Treatment of new-onset type 1 diabetes with peptide DiaPep277 is safe and associated with preserved beta-cell function: extension of a randomized, double-blind, phase II trial

Immunotherapies for prevention and treatment of type 1 diabetes

Type 1 diabetes (T1D) is characterized by the autoimmune destruction of insulin-producing β-cells of the pancreatic islets necessitating lifelong insulin therapy. Despite significant advancements in diabetes technology with increasingly sophisticated methods of insulin delivery and glucose monitoring, people with T1D remain at risk of severe complications like hypoglycemia and diabetic ketoacidosis. There has long been an interest in altering the immune response in T1D to prevent or cure T1D across its various stages with limited efficacy. This review highlights immunomodulatory approaches over the years including the anti-CD3 monoclonal antibody teplizumab which is now approved to delay onset of T1DM and other interventions under current investigation.

The relationship between SARS-CoV-2 infection and type 1 diabetes mellitus

Environmental factors, in particular viral infections, are thought to have an important role in the pathogenesis of type 1 diabetes mellitus (T1DM). The COVID-19 pandemic reinforced this hypothesis as many observational studies and meta-analyses reported a notable increase in the incidence of T1DM following infection with SARS-CoV-2 as well as an association between SARS-CoV-2 infection and the risk of new-onset T1DM. Experimental evidence suggests that human β-cells express SARS-CoV-2 receptors and that SARS-CoV-2 can infect and replicate in β-cells, resulting in structural or functional alterations of these cells. These alterations include reduced numbers of insulin-secreting granules, impaired pro-insulin (or insulin) secretion, and β-cell transdifferentiation or dedifferentiation. The inflammatory environment induced by local or systemic SARS-CoV-2 infection might result in a set of signals (such as pro-inflammatory cytokines) that lead to β-cell alteration or apoptosis or to a bystander activation of T cells and disruption of peripheral tolerance that triggers autoimmunity. Other mechanisms, such as viral persistence, molecular mimicry and activation of endogenous human retroviruses, are also likely to be involved in the pathogenesis of T1DM following SARS-CoV-2 infection. This Review addresses the issue of the involvement of SARS-CoV-2 infection in the development of T1DM using evidence from epidemiological, clinical and experimental studies.

A peptide derived from HSP60 reduces proinflammatory cytokines and soluble mediators: a therapeutic approach to inflammation

Cytokines are secretion proteins that mediate and regulate immunity and inflammation. They are crucial in the progress of acute inflammatory diseases and autoimmunity. In fact, the inhibition of proinflammatory cytokines has been widely tested in the treatment of rheumatoid arthritis (RA). Some of these inhibitors have been used in the treatment of COVID-19 patients to improve survival rates. However, controlling the extent of inflammation with cytokine inhibitors is still a challenge because these molecules are redundant and pleiotropic. Here we review a novel therapeutic approach based on the use of the HSP60-derived Altered Peptide Ligand (APL) designed for RA and repositioned for the treatment of COVID-19 patients with hyperinflammation. HSP60 is a molecular chaperone found in all cells. It is involved in a wide diversity of cellular events including protein folding and trafficking. HSP60 concentration increases during cellular stress, for example inflammation. This protein has a dual role in immunity. Some HSP60-derived soluble epitopes induce inflammation, while others are immunoregulatory. Our HSP60-derived APL decreases the concentration of cytokines and induces the increase of FOXP3+ regulatory T cells (Treg) in various experimental systems. Furthermore, it decreases several cytokines and soluble mediators that are raised in RA, as well as decreases the excessive inflammatory response induced by SARS-CoV-2. This approach can be extended to other inflammatory diseases.

Leverage biomaterials to modulate immunity for type 1 diabetes

The pathogeny of type 1 diabetes (T1D) is mainly provoked by the β-cell loss due to the autoimmune attack. Critically, autoreactive T cells firsthand attack β-cell in islet, that results in the deficiency of insulin in bloodstream and ultimately leads to hyperglycemia. Hence, modulating immunity to conserve residual β-cell is a desirable way to treat new-onset T1D. However, systemic immunosuppression makes patients at risk of organ damage, infection, even cancers. Biomaterials can be leveraged to achieve targeted immunomodulation, which can reduce the toxic side effects of immunosuppressants. In this review, we discuss the recent advances in harness of biomaterials to immunomodulate immunity for T1D. We investigate nanotechnology in targeting delivery of immunosuppressant, biological macromolecule for β-cell specific autoreactive T cell regulation. We also explore the biomaterials for developing vaccines and facilitate immunosuppressive cells to restore immune tolerance in pancreas.

Opportunities for an atherosclerosis vaccine: From mice to humans

Atherosclerosis, the major underlying cause of cardiovascular diseases (CVD), is the number one killer globally. The disease pathogenesis involves a complex interplay between metabolic and immune components. Although lipid-lowering drugs such as statins curb the risks associated with CVD, significant residual inflammatory risk remains. Substantial evidence from experimental models and clinical studies has established the role of inflammation and immune effector mechanisms in the pathogenesis of atherosclerosis. Several stages of the disease are affected by host-mediated antigen-specific adaptive immune responses that play either protective or proatherogenic roles. Therefore, strategies to boost an anti-atherogenic humoral and T regulatory cell response are emerging as preventative or therapeutic strategies to lowering inflammatory residual risks. Vaccination holds promise as an efficient, durable and relatively inexpensive approach to induce protective adaptive immunity in atherosclerotic patients. In this review, we discuss the status and opportunities for a human atherosclerosis vaccine. We describe (1) some of the immunomodulatory therapeutic interventions tested in atherosclerosis (2) the immune targets identified in pre-clinical and clinical investigations (3) immunization strategies evaluated in animal models (4) past and ongoing clinical trials to examine the safety and efficacy of human atherosclerosis vaccines and (5) strategies to improve and optimize vaccination in humans (antigen selection, formulation, dose and delivery).

Current Status on Immunological Therapies for Type 1 Diabetes Mellitus

PURPOSE OF REVIEW

Type 1 diabetes (T1D) occurs when there is destruction of beta cells within the islets of Langerhans in the pancreas due to autoimmunity. It is considered a complex disease, and different complications can surface and worsen the condition if T1D is not managed well. Since it is an incurable disease, numerous treatments and therapies have been postulated in order to control T1D by balancing hyperglycemia control while minimizing hypoglycemic episodes. The purpose of this review is to primarily look into the current state of the available immunological therapies and their advantages for the treatment of T1D.

