GAD vaccine reduces insulin loss in recently diagnosed type 1 diabetes: findings from a Bayesian meta-analysis

Disease-modifying pharmacological treatments of type 1 diabetes: Molecular mechanisms, target checkpoints, and possible combinatorial treatments

After a century of extensive scientific investigations, there is still no curative or disease-modifying treatment available that can provide long-lasting remission for patients diagnosed with type 1 diabetes (T1D). Although T1D has historically been regarded as a classic autoimmune disorder targeting and destroying pancreatic islet β-cells, significant research has recently demonstrated that β-cells themselves also play a substantial role in the disease's progression, which could explain some of the unfavorable clinical outcomes. We offer a thorough review of scientific and clinical insights pertaining to molecular mechanisms behind pathogenesis and the different therapeutic interventions in T1D covering over 20 possible pharmaceutical intervention treatments. The interventions are categorized as immune therapies, treatments targeting islet endocrine dysfunctions, medications with dual modes of action in immune and islet endocrine cells, and combination treatments with a broader spectrum of activity. We suggest that these collective findings can provide a valuable platform to discover new combinatorial synergies in search of the curative disease-modifying intervention for T1D. SIGNIFICANCE STATEMENT: This research delves into the underlying causes of T1D and identifies critical mechanisms governing β-cell function in both healthy and diseased states. Thus, we identify specific pathways that could be manipulated by existing or new pharmacological interventions. These interventions fall into several categories: (1) immunomodifying therapies individually targeting immune cell processes, (2) interventions targeting β-cells, (3) compounds that act simultaneously on both immune cell and β-cell pathways, and (4) combinations of compounds simultaneously targeting immune and β-cell pathways.

Redosing with Intralymphatic GAD-Alum in the Treatment of Type 1 Diabetes: The DIAGNODE-B Pilot Trial

Immunotherapies aimed at preserving residual beta cell function in type 1 diabetes have been successful, although the effect has been limited, or raised safety concerns. Transient effects often observed may necessitate redosing to prolong the effect, although this is not always feasible or safe. Treatment with intralymphatic GAD-alum has been shown to be tolerable and safe in persons with type 1 diabetes and has shown significant efficacy to preserve C-peptide with associated clinical benefit in individuals with the human leukocyte antigen DR3DQ2 haplotype. To further explore the feasibility and advantages of redosing with intralymphatic GAD-alum, six participants who had previously received active treatment with intralymphatic GAD-alum and carried HLA DR3-DQ2 received one additional intralymphatic dose of 4 μg GAD-alum in the pilot trial DIAGNODE-B. The participants also received 2000 U/day vitamin D (Calciferol) supplementation for two months, starting one month prior to the GAD-alum injection. During the 12-month follow-up, residual beta cell function was estimated with Mixed-Meal Tolerance Tests, and clinical and immune responses were observed. C-peptide decreased minimally, and most patients showed stable HbA1c and IDAA1c. The mean % TIR increased while the mean daily insulin dose decreased at month 12 compared to the baseline. Redosing with GAD-alum seems to be safe and tolerable, and may prolong the disease modification elicited by the original GAD-alum treatment.

Shifting the paradigm of type 1 diabetes: a narrative review of disease modifying therapies

A new diagnosis of type 1 diabetes (T1D) may be accompanied by numerous lifelong financial, emotional, and physical challenges, thus advancements in therapies that can delay the onset of clinical disease are crucial. T1D is an autoimmune condition involving destruction of pancreatic beta cells leading to insulin deficiency, hyperglycemia, and long-term insulin dependence. The pathogenesis of T1D is classified into stages, with the first signal being the detection of autoantibodies without any glycemic changes. In the second stage, dysglycemia develops without symptoms, and in stage 3, symptoms of hyperglycemia become apparent, and at this time a clinical diagnosis of T1D is made. As a greater understanding of these stages of T1D have evolved, research efforts have been devoted to delaying the onset of clinical disease. To date, only one medication, teplizumab, has been approved by the Food and Drug Administration (FDA) for the treatment of stage 2 T1D. This narrative review present published trials and ongoing research on disease modifying therapies (DMT) in T1D, the mechanisms of action for each therapy, and the stages of T1D that these interventions are being studied.

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.

Screening and Prevention of Type 1 Diabetes: Where Are We?

A diagnosis of type 1 diabetes (T1D) and the subsequent requirement for exogenous insulin treatment is associated with considerable acute and chronic morbidity and a substantial effect on patient quality of life. Importantly, a large body of work suggests that early identification of presymptomatic T1D can accurately predict clinical disease, and when paired with education and monitoring, can yield improved health outcomes. Furthermore, a growing cadre of effective disease-modifying therapies provides the potential to alter the natural history of early stages of T1D. In this mini review, we highlight prior work that has led to the current landscape of T1D screening and prevention, as well as challenges and next steps moving into the future of these rapidly evolving areas of patient care.

A 1-year pilot study of intralymphatic injections of GAD-alum in individuals with latent autoimmune diabetes in adults (LADA) with signs of high immunity: No safety concerns and resemblance to juvenile type 1 diabetes

AIMS

To test, for the first time in latent autoimmune diabetes in adults (LADA), the effects of autoantigen-specific immunotherapy by intralymphatic administration of aluminium-formulated recombinant human glutamic acid decarboxylase 65 (GAD-alum); specifically, to test if this treatment is safe, to test whether it induces a strong immunological response akin to a similar protocol in type 1 diabetes and to look for associations with preserved beta-cell function.

MATERIALS AND METHODS

Three GAD-alum injections, 4 μg each, were administered 1 month apart into an inguinal lymph node in 14 people with newly diagnosed LADA (age 30-62 years) presenting with high levels of antibodies against glutamic acid decarboxylase (GADA). Adverse effects, immunological variables and beta-cell function were monitored, with detailed measurements at 5 and 12 months from baseline.

