Anti-cytokine therapies in T1D: Concepts and strategies

T helper 17 cells and interleukin-17 immunity in type 1 diabetes: From pathophysiology to targeted immunotherapies

Type 1 diabetes (T1D) is a chronic organ-specific autoimmune disorder characterized by a progressive loss of the insulin-secreting pancreatic beta cells, which ultimately results in insulinopenia, hyperglycemia and lifelong need for exogenous insulin therapy. In the pathophysiological landscape of T1D, T helper 17 cells (Th17 cells) and their hallmark cytokine, interleukin (IL)-17, play pivotal roles from disease onset to disease progression. In this narrative mini-review, we discuss the dynamic interplay between Th17 cells and IL-17 in the context of T1D, providing insights into the underlying immunologic mechanisms contributing to the IL-17-immunity-mediated pancreatic beta-cell destruction. Furthermore, we summarized the main animal and clinical studies that investigated Th17- and IL-17-targeted interventions as promising immunotherapies able to alter the natural history of T1D.

ISG15 increases the apoptosis of β cells in type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease characterized by hyperglycemia caused by the destruction of insulin-producing β cells. Viral infection is an important environmental factor which is associated with the islet autoimmunity in genetically susceptible individuals. Loss of β-cells and triggering of insulitis following viral infection could result from several non-exclusive mechanisms. Despite a significant increase in ISG15 levels following viral infection, the specific role of ISG15 in the impairment of insulin-producing β-cells is unclear. To address this issue at the clinical level, we conducted this experimental work, and found elevated levels of ISG15 in the peripheral blood of T1D patients, suggesting a potential link between ISG15 and T1D. In the T1D animal model, we discovered that both ISG15 levels and cellular apoptosis were increased in pancreatic islet tissue. To investigate at the cellular level, we cultured MIN6 cells in the presence of supernatants derived from iBMDM cells transfected with poly(I:C) (PIC), a viral mimic. This exposure led to an upregulation of ISG15 expression in MIN6 cells, which was accompanied by the suppression of their functional capabilities and viability. Intriguingly, the direct transfection of MIN6 cells with PIC increased the expression of ISG15. We further found that elevated levels of ISG15 had a direct inhibitory effect on insulin secretion and it also contributed to β-cell apoptosis in a TNF-α-dependent manner. In conclusion, our study revealed a potential underlying mechanism through which ISG15 increases the apoptosis of β-cells, providing valuable insights that could facilitate the development of T1D treatment strategies.

Therapy concepts in type 1 diabetes mellitus treatment: disease modifying versus curative approaches

For many autoimmune diseases, including type 1 diabetes mellitus (T1DM), efforts have been made to modify the disease process through pharmacotherapy. The ultimate goal must be to develop therapies with curative potential by achieving an organ without signs of parenchymal cell destruction and without signs of immune cell infiltration. In the case of the pancreas, this means regenerated and well-preserved beta cells in the islets without activated infiltrating immune cells. Recent research has opened up the prospect of successful antibody combination therapy for autoimmune diabetes with curative potential. This goal cannot be achieved with monotherapies. The requirements for the implementation of such a therapy with curative potential for the benefit of patients with T1DM and LADA (latent autoimmune diabetes in adults) are considered.

Impacts of circulating cytokine levels and gene polymorphism predisposition on type 1 diabetes mellitus

PURPOSE

A wide range of cytokines has been demonstrated to be involved in the etiology of type 1 diabetes mellitus (T1DM). Gene polymorphisms may potentially contribute to a hereditary predisposition toward circulating cytokine levels as (high, intermediate, or low) since they can affect cytokine production or function. The aim of this study was to investigate the roles of cytokine levels and the association of single-nucleotide polymorphisms (SNPs) within cytokine genes with T1DM in Saudi children.

METHODS

Totals of 91 well-characterized T1DM patients and 91 T1DM-free control subjects were enrolled in this study.

RESULTS

The levels of 3 circulating cytokines (transforming growth factor [TGF]-β1, interleukin [IL]-10, and IL-6) and 6 SNPs in 3 cytokine genes (TGF-β1 [rs1800470 and rs1800471], IL-10 [rs1800896, rs1800871, and rs1800872], and IL-6 [rs1800795]) that contribute to genetic susceptibility were measured by enzyme-linked immunosorbent assay and polymerase chain reaction with sequence-specific primers. Our fn dings show that TGF-β1 serum levels were signifcantly lower in the children with T1DM than in the control participants. The TGF-β1 genotypes with a high-production phenotype were signifcantly less frequent and those with a lowproduction phenotype were signifcantly more frequent in the children with T1DM compared to the control participants. respectively. Furthermore, the IL-6 genotype frequency with low level of IL-6 production were signifcantly increased in the T1DM group compared to the control group. Moreover, our data demonstrated no appreciable diferences in circulating serum level or genotype and phenotype of IL- 10 between the patients and controls.

CONCLUSION

This kind of measurement, which considers the prediction of T1DM, may be useful in assessing the severity of T1DM and susceptibility to T1DM among Saudi children.

The causal relationship between autoimmune diseases and rhinosinusitis, and the mediating role of inflammatory proteins: a Mendelian randomization study

Observational studies have linked autoimmune diseases (ADs) with rhinosinusitis (RS) manifestations. To establish a causal relationship between ADs and RS, and to explore the potential mediating role of inflammatory mediators between ADs and RS, we utilized Mendelian randomization (MR) analysis. Using a two-sample MR methodology, we examined the causality between multiple sclerosis (MS), rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriasis (PsO), type 1 diabetes (T1D), Sjogren's syndrome (SS), celiac disease (CeD), Crohn's disease (CD), hypothyroidism (HT), Graves' disease (GD), and Hashimoto's thyroiditis and their association with chronic and acute rhinosinusitis (CRS and ARS, respectively).To achieve this, we employed three distinct MR techniques: inverse variance weighting (IVW), MR-Egger, and the weighted median method. Our analysis also included a variety of sensitivity assessments, such as Cochran's Q test, leave-one-out analysis, MR-Egger intercept, and MR-PRESSO, to ensure the robustness of our findings. Additionally, the study explored the role of inflammation proteins as a mediator in these relationships through a comprehensive two-step MR analysis. Among the ADs, MS, RA, T1D, CeD, and HT were determined as risk factors for CRS. Only CeD exhibited a causal relationship with ARS. Subsequent analyses identified interleukin-10 (IL-10) as a potential mediator for the association of MS, RA and HT with CRS, respectively., while C-X-C motif chemokine 10 levels (CXCL10) and T-cell surface glycoprotein CD6 isoform levels (CD6) were found to influence HT's effect on CRS. Our findings demonstrate a causative link between specific autoimmune diseases and rhinosinusitis, highlighting IL-10, CXCL10, and CD6 as potential mediators in this association.

Revolutionizing type 1 diabetes management: Exploring oral insulin and adjunctive treatments

Type 1 diabetes (T1D) is a chronic autoimmune condition that affects millions of people worldwide. Insulin pumps or injections are the standard treatment options for this condition. This article provides a comprehensive overview of the several type 1 diabetes treatment options, focusing on oral insulin. The article is divided into parts that include immune-focused treatments, antigen vaccination, cell-directed interventions, cytokine-directed interventions, and non-immunomodulatory adjuvant therapy. Under the section on non-immunomodulatory adjunctive treatment, the benefits and drawbacks of medications such as metformin, amylin, sodium-glucose cotransporter inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 Ras), and verapamil are discussed. The article also discusses the advantages of oral insulin, including increased patient compliance and more dependable and regular blood sugar control. However, several variables, including the enzymatic and physical barriers of the digestive system, impair the administration of insulin via the mouth. Researchers have looked at a few ways to get over these challenges, such as changing the structure of the insulin molecule, improving absorption with the use of absorption enhancers or nanoparticles, and taking oral insulin together with other medications. Even with great advancements in the use of these treatment strategies, T1D still needs improvement in the therapeutic difficulties. Future studies in these areas should focus on creating tailored immunological treatments, looking into combination medications, and refining oral insulin formulations in an attempt to better control Type 1 Diabetes. The ultimate objective is to create accurate, customized strategies that will enhance glycemic management and the quality of life for individuals with the condition.

