GAD-alum immunotherapy in type 1 diabetes expands bifunctional Th1/Th2 autoreactive CD4 T cells

Application and Progression of Single-Cell RNA Sequencing in Diabetes Mellitus and Diabetes Complications

Diabetes is a systemic metabolic disorder primarily caused by insulin deficiency and insulin resistance, leading to chronic hyperglycemia. Prolonged diabetes can result in metabolic damage to multiple organs, including the heart, brain, liver, muscles, and adipose tissue, thereby causing various chronic fatal complications such as diabetic retinopathy, diabetic cardiomyopathy, and diabetic nephropathy. Single-cell RNA sequencing (scRNA-seq) has emerged as a valuable tool for investigating the cell diversity and pathogenesis of diabetes and identifying potential therapeutic targets in diabetes or diabetes complications. This review provides a comprehensive overview of recent applications of scRNA-seq in diabetes-related researches and highlights novel biomarkers and immunotherapy targets with cell-type information for diabetes and its associated complications.

Preclinical Development of a Tolerogenic Peptide From Glutamate Decarboxylase as a Candidate for Antigen-Specific Immunotherapy in Type 1 Diabetes

Dysregulation and loss of immune tolerance toward pancreatic β-cell autoantigens are features of type 1 diabetes (T1D). Until recently, life-long insulin injection was the only approved treatment for T1D, but it does not address the underlying disease pathology. The aim for antigen-specific immunotherapy (ASI) is to restore tolerance. ASI holds potential as a new therapeutic strategy for treating autoimmune diseases with well-characterized antigens. Peptide ASI using processing-independent CD4+ T-cell epitopes (PIPs) shows promising results in several autoimmune diseases. Here, we successfully applied the principles of PIP design to the T1D autoantigen glutamate decarboxylase 65 (GAD65). Peptides spanning GAD65 predicted to be pan-HLA-DR binding were selected. Peptide 10 (P10) displayed enriched responses in peripheral blood mononuclear cells from people with T1D. The minimal epitope of the P10 peptide was fine mapped using T-cell hybridomas generated from HLA-DRB1*04:01 transgenic mice. This minimal epitope, P10Sol, was demonstrated, using a novel activation-induced marker assay, to induce tolerance to the parent peptide in the transgenic mice. Finally, we show that GAD65 P10Sol PIP is recognized by CD4+ T cells from people with T1D who possess a range of HLA-DR alleles and, therefore, can be defined as a pan-DR-binding peptide with therapeutic potential.

ARTICLE HIGHLIGHTS

There are currently no approved antigen-specific immunotherapies (ASIs) for people with type 1 diabetes (T1D). We aimed to develop a peptide for ASI for T1D based on the T1D-associated auto-antigen glutamate decarboxylase 65 (GAD65). A minimal and soluble peptide derived from GAD65 was demonstrated to induce tolerance in an HLA transgenic mouse. Our data suggest this peptide derived from the GAD65 islet protein should be tested for therapeutic potential in people with T1D who have residual β-cell function.

Antigen-specific immunotherapies for autoimmune disease

Antigen-specific therapies have a long history in the treatment of allergy but have not been successful in autoimmunity. However, in the past 20 years, advances in the definition of the self-antigens that promote autoimmunity and the growing understanding of the mechanisms that maintain tolerance in health but fail in autoimmunity have led to antigen-specific approaches being considered for the treatment of autoimmune diseases. The core goal of each antigen-specific treatment approach is to remove the immune response that promotes autoimmunity whilst sparing protective responses. Approaches to antigen-specific therapy range from targeted deletion of autoreactive lymphocytes to tolerization of autoreactive T cells and active inhibition of autoimmune responses. Technologies such as vaccines, nanoparticles, cell-based therapies and gene editing are being harnessed to achieve these goals. Remaining challenges include the selection of the best antigen to target, modality and timing of administration of these therapies and the disease in which the therapies are used; overcoming these challenges will be vital to move antigen-specific therapies forward. Once established, antigen-specific therapy has the potential to be applied broadly in the area of autoimmunity.

