Regulate TNFR1-Dependent Cytotoxic Activity of TNF

Understanding the exact mechanisms of the activation of proinflammatory immune response receptors is very important for the targeted regulation of their functioning. In this work, we were able to identify the sites of the molecules in the proinflammatory cytokine TNF (tumor necrosis factor) and its TNFR1 (tumor necrosis factor receptor 1), which are necessary for the two-stage cytotoxic signal transduction required for tumor cell killing. A 12-membered TNFR1 peptide was identified and synthesized, interacting with the ligands of this receptor protein's TNF and Tag7 and blocking their binding to the receptor. Two TNF cytokine peptides interacting with different sites of TNFR1 receptors were identified and synthesized. It has been demonstrated that the long 16-membered TNF peptide interferes with the binding of TNFR1 ligands to this receptor, and the short 6-membered peptide interacts with the receptor site necessary for the transmission of a cytotoxic signal into the cell after the ligands' interaction with the binding site. This study may help in the development of therapeutic approaches to regulate the activity of the cytokine TNF.

Visfatin and Rheumatoid Arthritis: Pathogenetic Implications and Clinical Utility

Objective:

Analysis and generalization of data related to visfatin involvement in the pathogenesis of inflammation at various stages of rheumatoid arthritis.

Data Synthesis:

Visfatin is an adipocytokine which has also been identified in non-adipose tissues. It influences directly on the maturation of B cells, which are involved in autoantibody production and T cell activation. Visfatin can promote inflammation via regulation of pro-inflammatory cytokines including TNF, IL-1β and IL-6. The concentration of circulating visfatin in rheumatoid arthritis patients is higher compared to healthy individuals. Several studies suggest that visfatin level is associated with rheumatoid arthritis activity, and its elevation may precede clinical signs of the relapse. In murine collagen-induced arthritis, visfatin levels were also found to be elevated both in inflamed synovial cells and in joint vasculature. Visfatin blockers have been shown to confer fast and long-term attenuation of pathological processes; however, most of their effects are transient. Other factors responsible for hyperactivation of the immune system can participate in this process at a later stage. Treatment of rheumatoid arthritis with a combination of these blockers and inhibitors of other mediators of inflammation can potentially improve treatment outcomes compared to current therapeutic strategies. Recent advances in the treatment of experimental arthritis in mice as well as the application of emerging treatment strategies obtained from oncology for rheumatoid arthritis management could be a source of novel adipokine-mediated anti-rheumatic drugs.

Conclusion:

The ongoing surge of interest in anticytokine therapy makes further study of visfatin highly relevant as it may serve as a base for innovational RA treatment.

Elevated serum levels of interleukin-1β and interleukin-33 in patients with systemic sclerosis in Chinese population

PURPOSE OF THE STUDY

Systemic sclerosis (SSc) is a multisystem autoimmune disease. Although the pathogenesis of the disease remains incompletely understood, some cytokines or growth factors which regulate SSc induction may be involved in the injury of endothelial cells and the modulation of leukocyte function. We aimed to perform this case-control study to determine serum levels of interleukin (IL)-1α, IL-1β, IL-18 and IL-33 and their associations with clinical manifestations in SSc patients.

MATERIALS AND METHODS

There were 56 patients with SSc and 56 healthy individuals who were recruited from local hospital between 2012 and 2014. Serum IL-1α, IL-1β, IL-18 and IL-33 levels were measured with specific enzyme-linked immunosorbent assay kits.

RESULTS

Univariate analysis revealed that serum IL-1β, IL-18 and IL-33 levels in SSc patients were significantly higher than that in healthy controls. After adjusting possible confounding factors (sex, age, smoking and drinking) by multivariable analyses, serum IL-1β levels (OR = 1.082; 95 % CI: 1.013-1.155) and serum IL-33 levels (OR = 1.100; 95 %CI: 1.022-1.185) were still related factors. There were interrelationships among the serum levels of IL-1α, IL-1β, IL-18 and IL-33 and these associations were not consistent in SSc patients and controls. No associations of serum IL-1α, IL-1β, IL-18 and IL-33 levels with clinical parameters were found.

CONCLUSION

IL-1β and IL-33 may contribute to the development of SSc. While there were no direct associations between these cytokines and disease manifestations, they still could be considered as serum markers of development of SSc. Further studies are required to validate this incipient data.