From islet transplantation to beta-cell regeneration: an update on beta-cell-based therapeutic approaches in type 1 diabetes

INTRODUCTION

Type 1 diabetes (T1D) mellitus is an autoimmune disease in which immune cells, predominantly effector T cells, destroy insulin-secreting beta-cells. Beta-cell destruction led to various consequences ranging from retinopathy and nephropathy to neuropathy. Different strategies have been developed to achieve normoglycemia, including exogenous glucose compensation, whole pancreas transplantation, islet transplantation, and beta-cell replacement.

AREAS COVERED

The last two decades of experience have shown that indigenous glucose compensation through beta-cell regeneration and protection is a peerless method for T1D therapy. Tremendous studies have tried to find an unlimited source for beta-cell regeneration, on the one hand, and beta-cell protection against immune attack, on the other hand. Recent advances in stem cell technology, gene editing methods, and immune modulation approaches provide a unique opportunity for both beta-cell regeneration and protection.

EXPERT OPINION

Pluripotent stem cell differentiation into the beta-cell is considered an unlimited source for beta-cell regeneration. Devising engineered pancreas-specific regulatory T cells using Chimeric Antigen Receptor (CAR) technology potentiates an effective immune tolerance induction for beta-cell protection. Beta-cell regeneration using pluripotent stem cells and beta-cell protection using pancreas-specific engineered regulatory T cells promises to develop a curative protocol in T1D.

The use of shotgun label-free quantitative proteomic mass spectrometry to evaluate the inflammatory response in aqueous humor from horses with uveitis compared to ophthalmologically healthy horses

OBJECTIVE

The objective of this study was to use shotgun label-free tandem mass spectrometry (LF-MS/MS) to evaluate aqueous humor (AH) from horses with uveitis (UH) compared to ophthalmologically healthy horses (HH).

ANIMALS STUDIED

Twelve horses diagnosed with uveitis based on ophthalmic examination and six ophthalmologically healthy horses (postmortem) purchased for teaching purposes.

PROCEDURES

All horses received a complete ophthalmic examination and physical exam. Aqueous paracentesis was performed on all horses and AH total protein concentrations were measured with nanodrop (TPn) and refractometry (TPr). AH samples were analyzed with shotgun LF-MS/MS and proteomic data were compared between groups using Wilcoxon rank-sum test.

RESULTS

A total of 147 proteins were detected, 11 proteins had higher abundance in UH, and 38 proteins had lower abundance in UH. Proteins with higher abundance included apolipoprotein E, alpha-2-macroglobulin (A2M), alpha-2-HS-glycoprotein, prothrombin, fibrinogen, complement component 4 (C4), joining chain for IgA and IgM, afamin, and amine oxidase. There were positive correlations between TPn (p = .003) and TPr (p = .0001) compared to flare scores.

CONCLUSION

Differential abundance of A2M, prothrombin, fibrinogen, and C4 indicate upregulation of the complement and coagulation cascade in equine uveitis. Proinflammatory cytokines and the complement cascade have potential as therapeutic targets for equine uveitis.

Targeting IL-12 family cytokines: A potential strategy for type 1 and type 2 diabetes mellitus

Diabetes is a common metabolic disease characterized by an imbalance in blood glucose levels. The pathogenesis of diabetes involves the essential role of cytokines, particularly the IL-12 family cytokines. These cytokines, which have a similar structure, play multiple roles in regulating the immune response. Recent studies have emphasized the importance of IL-12 family cytokines in the development of both type 1 and type 2 diabetes mellitus. As a result, they hold promise as potential therapeutic targets for the treatment of these conditions. This review focuses on the potential of targeting IL-12 family cytokines for diabetes therapy based on their roles in the pathogenesis of both types of diabetes. We have summarized various therapies that target IL-12 family cytokines, including drug therapy, combination therapy, cell therapy, gene therapy, cytokine engineering therapy, and gut microbiota modulation. By analyzing the advantages and disadvantages of these therapies, we have evaluated their feasibility for clinical application and proposed possible solutions to overcome any challenges. In conclusion, targeting IL-12 family cytokines for diabetes therapy provides updated insights into their potential benefits, such as controlling inflammation, preserving islet β cells, reversing the onset of diabetes, and impeding the development of diabetic complications.

Pro-inflammatory cytokines in aqueous humor from dogs with anterior uveitis and post-operative ocular hypertension following phacoemulsification, primary glaucoma, and normal healthy eyes

Background

The aim of this study was to evaluate the levels of pro-inflammatory cytokines in aqueous humor (AH) from dogs with anterior uveitis and post-operative ocular hypertension (POH) following phacoemulsification, in AH from dogs with primary glaucoma, and in normal healthy eyes with no signs of anterior uveitis or other ocular diseases.

Methods

An exploratory study including 21 samples of AH collected from 15 dogs; post-phacoemulsification with anterior uveitis and POH (‘POH group’, n = 10 samples), primary glaucoma (‘glaucoma group’, n = 6 samples), and normal (‘normal group’, n = 5 samples). Target mass spectrometry via multiple reaction monitoring (MRM-MS) with the Canine Cytokine SpikeMix™ as internal standard was used to measure the pro-inflammatory cytokine levels.

Results

The MRM-MS method measured 15 pro-inflammatory cytokines. Tumor-necrosis-factor-alpha (TNFα) and interleukin-18 (IL-18) levels in AH were different between all three groups (glaucoma>POH>normal) (p = .05, p = .02, respectively). Additionally, IL-6 was higher in the ‘POH group’ compared to the ‘glaucoma group’ (p = .04) and IL-4 was higher in the ‘POH group’ compared to the ‘normal group’ (p = .04). Intraocular pressure (IOP) was positively associated with increased AH levels of IL-18 (Spearman correlation = .64, p = .03).

Conclusions

MRM-MS using the Canine Cytokine SpikeMix™ as an internal standard was established as a method to detect pro-inflammatory cytokine levels in canine AH. The study demonstrated increased levels of IL-4, IL-6, IL-18, and TNFα in AH from canines with POH following phacoemulsification. Primary glaucomatous eyes had the highest levels of IL-18 and TNFα which may indicate that inflammation plays a role in the pathogenesis of primary glaucoma in dogs.

Immunotherapy for type 1 diabetes mellitus by adjuvant-free Schistosoma japonicum-egg tip-loaded asymmetric microneedle patch (STAMP)

Background

Type 1 diabetes mellitus (T1DM) is an autoimmune disease mediated by autoreactive T cells and dominated by Th1 response polarization. Insulin replacement therapy faces great challenges to this autoimmune disease, requiring highly frequent daily administration. Intriguingly, the progression of T1DM has proven to be prevented or attenuated by helminth infection or worm antigens for a relatively long term. However, the inevitable problems of low safety and poor compliance arise from infection with live worms or direct injection of antigens. Microneedles would be a promising candidate for local delivery of intact antigens, thus providing an opportunity for the clinical immunotherapy of parasitic products.

Methods

We developed a Schistosoma japonicum-egg tip-loaded asymmetric microneedle patch (STAMP) system, which serves as a new strategy to combat TIDM. In order to improve retention time and reduce contamination risk, a specific imperfection was introduced on the STAMP (asymmetric structure), which allows the tip to quickly separate from the base layer, improving reaction time and patient’s comfort. After loading Schistosoma japonicum-egg as the immune regulator, the effects of STAMP on blood glucose control and pancreatic pathological progression improvement were evaluated in vivo. Meanwhile, the immunoregulatory mechanism and biosafety of STAMP were confirmed by histopathology, qRT-PCR, ELISA and Flow cytometric analysis.

Results

Here, the newly developed STAMP was able to significantly reduce blood glucose and attenuate the pancreatic injury in T1DM mice independent of the adjuvants. The isolated Schistosoma japonicum-eggs micron slowly degraded in the skin and continuously released egg antigen for at least 2 weeks, ensuring localization and safety of antigen stimulation. This phenomenon should be attributed to the shift of Th2 immune response to reduce Th1 polarization.

Conclusion

Our results exhibited that STAMP could significantly regulate the blood glucose level and attenuate pancreatic pathological injury in T1DM mice by balancing the Th1/Th2 immune responses, which is independent of adjuvants. This technology opens a new window for the application of parasite products in clinical immunotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01581-9.