RESULTS

Clinical adverse effects were minor and transient and measured laboratory variables were unaffected. All participants completed the study. Treatment raised levels of GADA, elicited strong effects on reactivity of peripheral blood mononuclear cells to GAD and raised cytokine/chemokine levels. Beta-cell function appeared stable preferentially in the seven participants carrying human leukocyte antigen (HLA) haplotypes DR3DQ2, as assessed by C-peptide glucagon tests (P < 0.05 vs. seven non-carriers).

CONCLUSION

Intralymphatic treatment with GAD-alum in LADA is without clinical or other safety concerns over a 12-month period. As in a similar protocol used in type 1 diabetes, treatment exerts a strong immunological impact and is compatible with protection of beta-cell function preferentially in HLA-DR3DQ2 LADA patients. These findings pave the way for a randomized controlled trial in this important subgroup of LADA patients.

GABA and Combined GABA with GAD65-Alum Treatment Alters Th1 Cytokine Responses of PBMCs from Children with Recent-Onset Type 1 Diabetes

Type 1 diabetes (T1D) is an autoimmune disease culminating in the destruction of insulin-producing pancreatic cells. There is a need for the development of novel antigen-specific strategies to delay cell destruction, including combinatorial strategies that do not elicit systemic immunosuppression. Gamma-aminobutyric acid (GABA) is expressed by immune cells, β-cells, and gut bacteria and is immunomodulatory. Glutamic-acid decarboxylase 65 (GAD65), which catalyzes GABA from glutamate, is a T1D autoantigen. To test the efficacy of combinatorial GABA treatment with or without GAD65-immunization to dampen autoimmune responses, we enrolled recent-onset children with T1D in a one-year clinical trial (ClinicalTrials.gov NCT02002130) and examined T cell responses. We isolated peripheral blood mononuclear cells and evaluated cytokine responses following polyclonal activation and GAD65 rechallenge. Both GABA alone and GABA/GAD65-alum treatment inhibited Th1 cytokine responses over the 12-month study with both polyclonal and GAD65 restimulation. We also investigated whether patients with HLA-DR3-DQ2 and HLA-DR4-DQ8, the two highest-risk human leukocyte antigen (HLA) haplotypes in T1D, exhibited differences in response to GABA alone and GABA/GAD65-alum. HLA-DR4-DQ8 patients possessed a Th1-skewed response compared to HLA-DR3-DQ2 patients. We show that GABA and GABA/GAD65-alum present an attractive immunomodulatory treatment for children with T1D and that HLA haplotypes should be considered.

Autoimmune susceptible HLA class II motifs facilitate the presentation of modified neoepitopes to potentially autoreactive T cells

Rheumatoid arthritis (RA), multiple sclerosis (MS), type 1 diabetes (T1D), and celiac disease (CD), are strongly associated with susceptible HLA class II haplotypes. The peptide-binding pockets of these molecules are polymorphic, thus each HLA class II protein presents a distinct set of peptides to CD4⁺ T cells. Peptide diversity is increased through post-translational modifications, generating non-templated sequences that enhance HLA binding and/or T cell recognition. The high-risk HLA-DR alleles that confer susceptibility to RA are notable for their ability to accommodate citrulline, promoting responses to citrullinated self-antigens. Likewise, HLA-DQ alleles associated with T1D and CD favor the binding of deamidated peptides. In this review, we discuss structural features that promote modified self-epitope presentation, provide evidence supporting the relevance of T cell recognition of such antigens in disease processes, and make a case that interrupting the pathways that generate such epitopes and reprogramming neoepitope-specific T cells are key strategies for effective therapeutic intervention.

The Magic Staff: A Comprehensive Overview of Baculovirus-Based Technologies Applied to Human and Animal Health

Baculoviruses are enveloped, insect-specific viruses with large double-stranded DNA genomes. Among all the baculovirus species, Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is the most studied. Due to its characteristics regarding biosafety, narrow host range and the availability of different platforms for modifying its genome, AcMNPV has become a powerful biotechnological tool. In this review, we will address the most widespread technological applications of baculoviruses. We will begin by summarizing their natural cycle both in larvae and in cell culture and how it can be exploited. Secondly, we will explore the different baculovirus-based protein expression systems (BEVS) and their multiple applications in the pharmaceutical and biotechnological industry. We will focus particularly on the production of vaccines, many of which are either currently commercialized or in advanced stages of development (e.g., Novavax, COVID-19 vaccine). In addition, recombinant baculoviruses can be used as efficient gene transduction and protein expression vectors in vertebrate cells (e.g., BacMam). Finally, we will extensively describe various gene therapy strategies based on baculoviruses applied to the treatment of different diseases. The main objective of this work is to provide an extensive up-to-date summary of the different biotechnological applications of baculoviruses, emphasizing the genetic modification strategies used in each field.

A randomized trial of oral gamma aminobutyric acid (GABA) or the combination of GABA with glutamic acid decarboxylase (GAD) on pancreatic islet endocrine function in children with newly diagnosed type 1 diabetes

Gamma aminobutyric acid(GABA) is synthesized by glutamate decarboxylase(GAD) in β-cells. Regarding Type 1 diabetes(T1D), animal/islet-cell studies found that GABA promotes insulin secretion, inhibits α-cell glucagon and dampens immune inflammation, while GAD immunization may also preserve β-cells. We evaluated the safety and efficacy of oral GABA alone, or combination GABA with GAD, on the preservation of residual insulin secretion in recent-onset T1D. Herein we report a single-center, double-blind, one-year, randomized trial in 97 children conducted March 2015 to June 2019(NCT02002130). Using a 2:1 treatment:placebo ratio, interventions included oral GABA twice-daily(n = 41), or oral GABA plus two-doses GAD-alum(n = 25), versus placebo(n = 31). The primary outcome, preservation of fasting/meal-stimulated c-peptide, was not attained. Of the secondary outcomes, the combination GABA/GAD reduced fasting and meal-stimulated serum glucagon, while the safety/tolerability of GABA was confirmed. There were no clinically significant differences in glycemic control or diabetes antibody titers. Given the low GABA dose for this pediatric trial, future investigations using higher-dose or long-acting GABA formulations, either alone or with GAD-alum, could be considered, although GABA alone or in combination with GAD-alum did nor preserve beta-cell function in this trial.