Targets of immunomodulation in bacterial endophthalmitis

Bacterial infection of the posterior segment of the eye (endophthalmitis) leads to a robust host response that often results in irreversible damage to the layers of the retina, significant vision loss, and in some patients, enucleation of the globe. While a great deal of effort has gone into understanding the role of bacterial virulence factors in disease initiation and propagation, it is becoming increasingly clear that the host response to infection plays a major role in causing the damage associated with endophthalmitis. Researchers have identified the host receptors which detect infecting organisms and initiate the cascade of events that result in inflammation. This inflammation may damage nonregenerative tissues of the eye while attempting to clear the infection. Both Gram-positive and Gram-negative bacteria can cause endophthalmitis. These organisms initiate an immune response by activating toll-like receptor (TLR) pathways. Once an inflammatory response is initiated, the expression of immunomodulators, such as proinflammatory chemokines and cytokines, affect the recruitment of PMNs and other inflammatory cells into the eye. We and others have reported that knockout mice that do not express specific inflammatory pathways and molecules have an attenuated response to infection and retain significant retinal function. These findings suggest that host immune mediators are important components of the response to infections in the posterior segment of the eye, and the timing and level of their production may be related to the severity of the damage and the ultimate visual outcome. If that is the case, a better understanding of the complex and often redundant role of these pathways and inflammatory mediators may identify host molecules as potential anti-inflammatory therapeutic targets. This review highlights potential anti-inflammatory targets during acute inflammation in endophthalmitis, compares and contrasts those with findings in other models of ocular inflammation, and translates current immunomodulatory strategies for other types of infection and inflammation to this blinding disease. Given the poor visual outcomes seen in patients treated with antibiotics alone or in combination with corticosteroids, immunomodulation in addition to antibiotic therapy might be more effective in preserving vision than current regimens.

Biofunctional Nanofibrous Substrate for Local TNF-Capturing as a Strategy to Control Inflammation in Arthritic Joints

Rheumatoid arthritis (RA) is an autoimmune disease that affects the synovial cavity of joints, and its pathogenesis is associated with an increased expression of pro-inflammatory cytokines, namely tumour necrosis factor-alpha (TNF-α). It has been clinically shown to have an adequate response to systemic administration of TNF-α inhibitors, although with many shortcomings. To overcome such limitations, the immobilization of a TNF-α antibody on a nanofibrous substrate to promote a localized action is herein proposed. By using this approach, the antibody has its maximum therapeutic efficacy and a prolonged therapeutic benefit, avoiding the systemic side-effects associated with conventional biological agents' therapies. To technically achieve such a purpose, the surface of electrospun nanofibers is initially activated and functionalized, allowing TNF-α antibody immobilization at a maximum concentration of 6 µg/mL. Experimental results evidence that the biofunctionalized nanofibrous substrate is effective in achieving a sustained capture of soluble TNF-α over time. Moreover, cell biology assays demonstrate that this system has no deleterious effect over human articular chondrocytes metabolism and activity. Therefore, the developed TNF-capturing system may represent a potential therapeutic approach for the local management of severely affected joints.

The right place of interleukin-1 inhibitors in the treatment of Behçet's syndrome: a systematic review

Behçet's syndrome (BS) is a chronic (auto)-inflammatory disorder characterized by different clusters of symptoms, including mucocutaneous and ocular involvements. Interleukin-1 inhibitors anakinra (ANA), canakinumab (CAN), and gevokizumab (GEV) represent a promising therapeutic alternative in BS. To date, evidence on the use of ANA, CAN, and GEV is mainly based on small isolated studies or case series, and the real place of anti-IL1 agents in the treatment of BS is still unclear. We performed a systematic review of current evidence on the efficacy and safety of anti-IL1 agents in BS. The PubMed search yielded a total of 398 references, from which we retrieved 24 studies for inclusion (4 clinical trials, 6 observational studies, 14 case reports, case series or letters to the editor). Four studies evaluated the overall efficacy of IL-1 inhibitors, 15 studies focused on the specific efficacy of ANA, whereas efficacy of CAN and GEV was evaluated in 8 and 3 studies, respectively. Both ANA and CAN were associated with good control of mucocutaneous and ocular manifestations. ANA resulted effective also for osteoarticular manifestations. GEV was studied only for ocular manifestations, but gave contrasting results. Discordant evidence supports the use of ANA and CAN in pediatric setting and for first-line treatment of general BS manifestations. Most frequent side effects were local or diffuse cutaneous reactions and injection site reactions, particularly for ANA treatment. Blocking the IL-1 pathway could be an effective therapeutic strategy in particular BS involvements.

Development and Role in Therapy of Canakinumab in Adult-Onset Still's Disease

Adult-onset Still's disease (AOSD) is a rare inflammatory disease of unknown etiology typically characterized by episodes of spiking fever, evanescent rash, arthralgia, leukocytosis, and hyperferritinemia. The pivotal role of interleukin (IL)-1 and other pro-inflammatory cytokines gives rise to the development of new targeted therapies. Currently, AOSD patients can benefit from efficient and well tolerated biologic agents, such as IL-1, IL-6, and tumour necrosis factor (TNF)-α antagonists. Canakinumab, a human monoclonal anti-IL-1β antibody, is indicated for the treatment of different autoinflammatory syndromes in adults, adolescents, and children and it has recently been approved for AOSD treatment. In this article, we summarize the structural and biochemical data describing the molecular interactions between Canakinumab and its target antigen. Some special considerations of the pharmacological properties of Canakinumab are included. We also review the safety, efficacy and tolerability of this drug for the treatment of AOSD.