CAR Treg: A new approach in the treatment of autoimmune diseases

Regulatory T cells (Tregs) have the role of regulating self-tolerance, and suppressing immune responses. Defects in Treg function and number can lead to in loss of tolerance or autoimmune disease. To treat or control autoimmune diseases, one of the options is to develop immune tolerance for Tregs cell therapy, which includes promotion and activation. Recently, cell-based treatment as a promising approach to increase cells function and number has been developed. Cell therapy by chimeric T antigen receptor (CAR-T) cells has shown significant efficacy in the treatment of leukemia, which has led researchers to use CAR-T cells in other diseases like autoimmune diseases. Here, we describe the existing treatments for autoimmune diseases and the available treatments based on Treg, their benefits and restrictions for implementation in clinical trials. We also discussed potential solutions to overcome these limitations. It seems novel designs of CARs to be new hope for autoimmune diseases and expected to be a potential cure option in a wide array of disease in the future. Therefore, it is very important to address this issue and increase information about it.

Targeting Mitochondrial-Derived Reactive Oxygen Species in T Cell-Mediated Autoimmune Diseases

Mitochondrial dysfunction resulting in oxidative stress could be associated with tissue and cell damage common in many T cell-mediated autoimmune diseases. Autoreactive CD4 T cell effector subsets (Th1,Th17) driving these diseases require increased glycolytic metabolism to upregulate key transcription factors (TF) like T-bet and RORγt that drive differentiation and proinflammatory responses. However, research in immunometabolism has demonstrated that mitochondrial-derived reactive oxygen species (ROS) act as signaling molecules contributing to T cell fate and function. Eliminating autoreactive T cells by targeting glycolysis or ROS production is a potential strategy to inhibit autoreactive T cell activation without compromising systemic immune function. Additionally, increasing self-tolerance by promoting functional immunosuppressive CD4 T regulatory (Treg) cells is another alternative therapeutic for autoimmune disease. Tregs require increased ROS and oxidative phosphorylation (OxPhos) for Foxp3 TF expression, differentiation, and anti-inflammatory IL-10 cytokine synthesis. Decreasing glycolytic activity or increasing glutathione and superoxide dismutase antioxidant activity can also be beneficial in inhibiting cytotoxic CD8 T cell effector responses. Current treatment options for T cell-mediated autoimmune diseases such as Type 1 diabetes (T1D), multiple sclerosis (MS), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE) include global immunosuppression, antibodies to deplete immune cells, and anti-cytokine therapy. While effective in diminishing autoreactive T cells, they can also compromise other immune responses resulting in increased susceptibility to other diseases and complications. The impact of mitochondrial-derived ROS and immunometabolism reprogramming in autoreactive T cell differentiation could be a potential target for T cell-mediated autoimmune diseases. Exploiting these pathways may delay autoimmune responses in T1D.

Lentiviral gene therapy vectors encoding VIP suppressed diabetes-related inflammation and augmented pancreatic beta-cell proliferation

Type 1 diabetes (T1DM) is an autoimmune condition in which the immune system attacks and destroys insulin-producing beta cells in the pancreas leading to hyperglycemia. Vasoactive intestinal peptide (VIP) manifests insulinotropic and anti-inflammatory properties, which are useful for the treatment of diabetes. Because of its limited half-life due to DPP-4-mediated degradation, constant infusions or multiple injections are needed to observe any therapeutic benefit. Since gene therapy has the potential to treat genetic diseases, an HIV-based lentiviral vector carrying VIP gene (LentiVIP) was generated to provide a stable VIP gene expression in vivo. The therapeutic efficacy of LentiVIP was tested in a multiple low-dose STZ-induced animal model of T1DM. LentiVIP delivery into diabetic animals reduced hyperglycemia, improved glucose tolerance, and prevented weight loss. Also, a decrease in serum CRP levels, and serum oxidant capacity, but an increase in antioxidant capacity were observed in LentiVIP-treated animals. Restoration of islet cell mass was correlated with an increase in pancreatic beta-cell proliferation. These beneficial results suggest the therapeutic effect of LentiVIP is due to the repression of diabetes-induced inflammation, its insulinotropic properties, and VIP-induced beta-cell proliferation.

Transcriptional networks in at-risk individuals identify signatures of type 1 diabetes progression

Type 1 diabetes (T1D) is a disease of insulin deficiency that results from autoimmune destruction of pancreatic islet β cells. The exact cause of T1D remains unknown, although asymptomatic islet autoimmunity lasting from weeks to years before diagnosis raises the possibility of intervention before the onset of clinical disease. The number, type, and titer of islet autoantibodies are associated with long-term disease risk but do not cause disease, and robust early predictors of individual progression to T1D onset remain elusive. The Environmental Determinants of Diabetes in the Young (TEDDY) consortium is a prospective cohort study aiming to determine genetic and environmental interactions causing T1D. Here, we analyzed longitudinal blood transcriptomes of 2013 samples from 400 individuals in the TEDDY study before both T1D and islet autoimmunity. We identified and interpreted age-associated gene expression changes in healthy infancy and age-independent changes tracking with progression to both T1D and islet autoimmunity, beginning before other evidence of islet autoimmunity was present. We combined multivariate longitudinal data in a Bayesian joint model to predict individual risk of T1D onset and validated the association of a natural killer cell signature with progression and the model's predictive performance on an additional 356 samples from 56 individuals in the independent Type 1 Diabetes Prediction and Prevention study. Together, our results indicate that T1D is characterized by early and longitudinal changes in gene expression, informing the immunopathology of disease progression and facilitating prediction of its course.

The Role of T Cell Receptor Signaling in the Development of Type 1 Diabetes

T cell receptor (TCR) signaling influences multiple aspects of CD4⁺ and CD8⁺ T cell immunobiology including thymic development, peripheral homeostasis, effector subset differentiation/function, and memory formation. Additional T cell signaling cues triggered by co-stimulatory molecules and cytokines also affect TCR signaling duration, as well as accessory pathways that further shape a T cell response. Type 1 diabetes (T1D) is a T cell-driven autoimmune disease targeting the insulin producing β cells in the pancreas. Evidence indicates that dysregulated TCR signaling events in T1D impact the efficacy of central and peripheral tolerance-inducing mechanisms. In this review, we will discuss how the strength and nature of TCR signaling events influence the development of self-reactive T cells and drive the progression of T1D through effects on T cell gene expression, lineage commitment, and maintenance of pathogenic anti-self T cell effector function.

Classic Type 1 Diabetes Mellitus and Fulminant Type 1 Diabetes Mellitus: Similarity and Discrepancy of Immunological Characteristics and Cytokine Profile

PURPOSE

We aimed to explore the immunological characteristics and cytokine profile of the initial stage of type 1 diabetes.

PATIENTS AND METHODS

In total, 123 age- and sex-matched subjects with newly diagnosed classic type 1 diabetes mellitus (T1ADM), fulminant type 1 diabetes mellitus (FT1DM), and normal glucose tolerance (NGT) were enrolled. Serum cytokine levels were measured using Milliplex MAP multifactor detection.

RESULTS

There was a significant increase in the levels of transforming growth factor β (TGFβ1) and TGFβ2 and decrease in programmed death-1 (PD-1), PD ligand 1 (PD-L1), pro-inflammatory cytokines, and anti-inflammatory cytokines in type 1 diabetes patients compared with the NGT subjects (all P < 0.05). There was no significant difference in C-reactive protein (CRP) and blood routine indicators between the two groups. Type 1 diabetes was further divided into T1ADM and FT1DM subgroups. FT1DM patients had much higher CRP levels than T1ADM patients (4.90 [0.95-26.05] mg/L vs 0.39 [0.20-0.74] mg/L, P < 0.01). Blood routine results showed that the number of leukocytes was significantly increased in FT1DM compared with that in T1ADM (9.2 [5.1-18.8] × 10⁹ cells/L vs 5.4 [4.5-6.7] × 10⁹ cells/L, P < 0.01). In FT1DM patients, neutrophil% was increased, and lymphocyte% was declined significantly, compared with that in T1ADM patients (neutrophil%: 80.2 [59.2-85.2]% vs 59.5 [54.8-64.0]%; lymphocyte%: 18.3 [10.1-32.3]% vs 32.6 [26.8-35.9]%; both P < 0.01). However, there was no difference between FT1DM and T1ADM in cytokine profile except for the decrease in CTLA-4 in T1ADM (P < 0.05).