Phase III, randomised, double-blind, placebo-controlled, multicentre trial to evaluate the efficacy and safety of rhGAD65 to preserve endogenous beta cell function in adolescents and adults with recently diagnosed type 1 diabetes, carrying the genetic HLA DR3-DQ2 haplotype: the DIAGNODE-3 study protocol

INTRODUCTION

Type 1 diabetes (T1D) is an autoimmune disease leading to the destruction of the insulin-producing beta cells resulting in insulin deficiency and hyperglycaemic. Today, no approved therapy exists to halt this detrimental immunologic process. In a recent phase 2b study, intralymphatic administration of recombinant human glutamic acid decarboxylase 65 kDa (rhGAD65) adsorbed to Alhydrogel adjuvant to individuals recently diagnosed with T1D and carrying the HLA DR3-DQ2 haplotype showed promising results in preserving endogenous insulin secretion, confirming the results of a large meta-analysis of three randomised placebo-controlled trials of subcutaneous rhGAD65. The aim of the current precision medicine phase 3 study is to determine whether intralymphatic administration of rhGAD65 preserves insulin secretion and improves glycaemic control in presumed responder individuals with recently diagnosed T1D carrying HLA DR3-DQ2.

METHODS AND ANALYSIS

Individuals ≥12 and <29 years recently diagnosed with T1D (<6 months) will be screened for the HLA DR3-DQ2 haplotype, endogenous insulin production estimated by fasting C-peptide and presence of GAD65 antibodies. 330 patients are planned to be randomised to 3 monthly intralymphatic injections of rhGAD65 or placebo (both accompanied by oral vitamin D supplementation), followed by 22 months of follow-up. The study is powered to detect a treatment effect in the two coprimary endpoints; change from baseline in AUC_(0-120min) C-peptide levels during a mixed meal tolerance test, and change from baseline in glycaemic control estimated by haemoglobin A1c at 24 months. Secondary endpoints include effects on glucose patterns collected by masked continuous glucose monitoring, proportion of patients in partial remission and number of episodes of severe hypoglycaemia and/or diabetic ketoacidosis.

ETHICS AND DISSEMINATION

The trial is approved by Ethics Committees in Poland (124/2021), the Netherlands (R21.089), Sweden (2021-05063), Czech Republic (EK-1144/21), Germany (2021361) and Spain (21/2021). Results will be published in international peer-reviewed scientific journals and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

EudraCT identifier: 2021-002731-32, NCT identifier: NCT05018585.

Genetic engineering of baculovirus-insect cell system to improve protein production

The Baculovirus Expression Vector System (BEVS), a mature foreign protein expression platform, has been available for decades, and has been effectively used in vaccine production, gene therapy, and a host of other applications. To date, eleven BEVS-derived products have been approved for use, including four human vaccines [Cervarix against cervical cancer caused by human papillomavirus (HPV), Flublok and Flublok Quadrivalent against seasonal influenza, Nuvaxovid/Covovax against COVID-19], two human therapeutics [Provenge against prostate cancer and Glybera against hereditary lipoprotein lipase deficiency (LPLD)] and five veterinary vaccines (Porcilis Pesti, BAYOVAC CSF E2, Circumvent PCV, Ingelvac CircoFLEX and Porcilis PCV). The BEVS has many advantages, including high safety, ease of operation and adaptable for serum-free culture. It also produces properly folded proteins with correct post-translational modifications, and can accommodate multi-gene- or large gene insertions. However, there remain some challenges with this system, including unstable expression and reduced levels of protein glycosylation. As the demand for biotechnology increases, there has been a concomitant effort into optimizing yield, stability and protein glycosylation through genetic engineering and the manipulation of baculovirus vector and host cells. In this review, we summarize the strategies and technological advances of BEVS in recent years and explore how this will be used to inform the further development and application of this system.

Vaccine for Diabetes-Where Do We Stand?

Diabetes is an endocrinological disorder with a rapidly increasing number of patients globally. Over the last few years, the alarming status of diabetes has become a pivotal factor pertaining to morbidity and mortality among the youth as well as middle-aged people. Current developments in our understanding related to autoimmune responses leading to diabetes have developed a cause for concern in the prospective usage of immunomodulatory agents to prevent diabetes. The mechanism of action of vaccines varies greatly, such as removing autoreactive T cells and inhibiting the interactions between immune cells. Currently, most developed diabetes vaccines have been tested in animal models, while only a few human trials have been completed with positive outcomes. In this review, we investigate the undergoing clinical trial studies for the development of a prototype diabetes vaccine.

Glutamic acid decarboxylase immunotherapy for type 1 diabetes

PURPOSE OF REVIEW

To describe recent development of an autoantigen (GAD) treatment towards well tolerated and efficacious precision medicine in type 1 diabetes.

RECENT FINDINGS

Although subcutaneous GAD-alum treatment failed to reach primary endpoint in a phase III trial, metanalyses showed a 97% probability of efficacy, and clear efficacy in patients carrying Hyman Leucoycte Antigen (HLA) DR3DQ2. Efforts have been made to improve efficacy by trying combination therapies with vitamin D + Ibuprofen resp vitamin D + Etanercept (TNF-α inhibition), without any breakthrough until the administration of GAD-alum was changed from subcutaneous to intralymphatic. With a very small dose of GAD-alum (4 μg) given into an inguinal lymph three times with 1 month interval, the efficacy in patients with HLADR3DQ2 has been impressive, with significantly better beta cell preservation than patients who got placebo in a double-blind randomized trial, and clinical efficacy with more patients in partial remission (IDAA1c < 9) and larger proportion of patients with CGM-measured blood glucose Time In Range (TIR), significantly correlated to the C-peptide values. The treatment has been easy for patients and healthcare without treatment-related risk or adverse events.