Physiological and pathogenic T cell autoreactivity converge in type 1 diabetes

Autoimmune diseases result from autoantigen-mediated activation of adaptive immunity; intriguingly, autoantigen-specific T cells are also present in healthy donors. An assessment of dynamic changes of this autoreactive repertoire in both health and disease is thus warranted. Here we investigate the physiological versus pathogenic autoreactive processes in the context of Type 1 diabetes (T1D) and one of its landmark autoantigens, glutamic acid decarboxylase 65 (GAD65). Using single cell gene expression profiling and tandem T cell receptor (TCR) sequencing, we find that GAD65-specific true naïve cells are present in both health and disease, with GAD65-specific effector and memory responses showing similar ratios in healthy donors and patients. Deeper assessment of phenotype and TCR repertoire uncover differential features in GAD65-specific TCRs, including lower clonal sizes of healthy donor-derived clonotypes in patients. We thus propose a model whereby physiological autoimmunity against GAD65 is needed during early life, and that alterations of these physiological autoimmune processes in predisposed individuals trigger overt Type 1 diabetes.

The application of predictive value of diabetes autoantibody profile combined with clinical data and routine laboratory indexes in the classification of diabetes mellitus

Objective

Currently, distinct use of clinical data, routine laboratory indicators or the detection of diabetic autoantibodies in the diagnosis and management of diabetes mellitus is limited. Hence, this study was aimed to screen the indicators, and to establish and validate a multifactorial logistic regression model nomogram for the non-invasive differential prediction of type 1 diabetes mellitus.

Methods

Clinical data, routine laboratory indicators, and diabetes autoantibody profiles of diabetic patients admitted between September 2018 and December 2022 were retrospectively analyzed. Logistic regression was used to select the independent influencing factors, and a prediction nomogram based on the multiple logistic regression model was constructed using these independent factors. Moreover, the predictive accuracy and clinical application value of the nomogram were evaluated using Receiver Operating Characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), and clinical impact curves (CIC).

Results

A total of 522 diabetic patients were included in this study. These patients were randomized into training and validation sets in a 7:3 ratio. The predictors screened included age, prealbumin (PA), high-density lipoprotein cholesterol (HDL-C), islet cells autoantibodies (ICA), islets antigen 2 autoantibodies (IA-2A), glutamic acid decarboxylase antibody (GADA), and C-peptide levels. Based on these factors, a multivariate model nomogram was constructed, which had an Area Under Curve (AUC) of 0.966 and 0.961 for the training set and validation set, respectively. Subsequently, the calibration curves demonstrated a strong accuracy of the graph; the DCA and CIC results indicated that the graph could be used as a non-invasive valid predictive tool for the differential diagnosis of type 1 diabetes mellitus, clinically.

Conclusion

The established prediction model combining patient's age, PA, HDL-C, ICA, IA-2A, GADA, and C-peptide can assist in differential diagnosis of type 1 diabetes mellitus and type 2 diabetes mellitus and provides a basis for the clinical as well as therapeutic management of the disease.

Schistosoma-related molecules as a new strategy to combat type 1 diabetes through immune regulation

The study of immune regulation mechanisms induced by parasites may help develop new treatment methods for inflammatory diseases including type 1 diabetes, which is related to type 1 immune responses. The negative correlation between schistosomiasis infection and type 1 diabetes has been confirmed, and the mechanism of Schistosoma-mediated prevention of type 1 diabetes may be related to the adaptive and innate immune systems. Schistosoma-related molecules affect immune cell composition and macrophage polarization and stimulate an increase in natural killer T cells. Furthermore, Schistosoma-related molecules can regulate the adaptive immune responses related to the prevention of type 1 diabetes and change the Th1/Th2 and Th17/Treg axis. Our previous review showed the role of regulatory T cells in the protective of type 1 diabetes mediated by Schistosoma. Here, we aim to review the other mechanisms of schistosomiasis infection and Schistosoma-related products in regulating the immune response associated with the treatment of type 1 diabetes.