CONCLUSION

Compared with T1ADM, CRP and leukocytes' levels were increased significantly in FT1DM, with an increase in neutrophil% and decline in lymphocyte%, suggesting that FT1DM may have more abrupt onset and occur as a more serious subtype of type 1 diabetes mellitus.

Translation of curative therapy concepts with T cell and cytokine antibody combinations for type 1 diabetes reversal in the IDDM rat

Abstract

Proinflammatory cytokines released from the pancreatic islet immune cell infiltrate in type 1 diabetes (T1D) cause insulinopenia as a result of severe beta cell loss due to apoptosis. Diabetes prevention strategies targeting different cytokines with antibodies in combination with a T cell antibody, anti-TCR, have been assessed for therapy success in the LEW.1AR1-iddm (IDDM) rat, an animal model of human T1D. Immediately after diabetes manifestation, antibody combination therapies were initiated over 5 days with anti-TNF-α (tumour necrosis factor), anti-IL-1β (interleukin), or anti-IFN-γ (interferon) together with anti-TCR for the reversal of the diabetic metabolic state in the IDDM rat. Anti-TCR alone showed only a very limited therapy success with respect to a reduction of immune cell infiltration and beta cell mass regeneration. Anti-TCR combinations with anti-IL-1β or anti-IFN-γ were also not able to abolish the increased beta cell apoptosis rate and the activated immune cell infiltrate leading to a permanent beta cell loss. In contrast, all anti-TCR combinations with anti-TNF-α provided sustained therapy success over 60 to 360 days. The triple combination of anti-TCR with anti-TNF-α plus anti-IL-1β was most effective in regaining sustained normoglycaemia with an intact islet structure in a completely infiltration-free pancreas and with a normal beta cell mass. Besides the triple combination, the double antibody combination of anti-TCR with anti-TNF-α proved to be the most suited therapy for reversal of the T1D metabolic state due to effective beta cell regeneration in an infiltration free pancreas.

Key messages

Anti-TCR is a cornerstone in combination therapy for autoimmune diabetes reversal.

The combination of anti-TCR with anti-TNF-α was most effective in reversing islet immune cell infiltration.

Anti-TCR combined with anti-IL-1β was not effective in this respect.

The combination of anti-TCR with anti-TNF-α showed a sustained effect over 1 year.

Electronic supplementary material

The online version of this article (10.1007/s00109-020-01941-8) contains supplementary material, which is available to authorized users.

Nanotechnology's application in Type 1 diabetes

Type 1 diabetes mellitus (T1D) is an autoimmune disease caused by the immune system attacking islet cells. T1D, with a long prediabetes period, and the incidence of T1D increases with age during childhood and peaks at 10-14 years. And once it gets overt, it requires lifelong insulin replace treatment. Therefore, the diagnosis of early-stage T1D and effective treatments are important for the management of T1D patients. The imaging methods, such as magnetic resonance imaging (MRI) and so on, were applied in diagnosis of the early stage T1D and its development tracking. The addition of nanomaterials, especially in MRI, can improve the quality of T1D imaging for the diagnosis of T1D at early stage and cause less harm to human body. Meantime, among various treatment options, islet transplantation and immunotherapy are promising, effective, and less independent on insulin. The addition of nanotechnology can effectively reduce the attack of the immune system on drugs and cells, making the therapeutic drug more targeted in the body and prolonging the action time between drugs and cells, thus its addition makes these therapy safer and more efficient. In this review, we attempt to summarize the recent advances in the development of nanotechnology advances of T1D including using nanomaterials for the diagnosis and immunological imaging of T1D, protecting the transplanted islet cells from immune system attack, and delivering relevant molecules to targeted immunocytes. This article is categorized under: Diagnostic Tools > in vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Emerging Technologies Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement.

Cytokines in type 1 diabetes: mechanisms of action and immunotherapeutic targets

Cytokines play crucial roles in orchestrating complex multicellular interactions between pancreatic β cells and immune cells in the development of type 1 diabetes (T1D) and are thus potential immunotherapeutic targets for this disorder. Cytokines that can induce regulatory functions-for example, IL-10, TGF-β and IL-33-are thought to restore immune tolerance and prevent β-cell damage. By contrast, cytokines such as IL-6, IL-17, IL-21 and TNF, which promote the differentiation and function of diabetogenic immune cells, are thought to lead to T1D onset and progression. However, targeting these dysregulated cytokine networks does not always result in consistent effects because anti-inflammatory or proinflammatory functions of cytokines, responsible for β-cell destruction, are context dependent. In this review, we summarise the current knowledge on the involvement of well-known cytokines in both the initiation and destruction phases of T1D and discuss advances in recently discovered roles of cytokines. Additionally, we emphasise the complexity and implications of cytokine modulation therapy and discuss the ways in which this strategy has been translated into clinical trials.

Remission of autoimmune diabetes by anti-TCR combination therapies with anti-IL-17A or/and anti-IL-6 in the IDDM rat model of type 1 diabetes

BACKGROUND

The cytokine IL-17 is a key player in autoimmune processes, while the cytokine IL-6 is responsible for the chronification of inflammation. However, their roles in type 1 diabetes development are still unknown.

METHODS

Therefore, therapies for 5 days with anti-IL-17A or anti-IL-6 in combination with a T cell-specific antibody, anti-TCR, or in a triple combination were initiated immediately after disease manifestation to reverse the diabetic metabolic state in the LEW.1AR1-iddm (IDDM) rat, a model of human type 1 diabetes.

RESULTS

Monotherapies with anti-IL-6 or anti-IL-17 showed no sustained anti-diabetic effects. Only the combination therapy of anti-TCR with anti-IL-6 or anti-IL-17 at starting blood glucose concentrations up to 12 mmol/l restored normoglycaemia. The triple antibody combination therapy was effective even up to very high initial blood glucose concentrations (17 mmol/l). The β cell mass was raised to values of around 6 mg corresponding to those of normoglycaemic controls. In parallel, the apoptosis rate of β cells was reduced and the proliferation rate increased as well as the islet immune cell infiltrate was strongly reduced in double and abolished in triple combination therapies.

CONCLUSIONS

The anti-TCR combination therapy with anti-IL-17 preferentially raised the β cell mass as a result of β cell proliferation while anti-IL-6 strongly reduced β cell apoptosis and the islet immune cell infiltrate with a modest increase of the β cell mass only. The triple combination therapy achieved both goals in a complimentary anti-autoimmune and anti-inflammatory action resulting in sustained normoglycaemia with normalized serum C-peptide concentrations.

Heparanase and Type 1 Diabetes

Type 1 diabetes (T1D) results from autoimmune destruction of insulin-producing beta cells in pancreatic islets. The degradation of the glycosaminoglycan heparan sulfate (HS) by the endo-β-D-glycosidase heparanase plays a critical role in multiple stages of the disease process. Heparanase aids (i) migration of inflammatory leukocytes from the vasculature to the islets, (ii) intra-islet invasion by insulitis leukocytes, and (iii) selective destruction of beta cells. These disease stages are marked by the solubilization of HS in the subendothelial basement membrane (BM), HS breakdown in the peri-islet BM, and the degradation of HS inside beta cells, respectively. Significantly, healthy islet beta cells are enriched in highly sulfated HS which is essential for their viability, protection from damage by reactive oxygen species (ROS), beta cell function and differentiation. Consequently, mouse and human beta cells but not glucagon-producing alpha cells (which contain less-sulfated HS) are exquisitely vulnerable to heparanase-mediated damage. In vitro, the death of HS-depleted mouse and human beta cells can be prevented by HS replacement using highly sulfated HS mimetics or analogues. T1D progression in NOD mice and recent-onset T1D in humans correlate with increased expression of heparanase by circulating leukocytes of myeloid origin and heparanase-expressing insulitis leukocytes. Treatment of NOD mice with the heparanase inhibitor and HS replacer, PI-88, significantly reduced T1D incidence by 50%, impaired the development of insulitis and preserved beta cell HS. These outcomes identified heparanase as a novel destructive tool in T1D, distinct from the conventional cytotoxic and apoptosis-inducing mechanisms of autoreactive T cells. In contrast to exogenous catalytically active heparanase, endogenous heparanase may function in HS homeostasis, gene expression and insulin secretion in normal beta cells and immune gene expression in leukocytes. In established diabetes, the interplay between hyperglycemia, local inflammatory cells (e.g. macrophages) and heparanase contributes to secondary micro- and macro-vascular disease. We have identified dual activity heparanase inhibitors/HS replacers as a novel class of therapeutic for preventing T1D progression and potentially for mitigating secondary vascular disease that develops with long-term T1D.