RECENT FINDINGS

Over the years, immunological therapy has become the center of attraction to treat T1D. Immunomodulatory approaches on non-antigens involving agents such as cyclosporine A, mycophenolate mofetil, anti-CD20, cytotoxic T cells, anti-TNF, anti-CD3, and anti-thymocyte globulin as well as immunomodulative approaches on antigens such as insulin, glutamic acid decarboxylase, and heat shock protein 60 have been studied. Aside from these two approaches, studies and trials have also been conducted on regulatory T cells, dendritic cells, interleukin 2, interleukin 4, M2 macrophages, and rapamycin/interleukin 2 combination therapy to test their effects on patients with T1D. Many of these agents have successfully suppressed T1D in non-obese diabetic (NOD) mice and in human trials. However, some have shown negative results. To date, the insights into the management of the immune system have been increasing rapidly to search for potential therapies and treatments for T1D. Nevertheless, some of the challenges are still inevitable. A lot of work and effort need to be put into the investigation on T1D through immunological therapy, particularly to reduce complications to improve and enhance clinical outcomes.

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.

Antigen-Specific Tolerization and Targeted Delivery as Therapeutic Strategies for Autoimmune Diseases

The prevalence of autoimmune disorders is increasing steadily and there is no permanent cure available. Immunomodulation through repeated exposure of antigens, known as antigen-specific immune tolerance or antigen-specific immunotherapy (ASI), is a promising approach to treat or prevent autoimmune disorders. Different optimization protocols (immunization routes, delivery systems, and approaches) are being developed to implement ASI against self-proteins. Including appropriate adjuvants, altered peptide ligand, and using multipeptides are approaches that can be used to specifically target autoimmunity. This review explores various ASI application methods, including different routes of antigen-specific sensitization, delivery systems, immunomodulators containing specific antigens, and other targeted approaches that have been successfully demonstrated to have therapeutic effects on autoimmune diseases.

Immature Dendritic Cell Therapy Confers Durable Immune Modulation in an Antigen-Dependent and Antigen-Independent Manner in Nonobese Diabetic Mice

Dendritic cell (DC) immunotherapy has been effective for prevention of type 1 diabetes (T1D) in NOD mice but fails to protect if initiated after active autoimmunity. As autoreactivity expands inter- and intramolecularly during disease progression, we investigated whether DCs unpulsed or pulsed with β cell antigenic dominant determinants (DD), subdominant determinants (SD), and ignored determinants (ID) could prevent T1D in mice with advanced insulitis. We found that diabetes was significantly delayed by DC therapy. Of interest, DCs pulsed with SD or ID appeared to provide better protection. T lymphocytes from DC-treated mice acquired spontaneous proliferating capability during in vitro culture, which could be largely eliminated by IL-2 neutralizing antibodies. This trend maintained even 29 weeks after discontinuing DC therapy and appeared antigen-independent. Furthermore, CD4+Foxp3+ T regulatory cells (Tregs) from DC-treated mice proliferated more actively in vitro compared to the controls, and Tregs from DC-treated mice showed significantly enhanced immunosuppressive activities in contrast to those from the controls. Our study demonstrates that DC therapy leads to long-lasting immunomodulatory effects in an antigen-dependent and antigen-independent manner and provides evidence for peptide-based intervention during a clinically relevant window to guide DC-based immunotherapy for autoimmune diabetes.

Targeting of tolerogenic dendritic cells towards heat-shock proteins: a novel therapeutic strategy for autoimmune diseases?

Tolerogenic dendritic cells (tolDCs) are a promising therapeutic tool to restore immune tolerance in autoimmune diseases. The rationale of using tolDCs is that they can specifically target the pathogenic T-cell response while leaving other, protective, T-cell responses intact. Several ways of generating therapeutic tolDCs have been described, but whether these tolDCs should be loaded with autoantigen(s), and if so, with which autoantigen(s), remains unclear. Autoimmune diseases, such as rheumatoid arthritis, are not commonly defined by a single, universal, autoantigen. A possible solution is to use surrogate autoantigens for loading of tolDCs. We propose that heat-shock proteins may be a relevant surrogate antigen, as they are evolutionarily conserved between species, ubiquitously expressed in inflamed tissues and have been shown to induce regulatory T cells, ameliorating disease in various arthritis mouse models. In this review, we provide an overview on how immune tolerance may be restored by tolDCs, the problem of selecting relevant autoantigens for loading of tolDCs, and why heat-shock proteins could be used as surrogate autoantigens.

A rationally designed peptide IA-2-P2 against type 1 diabetes in streptozotocin-induced diabetic mice

Recent studies have investigated the potential of type 1 diabetes mellitus-related autoantigens, such as heat shock protein 60, to induce immunological tolerance or to suppress the immune response. A functional 24-residue peptide derived from heat shock protein 60 (P277) has shown anti-type 1 diabetes mellitus potential in experimental animals and in clinical studies, but it also carries a potential atherogenic effect. In this study, we have modified P277 to retain an anti-type 1 diabetes mellitus effect and minimize the atherogenic potential by replacing the P277 B epitope with another diabetes-associated autoantigen, insulinoma antigen-2 (IA-2), to create the fusion peptide IA-2-P2. In streptozotocin-induced diabetic C57BL/6J mice, the IA-2-P2 peptide displayed similar anti-diabetic effects to the control P277 peptide. Also, the IA-2-P2 peptide did not show atherogenic activity in a rabbit model. Our findings indicate the potential of IA-2-P2 as a promising vaccine against type 1 diabetes mellitus.

Heat shock proteins (HSPs) in the homeostasis of regulatory T cells (Tregs)

Heat shock proteins (HSPs) belong to the family of conservative polypeptides with a high homology of the primary structure. The uniqueness of this family lies in their ability to interact with a large number of different proteins and provide protection from cellular and environmental stress factors as molecular chaperones to keep protein homeostasis. While intracellular HSPs play a mainly protective role, extracellular or membrane-bound HSPs mediate immunological functions and immunomodulatory activity. In immune system are subsets of cells including regulatory T cells (Tregs) with suppressive functions. HSPs are implicated in the function of innate and adaptive immune systems, stimulate T lymphocyte proliferation and immunomodulatory functions, increase the effectiveness of cross-presentation of antigens, and induce the secretion of cytokines. HSPs are also important in the induction, proliferation, suppressive function, and cytokine production of Tregs, which are a subset of CD4+ T cells maintaining peripheral tolerance. Together HSPs and Tregs are potential tools for future clinical interventions in autoimmune disease.

