Peptides derived from insulin granule proteins are targeted by CD8+ T cells across MHC Class I restrictions in humans and NOD mice

The antigenic peptides processed by β cells and presented through surface HLA Class I molecules are poorly characterized. Each HLA variant, e.g. the most common HLA-A2 and HLA-A3, carries some peptide-binding specificity. Hence, features that, despite these specificities, remain shared across variants may reveal factors favoring β-cell immunogenicity. Building on our previous description of the HLA-A2/A3 peptidome of β cells, we analyzed the HLA-A3-restricted peptides targeted by circulating CD8+ T cells. Several peptides were recognized by CD8+ T cells within a narrow frequency (1-50/106), which was similar in donors with and without type 1 diabetes and harbored variable effector/memory fractions. These epitopes could be classified as conventional peptides or neo-epitopes, generated either via peptide cis-splicing or mRNA splicing, e.g. secretogranin-5 (SCG5)-009. As reported for HLA-A2-restricted peptides, several epitopes originated from β-cell granule proteins, e.g. SCG3, SCG5 and urocortin-3. Similarly, H-2Kd-restricted CD8+ T cells recognizing the murine orthologues of SCG5, urocortin-3, and proconvertase-2 infiltrated the islets of NOD mice and transferred diabetes into NOD/scid recipients. The finding of granule proteins targeted in both humans and NOD mice supports their disease relevance and identifies the insulin granule as a rich source of epitopes, possibly reflecting its impaired processing in type 1 diabetes.

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Dextran Sulfate Protects Pancreatic β-Cells, Reduces Autoimmunity and Ameliorates Type 1 Diabetes

10.2337/figshare.12245363.v1 ◽

2020 ◽

Author(s):

Ada Admin ◽

Geming Lu ◽

Francisco Rausell-Palamos ◽

Jiamin Zhang ◽

Zihan Zheng ◽

...

Keyword(s):

T Cells ◽

Type 1 Diabetes ◽

Heparan Sulfate ◽

Dextran Sulfate ◽

Nod Mice ◽

Β Cells ◽

Β Cell ◽

Pancreatic Β Cells

A failure in self-tolerance leads to autoimmune destruction of pancreatic β-cells and type 1 diabetes (T1D). Low molecular weight dextran sulfate (DS) is a sulfated semi-synthetic polysaccharide with demonstrated cytoprotective and immunomodulatory properties in vitro. However, whether DS can protect pancreatic β-cells, reduce autoimmunity and ameliorate T1D is unknown. Here we report that DS, but not dextran, protects human β-cells against cytokine-mediated cytotoxicity in vitro. DS also protects mitochondrial function and glucose-stimulated insulin secretion and reduces chemokine expression in human islets in a pro-inflammatory environment. Interestingly, daily treatment with DS significantly reduces diabetes incidence in pre-diabetic non-obese diabetic (NOD) mice, and most importantly, reverses diabetes in early-onset diabetic NOD mice. DS decreases β-cell death, enhances islet heparan sulfate (HS)/heparan sulfate proteoglycan (HSPG) expression and preserves β-cell mass and plasma insulin in these mice. DS administration also increases the expression of the inhibitory co-stimulatory molecule programmed death-1 (PD-1) in T-cells, reduces interferon-γ+ CD4+ and CD8+ T-cells and enhances the number of FoxP3+ cells. Collectively, these studies demonstrate that the action of one single molecule, DS, on β-cell protection, extracellular matrix preservation and immunomodulation can reverse diabetes in NOD mice highlighting its therapeutic potential for the treatment of T1D.

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Dextran Sulfate Protects Pancreatic β-Cells, Reduces Autoimmunity and Ameliorates Type 1 Diabetes

10.2337/figshare.12245363 ◽

2020 ◽

Author(s):

Ada Admin ◽

Geming Lu ◽

Francisco Rausell-Palamos ◽

Jiamin Zhang ◽

Zihan Zheng ◽

...