New Insights into Immunotherapy Strategies for Treating Autoimmune Diabetes

Type 1 diabetes mellitus (T1D) is an autoimmune illness that affects millions of patients worldwide. The main characteristic of this disease is the destruction of pancreatic insulin-producing beta cells that occurs due to the aberrant activation of different immune effector cells. Currently, T1D is treated by lifelong administration of novel versions of insulin that have been developed recently; however, new approaches that could address the underlying mechanisms responsible for beta cell destruction have been extensively investigated. The strategies based on immunotherapies have recently been incorporated into a panel of existing treatments for T1D, in order to block T-cell responses against beta cell antigens that are very common during the onset and development of T1D. However, a complete preservation of beta cell mass as well as insulin independency is still elusive. As a result, there is no existing T1D targeted immunotherapy able to replace standard insulin administration. Presently, a number of novel therapy strategies are pursuing the goals of beta cell protection and normoglycemia. In the present review we explore the current state of immunotherapy in T1D by highlighting the most important studies in this field, and envision novel strategies that could be used to treat T1D in the future.

MicroRNA-181c Inhibits Interleukin-6-mediated Beta Cell Apoptosis by Targeting TNF-α Expression

We have previously reported that long-term treatment of beta cells with interleukin-6 (IL-6) is pro-apoptotic. However, little is known about the regulatory mechanisms that are involved. Therefore, we investigated pro-apoptotic changes in mRNA expression in beta cells in response to IL-6 treatment. We analyzed a microarray with RNA from INS-1 beta cells treated with IL-6, and found that TNF-α mRNA was significantly upregulated. Inhibition of TNF-α expression by neutralizing antibodies significantly decreased annexin V staining in cells compared with those treated with a control antibody. We identified three microRNAs that were differentially expressed in INS-1 cells incubated with IL-6. In particular, miR-181c was significantly downregulated in IL-6-treated cells compared with control cells and the decrease of miR-181c was attenuated by STAT-3 signaling inhibition. TNF-α mRNA was a direct target of miR-181c and upregulation of miR-181c by mimics, inhibited IL-6-induced increase in TNF-α mRNA expression. Consequently, reduction of TNF-α mRNA caused by miR-181c mimics enhanced cell viability in IL-6 treated INS-1 cells. These results demonstrated that miR-181c regulation of TNF-α expression plays a role in IL-6-induced beta cell apoptosis.

Advances in immunotherapy of type I diabetes

Type 1 diabetes mellitus (T1DM) is an autoimmune disease affecting 3 million individuals in the U.S. The pathogenesis of T1DM is driven by immune-mediated destruction of pancreatic β cells, the source of glucose regulator insulin. While T1DM can be successfully managed with insulin replacement therapy, approaches that can modify the underlying immuno-pathology of β cell destruction has been long sought after. Immunotherapy can attenuate T cell responses against β cell antigens. Given the detailed cellular and molecular definitions of T1DM immune responses, rational immunomodulation can be and have been developed in mouse models, and in some instances, tested in humans. The possibility of identifying individuals who are predisposed to T1DM through genotyping lend to the possibility of preventive vaccines. While much has been accomplished in delineating the mechanisms of immunotherapies, some of which are being tested in humans, long-term preservation of β cells and insulin independency has not been achieved. In this regard, the drug delivery field has much to offer in maximizing the benefits of immune modulators by optimizing spatiotemporal presentation of antigens and costimulatory signals. In this review, we attempt to capture the current state of T1DM immunotherapy by highlighting representative studies.

Neutralization Versus Reinforcement of Proinflammatory Cytokines to Arrest Autoimmunity in Type 1 Diabetes

As physiological pathways of intercellular communication produced by all cells, cytokines are involved in the pathogenesis of inflammatory insulitis as well as pivotal mediators of immune homeostasis. Proinflammatory cytokines including interleukins, interferons, transforming growth factor-β, tumor necrosis factor-α, and nitric oxide promote destructive insulitis in type 1 diabetes through amplification of the autoimmune reaction, direct toxicity to β-cells, and sensitization of islets to apoptosis. The concept that neutralization of cytokines may be of therapeutic benefit has been tested in few clinical studies, which fell short of inducing sustained remission or achieving disease arrest. Therapeutic failure is explained by the redundant activities of individual cytokines and their combinations, which are rather dispensable in the process of destructive insulitis because other cytolytic pathways efficiently compensate their deficiency. Proinflammatory cytokines are less redundant in regulation of the inflammatory reaction, displaying protective effects through restriction of effector cell activity, reinforcement of suppressor cell function, and participation in islet recovery from injury. Our analysis suggests that the role of cytokines in immune homeostasis overrides their contribution to β-cell death and may be used as potent immunomodulatory agents for therapeutic purposes rather than neutralized.

Loss of intra-islet heparan sulfate is a highly sensitive marker of type 1 diabetes progression in humans

Type 1 diabetes (T1D) is an autoimmune disease in which insulin-producing beta cells in pancreatic islets are progressively destroyed. Clinical trials of immunotherapies in recently diagnosed T1D patients have only transiently and partially impacted the disease course, suggesting that other approaches are required. Our previous studies have demonstrated that heparan sulfate (HS), a glycosaminoglycan conventionally expressed in extracellular matrix, is present at high levels inside normal mouse beta cells. Intracellular HS was shown to be critical for beta cell survival and protection from oxidative damage. T1D development in Non-Obese Diabetic (NOD) mice correlated with loss of islet HS and was prevented by inhibiting HS degradation by the endoglycosidase, heparanase. In this study we investigated the distribution of HS and heparan sulfate proteoglycan (HSPG) core proteins in normal human islets, a role for HS in human beta cell viability and the clinical relevance of intra-islet HS and HSPG levels, compared to insulin, in human T1D. In normal human islets, HS (identified by 10E4 mAb) co-localized with insulin but not glucagon and correlated with the HSPG core proteins for collagen type XVIII (Col18) and syndecan-1 (Sdc1). Insulin-positive islets of T1D pancreases showed significant loss of HS, Col18 and Sdc1 and heparanase was strongly expressed by islet-infiltrating leukocytes. Human beta cells cultured with HS mimetics showed significantly improved survival and protection against hydrogen peroxide-induced death, suggesting that loss of HS could contribute to beta cell death in T1D. We conclude that HS depletion in beta cells, possibly due to heparanase produced by insulitis leukocytes, may function as an important mechanism in the pathogenesis of human T1D. Our findings raise the possibility that intervention therapy with dual activity HS replacers/heparanase inhibitors could help to protect the residual beta cell mass in patients recently diagnosed with T1D.

Regulatory T cell dysfunction in type 1 diabetes: what's broken and how can we fix it?

Type 1 diabetes is an autoimmune disease characterised by the destruction of insulin producing beta cells in the pancreas. Whilst it remains unclear what the original triggering factors for this destruction are, observations from the natural history of human type 1 diabetes, including incidence rates in twins, suggest that the disease results from a combination of genetic and environmental factors. Whilst many different immune cells have been implicated, including members of the innate and adaptive immune systems, a view has emerged over the past 10 years that beta cell damage is mediated by the combined actions of CD4⁺ and CD8⁺ T cells with specificity for islet autoantigens. In health, these potentially pathogenic T cells are held in check by multiple regulatory mechanisms, known collectively as 'immunological tolerance'. This raises the question as to whether type 1 diabetes develops, at least in part, as a result of a defect in one or more of these control mechanisms. Immunological tolerance includes both central mechanisms (purging of the T cell repertoire of high-affinity autoreactive T cells in the thymus) and peripheral mechanisms, a major component of which is the action of a specialised subpopulation of T cells, known as regulatory T cells (Tregs). In this review, we highlight the evidence suggesting that a reduction in the functional capacity of different Treg populations contributes to disease development in type 1 diabetes. We also address current controversies regarding the putative causes of this defect and discuss strategies to correct it as a means to reduce or prevent islet destruction in a clinical setting.