SUMMARY

Intralymphatic GAD-alum treatment in type 1 diabetes patients carrying HLA DR3DQ2 seems to be an attractive immune intervention.

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.

Intra-lymphatic administration of GAD-alum in type 1 diabetes: long-term follow-up and effect of a late booster dose (the DIAGNODE Extension trial)

AIM

To evaluate the long-term effect of intra-lymphatic administration of GAD-alum and a booster dose 2.5 years after the first intervention (DIAGNODE Extension study) in patients with recent-onset type 1 diabetes.

METHODS

DIAGNODE-1: Samples were collected from 12 patients after 30 months who had received 3 injections of 4 μg GAD-alum into a lymph node with one-month interval. DIAGNODE Extension study: First in human, a fourth booster dose of autoantigen (GAD-alum) was given to 3 patients at 31.5 months, who were followed for another 12 months. C-peptide was measured during mixed meal tolerance tests (MMTTs). GADA, IA-2A, GADA subclasses, GAD₆₅-induced cytokines, PBMCs proliferation and T cells markers were analyzed.

RESULTS

After 30-month treatment, efficacy was still seen in 8/12 patients (good responders, GR). Partial remission (IDAA1c < 9) had decreased compared to 15 months, but did not differ from baseline, and HbA1c remained stable. GAD₆₅-specific immune responses induced by the treatment started to wane after 30 months, and most changes observed at 15 months were undetectable. GADA subclasses IgG2, IgG3 and IgG4 were predominant in the GR along with IgG1. A fourth intra-lymphatic GAD-alum dose to three patients after 31.5 months gave no adverse events. In all three patients, C-peptide seemed to increase the first 6 months, and thereafter, C-peptide, HbA1c, insulin requirement and IDAA1c remained stable.

CONCLUSION

The effect of intra-lymphatic injections of GAD-alum had decreased after 30 months. Good responders showed a specific immune response. Administration of a fourth booster dose after 31.5 months was safe, and there was no decline in C-peptide observed during the 12-month follow-up.

Designing Personalized Antigen-Specific Immunotherapies for Autoimmune Diseases-The Case for Using Ignored Target Cell Antigen Determinants

We have proposed that antigen-specific immunotherapies (ASIs) for autoimmune diseases could be enhanced by administering target cell antigen epitopes (determinants) that are immunogenic but ignored by autoreactive T cells because these determinants may have large pools of naïve cognate T cells available for priming towards regulatory responses. Here, we identified an immunogenic preproinsulin determinant (PPI_L4-20) that was ignored by autoimmune responses in type 1 diabetes (T1D)-prone NOD mice. The size of the PPI_L4-20-specific splenic naive T cell pool gradually increased from 2–12 weeks in age and remained stable thereafter, while that of the major target determinant insulin B-chain_9-23 decreased greatly after 12 weeks in age, presumably due to recruitment into the autoimmune response. In 15–16 week old mice, insulin B-chain_9-23/alum immunization induced modest-low level of splenic T cell IL-10 and IL-4 responses, little or no spreading of these responses, and boosted IFNγ responses to itself and other autoantigens. In contrast, PPI_L4-20/alum treatment induced robust IL-10 and IL-4 responses, which spread to other autoantigens and increased the frequency of splenic IL-10-secreting Treg and Tr-1-like cells, without boosting IFNγ responses to ß-cell autoantigens. In newly diabetic NOD mice, PPI_L4-20, but not insulin B-chain_9-23 administered intraperitoneally (with alum) or intradermally (as soluble antigen) supplemented with oral GABA induced long-term disease remission. We discuss the potential of personalized ASIs that are based on an individual’s naïve autoantigen-reactive T cell pools and the use of HLA-appropriate ignored autoantigen determinants to safely enhance the efficacy of ASIs.

Intralymphatic GAD-alum Injection Modulates B Cell Response and Induces Follicular Helper T Cells and PD-1+ CD8+ T Cells in Patients With Recent-Onset Type 1 Diabetes

Antigen-specific immunotherapy is an appealing strategy to preserve beta-cell function in type 1 diabetes, although the approach has yet to meet its therapeutic endpoint. Direct administration of autoantigen into lymph nodes has emerged as an alternative administration route that can improve the efficacy of the treatment. In the first open-label clinical trial in humans, injection of aluminum-formulated glutamic acid decarboxylase (GAD-alum) into an inguinal lymph node led to the promising preservation of C-peptide in patients with recent-onset type 1 diabetes. The treatment induced a distinct immunomodulatory effect, but the response at the cell level has not been fully characterized. Here we used mass cytometry to profile the immune landscape in peripheral blood mononuclear cells from 12 participants of the study before and after 15 months of treatment. The immunomodulatory effect of the therapy included reduction of naïve and unswitched memory B cells, increase in follicular helper T cells and expansion of PD-1+ CD69+ cells in both CD8+ and double negative T cells. In vitro stimulation with GAD₆₅ only affected effector CD8+ T cells in samples collected before the treatment. However, the recall response to antigen after 15 months included induction of CXCR3+ and CD11c+Tbet+ B cells, PD-1+ follicular helper T cells and exhausted-like CD8+ T cells. This study provides a deeper insight into the immunological changes associated with GAD-alum administration directly into the lymph nodes.