Keyword(s):

T Cells ◽

Type 1 Diabetes ◽

Heparan Sulfate ◽

Dextran Sulfate ◽

Nod Mice ◽

Β Cells ◽

Β Cell ◽

Pancreatic Β Cells

A failure in self-tolerance leads to autoimmune destruction of pancreatic β-cells and type 1 diabetes (T1D). Low molecular weight dextran sulfate (DS) is a sulfated semi-synthetic polysaccharide with demonstrated cytoprotective and immunomodulatory properties in vitro. However, whether DS can protect pancreatic β-cells, reduce autoimmunity and ameliorate T1D is unknown. Here we report that DS, but not dextran, protects human β-cells against cytokine-mediated cytotoxicity in vitro. DS also protects mitochondrial function and glucose-stimulated insulin secretion and reduces chemokine expression in human islets in a pro-inflammatory environment. Interestingly, daily treatment with DS significantly reduces diabetes incidence in pre-diabetic non-obese diabetic (NOD) mice, and most importantly, reverses diabetes in early-onset diabetic NOD mice. DS decreases β-cell death, enhances islet heparan sulfate (HS)/heparan sulfate proteoglycan (HSPG) expression and preserves β-cell mass and plasma insulin in these mice. DS administration also increases the expression of the inhibitory co-stimulatory molecule programmed death-1 (PD-1) in T-cells, reduces interferon-γ+ CD4+ and CD8+ T-cells and enhances the number of FoxP3+ cells. Collectively, these studies demonstrate that the action of one single molecule, DS, on β-cell protection, extracellular matrix preservation and immunomodulation can reverse diabetes in NOD mice highlighting its therapeutic potential for the treatment of T1D.

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Effective Destruction of Fas-deficient Insulin-producing β Cells in Type 1 Diabetes

Journal of Experimental Medicine ◽

10.1084/jem.20030698 ◽

2003 ◽

Vol 198 (7) ◽

pp. 1103-1106 ◽

Cited By ~ 52

Author(s):

Irina Apostolou ◽

Zhenyue Hao ◽

Klaus Rajewsky ◽

Harald von Boehmer

Keyword(s):

T Cells ◽

Cell Death ◽

Type 1 Diabetes ◽

Autoimmune Diabetes ◽

Nod Mice ◽

Β Cells ◽

Β Cell ◽

Influenza Hemagglutinin ◽

Insulin Promoter

In type 1 diabetes, autoimmune T cells cause destruction of pancreatic β cells by largely unknown mechanism. Previous analyses have shown that β cell destruction is delayed but can occur in perforin-deficient nonobese diabetic (NOD) mice and that Fas-deficient NOD mice do not develop diabetes. However, because of possible pleiotropic functions of Fas, it was not clear whether the Fas receptor was an essential mediator of β cell death in type 1 diabetes. To directly test this hypothesis, we have generated a β cell–specific knockout of the Fas gene in a transgenic model of type 1 autoimmune diabetes in which CD4+ T cells with a transgenic TCR specific for influenza hemagglutinin (HA) are causing diabetes in mice that express HA under control of the rat insulin promoter. Here we show that the Fas-deficient mice develop autoimmune diabetes with slightly accelerated kinetics indicating that Fas-dependent apoptosis of β cells is a dispensable mode of cell death in this disease.

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Nonlinear Analysis for a Type-1 Diabetes Model with Focus on T-Cells and Pancreatic β-Cells Behavior

Mathematical and Computational Applications ◽

10.3390/mca25020023 ◽

2020 ◽

Vol 25 (2) ◽

pp. 23

Author(s):

Diana Gamboa ◽

Carlos E. Vázquez ◽

Paul J. Campos

Keyword(s):

T Cells ◽

Type 1 Diabetes ◽

Cell Population ◽

Closed Loop ◽

Pancreatic Β Cell ◽

Activated Macrophages ◽

Β Cells ◽

Β Cell ◽

Pancreatic Β Cells

Type-1 diabetes mellitus (T1DM) is an autoimmune disease that has an impact on mortality due to the destruction of insulin-producing pancreatic β -cells in the islets of Langerhans. Over the past few years, the interest in analyzing this type of disease, either in a biological or mathematical sense, has relied on the search for a treatment that guarantees full control of glucose levels. Mathematical models inspired by natural phenomena, are proposed under the prey–predator scheme. T1DM fits in this scheme due to the complicated relationship between pancreatic β -cell population growth and leukocyte population growth via the immune response. In this scenario, β -cells represent the prey, and leukocytes the predator. This paper studies the global dynamics of T1DM reported by Magombedze et al. in 2010. This model describes the interaction of resting macrophages, activated macrophages, antigen cells, autolytic T-cells, and β -cells. Therefore, the localization of compact invariant sets is applied to provide a bounded positive invariant domain in which one can ensure that once the dynamics of the T1DM enter into this domain, they will remain bounded with a maximum and minimum value. Furthermore, we analyzed this model in a closed-loop scenario based on nonlinear control theory, and proposed bases for possible control inputs, complementing the model with them. These entries are based on the existing relationship between cell–cell interaction and the role that they play in the unchaining of a diabetic condition. The closed-loop analysis aims to give a deeper understanding of the impact of autolytic T-cells and the nature of the β -cell population interaction with the innate immune system response. This analysis strengthens the proposal, providing a system free of this illness—that is, a condition wherein the pancreatic β -cell population holds and there are no antigen cells labeled by the activated macrophages.