Construction of Artificial TNF-Binding Proteins Based on the 10th Human Fibronectin Type III Domain Using Bacterial Display

Construction of antibody mimetics on the base of alternative scaffold proteins is a promising strategy for obtaining new products for medicine and biotechnology. The aim of our work was to optimize the cell display system for the 10th human fibronectin type III domain (¹⁰Fn3) scaffold protein based on the AT877 autotransporter from Psychrobacter cryohalolentis K5^T and to construct new artificial TNF-binding proteins. We obtained a ¹⁰Fn3 gene combinatorial library and screened it using the bacterial display method. After expression of the selected ¹⁰Fn3 variants in Escherichia coli cells and analysis of their TNF-binding activity, we identified proteins that display high affinity for TNF and characterized their properties.

The effect of selected molecules influencing the detrimental host immune response on a course of rabies virus infection in a murine model

Rabies is invariably fatal, when post-exposure prophylaxis is administered after the onset of clinical symptoms. In many countries, rabies awareness is very low and the availability of post-exposure prophylaxis, as recommended by WHO guidelines, is very limited or non-existent, probably as a consequence of high cost. Therefore, new concepts for rabies therapy are needed. Innate immune mechanisms involving the production of pro-inflammatory cytokines and chemokines, activated after rabies infection, are thought to be involved in the neuropathogenesis of rabies. These mechanisms can contribute to a detrimental host response to the rabies virus (RABV) infection. The use of inhibitors of cytokines/chemokines are supposed to extend the survival of a sick individual. Inhibitors of TNF-α, IL-6 and MAPKs were used in RABV inoculated mice to define their influence on the survival time of rabid mice. The study demonstrated that all inhibitors extended mice survival, but at different rates. A log-rank test confirmed the statistically significant survival of mice treated with TNF-α (p = .0087) and MAPKs inhibitors (p = .0024). A delay in the time of onset of rabies was also recorded, in mice given TNF-α and MAPKs inhibitors. The highest virus load was found in the spinal cord and the lowest in the cortex, regardless of the experimental group. Significant TNF-α (p ≤ .0001) and IL-6 (p ≤ .0001) gene upregulation was observed in mice, as a consequence of RABV infection. Regarding MAPKs pathways, there was significant upregulation of the caspase 3 (p = .012, p = .0026) and Mcl-1 (p = .0348, p = .0153) genes, whereas significant downregulation of the cytochrome C (p ≤ .0001), Bcl2 (p = .0002, p = .0007) and JNK3 (p = .042) genes. Rabies pathogenesis is multifactorial, involving both virus and host influences on the course of the infection.

Anti-Inflammatory Effects of Modified Adenoviral Vectors for Gene Therapy: A View through Animal Models Tested

The central dogma of gene therapy relies on the application of novel therapeutic genes to treat or prevent diseases. The main types of vectors used for gene transfer are adenovirus, retrovirus, lentivirus, liposome, and adeno-associated virus vectors. Gene therapy has emerged as a promising alternative for the treatment of inflammatory diseases. The main targets are cytokines, co-stimulatory molecules, and different types of cells from hematological and mesenchymal sources. In this review, we focus on molecules with anti-inflammatory effects used for in vivo gene therapy mediated by adenoviral gene transfer in the treatment of immune-mediated inflammatory diseases, with particular emphasis on autoinflammatory and autoimmune diseases.

TNF Neutralization Results in the Delay of Transplantable Tumor Growth and Reduced MDSC Accumulation

Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of immature myeloid cells (IMCs) that, under normal conditions, may differentiate into mature macrophages, granulocytes, and dendritic cells. However, under pathological conditions associated with inflammation, cancer, or infection, such differentiation is inhibited leading to IMC expansion. Under the influence of inflammatory cytokines, these cells become MDSCs, acquire immunosuppressive phenotype, and accumulate in the affected tissue, as well as in the periphery. Immune suppressive activity of MDSCs is partly due to upregulation of arginase 1, inducible nitric oxide synthase, and anti-inflammatory cytokines, such as IL-10 and TGF-β. These suppressive factors can enhance tumor growth by repressing T-cell-mediated anti-tumor responses. TNF is a critical factor for the induction, expansion, and suppressive activity of MDSCs. In this study, we evaluated the effects of systemic TNF ablation on tumor-induced expansion of MDSCs in vivo using TNF humanized (hTNF KI) mice. Both etanercept and infliximab treatments resulted in a delayed growth of MCA 205 fibrosarcoma in hTNF KI mice, significantly reduced tumor volume, and also resulted in less accumulated MDSCs in the blood 3 weeks after tumor cell inoculation. Thus, our study uncovers anti-tumor effects of systemic TNF ablation in vivo.

The dual roles of cytokines in Alzheimer's disease: update on interleukins, TNF-α, TGF-β and IFN-γ

Alzheimer's disease (AD) is one of the most common neurodegenerative disorders in the elderly. Although the mechanisms underlying AD neurodegeneration are not fully understood, it is well recognized that inflammation plays a crucial role in the initiation and/or deterioration of AD neurodegeneration. Increasing evidence suggests that different cytokines, including interleukins, TNF-α, TGF-β and IFN-γ, are actively participated in AD pathogenesis and may serve as diagnostic or therapeutic targets for AD neurodegeneration. Here, we review the progress in understanding the important role that these cytokines or neuroinflammation has played in AD etiology and pathogenesis.