Immune Intervention and Preservation of Pancreatic Beta Cell Function in Type 1 Diabetes

Type 1 diabetes (T1D) results from the immune-mediated destruction of insulin-producing β cells located within the pancreatic islets of Langerhans. The autoimmune process leads to a deficiency in insulin production and resultant hyperglycemia requiring lifelong treatment with insulin administration. T1D continues to dramatically increase in incidence, especially in young children. Substantial knowledge surrounding human disease pathogenesis exists, such that T1D is now predictable with the measurement of antibodies in the peripheral blood directed against insulin and other β cell proteins. With the ability to predict, it naturally follows that T1D should be preventable. As such, over the last two decades, numerous well-controlled clinical trials have been completed attempting to prevent diabetes onset or maintain residual β cell function after clinical onset, all providing relatively disappointing results. Here, we review the T1D prevention efforts, the current landscape of clinical therapies, and end with a discussion regarding the future outlook for preventing T1D.

Heat Shock Proteins and Diabetes

Diabetes is a chronic disease, and its prevalence continues to rise and can increase the risk for the progression of microvascular (such as nephropathy, retinopathy and neuropathy) and also macrovascular complications. Diabetes is a condition in which the oxidative stress and inflammation rise. Heat shock proteins (HSPs) are a highly conserved family of proteins that are expressed by all cells exposed to environmental stress, and they have diverse functions. In patients with diabetes, the expression and levels of HSPs decrease, but these chaperones can aid in improving some complications of diabetes, such as oxidative stress and inflammation. (The suppression of some HSPs is associated with a generalized increase in tissue inflammation.) In this review, we summarize the current understanding of HSPs in diabetes as well as their complications, and we also highlight their potential role as therapeutic targets in diabetes.

Tolerization against atherosclerosis using heat shock protein 60

Atherosclerosis is a chronic inflammatory disease of the artery wall, and both innate and adaptive immunity play important roles in the pathogenesis of this disease. In several experimental and human experiments of early atherosclerotic lesions, it has been shown that the first pathogenic event in atherogenesis is intimal infiltration of T cells at predilection sites. These T cells react to heat shock protein 60 (HSP60), which is a ubiquitous self-antigen expressed on the surface of endothelial cells (ECs) together with adhesion molecules in response to classical risk factors for atherosclerosis. When HSP60 is expressed on the EC surface, it can act as a "danger-signal" for both cellular and humoral immune reactions. Acquired by infection or vaccination, beneficial protective immunity to microbial HSP60 and bona fide autoimmunity to biochemically altered autologous HSP60 is present in all humans. Thus, the development of atherosclerosis during aging is paid by the price for lifelong protective preexisting anti-HSP60 immunity by harmful (auto)immune cross-reactive attack on arterial ECs maltreated by atherosclerosis risk factors. This is supported by experiments, which shows that bacterial HSP60 immunization can lead and accelerate experimental atherosclerosis. This review article presents accumulating proof that supports the idea that tolerization with antigenic HSP60 protein or its peptides may arrest or even prevent atherosclerosis by increased production of regulatory T cells and/or anti-inflammatory cytokines. Recent data indicates that HSP60, or more likely some of its derivative peptides, has immunoregulatory functions. Therefore, these peptides may have important potential for being used as diagnostic agents or therapeutic targets.

Autoimmune Diabetes: An Overview of Experimental Models and Novel Therapeutics

Type 1 diabetes (T1D) results from a chronic and selective destruction of insulin-secreting β-cells within the islets of Langerhans of the pancreas by autoreactive CD4(+) and CD8(+) T lymphocytes. The use of animal models of T1D was instrumental for deciphering the steps of the autoimmune process leading to T1D. The non-obese diabetic (NOD) mouse and the bio-breeding (BB) rat spontaneously develop the disease similar to the human pathology in terms of the immune responses triggering autoimmune diabetes and of the genetic and environmental factors influencing disease susceptibility. The generation of genetically modified models allowed refining our understanding of the etiology and the pathogenesis of the disease. In the present review, we provide an overview of the experimental models generated and used to gain knowledge on the molecular and cellular mechanisms underlying the breakdown of self-tolerance in T1D and the progression of the autoimmune response. Immunotherapeutic interventions designed in these animal models and translated into the clinical arena in T1D patients will also be discussed.

Therapeutic potential of umbilical cord blood cells for type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) is a chronic disorder that results from autoimmune-mediated destruction of pancreatic islet β-cells. However, to date, no conventional intervention has successfully treated the disease. The optimal therapeutic method for T1DM should effectively control the autoimmunity, restore immune homeostasis, preserve residual β-cells, reverse β-cell destruction, and protect the regenerated insulin-producing cells against re-attack. Umbilical cord blood is rich in regulatory T (T(reg)) cells and multiple types of stem cells that exhibit immunomodulating potential and hold promise in their ability to restore peripheral tolerance towards pancreatic islet β-cells through remodeling of immune responses and suppression of autoreactive T cells. Recently, reinfusion of autologous umbilical cord blood or immune cells from cord blood has been proposed as a novel therapy for T1DM, with the advantages of no risk to the donors, minimal ethical concerns, a low incidence of graft-versus-host disease and easy accessibility. In this review, we revisit the role of autologous umbilical cord blood or immune cells from cord blood-based applications for the treatment of T1DM.

Prevention and reversal of type 1 diabetes--past challenges and future opportunities

Over the past three decades there have been a number of clinical trials directed at interdicting the type 1 diabetes (T1D) disease process in an attempt to prevent the development of the disease in those at increased risk or to stabilize-potentially even reverse-the disease in people with T1D, usually of recent onset. Unfortunately, to date there has been no prevention trial that has resulted in delay or prevention of T1D. And, trials in people with T1D have had mixed results with some showing promise with at least transient improvement in β-cell function compared with randomized control groups, while others have failed to slow the decline in β-cell function when compared with placebo. This Perspective will assess the past and present challenges in this effort and provide an outline for potential future opportunities.