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Potential Mimicry of Viral and Pancreatic β Cell Antigens Through Non-Spliced and cis-Spliced Zwitter Epitope Candidates in Type 1 Diabetes

Frontiers in Immunology ◽

10.3389/fimmu.2021.656451 ◽

2021 ◽

Vol 12 ◽

Author(s):

Michele Mishto ◽

Artem Mansurkhodzhaev ◽

Teresa Rodriguez-Calvo ◽

Juliane Liepe

Keyword(s):

Type 1 Diabetes ◽

T Cell ◽

Viral Infections ◽

Hla Class I ◽

Class I ◽

Pancreatic Β Cell ◽

Β Cells ◽

Β Cell ◽

Pancreatic Β Cells

Increasing evidence suggests that post-translational peptide splicing can play a role in the immune response under pathological conditions. This seems to be particularly relevant in Type 1 Diabetes (T1D) since post-translationally spliced epitopes derived from T1D-associated antigens have been identified among those peptides bound to Human Leucocyte Antigen (HLA) class I and II complexes. Their immunogenicity has been confirmed through CD4+ and CD8+ T cell-mediated responses in T1D patients. Spliced peptides theoretically have a large sequence variability. This might increase the frequency of viral-human zwitter peptides, i.e. peptides that share a complete sequence homology irrespective of whether they originate from human or viral antigens, thereby impinging upon the discrimination between self and non-self antigens by T cells. This might increase the risk of autoimmune responses triggered by viral infections. Since enteroviruses and other viral infections have historically been associated with T1D, we investigated whether cis-spliced peptides derived from selected viruses might be able to trigger CD8+ T cell-mediated autoimmunity. We computed in silico viral-human non-spliced and cis-spliced zwitter epitope candidates, and prioritized peptide candidates based on: (i) their binding affinity to HLA class I complexes, (ii) human pancreatic β cell and medullary thymic epithelial cell (mTEC) antigens’ mRNA expression, (iii) antigen association with T1D, and (iv) potential hotspot regions in those antigens. Neglecting potential T cell receptor (TCR) degeneracy, no viral-human zwitter non-spliced peptide was found to be an optimal candidate to trigger a virus-induced CD8+ T cell response against human pancreatic β cells. Conversely, we identified some zwitter peptide candidates, which may be produced by proteasome-catalyzed peptide splicing, and might increase the likelihood of pancreatic β cells recognition by virus-specific CD8+ T cell clones, therefore promoting β cell destruction in the context of viral infections.

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Detecting Insulitis in Type 1 Diabetes with Ultrasound Phase-change Contrast Agents

10.1101/2020.10.28.359687 ◽

2020 ◽

Author(s):

David G. Ramirez ◽

Awaneesh K. Upadhyay ◽

Vinh T. Pham ◽

Mark Ciccaglione ◽

Mark A Borden ◽

...

Keyword(s):