Latent Autoimmune Diabetes in Adults: Background, Safety and Feasibility of an Ongoing Pilot Study With Intra-Lymphatic Injections of GAD-Alum and Oral Vitamin D

BACKGROUND

Latent Autoimmune Diabetes in Adults (LADA) constitutes around 10% of all diabetes. Many LADA patients gradually lose their insulin secretion and progress to insulin dependency. In a recent trial BALAD (Behandling Av LADa) early insulin treatment compared with sitagliptin failed to preserve insulin secretion, which deteriorated in individuals displaying high levels of antibodies to GAD (GADA). These findings prompted us to evaluate a treatment that directly affects autoimmunity. Intra-lymphatic GAD-alum treatment has shown encouraging results in Type 1 diabetes patients. We therefore tested the feasibility of such therapy in LADA-patients (the GADinLADA pilot study).

MATERIAL AND METHODS

Fourteen GADA-positive (>190 RU/ml), insulin-independent patients 30-70 years old, with LADA diagnosed within < 36 months were included in an open-label feasibility trial. They received an intra-nodal injection of 4 μg GAD-alum at Day 1, 30 and 60 plus oral Vitamin D 2000 U/d from screening 30 days before (Day -30) for 4 months if the vitamin D serum levels were below 100 nmol/L (40 ng/ml). Primary objective is to evaluate safety and feasibility. Mixed Meal Tolerance Test and i.v. Glucagon Stimulation Test at baseline and after 5 and 12 months are used for estimation of beta cell function. Results will be compared with those of the recent BALAD study with comparable patient population. Immunological response is followed.

RESULTS

Preliminary results show feasibility and safety, with almost stable beta cell function and metabolic control during follow-up so far (5 months).

CONCLUSIONS

Intra-lymphatic GAD-alum treatment is an option to preserve beta cell function in LADA-patients. An ongoing trial in 14 LADA-patients show feasibility and safety. Clinical and immunological responses will determine how to proceed with future trials.

Combined Etanercept, GAD-alum and vitamin D treatment: an open pilot trial to preserve beta cell function in recent onset type 1 diabetes

AIM

We aimed to study the feasibility and tolerability of a combination therapy consisting of glutamic acid decarboxylase (GAD-alum), Etanercept and vitamin D in children and adolescents with newly diagnosed with type 1 diabetes (T1D), and evaluate preservation of beta cell function.

MATERIAL AND METHODS

Etanercept Diamyd Combination Regimen is an open-labelled multi-centre study pilot trial which enrolled 20 GAD antibodies positive T1D patients (7 girls and 13 boys), aged (mean ±SD): 12.4 ± 2.3 (8.3-16.1) years, with a diabetes duration of 81.4 ± 22.1 days. Baseline fasting C-peptide was 0.24 ± 0.1 (0.10-0.35) nmol/l. The patients received Day 1-450 Vitamin D (Calciferol) 2000 U/d per os, Etanercept sc Day 1-90 0.8 mg/kg once a week and GAD-alum sc injections (20 μg, Diamyd™) Day 30 and 60. They were followed for 30 months.

RESULTS

No treatment related serious adverse events were observed. After 6 months 90-min stimulated C-peptide had improved in 8/20 patients and C-peptide area under the curve (AUC) after Mixed Meal Tolerance Test in 5 patients, but declined thereafter, while HbA1c and insulin requirement remained close to baseline. Administration of Etanercept did not reduce tumour necrosis factor (TNF) spontaneous secretion from peripheral blood mononuclear cells, but rather GAD65-induced TNF-α increased. Spontaneous interleukin-17a secretion increased after the administration of Etanercept, and GAD65-induced cytokines and chemokines were also enhanced following 1 month of Etanercept administration.

CONCLUSIONS

Combination therapy with parallel treatment with GAD-alum, Etanercept and vitamin D in children and adolescents with type 1 diabetes was feasible and tolerable but had no beneficial effects on the autoimmune process or beta cell function.

Intralymphatic Glutamic Acid Decarboxylase With Vitamin D Supplementation in Recent-Onset Type 1 Diabetes: A Double-Blind, Randomized, Placebo-Controlled Phase IIb Trial

OBJECTIVE

To evaluate the efficacy of aluminum-formulated intralymphatic glutamic acid decarboxylase (GAD-alum) therapy combined with vitamin D supplementation in preserving endogenous insulin secretion in all patients with type 1 diabetes (T1D) or in a genetically prespecified subgroup.

RESEARCH DESIGN AND METHODS

In a multicenter, randomized, placebo-controlled, double-blind trial, 109 patients aged 12-24 years (mean ± SD 16.4 ± 4.1) with a diabetes duration of 7-193 days (88.8 ± 51.4), elevated serum GAD65 autoantibodies, and a fasting serum C-peptide >0.12 nmol/L were recruited. Participants were randomized to receive either three intralymphatic injections (1 month apart) with 4 μg GAD-alum and oral vitamin D (2,000 IE daily for 120 days) or placebo. The primary outcome was the change in stimulated serum C-peptide (mean area under the curve [AUC] after a mixed-meal tolerance test) between baseline and 15 months.

RESULTS

Primary end point was not met in the full analysis set (treatment effect ratio 1.091 [CI 0.845-1.408]; P = 0.5009). However, GAD-alum-treated patients carrying HLA DR3-DQ2 (n = 29; defined as DRB1*03, DQB1*02:01) showed greater preservation of C-peptide AUC (treatment effect ratio 1.557 [CI 1.126-2.153]; P = 0.0078) after 15 months compared with individuals receiving placebo with the same genotype (n = 17). Several secondary end points showed supporting trends, and a positive effect was seen in partial remission (insulin dose-adjusted HbA_1c ≤9; P = 0.0310). Minor transient injection site reactions were reported.

CONCLUSION

Intralymphatic administration of GAD-alum is a simple, well-tolerated treatment that together with vitamin D supplementation seems to preserve C-peptide in patients with recent-onset T1D carrying HLA DR3-DQ2. This constitutes a disease-modifying treatment for T1D with a precision medicine approach.

