Factors impeding the discovery of an intervention-based treatment for type 1 diabetes

Long-term blood glucose control via glucose-activated transcriptional regulation of insulin analogue in type 1 diabetes mice

AIM

To achieve glucose-activated transcriptional regulation of insulin analogue in skeletal muscle of T1D mice, thereby controlling blood glucose levels and preventing or mitigating diabetes-related complications.

MATERIALS AND METHODS

We developed the GANIT (Glucose-Activated NFAT-regulated INSA-F Transcription) system, an innovative platform building upon the previously established intramuscular plasmid DNA (pDNA) delivery and expression system. In the GANIT system, skeletal muscle cells are genetically engineered to endogenously produce the insulin analogue INSA-F (Insulin Aspart with Furin cleavage sites). The transcription of INSA-F is precisely controlled by a glucose-responsive promoter containing NFAT (Nuclear Factor of Activated T-cells) regulatory motifs, which can be activated in response to changes in extracellular glucose concentrations. This design enables glucose-dependent regulation of insulin analogue expression, mimicking physiological glucose-responsive insulin secretion.

RESULTS

T1D mice that received two GANIT treatments over a 2-month experimental period demonstrated significant improvements in glucose homeostasis, glucose tolerance and glycated haemoglobin (HbA1c) levels. Additionally, the treatment effectively reduced oxidative stress and alleviated cardiac and renal fibrosis, while maintaining a favourable biosafety profile.

CONCLUSION

The GANIT system provides significant advantages in terms of efficiency, convenience and cost-effectiveness, making it a promising approach for regulating blood glucose levels and alleviating diabetes-related complications in insulin-deficient diabetes.

DGCR2 targeting affibody molecules for delivery of drugs and imaging reagents to human beta cells

A distinctive feature of both type 1 and type 2 diabetes is the waning of insulin-secreting beta cells in the pancreas. New methods for direct and specific targeting of the beta cells could provide platforms for delivery of pharmaceutical reagents. Imaging techniques such as Positron Emission Tomography (PET) rely on the efficient and specific delivery of imaging reagents, and could greatly improve our understanding of diabetes etiology as well as providing biomarkers for viable beta-cell mass in tissue, in both pancreas and in islet grafts.The DiGeorge Syndrome Critical Region Gene 2 (DGCR2) protein has been suggested as a beta-cell specific protein in the pancreas, but so far there has been a lack of available high-affinity binders suitable for targeted drug delivery or molecular imaging. Affibody molecules belong to a class of small affinity proteins with excellent properties for molecular imaging. Here, we further validate the presence of DGCR2 in pancreatic and stem cell (SC)-derived beta cells, and then describe the generation and selection of several Affibody molecules candidates that target human DGCR2. Using an in-house developed directed evolution method, new DGCR2-binding Affibody molecules were generated and evaluated for thermal stability and affinity. The Affibody molecules variants were further developed as targeting agents for delivering imaging reagents to beta cell. The Affibody molecule ZDGCR2:AM106 displayed nanomolar affinity, suitable stability and biodistribution, with negligible toxicity to islets, qualifying it as a suitable lead candidate for further development as a tool for specific delivery of drugs and imaging reagents to beta cells.

Metabolic control, adherence to the gluten-free diet and quality of life among patients with type 1 diabetes and celiac disease

AIMS

In this cross-sectional study, we aimed to evaluate metabolic control, adherence to a gluten-free diet (GFD), and quality of life (QoL) in individuals with type 1 diabetes (T1D) and celiac disease (CD).

METHODS

We targeted individuals with T1D and CD at a major tertiary hospital in Saudi Arabia. We gathered retrospective data from medical records and prospectively assessed glycemic control using HbA1c and ambulatory glucose metrics, adherence to a GFD using the Celiac Dietary Adherence Test (CDAT), and QoL using the Celiac Disease Quality of Life survey (CD-QoL).

RESULTS

Forty-eight out of 1095 patients screened (4.38%) were included. Mean age and HbA1c were 21.3 (± 6.6) and 8.3% (± 0.8%). The average time in range% and above range% were 38.5 (range 24-68) and 29.6 (± 7.4). The median hypoglycemic events/month was 8, with a median duration of 80 min. The median overall CDAT and CD-QoL scores were 20.5 and 54. No significant correlations were observed between glucose management indicator (GMI), % in target, and CDAT/CD-QoL scores (all p > 0.05).