Impact of disease heterogeneity on treatment efficacy of immunotherapy in Type 1 diabetes: different shades of gray

Type 1 diabetes results from selective destruction of insulin-producing pancreatic β-cells by a progressive autoimmune process. Type 1 diabetes proves very heterogeneous in pathology, disease progression and efficacy of therapeutic intervention. Indeed, several immunotherapies that appear ineffective for the entire treated patient population in fact look promising in subgroups of patients. It therefore seems inconceivable that one standard therapy will provide the golden bullet of disease intervention. Instead, personalized medicine may improve immune intervention efficacy rates. We discuss the effect of disease heterogeneity on treatment outcome of immunotherapies, identifying apparent gaps in our understanding of treatment efficacy in subgroups of Type 1 diabetic patients as well as identifying future opportunities for immunotherapy.

On the origin of immunopathology

Stranded between medicine and experimental biology, immunology is buried in its own problems and remains distant from important areas of current biology, such as evolutionary theory, developmental biology and cognitive sciences. Immunology has treated the living system merely as the place or dimension in which immune activity takes place, inserted on a misleading axis (progressive responsiveness versus no response; memory versus tolerance) which neglects the analysis of a robustly stable dynamics which is always present and is neither tolerance nor immunity-a problem currently approached as one of "regulatory" activity. However, a regulatory response also demands regulation, leading to an endless recursion and the adoption of a stimulus-response framework inevitably drives us away from the physiological processes in which lymphocytes are involved. Herein, we propose that immunological physiology, like everything else in the body is dynamic and conservative. Immunopathology, including inherited immunodeficiencies, severe forms of infectious diseases, allergy and autoimmune diseases, are interferences with this stability which frequently include oligoclonal expansions of T lymphocytes. We suggest that this decrease in clonal diversity results from a loss of the stabilizing connectivity among lymphocytes and are not simply markers of immunopathology, but are rather expressions of basic pathogenic mechanisms. The so-called autoimmune diseases are examples of this disequilibrium. In the last decade the characterization of an enormous and diversified commensal microbiota has posed a new and pressing problem: how to explain the harmonic conviviality with trillions of foreign macromolecules. In addition, robustly stable relations towards macromolecular diet can be established by simple ingestion, a state presently labeled as "oral tolerance", a problem that has been buffered for decades as anti-inflammatory protection of the gut. A major change in terminology is necessary to describe this new panorama. We focus on two important gaps in immunological discussions: (a) the organism, seen simultaneously as the medium with which the immune system is constantly in touch and as the entity that mediates the contact with external materials; and (b) the observer, the immunologist, who operates as a human being in human languaging with other human beings, and characterizes immunological specificity. We acknowledge that we are proposing radical departures from current dogma and that we should justify them. Most of what we propose stem form a way of seeing called Biology of Cognition and Language, that derives from ideas of the neurobiologist/philosopher Humberto Maturana, also known as "autopoiesis theory".

Human platelet antigen (HPA)-1a peptides do not reliably suppress anti-HPA-1a responses using a humanized severe combined immunodeficiency (SCID) mouse model

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) occurs most frequently when human platelet antigen (HPA)-1a-positive fetal platelets are destroyed by maternal HPA-1a immunoglobulin (Ig)G antibodies. Pregnancies at risk are treated by administration of high-dose intravenous Ig (IVIG) to women, but this is expensive and often not well tolerated. Peptide immunotherapy may be effective for ameliorating some allergic and autoimmune diseases. The HPA-1a/1b polymorphism is Leu/Pro33 on β3 integrin (CD61), and the anti-HPA-1a response is restricted to HPA-1b1b and HLA-DRB3*0101-positive pregnant women with an HPA-1a-positive fetus. We investigated whether or not HPA-1a antigen-specific peptides that formed the T cell epitope could reduce IgG anti-HPA-1a responses, using a mouse model we had developed previously. Peripheral blood mononuclear cells (PBMC) in blood donations from HPA-1a-immunized women were injected intraperitoneally (i.p.) into severe combined immunodeficient (SCID) mice with peptides and HPA-1a-positive platelets. Human anti-HPA-1a in murine plasma was quantitated at intervals up to 15 weeks. HPA-1a-specific T cells in PBMC were identified by proliferation assays. Using PBMC of three donors who had little T cell reactivity to HPA-1a peptides in vitro, stimulation of anti-HPA-1a responses by these peptides occurred in vivo. However, with a second donation from one of these women which, uniquely, had high HPA-1a-specific T cell proliferation in vitro, marked suppression of the anti-HPA-1a response by HPA-1a peptides occurred in vivo. HPA-1a peptide immunotherapy in this model depended upon reactivation of HPA-1a T cell responses in the donor. For FNAIT, we suggest that administration of antigen-specific peptides to pregnant women might cause either enhancement or reduction of pathogenic antibodies.

Treg inducing adjuvants for therapeutic vaccination against chronic inflammatory diseases

Many existing therapies in autoimmune diseases are based on systemic suppression of inflammation and the observed side effects of these therapies illustrate the pressing need for more specific interventions. Regulatory T-cells (Treg) are pivotal controllers of (auto-aggressive) immune responses and inflammation, and decreased Treg numbers and/or functioning have been associated with autoimmune disease. Therefore, Treg became frequently studied targets for more specific immunotherapy. Especially antigen-specific targeting of Treg would enable local and tailor made interventions, while obviating the negative side effect of general immuno-suppression. Self-antigens that participate in inflammation, irrespective of the etiology of the different autoimmune diseases, are held to be candidate antigens for antigen-specific interventions. Rather than tolerance induction to disease inciting self-antigens, which are frequently unknown, general self-antigens expressed at sites of inflammation would allow targeting of disease independent, but inflammatory-site specific, regulatory mechanisms. Preferably, such self-antigens should be abundantly expressed and up-regulated at the inflammatory-site. In this perspective heat shock proteins (Hsp) have several characteristics that make them highly attractive targets for antigen-specific Treg inducing therapy. The development of an antigen-specific Treg inducing vaccine is a major novel goal in the field of immunotherapy in autoimmune diseases. However, progress is hampered not only by the lack of effective antigens, but also by the fact that other factors such as dose, route, and the presence or absence of an adjuvant, turned out to be critical unknowns, with respect to the effective induction of Treg. In addition, the use of a Treg inducing adjuvant might be required to achieve an effective regulatory response, in the case of ongoing inflammation. Future goals in clinical trials will be the optimization of natural Treg expansion (or the induction of adaptive Treg) without loss of their suppressive function or the concomitant induction of non-regulatory T-cells. Here, we will discuss the potential use of protein/peptide-based vaccines combined with Treg inducing adjuvants for the development of therapeutic vaccines against chronic inflammatory conditions.

