scholarly journals C-terminal modification of the insulin B:11–23 peptide creates superagonists in mouse and human type 1 diabetes

2017 ◽  
Vol 115 (1) ◽  
pp. 162-167 ◽  
Author(s):  
Yang Wang ◽  
Tomasz Sosinowski ◽  
Andrey Novikov ◽  
Frances Crawford ◽  
David B. Neau ◽  
...  
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
T Cell Activation ◽  
Posttranslational Modifications ◽  
Cell Activation ◽  
Nod Mice ◽  
Side Chain ◽  
C Terminus

A polymorphism at β57 in some major histocompatibility complex class II (MHCII) alleles of rodents and humans is associated with a high risk for developing type 1 diabetes (T1D). However, a highly diabetogenic insulin B chain epitope within the B:9–23 peptide is presented poorly by these alleles to a variety of mouse and human CD4 T cells isolated from either nonobese diabetic (NOD) mice or humans with T1D. We have shown for both species that mutations at the C-terminal end of this epitope dramatically improve presentation to these T cells. Here we present the crystal structures of these mutated peptides bound to mouse IAg7 and human HLA-DQ8 that show how the mutations function to improve T-cell activation. In both peptide binding grooves, the mutation of B:22R to E in the peptide changes a highly unfavorable side chain for the p9 pocket to an optimal one that is dependent on the β57 polymorphism, accounting for why these peptides bind much better to these MHCIIs. Furthermore, a second mutation of the adjacent B:21 (E to G) removes a side chain from the surface of the complex that is highly unfavorable for a subset of NOD mouse CD4 cells, thereby greatly enhancing their response to the complex. These results point out the similarities between the mouse and human responses to this B chain epitope in T1D and suggest there may be common posttranslational modifications at the C terminus of the peptide in vivo to create the pathogenic epitopes in both species.

scholarly journals Loss of Zbtb32 in NOD mice does not significantly alter T cell responses.

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 318
Author(s):  
William D. Coley ◽  
Yongge Zhao ◽  
Charles J. Benck ◽  
Yi Liu ◽  
Chie Hotta-Iwamura ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Nod Mice ◽  
Diabetes Incidence ◽  
T Cell Tolerance ◽  
Cell Tolerance

Background: We previously identified the transcriptional regulator Zbtb32 as a factor that can promote T cell tolerance in the Non-Obese Diabetic (NOD) mouse, a model of Type 1 diabetes. Antigen targeted to DCIR2+ dendritic cells (DCs) in vivo inhibited both diabetes and effector T cell expansion in NOD mice. Furthermore, Zbtb32 was preferentially induced in autoreactive CD4 T cells stimulated by these tolerogenic DCIR2+ DCs, and overexpression of Zbtb32 in islet-specific T cells inhibited the diabetes development by limiting T cell proliferation and cytokine production. Methods: To further understand the role of Zbtb32 in T cell tolerance induction, we have now used CRISPR to target the Zbtb32 gene for deletion directly in NOD mice and characterized the mutant mice. We hypothesized that the systemic loss of Zbtb32 in NOD mice would lead to increased T cell activation and increased diabetes pathogenesis. Results: Although NOD.Zbtb32-/- male NOD mice showed a trend towards increased diabetes incidence compared to littermate controls, the difference was not significant. Furthermore, no significant alteration in lymphocyte number or function was observed. Importantly, in vitro stimulation of lymphocytes from NOD.Zbtb32-/- mice did not produce the expected hypersensitive phenotype observed in other genetic strains, potentially due to compensation by homologous genes. Conclusions: The loss of Zbtb32 in the NOD background does not result in the expected T cell activation phenotype.

scholarly journals Regulatory T Cells Prevent Transfer of Type 1 Diabetes in NOD Mice Only When Their Antigen Is Present In Vivo

2008 ◽  
Vol 181 (7) ◽  
pp. 4516-4522 ◽  
Author(s):  
Daniel R. Tonkin ◽  
Jing He ◽  
Gene Barbour ◽  
Kathryn Haskins
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
Regulatory T Cells ◽  
Nod Mice

scholarly journals Prevention of type 1 diabetes in mice by tolerogenic vaccination with a strong agonist insulin mimetope

2011 ◽  
Vol 208 (7) ◽  
pp. 1501-1510 ◽  
Author(s):  
Carolin Daniel ◽  
Benno Weigmann ◽  
Roderick Bronson ◽  
Harald von Boehmer
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
Nod Mice ◽  
Nonobese Diabetic ◽  
Cell Clones ◽  
Autoimmune Attack ◽  
Agonistic Activity ◽  
Novel Strategy