Fucoidan alleviated autoimmune diabetes in NOD mice by regulating pancreatic autophagy through the AMPK/mTOR1/TFEB pathway

Objectives

The present study investigated the effect and its underlying mechanisms of fucoidan on Type 1 diabetes mellitus (T1DM) in non-obese diabetic (NOD) mice.

Materials and Methods

Twenty 7-week-old NOD mice were used in this study, and randomly divided into two groups (10 mice in each group): the control group and the fucoidan treatment group (600 mg/kg. body weight). The weight gain, glucose tolerance, and fasting blood glucose level in NOD mice were detected to assess the development of diabetes. The intervention lasted for 5 weeks. The proportions of Th1/Th2 cells from spleen tissues were tested to determine the anti-inflammatory effect of fucoidan. Western blot was performed to investigate the expression levels of apoptotic markers and autophagic markers. Apoptotic cell staining was visualized through TdT-mediated dUTP nick-end labeling (TUNEL).

Results

The results suggested that fucoidan ameliorated T1DM, as evidenced by increased body weight and improved glycemic control of NOD mice. Fucoidan down-regulated the Th1/Th2 cells ratio and decreased Th1 type pro-inflammatory cytokines' level. Fucoidan enhanced the mitochondrial autophagy level of pancreatic cells and increased the expressions of Beclin-1 and LC3B II/LC3B I. The expression of p-AMPK was up-regulated and p-mTOR1 was inhibited, which promoted the nucleation of transcription factor EB (TFEB), leading to autophagy. Moreover, fucoidan induced apoptosis of pancreatic tissue cells. The levels of cleaved caspase-9, cleaved caspase-3, and Bax were up-regulated after fucoidan treatment.

Conclusion

Fucoidan could maintain pancreatic homeostasis and restore immune disorder through enhancing autophagy via the AMPK/mTOR1/TFEB pathway in pancreatic cells.

Bischoff D, S Singh S, H. Hahn B. Peptide-based immunotherapy in lupus: Where are we now?

In autoimmune rheumatic diseases, immune hyperactivity and chronic inflammation associate with immune dysregulation and the breakdown of immune self-tolerance. A continued, unresolved imbalance between effector and regulatory immune responses further exacerbates inflammation that ultimately causes tissue and organ damage. Many treatment modalities have been developed to restore the immune tolerance and immmunoregulatory balance in autoimmune rheumatic diseases, including the use of peptide-based therapeutics or the use of nanoparticles-based nanotechnology. This review summarizes the state-of-the-art therapeutic use of peptide-based therapies in autoimmune rheumatic diseases, with a specific focus on lupus.

Monitoring islet specific immune responses in type 1 diabetes clinical immunotherapy trials

The number of immunotherapeutic clinical trials in type 1 diabetes currently being conducted is expanding, and thus there is a need for robust immune-monitoring assays which are capable of detecting and characterizing islet specific immune responses in peripheral blood. Islet- specific T cells can serve as biomarkers and as such can guide drug selection, dosing regimens and immunological efficacy. Furthermore, these biomarkers can be utilized in patient stratification which can then benchmark suitability for participation in future clinical trials. This review focusses on the commonly used immune-monitoring techniques including multimer and antigen induced marker assays and the potential to combine these with single cell transcriptional profiling which may provide a greater understanding of the mechanisms underlying immuno-intervention. Although challenges remain around some key areas such as the need for harmonizing assays, technological advances mean that multiparametric information derived from a single sample can be used in coordinated efforts to harmonize biomarker discovery and validation. Moreover, the technologies discussed here have the potential to provide a unique insight on the effect of therapies on key players in the pathogenesis of T1D that cannot be obtained using antigen agnostic approaches.

Peripheral blood mononuclear cells reactivity in recent-onset type I diabetes patients is directed against the leader peptide of preproinsulin, GAD65271-285 and GAD65431-450

Introduction

T cell reactivity against pancreatic autoantigens is considered one of the main contributors to the destruction of insulin-producing cells in type 1 diabetes (T1D). Over the years, peptide epitopes derived from these autoantigens have been described in NOD mice and in both HLA class II transgenic mice and humans. However, which ones are involved in the early onset or in the progressive phases of the disease is still unclear.