Clinical application of regulatory T cells in type 1 diabetes

Regulatory T cells (Tregs) are responsible for the maintenance of peripheral tolerance. Animal studies have shown that administration of Tregs can prevent type 1 diabetes (DM1). Several clinical trials attempted to induce Tregs with various agents, and thus provide long-term tolerance of β cells in DM1. Nevertheless, most of these studies have focused on clinical parameters (e.g. C-peptide) and not Treg numbers nor their function after treatment. Therefore, it is not possible to conclude if the majority of these therapies failed because the drugs did not induce Tregs, or if they failed despite Treg expansion. The current knowledge regarding Tregs, along with our experience in Treg therapy of patients with graft versus host disease, prompted us to use ex vivo expanded Tregs in 10 children with recent-onset DM1. No adverse effects in the treated individuals were observed. There was a significant increase in Treg number in peripheral blood immediately after the treatment administration, while the first clinical differences between treated and control patients were observed 4 months after Treg injection. Treated individuals had higher C-peptide levels and lower insulin requirements than non-treated children. Eleven months after diagnosis of DM1, there are still 2 individuals who are independent of exogenous insulin. These results indicate that autologous Tregs are a safe and well-tolerated therapy in children with DM1, which can inhibit or delay the destruction of pancreatic β cells. Additionally, Tregs can be a useful tool for local protection of transplanted pancreatic islets. Isolation and expansion of antigen-specific Tregs is one of the directions for future studies on cellular therapy of DM1.

Antigen-specific therapeutic approaches in Type 1 diabetes

Development of strategies capable of specifically curbing pathogenic autoimmune responses in a disease- and organ-specific manner without impairing foreign or tumor antigen-specific immune responses represents a long sought-after goal in autoimmune disease research. Unfortunately, our current understanding of the intricate details of the different autoimmune diseases that affect mankind, including type 1 diabetes, is rudimentary. As a result, progress in the development of the so-called "antigen-specific" therapies for autoimmunity has been slow and fraught with limitations that interfere with bench-to-bedside translation. Absent or incomplete understanding of mechanisms of action and lack of adequate immunological biomarkers, for example, preclude the rational design of effective drug development programs. Here, we provide an overview of antigen-specific approaches that have been tested in preclinical models of T1D and, in some cases, human subjects. The evidence suggests that effective translation of these approaches through clinical trials and into patients will continue to meet with failure unless detailed mechanisms of action at the level of the organism are defined.

Antigen-based vs. systemic immunomodulation in type 1 diabetes: the pros and cons

In type 1 diabetic patients insulin-producing pancreatic β-cells are destroyed by an orchestrated immune process involving self-reactive auto-antigen-specific CD4⁺ and CD8⁺ T cells. Efforts to reverse or prevent this destructive immunological cascade have led to promising results in animal models, however, the transition to the clinic has yet been unsuccessful. In addition, current clinical studies lack reliable biomarkers to circumscribe end-point parameters and define therapeutic success. Here, we give a current overview of both antigen-specific and non-specific systemic immunomodulatory approaches with a focus on the therapies verified or under evaluation in a clinical setting. While both approaches have their advantages and disadvantages, rationally designed combination therapies may yield the highest therapeutic efficacy. In order for future strategies to be effective, new well-defined biomarkers need to be developed and the extrapolation process of dose, timing and frequency from in vivo models to patients needs to be carefully reconsidered.

Heat shock protein bystander antigens for peptide immunotherapy in autoimmune disease

Mucosal administration of an antigen eliciting bystander suppression at the site of inflammation results in effective antigen-specific immunotherapy for autoimmune diseases. Heat shock proteins are bystander antigens that are effective in peptide-specific immunotherapy in both experimental and human autoimmune disease. The efficacy of preventive peptide immunotherapy is increased by enhancing peptide-specific immune responses with proinflammatory agents. Combining peptide-specific immunotherapy with general suppression of inflammation may improve its therapeutic effect.

Lessons from the mixed-meal tolerance test: use of 90-minute and fasting C-peptide in pediatric diabetes

OBJECTIVE

Mixed-meal tolerance test (MMTT) area under the curve C-peptide (AUC CP) is the gold-standard measure of endogenous insulin secretion in type 1 diabetes but is intensive and invasive to perform. The 90-min MMTT-stimulated CP ≥0.2 nmol/L (90CP) is related to improved clinical outcomes, and CP ≥0.1 nmol/L is the equivalent fasting measure (FCP). We assessed whether 90CP or FCP are alternatives to a full MMTT.

RESEARCH DESIGN AND METHODS

CP was measured during 1,334 MMTTs in 421 type 1 diabetes patients aged <18 years at 3, 9, 18, 48, and 72 months duration. We assessed: 1) correlation between mean AUC CP and 90CP or FCP; 2) sensitivity and specificity of 90CP ≥0.2 nmol/L and FCP ≥ 0.1 nmol/L to detect peak CP ≥0.2 nmol/L and the equivalent AUC CP; and 3) how the time taken to reach the CP peak varied with age of diagnosis and diabetes duration.

RESULTS

AUC CP was highly correlated to 90CP (r(s) = 0.96; P < 0.0001) and strongly correlated to FCP (r(s) = 0.84; P < 0.0001). AUC CP ≥23 nmol/L/150 min was the equivalent cutoff for peak CP ≥0.2 nmol/L (98% sensitivity/97% specificity). A 90CP ≥0.2 nmol/L correctly classified 96% patients using AUC or peak CP, whereas FCP ≥0.1 nmol/L classified 83 and 85% patients, respectively. There was only a small difference seen between peak and 90CP (median 0.02 nmol/L). The CP peak occurred earlier in patients with longer diabetes duration (6.1 min each 1-year increase in duration) and younger age (2.5 min each 1-year increase).

CONCLUSIONS

90CP is a highly sensitive and specific measure of AUC and peak CP in children and adolescents with type 1 diabetes and offers a practical alternative to a full MMTT.