The Four-Way Stop Sign: Viruses, 12-Lipoxygenase, Islets, and Natural Killer Cells in Type 1 Diabetes Progression

Natural killer (NK) cells represent an important effector arm against viral infection, and mounting evidence suggests that viral infection plays a role in the development of type 1 diabetes (T1D) in at least a portion of patients. NK cells recognize their target cells through a delicate balance of inhibitory and stimulatory receptors on their surface. If unbalanced, NK cells have great potential to wreak havoc in the pancreas due to the beta cell expression of the as-yet-defined NKp46 ligand through interactions with the activating NKp46 receptor found on the surface of most NK cells. Blocking interactions between NKp46 and its ligand protects mice from STZ-induced diabetes, but differential expression non-diabetic and diabetic donor samples have not been tested. Additional studies have shown that peripheral blood NK cells from human T1D patients have altered phenotypes that reduce the lytic and functional ability of the NK cells. Investigations of humanT1D pancreas tissues have indicated that the presence of NK cells may be beneficial despite their infrequent detection. In non-obese diabetic (NOD) mice, we have noted that NK cells express high levels of the proinflammatory mediator 12/15-lipoxygenase (12/15-LO), and decreased levels of stimulatory receptors. Conversely, NK cells of 12/15-LO deficient NOD mice, which are protected from diabetes development, express significantly higher levels of stimulatory receptors. Furthermore, the human NK92 cell line expresses the ALOX12 protein [human 12-lipoxygenase (12-LO), related to mouse 12/15-LO] via Western blotting. Human 12-LO is upregulated in the pancreas of both T1D and T2D human donors with insulin-containing islets, showing a link between 12-LO expression and diabetes progression. Therefore, our hypothesis is that NK cells in those susceptible to developing T1D are unable to function properly during viral infections of pancreatic beta cells due to increased 12-LO expression and activation, which contributes to increased interferon-gamma production and an imbalance in activating and inhibitory NK cell receptors, and may contribute to downstream autoimmune T cell responses. The work presented here outlines evidence from our lab, as well as published literature, supporting our hypothesis, including novel data.

Decoupling the Functional Pleiotropy of Stem Cell Factor by Tuning c-Kit Signaling

Most secreted growth factors and cytokines are functionally pleiotropic because their receptors are expressed on diverse cell types. While important for normal mammalian physiology, pleiotropy limits the efficacy of cytokines and growth factors as therapeutics. Stem cell factor (SCF) is a growth factor that acts through the c-Kit receptor tyrosine kinase to elicit hematopoietic progenitor expansion but can be toxic when administered in vivo because it concurrently activates mast cells. We engineered a mechanism-based SCF partial agonist that impaired c-Kit dimerization, truncating downstream signaling amplitude. This SCF variant elicited biased activation of hematopoietic progenitors over mast cells in vitro and in vivo. Mouse models of SCF-mediated anaphylaxis, radioprotection, and hematopoietic expansion revealed that this SCF partial agonist retained therapeutic efficacy while exhibiting virtually no anaphylactic off-target effects. The approach of biasing cell activation by tuning signaling thresholds and outputs has applications to many dimeric receptor-ligand systems.

The Inhibitory G Protein α-Subunit, Gαz, Promotes Type 1 Diabetes-Like Pathophysiology in NOD Mice

The α-subunit of the heterotrimeric Gz protein, Gαz, promotes β-cell death and inhibits β-cell replication when pancreatic islets are challenged by stressors. Thus, we hypothesized that loss of Gαz protein would preserve functional β-cell mass in the nonobese diabetic (NOD) model, protecting from overt diabetes. We saw that protection from diabetes was robust and durable up to 35 weeks of age in Gαz knockout mice. By 17 weeks of age, Gαz-null NOD mice had significantly higher diabetes-free survival than wild-type littermates. Islets from these mice had reduced markers of proinflammatory immune cell infiltration on both the histological and transcript levels and secreted more insulin in response to glucose. Further analyses of pancreas sections revealed significantly fewer terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL)-positive β-cells in Gαz-null islets despite similar immune infiltration in control mice. Islets from Gαz-null mice also exhibited a higher percentage of Ki-67-positive β-cells, a measure of proliferation, even in the presence of immune infiltration. Finally, β-cell-specific Gαz-null mice phenocopy whole-body Gαz-null mice in their protection from developing hyperglycemia after streptozotocin administration, supporting a β-cell-centric role for Gαz in diabetes pathophysiology. We propose that Gαz plays a key role in β-cell signaling that becomes dysfunctional in the type 1 diabetes setting, accelerating the death of β-cells, which promotes further accumulation of immune cells in the pancreatic islets, and inhibiting a restorative proliferative response.

Peripheral blood mononuclear cells of patients with latent autoimmune diabetes secrete higher levels of pro- & anti-inflammatory cytokines compared to those with type-1 diabetes mellitus following in vitro stimulation with β-cell autoantigens

BACKGROUND & OBJECTIVES

Type-1 diabetes mellitus (T1DM) and latent autoimmune diabetes in adults (LADA) share similar pathological features but differ in age of onset and progression. There is a scarcity of information on differences in CD4+ T-cell responses, particularly, cytokine secretion, between the two forms of autoimmune diabetes. Here proliferative potential and concentration of pro- and anti-inflammatory cytokines secreted by peripheral blood mononuclear cells (PBMCs) of T1DM and LADA patients were compared, after in vitro stimulation with β-cell autoantigens.

METHODS

A total of 19 patients with LADA, 37 with T1DM and 20 healthy controls were compared on the basis of lymphocyte proliferation and secretion of pro- and anti-inflammatory cytokines belonging to different T-helper types after in vitro stimulation of PBMCs with insulin and glutamic acid decarboxylase 65 (GAD65).

RESULTS

Following insulin stimulation, LADA group secreted higher concentration of interleukin-17 (IL-17) (P=0.02) and had higher proportion of interferon gamma (IFN-γ) secretors (P<0.001) than T1DM group. Post-GAD65 stimulation, higher proportion of LADA patients secreted IL-23 than T1DM group (P=0.02). Proportion of responders , as well as levels of secreted IL-10, were significantly higher in LADA than T1DM group, following stimulation with both insulin (P=0.01) and GAD65 (P=0.03). A significant positive correlation was observed between body mass index and IL-17 levels (r=0.41, P=0.04) and fasting plasma C-peptide with IL-10 levels (r=0.37, P=0.04).

INTERPRETATION & CONCLUSIONS

There are differences in the portfolio of cytokine secretion in diabetic subjects with varying rates of β-cell destruction as LADA subjects secrete higher levels of both pro- and anti-inflammatory cytokines on exposure to β-cell autoantigens, thus highlighting another distinguishing feature in the pathophysiology of the two forms of autoimmune diabetes.

Alpha cells, the main source of IL-1β in human pancreas

Interleukin-1β (IL-1β) is known to trigger beta cell dysfunction in vitro and could potentially play a role during the pathogenesis of type 1 diabetes and type 2 diabetes. However, several clinical trials attempting to block IL-1β function have had minimal success. We therefore re-investigated local expression of IL-1β in human diabetic and non-diabetic pancreata. We obtained pancreatic tissue sections from the Network for Pancreatic Organ Donors with Diabetes (nPOD) including non-diabetic (n = 9), non-diabetic auto-antibody positive (AAb+, n = 5), type 1 diabetes (n = 6), and type 2 diabetes (n = 6) donors. Islets were systematically investigated for the presence of IL-1β mRNA by in situ hybridization and IL-1β protein by indirect immunofluorescence. We found that intra-islet IL-1β was produced at comparable level in both non-diabetic and diabetic donors. Interestingly, the main source for IL-1β was alpha cells but not beta cells. Our findings call into question the role of IL-1β in the diabetic pancreas as it has been proposed in previous literature. Additionally, our results regarding the localization of IL-1β should lead to further investigation into the role of IL-1β in the physiology of pancreatic alpha cells.