Methods

In this work we have investigated, in early-onset T1D pediatric patients and HLA-matched controls from Sardinia, the potential of preproinsulin (PPI) and glutamate decarboxylase 65 (GAD65)-derived peptides to induce spontaneous T cell proliferation responses of peripheral blood mononuclear cells (PBMCs).

Results

Significant T cell responses against PPI1-18, PPI7-19 and PPI31-49, the first two belonging to the leader sequence of PPI, and GAD65271-285 and GAD65431-450, were found in HLA-DR4, -DQ8 and -DR3, -DQ2 T1D children.

Conclusions

These data show that cryptic epitopes from the leader sequence of the PPI and GAD65271-285 and GAD65431-450 peptides might be among the critical antigenic epitopes eliciting the primary autoreactive responses in the early phases of the disease. These results may have implications in the design of immunogenic PPI and GAD65 peptides for peptide-based immunotherapy.

Intralymphatic glutamic acid decarboxylase administration in type 1 diabetes patients induced a distinctive early immune response in patients with DR3DQ2 haplotype

GAD-alum given into lymph nodes to Type 1 diabetes (T1D) patients participating in a multicenter, randomized, placebo-controlled double-blind study seemed to have a positive effect for patients with DR3DQ2 haplotype, who showed better preservation of C-peptide than the placebo group. Here we compared the immunomodulatory effect of GAD-alum administered into lymph nodes of patients with T1D versus placebo with focus on patients with DR3DQ2 haplotype.

Methods

GAD autoantibodies, GADA subclasses, GAD₆₅-induced cytokine secretion (Luminex panel) and proliferation of peripheral mononuclear cells were analyzed in T1D patients (n=109) who received either three intra-lymphatic injections (one month apart) with 4 µg GAD-alum and oral vitamin D supplementation (2000 IE daily for 120 days), or placebo.

Results

Higher GADA, GADA subclasses, GAD₆₅-induced proliferation and cytokine secretion was observed in actively treated patients after the second injection of GAD-alum compared to the placebo group. Following the second injection of GAD-alum, actively treated subjects with DR3DQ2 haplotype had higher GAD₆₅-induced secretion of several cytokine (IL4, IL5, IL7, IL10, IL13, IFNγ, GM-CSF and MIP1β) and proliferation compared to treated individuals without DR3DQ2. Stratification of samples from GAD-alum treated patients according to C-peptide preservation at 15 months revealed that "good responder" individuals with better preservation of C-peptide secretion, independently of the HLA haplotype, had increased GAD₆₅-induced proliferation and IL13 secretion at 3 months, and a 2,5-fold increase of IL5 and IL10 as compared to "poor responders". The second dose of GAD-alum also induced a more pronounced cytokine secretion in "good responders" with DR3DQ2, compared to few "good responders" without DR3DQ2 haplotype.

Conclusion

Patients with DR3DQ2 haplotype had a distinct early cellular immune response to GAD-alum injections into the lymph node, and predominant GAD₆₅-induced IL13 secretion and proliferation that seems to be associated with a better clinical outcome. If confirmed in the ongoing larger randomized double-blind placebo-controlled clinical trial (DIAGNODE-3), including only patients carrying DR3DQ2 haplotype, these results might be used as early surrogate markers for clinical efficacy.

The need and benefit of immune monitoring to define patient and disease heterogeneity, mechanisms of therapeutic action and efficacy of intervention therapy for precision medicine in type 1 diabetes

The current standard of care for type 1 diabetes patients is limited to treatment of the symptoms of the disease, insulin insufficiency and its complications, not its cause. Given the autoimmune nature of type 1 diabetes, immunology is critical to understand the mechanism of disease progression, patient and disease heterogeneity and therapeutic action. Immune monitoring offers the key to all this essential knowledge and is therefore indispensable, despite the challenges and costs associated. In this perspective, I attempt to make this case by providing evidence from the past to create a perspective for future trials and patient selection.