Type 1 Diabetes ◽

Contrast Agents ◽

Cell Mass ◽

Nod Mice ◽

Therapeutic Interventions ◽

Β Cells ◽

Β Cell ◽

Diabetes Onset ◽

Ultrasound Contrast

AbstractType 1 diabetes (T1D) results from immune infiltration and destruction of insulin-producing β-cells within the pancreatic islets of Langerhans (insulitis), resulting in loss of glucose homeostasis. Early diagnosis during pre-symptomatic T1D would allow for therapeutic intervention prior to substantial loss of β-cell mass at T1D onset. There are limited methods to track the progression of insulitis and β-cell mass decline in pre-symptomatic T1D. During insulitis, the islet microvasculature increases permeability, such that sub-micron sized particles can extravasate and accumulate within the islet microenvironment. Ultrasound is a widely deployable and cost-effective clinical imaging modality. However, conventional microbubble contrast agents are restricted to the vasculature. Sub-micron sized nanodroplet (ND) phasechange agents can be vaporized into micron-sized bubbles; serving as a circulating microbubble precursor. We tested if NDs extravasate into the immune-infiltrated islet microenvironment. We performed ultrasound contrast-imaging following ND infusion in NOD mice and NOD;Rag1ko controls, and tracked diabetes development. We measured the biodistribution of fluorescently labeled NDs, with histological analysis of insulitis. Ultrasound contrast signal was elevated in the pancreas of 10w NOD mice following ND infusion and vaporization, but was absent in both the non-infiltrated kidney of NOD mice and pancreas of Rag1ko controls. High contrast elevation also correlated with rapid diabetes onset. In pancreata of NOD mice, infiltrated islets and nearby exocrine tissue were selectively labeled with fluorescent NDs. Thus, contrast ultrasound imaging with ND phase-change agents can detect insulitis prior to diabetes onset. This will be important for monitoring disease progression to guide and assess preventative therapeutic interventions for T1D.SignificanceThere is a need for imaging methods to detect type1 diabetes (T1D) progression prior to clinical diagnosis. T1D is a chronic disease that results from autoreactive T cells infiltrating the islet of Langerhans and destroying insulin-producing β-cells. Overt disease takes years to present and is only diagnosed after significant β-cells loss. As such, the possibility of therapeutic intervention to preserve β-cell mass is hampered by an inability to follow pre-symptomatic T1D progression. There are immunotherapies that can delay T1D development. However identifying ‘at risk’ individuals, and tracking whether therapeutic interventions are impacting disease progression, prior to T1D onset, is lacking. A method to detect insulitis and β-cell mass decline would present an opportunity to guide therapeutic treatments to prevent T1D.

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Demonstration of islet-autoreactive CD8 T cells in insulitic lesions from recent onset and long-term type 1 diabetes patients

Journal of Experimental Medicine ◽

10.1084/jem.20111187 ◽

2012 ◽

Vol 209 (1) ◽

pp. 51-60 ◽

Cited By ~ 368

Author(s):

Ken T. Coppieters ◽

Francesco Dotta ◽

Natalie Amirian ◽

Peter D. Campbell ◽

Thomas W.H. Kay ◽

...

Keyword(s):

T Cells ◽

Type 1 Diabetes ◽

T Cell ◽

Direct Proof ◽

Hla Class I ◽

Cd8 T Cell ◽

Class I ◽

Β Cell ◽

Cell Reactivity

A direct association of islet-autoreactive T cells with β cell destruction in human pancreatic islets from type 1 diabetes (T1D) patients has never been demonstrated, and little is known about disease progression after diagnosis. Frozen pancreas samples were obtained from 45 cadaveric T1D donors with disease durations ranging from 1 wk to >50 yr, 14 nondiabetic controls, 5 nondiabetics with islet autoantibodies, 2 cases of gestational diabetes, and 6 T2D patients. Sections were systematically analyzed for the presence of insulin-sufficient β cells, CD8+ insulitic lesions, and HLA class I hyperexpression. Finally, consecutive sections from HLA-A2–expressing individuals were probed for CD8 T cell reactivity against six defined islet autoantigens associated with T1D by in situ tetramer staining. Both single and multiple CD8 T cell autoreactivities were detected within individual islets in a subset of patients up to 8 yr after clinical diagnosis. Pathological features such as HLA class I hyperexpression and insulitis were specific for T1D and persisted in a small portion of the patients with longstanding disease. Insulitic lesions consistently presented in a multifocal pattern with varying degrees of infiltration and β cell loss across affected organs. Our observations provide the first direct proof for islet autoreactivity within human islets and underscore the heterogeneous and chronic disease course.

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Circulating β cell‐specific CD8 + T cells restricted by high‐risk HLA class I molecules show antigen experience in children with and at risk of type 1 diabetes

Clinical & Experimental Immunology ◽

10.1111/cei.13391 ◽

2019 ◽

Vol 199 (3) ◽

pp. 263-277 ◽

Cited By ~ 5

Author(s):

L. Yeo ◽

I. Pujol‐Autonell ◽

R. Baptista ◽

M. Eichmann ◽

D. Kronenberg‐Versteeg ◽

...

Keyword(s):

At Risk ◽

T Cells ◽

Type 1 Diabetes ◽

High Risk ◽

Cd8 T Cells ◽

Hla Class I ◽

Class I ◽

Β Cell ◽

Hla Class I Molecules

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Immune interventions to preserve β cell function in type 1 diabetes

Journal of Investigative Medicine ◽

10.1097/jim.0000000000000227 ◽

2016 ◽

Vol 64 (1) ◽

pp. 7-13 ◽

Cited By ~ 11

Author(s):

Mario R Ehlers

Keyword(s):

T Cells ◽

Type 1 Diabetes ◽

Regulatory T Cells ◽

Immune Modulation ◽

Cell Function ◽

Cell Mass ◽

Β Cells ◽

Β Cell

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

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