CONCLUSIONS

No significant effect of GFD on QoL or glycemic control was observed. Further prospective studies are warranted to establish solid evidence of the impact of GFD on individuals with T1D and CD.

Emergence of microneedles as a potential therapeutics in diabetes mellitus

Diabetes mellitus is a severe condition in which the pancreas produces inadequate insulin or the insulin generated is ineffective for utilisation by the body; as a result, insulin therapy is required for control blood sugar levels in patients having type 1 diabetes and is widely recommended in advanced type 2 diabetes patients with uncontrolled diabetes despite dual oral therapy, while subcutaneous insulin administration using hypodermic injection or pump-mediated infusion is the traditional route of insulin delivery and causes discomfort, needle phobia, reduced adherence, and risk of infection. Therefore, transdermal insulin delivery has been extensively explored as an appealing alternative to subcutaneous approaches for diabetes management which not only is non-invasive and easy, but also avoids first-pass metabolism and prevents gastrointestinal degradation. Microneedles have been commonly investigated in human subjects for transdermal insulin administration because they are minimally invasive and painless. The different types of microneedles developed for the transdermal delivery of anti-diabetic drugs are discussed in this review, including solid, dissolving, hydrogel, coated, and hollow microneedles. Numerous microneedle products have entered the market in recent years. But, before the microneedles can be effectively launched into the market, a significant amount of investigation is required to address the numerous challenges. In conclusion, the use of microneedles in the transdermal system is an area worth investigating because of its significant benefits over the oral route in the delivery of anti-diabetic medications and biosensing of blood sugar levels to assure improved clinical outcomes in diabetes management.

A mutant α1antitrypsin in complex with heat shock proteins as the primary antigen in type 1 diabetes in silico investigation

Based on previous results demonstrating that complexes of a mutant α1-antitrypsin with the heat shock proteins (HSP)70 and glucose-regulated protein94 (Grp94) circulate in the blood of patients with type 1 diabetes, we raised the hypothesis that these complexes could represent the primary antigen capable of triggering the autoimmune reactions leading to overt diabetes. As a first approach to this issue, we searched whether A1AT and HSPs had a sequence similarity to major islet antigen proteins so as to identify among the similar sequences those with potential relevance for the pathogenesis of diabetes. A thorough in silico analysis was performed to establish the score of similarity of the human proteins: A1AT, pro-insulin (INS), GAD65, IAPP, IA-2, ICA69, Grp94, HSP70 and HSP60. The sequences of A1AT and HSPs with the highest score of similarity to the islet peptides reported in the literature as the main autoantigens in human diabetes were recorded. At variance with other HSPs, also including HSP90 and Grp78, Grp94 contained the highest number and the longest sequences with structural similarity to A1AT and to well-known immunogenic peptides/epitopes of INS, GAD65, and IA-2. The similarity of A1AT with Grp94 and that of Grp94 with INS also suggested a functional relationship among the proteins. Specific sequences were identified in A1AT, Grp94 and HSP70, with the highest score of cross-similarity to a pattern of eight different islet protein epitopes. The similarity also involved recently discovered autoantigens in type 1 diabetes such as a hybrid peptides of insulin and the defective ribosomal insulin gene product. The significant similarity displayed by specific sequences of Grp94 and A1AT to the islet peptides considered main antigens in human diabetes, is a strong indication for testing these sequences as new peptides of immunogenic relevance in diabetes.

NK Cell Subsets Changes in Partial Remission and Early Stages of Pediatric Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic metabolic disease characterized by the autoimmune destruction of β-cells in the pancreatic islets. T1D is preceded by islet-specific inflammation led by several immune cells. Among them, natural killer (NK) cells are emerging as important players in T1D development. Human NK cells are characterized by CD56 and CD16 expression, which allows classifying NK cells into four subsets: 1) CD56dimCD16+ or effector NK cells (NKeff); 2) CD56brightCD16- or regulatory NK cells (NKreg); 3) intermediate CD56brightCD16+ NK cells; and 4) CD56dimCD16- NK cells, whose function is not well determined. Since many studies have shown that T1D progression is associated with changes in various immune cell types, we hypothesize that the kinetics of NK cell subsets in the blood could correlate with different stages of T1D. To that aim, pediatric patients newly diagnosed with T1D were recruited, and peripheral NK cell subsets were analyzed by flow cytometry at several disease checkpoints: disease onset, partial remission (PR), 8 months (for non-remitters), and 12 months of progression. Our results showed that total NK cells and their four subsets are altered at the early stages of T1D. A decrease in the counts and percentage of total NK cells and NKeff cells at the different disease stages was found when compared to controls. These results suggest the extravasation of these cells into the islets at disease onset, which is maintained throughout the follow-up. By contrast, NKreg cells increased during the early stages after T1D onset, and both intermediate NK cells and CD56dimCD16- NK cells diminished at the PR stage, which might reflect the immunoregulatory attempts and could be candidate biomarkers for this stage. Also, CD56dimCD16- NK cells increased during T1D progression. Finally, changes in CD16 expression were identified in the different T1D stages, highlighting a CD16 expression reduction in total NK cells and NKeff cells 1 year after diagnosis. That may reflect a state of exhaustion after multiple cell-to-cell interactions. Altogether, our preliminary data provide a longitudinal picture of peripheral NK cell subpopulations during the different T1D stages, which could be potential candidate biomarkers indicators of disease progression.