Immune interventions to preserve β cell function in type 1 diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease that leads to destruction of pancreatic β cells, lifelong dependence on insulin, and increased morbidity and mortality from diabetes-related complications. Preservation of residual β cells at diagnosis is a major goal because higher levels of endogenous insulin secretion are associated with better short- and long-term outcomes. For the past 3 decades, a variety of immune interventions have been evaluated in the setting of new-onset T1D, including nonspecific immunosuppression, pathway-specific immune modulation, antigen-specific therapies, and cellular therapies. To date, no single intervention has produced durable remission off therapy in most treated patients, but the field has gained valuable insights into disease mechanisms and potential immunologic correlates of success. In particular, T-cell–directed therapies, including therapies that lead to partial depletion or modulation of effector T cells and preservation or augmentation of regulatory T cells, have shown the most success and will likely form the backbone of future approaches. The next phase will see evaluation of rational combinations, comprising one or more of the following: an effector T-depleting or -modulating drug, a cytokine-based tolerogenic (regulatory T-cells–promoting) agent, and an antigen-specific component. The long term goal is to reestablish immunologic tolerance to β cells, thereby preserving residual β cells early after diagnosis or enabling restoration of β-cell mass from autologous stem cells or induced neogenesis in patients with established T1D.

Neonatal levels of adiponectin, interleukin-10 and interleukin-12 are associated with the risk of developing type 1 diabetes in childhood and adolescence: A nationwide Danish case-control study

BACKGROUND/AIM

An in-depth understanding of the early phase of type 1 diabetes (T1D) pathogenesis is important for targeting primary prevention. We examined if 14 preselected mediators of immune responses differed in neonates that later developed T1D compared to control neonates.

METHODS

The study is a case-control study with a 1:2 matching. The individuals were born between 1981 through 2002. Cases were validated using the National Patient Register and the Danish Childhood Diabetes Register. Interleukin(IL)-1β, IL-4, IL-6, IL-8, IL-10, IL-12p70, interferon gamma, tumor necrosis factor alpha, transforming growth factor beta 1 (active form), leptin, adiponectin, c-reactive protein, mannose-binding lectin and soluble triggering receptor expressed on myeloid cells-1 were measured by using a flowmetric Luminex xMAP® technology. We tested two models both including a number of possible confounders. In the first model (model 1) we also adjusted for HLA-DQB1 genotype. A total of 1930 groups of assay-matched cases and controls (4746 individuals) were included in the statistical analyses.

RESULTS

Adiponectin was negatively associated with later risk of T1D in both models (relative change (RC), model 1: 0.95, P=0.046 and model 2: 0.95, P=0.006). IL-10 and IL-12 were both positively associated with T1D risk in the model 2 (RC, 1.19, P=0.006 and 1.07, P=0.02, respectively)-these results were borderline significant in model 1, but showed the same direction as the results from model 2.

CONCLUSIONS

Our results indicate that specific immunological signatures are already present at time of birth in children developing T1D before the age of 18years.

Therapeutic anti-CD3 monoclonal antibodies: from bench to bedside

The induction of tolerance is a major goal of immunotherapy. Investigations over the last 20 years have shown that anti-CD3 monoclonal antibodies (mAbs) effectively treat autoimmune disease in animal models and have also shown promise in clinical trials. Tolerance induction by anti-CD3 mAbs is related to the induction of Tregs that control pathogenic autoimmune responses. Here, we review preclinical and clinical studies in which intravenous or mucosal administration of anti-CD3 mAbs has been employed and provide an outlook on future developments to enhance the efficacy of this promising therapeutic approach.

Immunotherapies currently in development for the treatment of type 1 diabetes

INTRODUCTION

Type I diabetes (T1DM) is an autoimmune disorder that affects the pancreas' ability to produce insulin. While T1DM can be managed using insulin therapy, patients face financial burden, serious complications and premature mortality, from the disease. Efforts have sought to define and ultimately suppress the underlying autoimmune attack that results in T1DM.

AREAS COVERED

The authors lay out promising immunosuppressive and immunomodulating drugs currently in development for T1DM and outline options for future immune treatment for the disorder. There have been several pharmacological strategies to combat the immune attack which will serve as the organization for this review: antigen-specific therapies; monoclonal antibodies; fusion proteins; alternate Treg affectors.

EXPERT OPINION

Immunosuppression and immunomodulation studies in T1DM demonstrated differing levels of slowing the progression of the immune attack; however, no single therapeutic approach provides a lasting halt of the immune attack and remission of the disease. The immunosuppressants (teplizumab, rituximab and abatacept) show promise in slowing the T1DM progressions for a specific subpopulation of T1DM patients, but this approach appears temporary and has the potential for unwanted side affects. Combination therapies may have the greatest chance of achieving durable cessation of the T1DM autoimmune attack.

Strategies for clinical trials in type 1 diabetes

During the past one to two decades, substantial progress has been made in our understanding of the immunopathology of type 1 diabetes (T1D) and the potential for immune interventions that can alter the natural history of the disease. This progress has resulted from the use of standardized study designs, endpoints, and, to a certain extent, mechanistic analyses in intervention trials in the setting of new-onset T1D. To date, most of these trials have involved single-agent interventions but, increasingly, future trials will test therapeutic combinations that are based on a compelling scientific rationale and testable mechanistic hypotheses. These increasingly complex trials will benefit from novel trial designs (such as factorial or adaptive designs), enhanced clinical endpoints that more directly assess islet pathology (such as β-cell death assays and islet or pancreatic imaging), improved responder analyses, and sophisticated mechanistic assays that provide deep phenotyping of lymphocyte subsets, gene expression profiling, in vitro T cell functional assessments, and antigen-specific responses. With this developing armamentarium of enhanced trial designs, endpoints, and clinical and mechanistic response analyses, we can expect substantial progress in better understanding the breakdown in immunologic tolerance in T1D and how to restore it to achieve significant and long-lasting preservation of islet function.

Regulatory T Cell Immunotherapy for Type 1 Diabetes: A Step Closer to Success?

Regulatory T cell (Treg) therapy has shown promises in experimental models of type 1 diabetes (T1D) and other autoimmune diseases. Now, Bluestone et al. (2015) report in a phase 1, dose-escalation study that ex vivo-expanded autologous polyclonal Treg therapy is safe and well tolerated in adult patients with recent-onset T1D.

TNF and ROS Crosstalk in Inflammation

Tumor necrosis factor (TNF) is tremendously important for mammalian immunity and cellular homeostasis. The role of TNF as a master regulator in balancing cell survival, apoptosis and necroptosis has been extensively studied in various cell types and tissues. Although these findings have revealed much about the direct impact of TNF on the regulation of NF-κB and JNK, there is now rising interest in understanding the emerging function of TNF as a regulator of the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). In this review we summarize work aimed at defining the role of TNF in the control of ROS/RNS signaling that influences innate immune cells under both physiological and inflammatory conditions.

Offloading treatment is linked to activation of proinflammatory cytokines and start of bone repair and remodeling in Charcot arthropathy patients

BACKGROUND

Proinflammatory cytokines are an integral part of the osteolytic activity of Charcot arthropathy but are also central to normal bone healing. As there are no previous longitudinal studies investigating their role during the recovery phase of Charcot, we set out to monitor systemic levels of proinflammatory cytokines from Charcot presentation until a clinically and radiographically documented chronic state has been reached.

METHODS

Twenty-eight consecutive Charcot patients were monitored during 2 years by repeated foot radiographs, MRI and plasma levels of interleukin [IL]-6, IL-8, IL-1β, Tumor Necrosis Factor [TNF]-α, and IL-1 receptor antibody (IL-1RA). Charcot patients were treated with total contact cast (TCC) on the first day of inclusion. Neuropathic diabetic controls (n = 20) and Healthy subjects (n = 20) served as reference.