Clinical potential of antigen-specific therapies in type 1 diabetes

In type 1 diabetes (T1D), pancreatic beta-cells are attacked and destroyed by the immune system, which leads to a loss of endogenous insulin secretion. The desirable outcome of therapeutic intervention in autoimmune diseases is the restoration of immune tolerance to prevent organ damage. Past trials with immune suppressive drugs highlight the fact that T1D is in principle a curable condition. However, the barrier in T1D therapy in terms of drug safety is set particularly high because of the predominantly young population and the good prognosis associated with modern exogenous insulin therapy. Thus, there is a general consensus that chronic immune suppression is associated with unacceptable long-term safety risks. On the other hand, immune-modulatory biologicals have recently failed to confer significant protection in phase 3 clinical trials. However, the concept of antigen-specific tolerization may offer a unique strategy to safely induce long-term protection against T1D. In this review, we analyze the potential reasons for the failure of the different tolerization therapies, and describe how the concept of antigen-specific toleraization may overcome the obstacles associated with clinical therapy in T1D.

Latent autoimmune diabetes in the adults (LADA) in Asia: from pathogenesis and epidemiology to therapy

Diabetes mellitus is a metabolic disorder resulting from a defect in insulin secretion, insulin action or both. An effect of this process is chronic hyperglycaemia with disorder of carbohydrate, fat and protein metabolism and with long-term complications of diabetes including retinopathy, nephropathy and neuropathy. Latent autoimmune diabetes in adults (LADA) is a type of autoimmune diabetes that resembles Type 1 diabetes (T1D), however, it shows a later onset and slower progression towards insulin necessity. Epidemiological studies suggest that LADA may account for 2-12% of all cases of diabetes in adult population. The epidemiology and phenotypic characteristics of LADA may vary between Caucasian and Asian diabetic patients as lifestyle, food habits and body mass index differ between these two populations. Data on LADA from population-based studies in Asia are sparse and only few studies have looked at it. A number of attractive therapeutic interventions may be envisaged for prevention of beta-cell loss in LADA, including hypoglycaemic and immunomodulatory agents. Because the autoimmune process in LADA seems to be slower than in childhood T1D, there is a wider window of opportunities for intervention. In deciding the best therapeutic approach, features of LADA should guide therapy including presence of other comorbidities that may influence the therapeutic choice.

Current and future immunomodulation strategies to restore tolerance in autoimmune diseases

Autoimmune diseases reflect a breakdown in self-tolerance that results from defects in thymic deletion of potentially autoreactive T cells (central tolerance) and in T-cell intrinsic and extrinsic mechanisms that normally control potentially autoreactive T cells in the periphery (peripheral tolerance). The mechanisms leading to autoimmune diseases are multifactorial and depend on a complex combination of genetic, epigenetic, molecular, and cellular elements that result in pathogenic inflammatory responses in peripheral tissues driven by self-antigen-specific T cells. In this article, we describe the different checkpoints of tolerance that are defective in autoimmune diseases as well as specific events in the autoimmune response which represent therapeutic opportunities to restore long-term tolerance in autoimmune diseases. We present evidence for the role of different pathways in animal models and the therapeutic strategies targeting these pathways in clinical trials in autoimmune diseases.

The impact of insulin administration during the mixed meal tolerance test

AIMS

The mixed meal tolerance test is the gold standard measure of endogenous insulin secretion. Practical issues limit the routine clinical use of this test, including omitting insulin prior to the ingestion of a high-carbohydrate liquid mixed meal, which can result in marked hyperglycaemia. We aimed to assess whether insulin omission is necessary during the mixed meal tolerance test and whether fasting C-peptide was a practical alternative to the test.

METHODS

Ninety-one adults with insulin-treated diabetes (Type 1 n = 56, Type 2 n = 35) underwent two mixed meal tolerance tests; one standard without insulin and one with the patient's usual morning insulin.

RESULTS

The 90-min serum C-peptide was highly correlated in the standard mixed meal tolerance test and the test with insulin (r = 0.98, P < 0.0001). There was a 20% reduction in the peak C-peptide value when insulin was given {test with insulin [0.39 (0.01-1.16) vs. test without insulin 0.48 (0.01-1.36) nmol/l, P = 0.001]}, but the original serum C-peptide cut-off for significant endogenous insulin secretion (≥ 0.2 nmol/l) still correctly classified 90/91 patients (98% sensitivity/100% specificity). Fasting serum C-peptide was highly correlated to 90-min serum C-peptide during the test (r = 0.97, P < 0.0001). A fasting serum C-peptide ≥ 0.07 nmol/l was the optimal cut-off (100% sensitivity and 97% specificity) for significant endogenous insulin secretion (defined as 90-min stimulated serum C-peptide ≥ 0.2 nmol/l).

CONCLUSIONS

Insulin omission may not always be necessary during a mixed meal tolerance test and fasting serum C-peptide may offer a practical alternative in insulin-treated patients.

Recognition of heat shock protein 60 epitopes in children with type 1 diabetes

BACKGROUND

Treatment with a specific HSP60 epitope in new onset of type 1 diabetes (T1D) patients has been shown to preserve endogenous insulin production. Previously, recognition of pan HLA-DR-binding HSP60 epitopes in various autoimmune diseases was found; this study investigated recognition of these epitopes in newly diagnosed T1D patients and correlated findings to the occurrence of a partial remission.

METHODS

Peripheral blood mononuclear cells of 18 children with T1D were prospectively collected at disease onset and a few months after diagnosis. Epitope-specific T-cell proliferation and cytokine production (intracellular and in culture supernatants) were measured. Results were compared with 31 longstanding T1D patients and ten healthy controls.

RESULTS

Although HSP60 epitope-specific T-cell proliferative responses were detected, overall proliferative responses were low. At onset, epitope-specific intracellular IFN-γ production was higher in T1D patients compared with healthy controls (p < 0.05). At follow-up, both IL-10 and IFN-γ production were higher in those without a partial remission than in those with a partial remission (both p < 0.05). Also, IL-10 and IFN-γ production were higher compared with onset for patients without a PR (both p < 0.01). In supernatants of HSP60 epitope-specific T-cell cultures, no substantial differences in cytokine production were found between T1D patients with and without a partial remission, either at onset or a few months after onset. As patient numbers were small, results should be interpreted with caution.

CONCLUSIONS

Pan-DR-binding HSP60 peptides induced low peptide-specific proliferative responses and peptide-specific production of some, mainly intracellular, cytokines in T1D patients. Recognition did not differ significantly between patient groups and various time points.