Immunomodulatory Dual-Sized Microparticle System Conditions Human Antigen Presenting Cells Into a Tolerogenic Phenotype In Vitro and Inhibits Type 1 Diabetes-Specific Autoreactive T Cell Responses

Current monotherapeutic agents fail to restore tolerance to self-antigens in autoimmune individuals without systemic immunosuppression. We hypothesized that a combinatorial drug formulation delivered by a poly-lactic-co-glycolic acid (PLGA) dual-sized microparticle (dMP) system would facilitate tunable drug delivery to elicit immune tolerance. Specifically, we utilized 30 µm MPs to provide local sustained release of granulocyte-macrophage colony-stimulating factor (GM-CSF) and transforming growth factor β1 (TGF-β1) along with 1 µm MPs to facilitate phagocytic uptake of encapsulated antigen and 1α,25(OH)2 Vitamin D3 (VD3) followed by tolerogenic antigen presentation. We previously demonstrated the dMP system ameliorated type 1 diabetes (T1D) and experimental autoimmune encephalomyelitis (EAE) in murine models. Here, we investigated the system's capacity to impact human cell activity in vitro to advance clinical translation. dMP treatment directly reduced T cell proliferation and inflammatory cytokine production. dMP delivery to monocytes and monocyte-derived dendritic cells (DCs) increased their expression of surface and intracellular anti-inflammatory mediators. In co-culture, dMP-treated DCs (dMP-DCs) reduced allogeneic T cell receptor (TCR) signaling and proliferation, while increasing PD-1 expression, IL-10 production, and regulatory T cell (Treg) frequency. To model antigen-specific activation and downstream function, we co-cultured TCR-engineered autoreactive T cell "avatars," with dMP-DCs or control DCs followed by β-cell line (ßlox5) target cells. For G6PC2-specific CD8+ avatars (clone 32), dMP-DC exposure reduced Granzyme B and dampened cytotoxicity. GAD65-reactive CD4+ avatars (clone 4.13) exhibited an anergic/exhausted phenotype with dMP-DC presence. Collectively, these data suggest this dMP formulation conditions human antigen presenting cells toward a tolerogenic phenotype, inducing regulatory and suppressive T cell responses.

Partial remission and early stages of pediatric type 1 diabetes display immunoregulatory changes. A pilot study

Type 1 diabetes (T1D) is a chronic metabolic disease of unknown etiology that results from β-cell destruction. The onset of the disease, which arises after a long asymptomatic period of autoimmune attack, may be followed by a relapsing and remitting progression, a phenomenon that is most evident during the partial remission phase (PR). This stage lasts for a few months, shows minor requirements of exogenous insulin and could be explained by a recovery of immunological tolerance. This study aims to identify new biomarkers at early stages of pediatric T1D that reflect immunoregulatory changes. To that end, pediatric patients with T1D (n = 52) and age-related control subjects (n = 30) were recruited. Immune response-related molecules and lymphocyte subsets were determined starting at T1D onset and until the second year of progression. Results showed that circulating TGF-β levels decreased during PR, and that betatrophin concentration was increased in all the considered stages without differing among studied checkpoints. Moreover, an increase of regulatory T, B and NK subsets was found during T1D progression, probably reflecting an attempt to restore self-tolerance. By contrast, a reduction in monocyte levels was observed at the early stages of diabetes. The results reveal significant changes in immunological parameters during the different early stages of T1D in children, which could ultimately serve as potential biomarkers to characterize the progression of T1D.