Nanobiotechnology-Modified Cellular and Molecular Therapy as a Novel Approach for Autoimmune Diabetes Management

Several cellular and molecular therapies such as stem cell therapy, cell replacement therapy, gene modification therapy, and tolerance induction therapy have been researched to procure a permanent cure for Type 1 Diabetes. However, due to the induction of undesirable side effects, their clinical utility is questionable. These anti-diabetic therapies can be modified with nanotechnological tools for reducing adverse effects by selectively targeting genes and/or receptors involved directly or indirectly in diabetes pathogenesis, such as the glucagon-like peptide 1 receptor, epidermal growth factor receptor, human leukocyte antigen (HLA) gene, miRNA gene and hepatocyte growth factor (HGF) gene. This paper will review the utilities of nanotechnology in stem cell therapy, cell replacement therapy, beta-cell proliferation strategies, immune tolerance induction strategies, and gene therapy for type 1 diabetes management.

Long-Term GAD-alum Treatment Effect on Different T-Cell Subpopulations in Healthy Children Positive for Multiple Beta Cell Autoantibodies

Objective

The objective of this study was to explore whether recombinant GAD65 conjugated hydroxide (GAD-alum) treatment affected peripheral blood T-cell subpopulations in healthy children with multiple beta cell autoantibodies.

Method

The Diabetes Prevention–Immune Tolerance 2 (DiAPREV-IT 2) clinical trial enrolled 26 children between 4 and 13 years of age, positive for glutamic acid decarboxylase autoantibody (GADA) and at least one other autoantibody (insulin, insulinoma antigen-2, or zinc transporter 8 autoantibody (IAA, IA-2A, or ZnT8A)) at baseline. The children were randomized to two doses of subcutaneously administered GAD-alum treatment or placebo, 30 days apart. Complete blood count (CBC) and immunophenotyping of T-cell subpopulations by flow cytometry were performed regularly during the 24 months of follow-up posttreatment. Cross-sectional analyses were performed comparing lymphocyte and T-cell subpopulations between GAD-alum and placebo-treated subjects.

Results

GAD-alum-treated children had lower levels of lymphocytes (10⁹ cells/L) (p = 0.006), T-cells (10³ cells/μL) (p = 0.008), T-helper cells (10³ cells/μL) (p = 0.014), and cytotoxic T-cells (10³ cells/μL) (p = 0.023) compared to the placebo-treated children 18 months from first GAD-alum injection. This difference remained 24 months after the first treatment for lymphocytes (p = 0.027), T-cells (p = 0.022), T-helper cells (p = 0.048), and cytotoxic T-cells (p = 0.018).

Conclusion

Our findings suggest that levels of total T-cells and T-cell subpopulations declined 18 and 24 months after GAD-alum treatment in healthy children with multiple beta-cell autoantibodies including GADA.

Alterations of Cytokine Profiles in Patients With Recurrent Implantation Failure

Serum cytokine profile and T helper (Th)1/Th2 cell balance are related to the success of embryo implantation, although not yet firmly linked to recurrent implantation failure (RIF), a repeated failure to achieve clinical pregnancy following multiple high-quality embryo transfer. In this prospective study, comprehensive bioinfomatic analysis and logistic regression analysis were used to compare the serum cytokine profiles of 41 RIF patients with those of 29 subjects with first-cycle successful pregnancy in the mid-luteal phase and to assess the alterations of cytokine profiles in patients with clinical pregnancy at five weeks post-transplantation. We found several elevated pro-inflammatory cytokines, decreased anti-inflammatory cytokines, and increased Th1/Th2 cytokine ratios in RIF patients compared to control subjects. Specifically, the receiver operating characteristic (ROC) curve generated using multiple indicators provides a high predictive value for diagnosing RIF (area under the curve [AUC] = 0.94, 95% confidence interval [CI] 0.87-1.00, P < 0.0001), with a sensitivity of 96.55% and a specificity of 87.50%. Meanwhile, at five weeks post-transplantation, patients in both groups diagnosed with clinical pregnancy exhibited increased levels of several cytokines compared with pre-pregnancy levels, and a gradual shift in Th1/Th2 balance toward Th2. These findings suggest that inflammatory serum cytokines and the predominance of Th1 cells likely contribute to RIF and possibly reflect the immune environment at the maternal-fetal interface, suggesting their value as outcome indicators in assisted reproductive therapy.