Heat shock proteins are therapeutic targets in autoimmune diseases and other chronic inflammatory conditions

INTRODUCTION

Exploitation of antigen-specific regulatory T cells (Tregs) as critical regulators in the control of chronic inflammatory diseases is hampered by the obscure nature of most disease-relevant autoantigens. Heat shock proteins (Hsp) are possible targets for Tregs due to their enhanced expression in inflamed (stressed) tissues and there is evidence that Hsp can induce anti-inflammatory immunoregulatory T-cell responses.

AREAS COVERED

Recent publications showing that exogenous administration of stress proteins has induced immunoregulation in various models of inflammatory disease have also been shown to be effective in first clinical trials in humans. Now, in the light of a growing interest in T-cell regulation, it is of interest to further explore the mechanisms through which Hsp can be utilized to trigger immunoregulatory pathways, capable of suppressing such a wide and diversified spectrum of inflammatory diseases.

EXPERT OPINION

Therapeutic approaches via exploitation of antigen-specific Tregs will benefit from tailor-made combination therapies. Combining current therapeutic approaches with Hsp-specific therapies thereby enhancing natural immune regulation might expedite the entry of antigen-specific regulatory T cells into the therapeutic arsenal of the anti-inflammatory therapeutics.

Immunotherapies in diabetes mellitus type 1

Type 1 diabetes is an autoimmune disease that gradually destructs insulin-producing beta cells. Over the years, clinicians' knowledge regarding the immunopathogenesis of this disease has greatly increased. Immunotherapies that can change the course of immune-mediated destruction and preserve and possibly regenerate the pancreatic beta cells seem to be promising in preclinical trials but so far have been unsuccessful in human studies. This article reviews the important immune interventions for type 1 diabetes that have been tried so far targeting the different stages of disease development and provides an insight into what the future might hold.

New and future immunomodulatory therapy in type 1 diabetes

Type 1 diabetes is a common autoimmune disease that affects millions of people worldwide and has an incidence that is increasing at a striking rate, especially in young children. It results from the targeted self-destruction of the insulin-secreting β cells of the pancreas and requires lifelong insulin treatment. The effects of chronic hyperglycemia - the result of insulin deficiency - include secondary endorgan complications. Over the past two decades our increased understanding of the pathogenesis of this disease has led to the development of new immunomodulatory treatments. None have yet received regulatory approval, but this report highlights recent progress in this area.

HSP60: issues and insights on its therapeutic use as an immunoregulatory agent

Heat shock proteins 60 (HSP60) is one of the most well studied member of the HSP family. Although found to be a target self antigen in pathological autoimmunity and HSP60-reactive T and B cells are part of immune responses in several infectious diseases, there is consistent experimental evidence that HSP60 displays dominant immunoregulatory properties. There are a series of reports on animal models showing that the administration of HSP60 can modulate inflammatory diseases. However, HSP60 has both immune-regulatory and inflammatory properties placing it as an essentially homeostatic antigen, but with potentially harmful effects as well. There have been a series of reports on the successful use of HSP60 and its peptides as immune-modulatory agent for several models of autoimmune diseases and in some clinical trials as well. We believe that the potential risks of HSP60 as a therapeutic agent can be controlled by addressing important factors determining its effects. These factors would be route of administration, appropriate peptides, time point of administration in the course of the disease, and possible association with other modulatory agents.

C-peptide response and HLA genotypes in subjects with recent-onset type 1 diabetes after immunotherapy with DiaPep277: an exploratory study

OBJECTIVE

To investigate whether lower risk HLA class II genotypes would influence the efficacy of DiaPep277 therapy in protecting β-cell function evaluated by C-peptide secretion in recent-onset type 1 diabetic subjects.

RESEARCH DESIGN AND METHODS

Data were collected from type 1 diabetic subjects enrolled in multicenter phase II studies with a randomized, double-blind, and placebo-controlled design in whom fasting and stimulated C-peptide levels were measured. HLA genotypes were classified in high, moderate, and low risk categories.

RESULTS

A total of 146 subjects (aged 4.3 to 58.5 years) were enrolled, including 76 children (<18 years old) and 70 adults. At baseline, there was a significant increase in fasting, maximal, and area under the curve (AUC) C-peptide from high to moderate and low risk HLA genotypes in adults (P for trend <0.04) but not in children. Children showed a decrease of the three parameters over time regardless of therapy and HLA genotype. DiaPep277-treated adults with low risk genotype had significantly higher maximal and AUC C-peptide versus placebo at 12 months (0.04 ± 0.07 vs. -0.28 ± 0.09 nmol/L, P < 0.01, and 0.53 ± 1.3 vs. -4.59 ± 1.5 nmol/L, P < 0.05, respectively). In the moderate risk genotype group, Δmaximal and AUC C-peptide values were significantly higher in DiaPep277-treated versus placebo-treated patients (P < 0.01 and P < 0.05, respectively).

CONCLUSIONS

This exploratory study demonstrates that type 1 diabetic adults with low and moderate risk HLA genotypes benefit the most from intervention with DiaPep277; the only subgroup with an increase of C-peptide at 12 months after diagnosis was the low risk DiaPep277-treated subgroup.

Interventions for latent autoimmune diabetes (LADA) in adults

BACKGROUND

Latent autoimmune diabetes in adults (LADA) is a slowly developing type 1 diabetes.

OBJECTIVES

To compare interventions used for LADA.

SEARCH STRATEGY

Studies were obtained from searches of electronic databases, supplemented by handsearches, conference proceedings and consultation with experts. Date of last search was December 2010.

SELECTION CRITERIA

Randomised controlled trials (RCT) and controlled clinical trials (CCT) evaluating interventions for LADA or type 2 diabetes with antibodies were included.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias. Studies were summarised using meta-analysis or descriptive methods.