Mobile health in the management of type 1 diabetes: a systematic review and meta-analysis

BACKGROUND

As an insulin-dependent disease, type 1 diabetes requires paying close attention to the glycemic control. Studies have shown that mobile health (mHealth) can improve the management of chronic diseases. However, the effectiveness of mHealth in controlling the glycemic control remains uncertain. The objective of this study was to carry out a systematic review and meta-analysis using the available literature reporting findings on mHealth interventions, which may improve the management of type 1 diabetes.

METHODS

We performed a systematic literature review of all studies in the PubMed, Web of Science, and EMbase databases that used mHealth (including mobile phones) in diabetes care and reported glycated hemoglobin (HbA1c) values as a measure of glycemic control. The fixed effects model was used for this meta-analysis.

RESULTS

This study analyzed eight studies, which involved a total of 602 participants. In the meta-analysis, the fixed effects model showed a statistically significant decrease in the mean of HbA1c in the intervention group: - 0.25 (95% confidence interval: - 0.41, - 0.09; P = 0.003, I² = 12%). Subgroup analyses indicated that the patient's age, the type of intervention, and the duration of the intervention influenced blood glucose control. Funnel plots showed no publication bias.

CONCLUSIONS

Mobile health interventions may be effective among patients with type 1 diabetes. A significant reduction in HbA1c levels was associated with adult age, the use of a mobile application, and the long-term duration of the intervention.

Relative Pancreas Volume Is Reduced in First-Degree Relatives of Patients With Type 1 Diabetes

OBJECTIVE

Pancreas size is reduced in patients at type 1 diabetes onset and in autoantibody (AAB)-positive donors without diabetes. We sought to determine whether pancreas volume (PV) imaging could improve understanding of the loss of pancreas size in first-degree relatives (FDRs) of patients with type 1 diabetes. We also examined relationships among PV, AAB status, and endocrine and exocrine functions.

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional study that included five groups: AAB^- control subjects (no diabetes and no first- or second-degree relatives with type 1 diabetes) (N = 49), AAB^- FDRs (N = 61), AAB⁺ FDRs (N = 67 total: n = 31 with a single positive AAB [AAB⁺ single] and n = 36 with multiple positive AABs [AAB⁺ multiple]), and patients with recent-onset type 1 diabetes (<1 year) (N = 52). Fasting subjects underwent 1.5T pancreatic MRI, and PV and relative PV (RPV) (PV-to-BMI ratio) were analyzed between groups and for correlations with HbA_1c, C-peptide, glucose, and trypsinogen.

RESULTS

All FDR groups had significantly lower RPV adjusted for BMI (RPV_BMI) than control subjects (all P < 0.05). Patients with type 1 diabetes had lower RPV_BMI than AAB^- FDR (P < 0.0001) and AAB⁺ multiple (P ≤ 0.013) subjects. Transformed data indicated that trypsinogen levels were lowest in patients with type 1 diabetes.

CONCLUSIONS

This study demonstrates, for the first time, all FDRs having significantly smaller RPV_BMI compared with AAB^- control subjects. Furthermore, RPV_BMI was significantly lower in patients with recent-onset type 1 diabetes than in the AAB^- FDR and AAB⁺ multiple groups. As such, RPV_BMI may be a novel noninvasive biomarker for predicting progression through stages of type 1 diabetes risk. This study highlights the potential paracrine relationships between the exocrine and endocrine pancreas in progression to type 1 diabetes in subjects at risk.

Why Don't We Have a Vaccine Against Autoimmune Diseases? - A Review

This review examines some of the reasons why we don't have a vaccine against autoimmune diseases and highlights the progress that has been made. Many autoimmune diseases, such as rheumatoid arthritis (RA), multiple sclerosis (MS) and type 1 diabetes (T1D), are driven by autoimmune T cell responses. Unlike vaccines for most infectious diseases, which elicit antibody responses, are intended for immuno-naive individuals and considered preventative, a vaccine for an autoimmune disease must be therapeutic and resolve or control the on-going autoimmune response and condition in the diseased host. Despite these differences, many of the same considerations for infectious disease vaccines must also be addressed to develop a therapeutic vaccine for autoimmune diseases. The disease initiator/triggers, antigens and autoantigens, nature of the immunopathogenic and protective/therapeutic immune response will be compared for infectious and autoimmune diseases as will approaches for developing vaccines including formulations, animal models and indicators of success. The rationale for a therapeutic vaccine for RA will be discussed in greater detail with a relatively limited discussion of T1D, MS and other autoimmune diseases.