The succinoglycan riclin restores beta cell function through the regulation of macrophages on Th1 and Th2 differentiation in type 1 diabetic mice

Bacterial succinoglycan is found suitable as a viscosifying and emulsifying agent in the food industry. Riclin is a de-succinyl succinoglycan from an Agrobacterium isolate. Our previous study has revealed that riclin exerts special anti-inflammatory effects in vitro and in vivo. This study aims to determine the effects of riclin on preventing against immunological injury of beta cells in a type 1 diabetic model. We found that orally riclin effectively restores beta-cell function and improves the complications of streptozotocin (STZ)-induced diabetes. Riclin also reduces STZ-induced liver and kidney damage, and balances the inappropriate ratio of T helper type 1 cell (Th1)/type 2 cell (Th2) in the spleen and pancreatic draining lymph nodes of the STZ-induced diabetic mice. In a co-culture system with the islet β cell MIN6 and macrophage RAW 264.7, riclin reduces the levels of IFN-γ and IL-1β, protecting against STZ-caused MIN6 cell injury. We identified that riclin specifically binds to the membrane of macrophages and regulates the ratio of IL-10 and IL-12, thereby inhibiting the macrophage-mediated polarization of Th1 cells and promoting the differentiation of Th2 cells, which depends on the dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) receptor. Moreover, orally riclin significantly decreases the incidence of STZ-induced hyperglycemia (7.1% in riclin vs. 92.9% in STZ), and prevents autoimmune diabetes in non-obese diabetic (NOD) mice, with 87.5% of mice free of diabetes compared to 46.6% of the control mice. These results suggest that riclin has potential to be a functional food to prevent and improve autoimmune diabetes and related diseases.

Next-gen therapeutics to spare and expand beta-cell mass

The most effective and physiological way to treat hyperglycemia is to restore beta-cell function and to rescue production of endogenous insulin. Increasing evidence suggests that both type 1 and type 2 diabetes are characterized by a significant defect in beta-cell mass, leading to the manifestation of the disease. Novel alternative approaches are needed to spare and expand beta-cell mass in patients with diabetes. This review sets out to describe the latest findings on how to restore the beta-cell mass and function in both forms of diabetes to modulate their progression.

Insights From Single Cell RNA Sequencing Into the Immunology of Type 1 Diabetes- Cell Phenotypes and Antigen Specificity

In the past few years, huge advances have been made in techniques to analyse cells at an individual level using RNA sequencing, and many of these have precipitated exciting discoveries in the immunology of type 1 diabetes (T1D). This review will cover the first papers to use scRNAseq to characterise human lymphocyte phenotypes in T1D in the peripheral blood, pancreatic lymph nodes and islets. These have revealed specific genes such as IL-32 that are differentially expressed in islet -specific T cells in T1D. scRNAseq has also revealed wider gene expression patterns that are involved in T1D and can predict its development even predating autoantibody production. Single cell sequencing of TCRs has revealed V genes and CDR3 motifs that are commonly used to target islet autoantigens, although truly public TCRs remain elusive. Little is known about BCR repertoires in T1D, but scRNAseq approaches have revealed that insulin binding BCRs commonly use specific J genes, share motifs between donors and frequently demonstrate poly-reactivity. This review will also summarise new developments in scRNAseq technology, the insights they have given into other diseases and how they could be leveraged to advance research in the type 1 diabetes field to identify novel biomarkers and targets for immunotherapy.