Glutamic Acid Decarboxylase Injection Into Lymph Nodes: Beta Cell Function and Immune Responses in Recent Onset Type 1 Diabetes Patients

In spite of intensive treatment Type 1 diabetes leads to serious complications. Preservation of residual beta cell function makes the disease milder, facilitates treatment, prevents complications and increase survival. So far immune interventions have had limited effect, and some serious adverse events and risks. In an open pilot trial we aimed to improve efficacy of GAD-alum treatment using lymph-node administration in combination with oral vitamin D. Here we report the clinical effect and focus on biomarkers for response to treatment. Patients (n = 12) aged 12 to 24 years with recent onset of Type 1 diabetes received 4 μg GAD-alum into lymph-node at day 30, 60, and 90, and oral Vitamin D 2000 U/d, days 1 to 120. Beta cell function was estimated by Mixed Meal Tolerance Tests. GADA, GADA subclasses, GAD₆₅-induced cytokines and proliferation, and T cells markers were analyzed. The treatment was tolerable with no adverse events. Fasting C-peptide and insulin requirement remained stable at 15 months, while HbA1c was lower than baseline. Stimulated C-peptide showed no change at 6 months but declined after 15 months (81% of baseline). Eleven patients remained in partial remission (IDAAC < 9). Patients (n = 9) with better clinical outcome had reduced proportion of IgG1 and increased IgG2, IgG3, and IgG4, increased IL-10 secretion, and reduction of proliferation and CD8⁺ T cells activation. Patients with poorer clinical response had higher baseline levels of GAD_65-induced cytokines and T-cell activation, and an increased ratio of effector/central memory T cells. Intra-lymphatic GAD treatment combined with Vitamin D might preserve beta cell function and improve clinical course in T1D. Patients with less benefit have a different quality of immune response both before and after treatment.

Efficacy of GAD-alum immunotherapy associated with HLA-DR3-DQ2 in recently diagnosed type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to determine if retention of C-peptide following immunotherapy using recombinant GAD65 conjugated to aluminium hydroxide (GAD-alum) is influenced by HLA risk haplotypes DR3-DQ2 and DR4-DQ8.

METHODS

HLA-dependent treatment effect of GAD-alum therapy on C-peptide retention in individuals with recent-onset type 1 diabetes was evaluated using individual-level patient data from three placebo-controlled, randomised clinical trials using a mixed repeated measures model.

RESULTS

A significant and dose-dependent effect was observed in individuals positive for the genotypes that include HLA-DR3-DQ2 but not HLA-DR4-DQ8 and in the broader subgroup of individuals positive for all genotypes that include HLA-DR3-DQ2 (i.e. including those also positive for HLA-DR4-DQ8). Higher doses (three or four injections) showed a treatment effect ratio of 1.596 (95% CI 1.132, 2.249; adjusted p = 0.0035) and 1.441 (95% CI 1.188, 1.749; adjusted p = 0.0007) vs placebo for the two respective HLA subgroups.

CONCLUSIONS/INTERPRETATION

GAD65-specific immunotherapy has a significant effect on C-peptide retention in individuals with recent-onset type 1 diabetes who have the DR3-DQ2 haplotype. Graphical abstract.

Induction of Antigen-Specific Tolerance in T Cell Mediated Diseases

The development of novel approaches to control unwanted immune responses represents an ambitious goal in the management of a number of clinical conditions, including autoimmunity, autoinflammatory diseases, allergies and replacement therapies, in which the T cell response to self or non-harmful antigens threatens the physiological function of tissues and organs. Current treatments for these conditions rely on the use of non-specific immunosuppressive agents and supportive therapies, which may efficiently dampen inflammation and compensate for organ dysfunction, but they require lifelong treatments not devoid of side effects. These limitations induced researchers to undertake the development of definitive and specific solutions to these disorders: the underlying principle of the novel approaches relies on the idea that empowering the tolerogenic arm of the immune system would restore the immune homeostasis and control the disease. Researchers effort resulted in the development of cell-free strategies, including gene vaccination, protein-based approaches and nanoparticles, and an increasing number of clinical trials tested the ability of adoptive transfer of regulatory cells, including T and myeloid cells. Here we will provide an overview of the most promising approaches currently under development, and we will discuss their potential advantages and limitations. The field is teaching us that the success of these strategies depends primarily on our ability to dampen antigen-specific responses without impairing protective immunity, and to manipulate directly or indirectly the immunomodulatory properties of antigen presenting cells, the ultimate in vivo mediators of tolerance.

Old Dog New Tricks: PLGA Microparticles as an Adjuvant for Insulin Peptide Fragment-Induced Immune Tolerance against Type 1 Diabetes

Poly[lactic-co-(glycolic acid)] (PLGA) is arguably one of the most versatile synthetic copolymers used for biomedical applications. In vivo delivery of multiple substances including cells, pharmaceutical compounds, and antigens has been achieved by using PLGA-based micro-/nanoparticles although, presently, the exact biological impact of PLGA particles on the immune system remains controversial. Type 1 diabetes (T1D) is one subtype of diabetes characterized by the attack of immune cells against self-insulin-producing pancreatic islet cells. Considering the autoimmune etiology of T1D and the recent use of PLGA particles for eliciting desired immune responses in various aspects of immunotherapy, for the present study, a combination of Ins2_9-23 peptide (a known autoantigen of T1D) and PLGA microparticles was selected for T1D prevention assessment in nonobese diabetic (NOD) mice, a well-known animal model with spontaneous development of T1D. Thus, inoculation of PLGA microparticles + Ins2_9-23 completely prevented T1D development, significantly better than untreated controls and mice treated by either PLGA microparticles or Ins2_9-23 per se. Subsequent mechanistic investigation further revealed a facilitative role of PLGA microparticles in immune tolerance induction. In summary, our data demonstrate an adjuvant potential of PLGA microparticles in tolerance induction and immune remodulation for effective prevention of autoimmune diseases such as 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.