Alpha-1 Antitrypsin Therapy for Autoimmune Disorders

Autoimmune diseases are conditions caused by an over reactive immune system that attacks self-tissues and organs. Although the pathogenesis of autoimmune disease is complex and multi-factorial, inflammation is commonly involved. Therefore, anti-inflammatory therapies hold potential for the treatment of autoimmune diseases. However, long-term control of inflammation is challenging and most of the currently used drugs have side effects. Alpha-1 antitrypsin (AAT) is an anti-inflammatory protein with a well-known safety profile. The therapeutic potential of AAT has been tested in several autoimmune disease models. The first study using a recombinant adeno-associated viral (rAAV) vector showed that AAT gene transfer prevented the development of type 1 diabetes (T1D) in the non-obese diabetic (NOD) mouse model. Subsequent studies showed that treatment with AAT protein prevented and reversed type 1 diabetes. The beneficial effects of AAT treatment have also been observed in other autoimmune disease models such as rheumatoid arthritis and systemic lupus erythematosus. This paper reviews the therapeutic application of AAT and discusses possible mechanisms of action in various autoimmune diseases.

Skin-Related Complications Among Adolescents With Type 1 Diabetes Using Insulin Pump Therapy

Background

To identify the skin-related complications in adolescents with type 1 diabetes (T1D) using the insulin pump therapy (IPT).

Methods

A total of 64 T1D adolescents (between ages 13 and 19) using the insulin pump were included in this cross-sectional study. They had visited the Diabetes Clinic at Diabetes Treatment Center, Prince Sultan Military Medical City, Saudi Arabia, for treatment from January 2018 to March 2018. Data on the prior and present skin-related complications, for a 6-month interval, were gathered via a closed/structured questionnaire. Besides this, demographic information was also recorded.

Results

From the patients in this study (n = 64), 9.3% experienced 3 or more skin-related complications, whereas 7.8% patients registered 2 and 25% had only 1 such disorder. However, in 37 patients (51.8%), there was no evidence of skin-related complications. Significantly, the female revealed a higher level of issues (P = .036), >3 years on IPT (P = .039), negligence of infusion set rotation (P = .001), needle length of 9 mm (P = .021), and beyond 3 days for catheter replacement (P = .022). The factors age, body mass index, diabetes duration, and insulin dosage remained quite unaffected. From the regression analysis, the factors female gender, catheter replacement, and infusion set rotation showed up as the independent risk factors for the skin complications.

Conclusions

The IPT users invariably experience dermatologic conditions. Through this study, female gender, length of IPT usage time, and infusion set rotations were identified as the independent risk factors responsible for the skin issues.

PD-L1 genetic overexpression or pharmacological restoration in hematopoietic stem and progenitor cells reverses autoimmune diabetes

Immunologically based clinical trials performed thus far have failed to cure type 1 diabetes (T1D), in part because these approaches were nonspecific. Because the disease is driven by autoreactive CD4 T cells, which destroy β cells, transplantation of hematopoietic stem and progenitor cells (HSPCs) has been recently offered as a therapy for T1D. Our transcriptomic profiling of HSPCs revealed that these cells are deficient in programmed death ligand 1 (PD-L1), an important immune checkpoint, in the T1D nonobese diabetic (NOD) mouse model. Notably, the immunoregulatory molecule PD-L1 plays a determinant role in controlling/inhibiting activated T cells and thus maintains immune tolerance. Furthermore, our genome-wide and bioinformatic analysis revealed the existence of a network of microRNAs (miRNAs) controlling PD-L1 expression, and silencing one of key altered miRNAs restored PD-L1 expression in HSPCs. We therefore sought to determine whether restoration of this defect would cure T1D as an alternative to immunosuppression. Genetically engineered or pharmacologically modulated HSPCs overexpressing PD-L1 inhibited the autoimmune response in vitro, reverted diabetes in newly hyperglycemic NOD mice in vivo, and homed to the pancreas of hyperglycemic NOD mice. The PD-L1 expression defect was confirmed in human HSPCs in T1D patients as well, and pharmacologically modulated human HSPCs also inhibited the autoimmune response in vitro. Targeting a specific immune checkpoint defect in HSPCs thus may contribute to establishing a cure for T1D.