Nine residues in HLA-DQ molecules determine with susceptibility and resistance to type 1 diabetes among young children in Sweden

HLA-DQ molecules account over 50% genetic risk of type 1 diabetes (T1D), but little is known about associated residues. Through next generation targeted sequencing technology and deep learning of DQ residue sequences, the aim was to uncover critical residues and their motifs associated with T1D. Our analysis uncovered (αa1, α44, α157, α196) and (β9, β30, β57, β70, β135) on the HLA-DQ molecule. Their motifs captured all known susceptibility and resistant T1D associations. Three motifs, “DCAA-YSARD” (OR = 2.10, p = 1.96*10⁻²⁰), “DQAA-YYARD” (OR = 3.34, 2.69*10⁻⁷²) and “DQDA-YYARD” (OR = 3.71, 1.53*10⁻⁶) corresponding to DQ2.5 and DQ8.1 (the latter two motifs) associated with susceptibility. Ten motifs were significantly associated with resistance to T1D. Collectively, homozygous DQ risk motifs accounted for 43% of DQ-T1D risk, while homozygous DQ resistant motifs accounted for 25% protection to DQ-T1D risk. Of the identified nine residues five were within or near anchoring pockets of the antigenic peptide (α44, β9, β30, β57 and β70), one was the N-terminal of the alpha chain (αa1), one in the CD4-binding region (β135), one in the putative cognate TCR-induced αβ homodimerization process (α157), and one in the intra-membrane domain of the alpha chain (α196). Finding these critical residues should allow investigations of fundamental properties of host immunity that underlie tolerance to self and organ-specific autoimmunity.

3D Bioprinting and Translation of Beta Cell Replacement Therapies for Type 1 Diabetes

Type 1 diabetes (T1D) is an autoimmune disorder in which the body's own immune system selectively attacks beta cells within pancreatic islets resulting in insufficient insulin production and loss of the ability to regulate blood glucose (BG) levels. Currently, the standard of care consists of BG level monitoring and insulin administration, which are essential to avoid the consequences of dysglycemia and long-term complications. Although recent advances in continuous glucose monitoring and automated insulin delivery systems have resulted in improved clinical outcomes for users, nearly 80% of people with T1D fail to achieve their target hemoglobin A1c (HbA1c) levels defined by the American Diabetes Association. Intraportal islet transplantation into immunosuppressed individuals with T1D suffering from impaired awareness of hypoglycemia has resulted in lower HbA1c, elimination of severe hypoglycemic events, and insulin independence, demonstrating the unique potential of beta cell replacement therapy (BCRT) in providing optimal glycemic control and a functional cure for T1D. BCRTs need to maximize cell engraftment, long-term survival, and function in the absence of immunosuppression to provide meaningful clinical outcomes to all people living with T1D. One innovative technology that could enable widespread translation of this approach into the clinic is three-dimensional (3D) bioprinting. Herein, we review how bioprinting could facilitate translation of BCRTs as well as the current and forthcoming techniques used for bioprinting of a BCRT product. We discuss the strengths and weaknesses of 3D bioprinting in this context in addition to the road ahead for the development of BCRTs. Impact statement Significant research developments in beta cell replacement therapies show its promise in providing a functional cure for type 1 diabetes (T1D); yet, their widespread clinical use has been difficult to achieve. This review provides a brief overview of the requirements for a beta cell replacement product followed by a discussion on both the promise and limitations of three-dimensional bioprinting in facilitating the fabrication of such products to enable translation into the clinic. Advancements in this area could be a key component to unlocking the safety and effectiveness of beta cell therapy for T1D.

Prevention of Type 1 Diabetes: Past Experiences and Future Opportunities

Type 1 diabetes (T1D) results from autoimmune destruction of insulin-producing beta-cells in the pancreas, caused by the interplay of genetic and environmental factors. Despite the introduction of advanced technologies for diabetes management, most patients fail to achieve target glycemic control, and T1D still has a high burden of long-term end-organ complications. Over several decades, multiple clinical trials have attempted to find prevention for T1D in at-risk individuals or to stabilize, ultimately reverse, the disease in those with T1D. To date, T1D remains yet incurable condition; however, recently improved understanding of the natural history of the disease may lead to new strategies to preserve or improve beta-cell function in those at increased risk and T1D patients. This publication aims to provide an overview of past experiences and recent findings in the prevention of T1D.

Assessing effector T cells in type 1 diabetes

PURPOSE OF REVIEW

The role of T cells specific for islet autoantigens is proven in pathogenesis of type 1 diabetes. Recently, there has been rapid expansion in the number of T-cell subsets identified, this has coincided with an increase in the repertoire of reported islet antigens mainly through the discovery of novel epitopes. A discussion of how these marry together is now warranted and timely.

