Aberrant expression of transglutaminase 2 in pancreas and thymus of NOD mice underscores the importance of deamidation in neoantigen generation.
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Q Exactive
ORGANISM(S): Mus Musculus (mouse)
SUBMITTER: 
Aisha Callebaut
LAB HEAD: Chantal Mathieu
PROVIDER: PXD034102 | Pride | 2022-07-21
REPOSITORIES: Pride
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Project description:Administration of low-dose IL-2 prevents and cures type 1 diabetes (T1D) in NOD mice by boosting pancreatic regulatory T cells (Tregs) and is currently being evaluated in humans. Here, to improve treatment efficacy we tested higher IL-2 doses that, despite further boosting Tregs, rapidly precipitated T1D in pre-diabetic mice due to generalized immune activation. Although the combination of rapamycin (RAPA) plus IL-2 prevents NOD T1D development, a recent clinical trial translating this strategy into patients was halted due to C-peptide decline. Here, we show that RAPA/IL-2 combination was also ineffective to cure new onset T1D in mice and, surprisingly, RAPA broke IL-2-induced tolerance in a reversible way. RAPA partially counteracted IL-2 effects on Tregs and the combined treatment unexpectedly, impaired glucose homeostasis at multiple levels, possibly explaining the clinical outcome. Our data help understand IL-2 alone or RAPA/IL-2 combination limitations and could lead to the design of improved T1D therapies.
2013-12-10 | E-MEXP-3789 | biostudies-arrayexpress
Project description:The peptides repertoire presented to CD8+ T cells by major histocompatibility complex (MHC) class I molecules, referred to as the MHC I-associated peptidome (MIP), regulates all critical events that occur during the lifetime of CD8+ T cells. The MIP presented by thymic antigen presenting cells (APCs) is crucial for shaping CD8+ T cell repertoire and self-tolerance, while the MIP presented by peripheral tissues and organs is not only involved in maintaining periphery CD8+ T cell survival and homeostasis, but also mediates immune surveillance and autoimmune responses of CD8+ T cells under pathological conditions. Type 1 diabetes (T1D) is an organ-specific autoimmune disease caused by the destruction pancreatic β cells, mediated primarily by autoreactive CD8+ T cells. Non-obese diabetic (NOD) mouse is one of important animal models of spontaneous autoimmune diabetes that shares several key features with human T1D. Here, we deeply analyzed the MIP derived from the primary tissues of thymus and pancreas in NOD mice using targeted database searches of mass spectrometry data. We demonstrated that the thymus MIP source proteins accommodated only a small portion of the transcriptome of thymus epithelial cells, and partially shared with the MIP source proteins derived from NOD mice pancreas and β cell line. The global view of the MHC I-associated self-peptides repertoire in the thymus and pancreas of NOD mice may serve as a biological reference to identify potential autoantigens targeted by autoreactive CD8+ T cells in T1D.
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Project description:Background: Activation of stress pathways intrinsic to the β cell are thought to both accelerate β cell death and increase β cell immunogenicity in type 1 diabetes (T1D). However, information on the timing and scope of these responses is lacking. Methods: To identify temporal and disease-related changes in islet β cell protein expression, SWATH-MS/MS proteomics analysis was performed on islets collected longitudinally from NOD mice and NOD-SCID mice rendered diabetic through T cell adoptive transfer. Findings: In islets collected from female NOD mice at 10, 12, and 14 weeks of age, we found a time-restricted upregulation of proteins involved in the maintenance of β cell function and stress mitigation, followed by loss of expression of protective proteins that heralded diabetes onset. Pathway analysis identified EIF2 signaling and the unfolded protein response, mTOR signaling, mitochondrial function, and oxidative phosphorylation as commonly modulated pathways in both diabetic NOD mice and NOD-SCID mice rendered acutely diabetic by adoptive transfer, highlighting this core set of pathways in T1D pathogenesis. In immunofluorescence validation studies, β cell expression of protein disulfide isomerase A1 (PDIA1) and 14-3-3b were found to be increased during disease progression in NOD islets, while PDIA1 plasma levels were increased in pre-diabetic NOD mice and in the serum of children with recent-onset T1D compared to age and sex-matched non-diabetic controls. Interpretation: We identified a common and core set of modulated pathways across distinct mouse models of T1D and identified PDIA1 as a potential human biomarker of β cell stress in T1D.
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Project description:This a model from the article:
Modelling the onset of Type 1 diabetes: can impaired macrophage phagocytosis make the difference between health and disease?
Maree AF, Kublik R, Finegood DT, Edelstein-Keshet L.Philos Transact A Math Phys Eng Sci.2006 May 15;364(1842):1267-82.
16608707,
Abstract:
A wave of apoptosis (programmed cell death) occurs normally in pancreatic beta-cells of newborn mice. We previously showed that macrophages from non-obese diabetic (NOD) mice become activated more slowly and engulf apoptotic cells at a lower rate than macrophages from control (Balb/c) mice. It has been hypothesized that this low clearance could result in secondary necrosis, escalating inflammation and self-antigen presentation that later triggers autoimmune, Type 1 diabetes (T1D). We here investigate whether this hypothesis could offer a reasonable and parsimonious explanation for onset of T1D in NOD mice. We quantify variants of the Copenhagen model (Freiesleben De Blasio et al. 1999 Diabetes 48, 1677), based on parameters from NOD and Balb/c experimental data. We show that the original Copenhagen model fails to explain observed phenomena within a reasonable range of parameter values, predicting an unrealistic all-or-none disease occurrence for both strains. However, if we take into account that, in general, activated macrophages produce harmful cytokines only when engulfing necrotic (but not apoptotic) cells, then the revised model becomes qualitatively and quantitatively reasonable. Further, we show that known differences between NOD and Balb/c mouse macrophage kinetics are large enough to account for the fact that an apoptotic wave can trigger escalating inflammatory response in NOD, but not Balb/c mice. In Balb/c mice, macrophages clear the apoptotic wave so efficiently, that chronic inflammation is prevented.
This model originates from BioModels Database: A Database of Annotated Published Models (http://www.ebi.ac.uk/biomodels/). It is copyright (c) 2005-2011 The BioModels.net Team.
For more information see the terms of use.
To cite BioModels Database, please use: Li C, Donizelli M, Rodriguez N, Dharuri H, Endler L, Chelliah V, Li L, He E, Henry A, Stefan MI, Snoep JL, Hucka M, Le Novère N, Laibe C (2010) BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models. BMC Syst Biol., 4:92.
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