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

AIMS/HYPOTHESIS

Antigen-specific therapy aims to modify inflammatory T cell responses in type 1 diabetes and restore immune tolerance. One strategy employs GAD65 conjugated to aluminium hydroxide (GAD-alum) to take advantage of the T helper (Th)2-biasing adjuvant properties of alum and thereby regulate pathological Th1 autoimmunity. We explored the cellular and molecular mechanism of GAD-alum action in the setting of a previously reported randomised placebo-controlled clinical trial conducted by Type 1 Diabetes TrialNet.

METHODS

In the clinical trial conducted by Type 1 Diabetes TrialNet, participants were immunised with 20 μg GAD-alum (twice or three times) or alum alone and peripheral blood mononuclear cell samples were banked at baseline and post treatment. In the present study, GAD-specific T cell responses were measured in these samples and GAD-specific T cell lines and clones were generated, which were then further characterised.

RESULTS

At day 91 post immunisation, we detected GAD-specific IL-13⁺ CD4 T cell responses significantly more frequently in participants immunised with GAD-alum (71% and 94% treated twice or three times, respectively) compared with those immunised with alum alone (38%; p = 0.003 and p = 0.0002, respectively) accompanied by high secreted levels of IL-13, IL-4 and IL-5, confirming a GAD-specific, GAD-alum-induced Th2 response. Of note, GAD-specific, IL-13⁺ CD4 T cells observed after immunisation co-secreted IFN-γ, displaying a bifunctional Th1/Th2 phenotype. Single-cell transcriptome analysis identified IL13 and IFNG expression in concert with the canonical Th2 and Th1 transcription factor genes GATA3 and TBX21, respectively. T cell receptor β-chain (TCRB) CDR3 regions of GAD-specific bifunctional T cells were identified in circulating naive and central memory CD4 T cell pools of non-immunised participants with new-onset type 1 diabetes and healthy individuals, suggesting the potential for bifunctional responses to be generated de novo by GAD-alum immunisation or via expansion from an existing public repertoire.

CONCLUSIONS/INTERPRETATION

GAD-alum immunisation activates and propagates GAD-specific CD4 T cells with a distinctive bifunctional phenotype, the functional analysis of which might be important in understanding therapeutic responses.

Peptide-Based Vaccination Therapy for Rheumatic Diseases

Rheumatic diseases are extremely heterogeneous diseases with substantial risks of morbidity and mortality, and there is a pressing need in developing more safe and cost-effective treatment strategies. Peptide-based vaccination is a highly desirable strategy in treating noninfection diseases, such as cancer and autoimmune diseases, and has gained increasing attentions. This review is aimed at providing a brief overview of the recent advances in peptide-based vaccination therapy for rheumatic diseases. Tremendous efforts have been made to develop effective peptide-based vaccinations against rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), while studies in other rheumatic diseases are still limited. Peptide-based active vaccination against pathogenic cytokines such as TNF-α and interferon-α (IFN-α) is shown to be promising in treating RA or SLE. Moreover, peptide-based tolerogenic vaccinations also have encouraging results in treating RA or SLE. However, most studies available now have been mainly based on animal models, while evidence from clinical studies is still lacking. The translation of these advances from experimental studies into clinical therapy remains impeded by some obstacles such as species difference in immunity, disease heterogeneity, and lack of safe delivery carriers or adjuvants. Nevertheless, advances in high-throughput technology, bioinformatics, and nanotechnology may help overcome these impediments and facilitate the successful development of peptide-based vaccination therapy for rheumatic diseases.

Autoantigen Treatment in Type 1 Diabetes: Unsolved Questions on How to Select Autoantigen and Administration Route

Autoantigen treatment has been tried for the prevention of type 1 diabetes (T1D) and to preserve residual beta-cell function in patients with a recent onset of the disease. In experimental animal models, efficacy was good, but was insufficient in human subjects. Besides the possible minor efficacy of peroral insulin in high-risk individuals to prevent T1D, autoantigen prevention trials have failed. Other studies on autoantigen prevention and intervention at diagnosis are ongoing. One problem is to select autoantigen/s; others are dose and route. Oral administration may be improved by using different vehicles. Proinsulin peptide therapy in patients with T1D has shown possible minor efficacy. In patients with newly diagnosed T1D, subcutaneous injection of glutamic acid decarboxylase (GAD) bound to alum hydroxide (GAD-alum) can likely preserve beta-cell function, but the therapeutic effect needs to be improved. Intra-lymphatic administration may be a better alternative than subcutaneous administration, and combination therapy might improve efficacy. This review elucidates some actual problems of autoantigen therapy in the prevention and/or early intervention of type 1 diabetes.

A Novel Quantitative Approach to Staging and Assessing Recovery from Type 1 Diabetes Mellitus: The Type 1 Diabetes Mellitus Metabolic Recovery Index

Discovery of insulin in 1921 changed the lives of patients with type 1 diabetes (T1DM) forever. What had been a death sentence became a manageable, albeit chronic, disease. Insulin did not cure the disease, as it did not address the actual disease process, but instead treated its sequelae, namely elevated blood sugars. Importantly, insulin administration fails to ensure normoglycaemia. Even with the most sophisticated ‘near closed-loop’ methods, glucose homeostasis is not restored to normal. T1DM patients face complications, both short-term, such as hypo- and hyperglycaemia, and long-term, with increased glycosylation of proteins leading to eye, kidney, nervous system and other sequelae. These complications are associated with significant morbidity and mortality even after intensive insulin treatment. Nearly 100 years after the discovery of insulin, we continue to face the challenge of addressing the disease process itself, in order to fundamentally improve the life of these patients. There are major efforts to achieve just that: to completely arrest the autoimmune process destroying the insulin-producing cells in the pancreas, or at least significantly slow the process to blunt and delay short- and long-term complications. The aim of this Communication is to propose a novel assessment tool that would serve as a quantitative outcome measure by which therapies, short of clinical cure, may be compared and their true benefit to the treatment of diabetes assessed.