RECENT FINDINGS

In this review, we will discuss the autoreactivity against neo-epitopes. We then explore the growing array of T-cell subsets for both CD4 T cells, including follicular and peripheral T helper cells, and CD8 T cells, discussing evolution from naïve to exhausted phenotypes. Finally, we detail how subsets correlate with disease stage and loss of β-cell function and are impacted by immunotherapy.

SUMMARY

The expanding list of T-cell subsets may be potentially encouraging in terms of elucidating disease mechanisms and have a role as biomarkers for disease progression. Furthermore, T-cell subsets can be used in stratifying patients for clinical trials and for monitoring immunotherapy outcomes. However, the definition of subsets needs to be refined in order to ensure that there is a uniform approach in designating T-cell subset attributes that is globally applied.

Combined vitamin D, ibuprofen and glutamic acid decarboxylase-alum treatment in recent onset Type I diabetes: lessons from the DIABGAD randomized pilot trial

Aim

Double-blind placebo-controlled intervention using glutamic acid decarboxylase (GAD)-alum, vitamin D and Ibuprofen in recent onset Type I diabetes (T1D).

Methods

64 patients (T1D since <4 months, age 10-17.99, fasting sC-peptide ≥0.12 nmol/l, GADA-positive) were randomized into Day(D) 1-90 400 mg/day Ibuprofen, D1-450 vitamin D 2000 IU/day, D15, 45 sc. 20 μg GAD-alum; as A but placebo instead of Ibuprofen; as B but 40 μg GAD-alum D15, 45; placebo.

Results

Treatment was safe and tolerable. No C-peptide preservation was observed. We observed a linear correlation of baseline C-peptide, HbA1c and insulin/per kilogram/24 h with change in C-peptide AUC at 15 months (r = -0.776, p < 0.0001).

Conclusion

Ibuprofen, vitamin D + GAD-alum did not preserve C-peptide. Treatment efficacy was influenced by baseline clinical and immunological factors and vitamin D concentration. Clinical Trial Registration: NCT01785108 (ClinicalTrials.gov).

Combined vitamin D, ibuprofen and glutamic acid decarboxylase-alum treatment in recent onset Type I diabetes: lessons from the DIABGAD randomized pilot trial

Aim:

Double-blind placebo-controlled intervention using glutamic acid decarboxylase (GAD)-alum, vitamin D and Ibuprofen in recent onset Type I diabetes (T1D).

Methods

64 patients (T1D since <4 months, age 10–17.99, fasting sC-peptide ≥0.12 nmol/l, GADA-positive) were randomized into Day(D) 1–90 400 mg/day Ibuprofen, D1–450 vitamin D 2000 IU/day, D15, 45 sc. 20 μg GAD-alum; as A but placebo instead of Ibuprofen; as B but 40 μg GAD-alum D15, 45; placebo.

Results:

Treatment was safe and tolerable. No C-peptide preservation was observed. We observed a linear correlation of baseline C-peptide, HbA1c and insulin/per kilogram/24 h with change in C-peptide AUC at 15 months (r = -0.776, p < 0.0001).

Conclusion:

Ibuprofen, vitamin D + GAD-alum did not preserve C-peptide. Treatment efficacy was influenced by baseline clinical and immunological factors and vitamin D concentration. Clinical Trial Registration: NCT01785108 (ClinicalTrials.gov).

In many countries, Type I diabetes with insufficient own insulin secretion is a common life-threatening disease in children and adults. There is no prevention and no cure. In spite of very intense treatment, the disease leads to serious complications. There is no efficaceous method to save own insulin secretion without serious risks and adverse events, but autoantigen treatment with glutamic acid decarboxylase has shown some efficacy. We have tried a combination therapy with vitamin D and anti-inflammatory treatment (ibuprofen). Vitamin D in combination with glutamic acid decarboxylase-alum seems to have beneficial effects, but not Ibuprofen. The effect is influenced by basal clinical and immunological status.