RESULTS

Plasma IL-6, IL-8, IL-1β and TNF-α in the acute and chronic phase of Charcot were below or at the level of diabetic controls and healthy, whereas IL-1RA/IL-1β ratio was continuously higher in Charcot patients. IL-6, TNF-α and IL-1RA began to increase one week after offloading to reach a peak after 4 months before gradually receding.

CONCLUSIONS

A sustained increase of IL-6 and TNF-α starting shortly after offloading and paralleled by accelerated bone healing on radiographs, suggest that offloading, by activating the inflammatory stage, has a key role to play in the onset of coupled bone remodeling. High IL-1RA/IL-1β ratio in Charcot patients at presentation supports a counter-balancing anti-inflammatory role for IL-1RA in the acute phase whereas a high ratio after two years, possibly due to renewed weight-bearing on a deformed foot, signal need for continued anti-inflammatory activity and contradicts a "cold" biological state in the chronic phase.

TNF-α Antibody Therapy in Combination With the T-Cell-Specific Antibody Anti-TCR Reverses the Diabetic Metabolic State in the LEW.1AR1-iddm Rat

Anti-tumor necrosis factor-α (TNF-α) therapy (5 mg/kg body weight), alone or combined with the T-cell-specific antibody anti-T-cell receptor (TCR) (0.5 mg/kg body weight), was performed over 5 days immediately after disease manifestation to reverse the diabetic metabolic state in the LEW.1AR1-iddm rat, an animal model of human type 1 diabetes. Only combination therapy starting at blood glucose concentrations below 15 mmol/L restored normoglycemia and normalized C-peptide. Increased β-cell proliferation and reduced apoptosis led to a restoration of β-cell mass along with an immune cell infiltration-free pancreas 60 days after the end of therapy. This combination of two antibodies, anti-TCR/CD3, as a cornerstone compound in anti-T-cell therapy, and anti-TNF-α, as the most prominent and effective therapeutic antibody in suppressing TNF-α action in many autoimmune diseases, was able to reverse the diabetic metabolic state. With increasing blood glucose concentrations during the disease progression, however, the proapoptotic pressure on the residual β-cell mass increased, ultimately reaching a point where the reservoir of the surviving β-cells was insufficient to allow a restoration of normal β-cell mass through regeneration. The present results may open a therapeutic window for reversal of diabetic hyperglycemia in patients, worthwhile of being tested in clinical trials.

CCL20 is elevated during obesity and differentially regulated by NF-κB subunits in pancreatic β-cells

Enhanced leukocytic infiltration into pancreatic islets contributes to inflammation-based diminutions in functional β-cell mass. Insulitis (aka islet inflammation), which can be present in both T1DM and T2DM, is one factor influencing pancreatic β-cell death and dysfunction. IL-1β, an inflammatory mediator in both T1DM and T2DM, acutely (within 1h) induced expression of the CCL20 gene in rat and human islets and clonal β-cell lines. Transcriptional induction of CCL20 required the p65 subunit of NF-κB to replace the p50 subunit at two functional κB sites within the CCL20 proximal gene promoter. The NF-κB p50 subunit prevents CCL20 gene expression during unstimulated conditions and overexpression of p50 reduces CCL20, but enhances cyclooxygenase-2 (COX-2), transcript accumulation after exposure to IL-1β. We also identified differential recruitment of specific co-activator molecules to the CCL20 gene promoter, when compared with the CCL2 and COX2 genes, revealing distinct transcriptional requirements for individual NF-κB responsive genes. Moreover, IL-1β, TNF-α and IFN-γ individually increased the expression of CCR6, the receptor for CCL20, on the surface of human neutrophils. We further found that the chemokine CCL20 is elevated in serum from both genetically obese db/db mice and in C57BL6/J mice fed a high-fat diet. Taken together, these results are consistent with a possible activation of the CCL20-CCR6 axis in diseases with inflammatory components. Thus, interfering with this signaling pathway, either at the level of NF-κB-mediated chemokine production, or downstream receptor activation, could be a potential therapeutic target to offset inflammation-associated tissue dysfunction in obesity and diabetes.

CXCR1/2 inhibition blocks and reverses type 1 diabetes in mice

Chemokines and their receptors have been associated with or implicated in the pathogenesis of type 1 diabetes (T1D), but the identification of a single specific chemokine/receptor pathway that may constitute a suitable target for the development of therapeutic interventions is still lacking. Here, we used multiple low-dose (MLD) streptozotocin (STZ) injections and the NOD mouse model to investigate the potency of CXCR1/2 inhibition to prevent inflammation- and autoimmunity-mediated damage of pancreatic islets. Reparixin and ladarixin, noncompetitive allosteric inhibitors, were used to pharmacologically blockade CXCR1/2. Transient blockade of said receptors was effective in preventing inflammation-mediated damage in MLD-STZ and in preventing and reversing diabetes in NOD mice. Blockade of CXCR1/2 was associated with inhibition of insulitis and modification of leukocytes distribution in blood, spleen, bone marrow, and lymph nodes. Among leukocytes, CXCR2(+) myeloid cells were the most decreased subpopulations. Together these results identify CXCR1/2 chemokine receptors as "master regulators" of diabetes pathogenesis. The demonstration that this strategy may be successful in preserving residual β-cells holds the potential to make a significant change in the approach to management of human T1D.

Anti-diabetic actions of carbon monoxide-releasing molecule (CORM)-A1: Immunomodulation and regeneration of islet beta cells

We have recently shown that carbon monoxide releasing molecule (CORM)-A1 prevents type 1 diabetes induced in C57BL/6 mice with multiple low doses of streptozotocin (MLDS) by shifting the Th1/Th17/M1 balance towards a Th2/M2 response. In the present work we tested the hypothesis that CORM-A1 might influence regulatory arm of the immune response, as well as beta cell regeneration. CORM-A1 (2 mg/kg/day) was administered for 10 days to mice induced with MLDS and/or depleted of low dose cyclophosphamide (CY)-sensitive FoxP3+ T regulatory (Treg) cells. Besides monitoring hyperglycaemia, ex vivo analysis of spleen, pancreatic lymph nodes (PLN) and pancreas was performed at the end of treatment. In CORM-A1-treated MLDS-induced mice the improvement of hyperglycaemia was observed only without depletion of CY-sensitive FoxP3+ Treg cells. This was accompanied by decreased levels of interleukin (IL)-12, IL-2 and early activation marker CD25 in the spleen and PLN and increased transforming growth factor (TGF)-β, resulting in reduced lymphocyte proliferation in both organs. In parallel, decreased transcript levels of IL-2, but increased mRNA expression of TGF-β, accompanied with up-regulation of Ki-67 protein expression was observed within pancreas. Together, the data suggested that besides the immunomodulatory potential, CORM-A1 probably induces beta cell regeneration.

Restoring the balance: immunotherapeutic combinations for autoimmune disease

Autoimmunity occurs when T cells, B cells or both are inappropriately activated, resulting in damage to one or more organ systems. Normally, high-affinity self-reactive T and B cells are eliminated in the thymus and bone marrow through a process known as central immune tolerance. However, low-affinity self-reactive T and B cells escape central tolerance and enter the blood and tissues, where they are kept in check by complex and non-redundant peripheral tolerance mechanisms. Dysfunction or imbalance of the immune system can lead to autoimmunity, and thus elucidation of normal tolerance mechanisms has led to identification of therapeutic targets for treating autoimmune disease. In the past 15 years, a number of disease-modifying monoclonal antibodies and genetically engineered biologic agents targeting the immune system have been approved, notably for the treatment of rheumatoid arthritis, inflammatory bowel disease and psoriasis. Although these agents represent a major advance, effective therapy for other autoimmune conditions, such as type 1 diabetes, remain elusive and will likely require intervention aimed at multiple components of the immune system. To this end, approaches that manipulate cells ex vivo and harness their complex behaviors are being tested in preclinical and clinical settings. In addition, approved biologic agents are being examined in combination with one another and with cell-based therapies. Substantial development and regulatory hurdles must be overcome in order to successfully combine immunotherapeutic biologic agents. Nevertheless, such combinations might ultimately be necessary to control autoimmune disease manifestations and restore the tolerant state.