Antigen-based immune modulation therapy for type 1 diabetes: the era of precision medicine

Precision medicine has emerged as a mantra for therapeutic approaches to complex diseases. The defining concept relies on a detailed insight into disease pathogenesis and therapeutic mechanism. Although the type 1 diabetes field has gained new insights into disease endotypes and indications of efficacy for several therapies, none of these is yet licensed, partly because of immune suppressive side-effects beyond control of islet autoimmunity. New strategies designed to regulate the immune system continue to emerge as basic science discoveries are made, including the use of antigen-based immunotherapies. A single agent or approach seems unlikely to halt disease progression in all people with or at risk of type 1 diabetes; as such, tailored methods relying on patient subgroups and knowledge of disease endotypes are gaining attention. Recent insights into disease mechanisms and emerging trial data are being translated into opportunities for tissue-specific prevention of progressive loss of β-cell function and survival. Results so far point to feasibility, safety, and tolerability of administration of islet autoantigens and peptides thereof into recipients with or at risk of type 1 diabetes. Findings from mechanistic studies suggest favourable changes in islet autoimmunity, with signs of immune regulation. Major challenges remain, including those related to dose and dosing frequency, route of administration, and use of adjuvants. However, the first steps towards tissue-specific and personalised medicine in type 1 diabetes have been made, which will guide future studies into induction of immune tolerance to intervene in the initiation and progression of islet autoimmunity and disease.

The challenge of modulating β-cell autoimmunity in type 1 diabetes

With the conceptual advance about four decades ago that type 1 diabetes represents an autoimmune disease, hope arose that immune-based therapies would soon emerge to prevent and reverse the disorder. However, despite dozens of clinical trials seeking to achieve these goals, the promise remains unfulfilled, at least in a pragmatic form. With the benefit of hindsight, several important reasons are likely to account for this disappointing outcome, including failure to appreciate disease heterogeneity, inappropriate use of rodent models of disease, inadequacies in addressing the immunological and metabolic contributions to the disease, suboptimal trial designs, and lack of a clear understanding of the pathogenesis of type 1 diabetes. In this Series paper, we convey how recent knowledge gains in these areas, combined with efforts related to disease staging and emerging mechanistic data from clinical trials, provide cautious optimism that immune-based approaches to prevent the loss of β cells in type 1 diabetes will emerge into clinical practice.

Recent Advances in the Development of Vaccines for Diabetes, Hypertension, and Atherosclerosis

Vaccines are commonly used in the prevention of infectious diseases. The basic principle of vaccination is to use specific antigens, endogenous or exogenous to stimulate immunity against the specific antigens or cells producing them. Autoantigen or oligo vaccination has been used for disease animal models. More recently humanized monoclonal antibodies have been successfully used for the treatment of neoplastic disorders or familial hypercholesterolemia. Humanized monoclonal antibody therapy needs repeated injection, and the therapy is expensive. Therapeutic vaccination can lead to persistent immunized or immune tolerant against the therapeutic molecule(s) or site. However, immunization against those endogenous substances may also elicit persistent autoimmune reaction or destruction that do harm to health. Therefore, rigorous studies are needed before any clinical application. In this review, we briefly reviewed vaccines used in protection against common metabolic diseases including atherosclerosis, hypertension, and diabetes mellitus.

Type 1 diabetes

Type 1 diabetes is a chronic autoimmune disease characterised by insulin deficiency and resultant hyperglycaemia. Knowledge of type 1 diabetes has rapidly increased over the past 25 years, resulting in a broad understanding about many aspects of the disease, including its genetics, epidemiology, immune and β-cell phenotypes, and disease burden. Interventions to preserve β cells have been tested, and several methods to improve clinical disease management have been assessed. However, wide gaps still exist in our understanding of type 1 diabetes and our ability to standardise clinical care and decrease disease-associated complications and burden. This Seminar gives an overview of the current understanding of the disease and potential future directions for research and care.

Intralymphatic Glutamic Acid Decarboxylase-Alum Administration Induced Th2-Like-Specific Immunomodulation in Responder Patients: A Pilot Clinical Trial in Type 1 Diabetes

GAD-alum given into lymph nodes to type 1 diabetes patients participating in an open-label pilot trial resulted in preservation of C-peptide similar to promising results from other trials. Here, we compared the immunomodulatory effect of giving GAD-alum directly into lymph nodes versus that induced by subcutaneous administration. Samples from T1D patients (n = 6) who received 4 μg GAD-alum into lymph nodes (LNs), followed by two booster injections one month apart, and from patients (n = 6) who received two subcutaneous injections (SC) (20 μg) given one month apart were compared. GADA, IA-2A, GADA subclasses, IgE, GAD₆₅-induced cytokines, PBMC proliferation, and T cell markers were analyzed. Lower doses of GAD-alum into LN induced higher GADA levels than SC injections and reduced proliferation and IgG1 GADA subclass, while enhancing IgG2, IgG3, and IgG4. The cytokine profile was dominated by the Th2-associated cytokine IL-13, and GAD₆₅ stimulation induced activated CD4 T cells. Patients responding clinically best account for most of the immunological changes. In contrast, SC treatment resulted in predominant IgG1, predominant IFN-γ, higher proliferation, and activated CD4 and CD8 cells. Patients from the LN group with best metabolic outcome seemed to have common immune correlates related to the treatment. This trial is registered with DIAGNODE (NCT02352974, clinicaltrials.gov) and DIABGAD (NCT01785108, clinicaltrials.gov).