MAIN RESULTS

Searches identified 13,306 citations. Fifteen publications (ten studies) were included, involving 1019 participants who were followed between three months to 10 years (1060 randomised). All studies had a high risk of bias. Sulphonylurea (SU) with insulin did not improve metabolic control significantly more than insulin alone at three months (one study, n = 15) and at 12 months (one study, n = 14) of treatment and follow-up. SU (with or without metformin) gave poorer metabolic control compared to insulin alone (mean difference in glycosylated haemoglobin A1c (HbA1c) from baseline to end of study, for insulin compared to oral therapy: -1.3% (95% confidence interval (CI) -2.4 to -0.1; P = 0.03, 160 participants, four studies, follow-up/duration of therapy: 12, 30, 36 and 60 months; however, heterogeneity was considerable). In addition, there was evidence that SU caused earlier insulin dependence (proportion requiring insulin at two years was 30% in the SU group compared to 5% in conventional care group (P < 0.001); patients classified as insulin dependent was 64% (SU group) and 12.5% (insulin group, P = 0.007). No intervention influenced fasting C-peptide, but insulin maintained stimulated C-peptide better than SU (one study, mean difference 7.7 ng/ml (95% CI 2.9 to 12.5)). In a five year follow-up of GAD65 (glutamic acid decarboxylase formulated with aluminium hydroxide), improvements in fasting and stimulated C-peptide levels (20 μg group) were maintained after five years. Short term (three months) follow-up in one study (n = 74) using Chinese remedies did not demonstrate a significant difference in improving fasting C-peptide levels compared to insulin alone (0.07 µg/L (95% CI -0.05 to 0.19). One study using vitamin D with insulin showed steady fasting C-peptide levels in the vitamin D group but declining fasting C-peptide levels (368 to 179 pmol/L, P = 0.006) in the insulin alone group at 12 months follow-up. Comparing studies was difficult as there was a great deal of heterogeneity in the studies and in their selection criteria. There was no information regarding health-related quality of life, complications of diabetes, cost or health service utilisation, mortality and limited evidence on adverse events (studies on oral agents or insulin reported no adverse events in terms of severe hypoglycaemic episodes).

AUTHORS' CONCLUSIONS

Two studies show SU leading to earlier insulin dependence and a meta-analysis of four studies with considerable heterogeneity showed poorer metabolic control if SU is prescribed for patients with LADA compared to insulin. One study showed that vitamin D with insulin may protect pancreatic beta cells in LADA. Novel treatments such as GAD65 in certain doses (20 μg) have been suggested to maintain fasting and stimulated C-peptide levels. However, there is no significant evidence for or against other lines of treatment of LADA.

DiaPep277 peptide therapy in the context of other immune intervention trials in type 1 diabetes

INTRODUCTION

Type 1 diabetes (T1D) is characterized by the autoimmune destruction of pancreatic β-cells. The aim of immune intervention is to arrest this autoimmune attack. DiaPep277, a major T-cell epitope of heat shock protein 60 (hsp60), has been shown to be effective in the modulation of the immune response in recent onset T1D and is the main focus of this review in the context of other ongoing trials using different approaches.

AREAS COVERED

The authors performed a literature search of Pubmed listed publications (from the last 10 years) and a website search of the company licensing DiaPep277. DiaPep277 has been investigated in Phase I - III trials in humans. Phase II trials showed a significant preservation of β-cell function in adult T1D patients (but not children) with an absence of adverse effects and not accompanied by lower glycosylated haemoglobin (HbA1c) levels or reduced daily insulin requirement compared with placebo-treated patients.

EXPERT OPINION

Administration of DiaPep277 is safe and represents a promising therapeutic strategy in patients with recent-onset T1D. The results of two large Phase III trials will tell us whether this therapy may change our current approach to treating T1D patients at diagnosis.

Antigen-based immune therapeutics for type 1 diabetes: magic bullets or ordinary blanks?

The ideal drug of modern medicine is the one that achieves its therapeutic target with minimal adverse effects. Immune therapy of Type 1 diabetes (T1D) is no exception, and knowledge of the antigens targeted by pathogenic T cells offers a unique opportunity towards this goal. Different antigen formulations are being considered, such as proteins or peptides, either in their native form or modified ad hoc, DNA plasmids, and cell-based agents. Translation from mouse to human should take into account important differences, particularly in the time scale of autoimmune progression, and intervention. Critical parameters such as administration route, dosing and interval remain largely empirical and need to be further dissected. T1D staging through immune surrogate markers before and after treatment will be key in understanding therapeutic actions and to finally turn ordinary blanks into magic bullets.

GAD-alum immunotherapy in Type 1 diabetes mellitus

Glutamic acid decarboxylase (GAD)-alum (Diamyd®, Diamyd Medical, Stockholm, Sweden) is an adjuvant-formulated vaccine incorporating recombinant human GAD65, the specific isoform of GAD expressed in human pancreatic β-cells and a major antigen targeted by autoreactive T lymphocytes in Type 1 diabetes mellitus. Intermittent vaccination with this protein is theorized to induce immune tolerance to GAD65, thereby potentially interrupting further β-cell destruction. Hence, clinical trials are ongoing to examine the efficacy and safety of GAD-alum immunotherapy in patients with autoimmune-mediated forms of diabetes, including Type 1 diabetes and latent autoimmune diabetes in adults.

Type 1 Diabetes: Etiology, Immunology, and Therapeutic Strategies

Type 1 diabetes (T1D) is a chronic autoimmune disease in which destruction or damaging of the beta-cells in the islets of Langerhans results in insulin deficiency and hyperglycemia. We only know for sure that autoimmunity is the predominant effector mechanism of T1D, but may not be its primary cause. T1D precipitates in genetically susceptible individuals, very likely as a result of an environmental trigger. Current genetic data point towards the following genes as susceptibility genes: HLA, insulin, PTPN22, IL2Ra, and CTLA4. Epidemiological and other studies suggest a triggering role for enteroviruses, while other microorganisms might provide protection. Efficacious prevention of T1D will require detection of the earliest events in the process. So far, autoantibodies are most widely used as serum biomarker, but T-cell readouts and metabolome studies might strengthen and bring forward diagnosis. Current preventive clinical trials mostly focus on environmental triggers. Therapeutic trials test the efficacy of antigen-specific and antigen-nonspecific immune interventions, but also include restoration of the affected beta-cell mass by islet transplantation, neogenesis and regeneration, and combinations thereof. In this comprehensive review, we explain the genetic, environmental, and immunological data underlying the prevention and intervention strategies to constrain T1D.

The HSP60 immune system network

Heat shock proteins (HSPs) were initially discovered as participants in the cellular response to stress. It is now clear, however, that self and microbial HSPs also play an important role in the control of the immune response. Here, we focus on HSP60 and its interactions with both the innate and adaptive immune system in mammals. We also consider that circulating HSP60 and the quantities and specificities of serum antibodies to HSP60 provide a biomarker to monitor the immune status of the individual. Thus, the dual role of HSP60 as an immune modulator and a biomarker, provides an opportunity to modulate immunity for therapeutic purposes, and to monitor the immune response in health and disease.