Type 1 Diabetes Mellitus in Saudi Arabia: A Soaring Epidemic

Type 1 diabetes mellitus (T1DM) is quite prevalent in the world, with a proportion of 1 in every 300 persons and steadily rising frequency of incidence of about 3% every year. More alarmingly, the incidence of T1DM among infants is also increasing, with children as young as 6 months succumbing to it, instead of that at a rather established vulnerable age of around seven and near puberty, when the hormones antagonize the action of insulin. These reports pose a unique challenge of developing efficient T1DM management system for the young children. The Kingdom of Saudi Arabia (KSA) is the largest country in the Middle East that occupies approximately four-fifths of the Arabian Peninsula supporting a population of more than 33.3 million people, of whom 26% are under the age of 14 years. As per the Diabetes Atlas (8th edition), 35,000 children and adolescents in Saudi Arabia suffer from T1DM, which makes Saudi Arabia rank the 8th in terms of numbers of TIDM patients and 4th country in the world in terms of the incidence rate (33.5 per 100,000 individuals) of TIDM. However, in comparison with that in the developed countries, the number of research interventions on the prevalence, incidence, and the sociodemographic aspects of T1DM is woefully inadequate. In this review we discuss different aspects of T1DM in Saudi Arabia drawing on the published literature currently available.

Reply to "Tolerogenic insulin peptide therapy precipitates type 1 diabetes"

In this issue of JEM, Bergman et al. (https://doi.org/10.1084/jem.20160471) challenge the data published in our previous JEM paper on the preventive effect of tolerogenic vaccination with a strong agonist insulin mimetope in type 1 diabetes. Here, we provide a response to these data and suggest that appropriate subimmunogenic conditions are required to induce Foxp3⁺ regulatory T cell conversion.

Inhibition of Phosphoinositide 3-Kinase p110delta Does Not Affect T Cell Driven Development of Type 1 Diabetes Despite Significant Effects on Cytokine Production

Type 1 diabetes is caused by the destruction of insulin producing beta cells by the immune system. The p110δ isoform of PI3K is expressed primarily in cells of haematopoietic origin and the catalytic activity of p110δ is important for the activation of these cells. Targeting of this pathway offers an opportunity to reduce immune cell activity without unwanted side effects. We have explored the effects of a specific p110δ isoform inhibitor, IC87114, on diabetogenic T cells both in vitro and in vivo, and find that although pharmacological inhibition of p110δ has a considerable impact on the production of pro-inflammatory cytokines, it does not delay the onset of diabetes after adoptive transfer of diabetogenic cells. Further, we demonstrate that combination treatment with CTLA4-Ig does not improve the efficacy of treatment, but instead attenuates the protective effects seen with CTLA4-Ig treatment alone. Our results suggest that decreased IL-10 production by Foxp3+ CD4+ T cells in the presence of IC87114 negates individual anti-inflammatory effects of IC8114 and CTLA4-Ig.

Antigen-Specific Regulatory T Cells and Low Dose of IL-2 in Treatment of Type 1 Diabetes

Regulatory T cells (Tregs) play an important role in preventing effector T-cell (Teff) targeting of self-antigens that can lead to tissue destruction in autoimmune settings, including type 1 diabetes (T1D). Autoimmunity is caused in part by an imbalance between Teff and Tregs. Early attempts to treat with immunosuppressive agents have led to serious side effects, thus requiring a more targeted approach. Low-dose IL-2 (LD IL-2) can provide immunoregulation with few side effects by preferentially acting on Tregs to drive tolerance. The concept of LD IL-2 as a therapeutic approach is supported by data in mouse models where autoimmunity is cured and further strengthened by success in human clinical studies in hepatitis C virus-induced vasculitis, chronic graft-versus-host disease, and Alopecia areata. Treatment will require identification of a safe therapeutic window, which is a difficult task given that patients are reported to have deficient or defective IL-2 production or signaling and have experienced mild activation of NK cells and eosinophils with LD IL-2 therapy. In T1D, an LD IL-2 clinical trial concluded that Tregs can be safely expanded in humans; however, the study was not designed to address efficacy. Antigen-specific therapies have also aimed at regulation of the autoimmune response but have been filled with disappointment despite an extensive list of diverse islet antigens tested in humans. This approach could be enhanced through the addition of LD IL-2 to the antigenic treatment regimen to improve the frequency and function of antigen-specific Tregs, without global immunosuppression. Here, we will discuss the use of LD IL-2 and islet antigen to enhance antigen-specific Tregs in T1D and focus on what is known about their immunological impact, their safety, and potential efficacy, and need for better methods to identify therapeutic effectiveness.