Type 1 diabetes (T1D) results from the destruction of insulin-secreting pancreatic β cells by autoreactive T cells. Insulin is an essential target of the autoimmune attack. Insulin epitopes recognized by diabetogenic T cell clones bind poorly to the class II I-Ag7 molecules of nonobese diabetic (NOD) mice, which results in weak agonistic activity of the peptide MHC complex. Here, we describe a strongly agonistic insulin mimetope that effectively converts naive T cells into Foxp3+ regulatory T cells in vivo, thereby completely preventing T1D in NOD mice. In contrast, natural insulin epitopes are ineffective. Subimmunogenic vaccination with strongly agonistic insulin mimetopes might represent a novel strategy to prevent T1D in humans at risk for the disease.

scholarly journals CD5 expressing CD8+ T cell subsets differ between children with Type 1 Diabetes and controls

2021 ◽  
Author(s):  
Josefine Wadenpohl ◽  
Julia Seyfarth ◽  
Paul Hehenkamp ◽  
Maximilian Hoffmann ◽  
Sebastian Kummer ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Type 1 Diabetes ◽  
T Cell ◽  
B Cell ◽  
Quantitative Pcr ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cd8 T Cell

Different lymphocyte subsets are involved in autoimmune pathogenesis of Type 1 Diabetes (T1D). Previous studies suggested a role of CD5 expressing T and B cells including rare unconventional lymphocytes with combined T- and B-cell features (DE cells). We performed algorithm-supported multi-parameter flow cytometry and quantitative PCR to investigate immune cell subsets and DE cells in children with T1D (n=20) and matched controls (n=20). Comparisons of conventional immune cells detected increased proportions of CD3+ T cells in T1D patients whereas CD19+ B cell proportions were comparable to controls. Self-organizing maps for flow cytometry analyses (FlowSOM) showed highly similar CD5 expressing B-cell subsets and no differences for DE cells were detected between the study groups by flow cytometry or specific quantitative PCR. Notably, differences in CD8 positive T cells were indicated by FlowSOM and similarity-based tSNE analyses. Study group comparison confirmed significantly reduced CD8+ T-cell proportions with moderate or low CD5 expression in T1D patients. Finally, In vitro experiments showed stable CD5 expression differences of CD8+ T cells after T-cell activation, cytokine stimulation and culture. We observed differences of T-cell co-receptor CD5 expression in T1D patients with potential relevance for immune regulation of CD8+ T-cell activation.

scholarly journals Loss of Zbtb32 in NOD mice does not significantly alter T cell responses.

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 318
Author(s):  
William D. Coley ◽  
Yongge Zhao ◽  
Charles J. Benck ◽  
Yi Liu ◽  
Chie Hotta-Iwamura ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Nod Mice ◽  
Diabetes Incidence ◽  
T Cell Tolerance ◽  
Cell Tolerance

Background:We previously identified the transcriptional regulator Zbtb32 as a factor that can promote T cell tolerance in the Non-Obese Diabetic (NOD) mouse, a model of Type 1 diabetes. Antigen targeted to DCIR2+dendritic cells (DCs)in vivoinhibited both diabetes and effector T cell expansion in NOD mice. Furthermore, Zbtb32 was preferentially induced in autoreactive CD4 T cells stimulated by these tolerogenic DCIR2+DCs, and overexpression of Zbtb32 in islet-specific T cells inhibited the diabetes development by limiting T cell proliferation and cytokine production.Methods:To further understand the role of Zbtb32 in T cell tolerance induction, we have now used CRISPR to target the Zbtb32 gene for deletion directly in NOD mice and characterized the mutant mice. We hypothesized that the systemic loss of Zbtb32 in NOD mice would lead to increased T cell activation and increased diabetes pathogenesis.Results:Although NOD.Zbtb32-/-male NOD mice showed a trend towards increased diabetes incidence compared to littermate controls, the difference was not significant. Furthermore, no significant alteration in lymphocyte number or function was observed. Importantly,in vitrostimulation of lymphocytes from NOD.Zbtb32-/-mice did not produce the expected hypersensitive phenotype observed in other genetic strains, potentially due to compensation by homologous genes.Conclusions:The loss of Zbtb32 in the NOD background does not result in the expected T cell activation phenotype.

scholarly journals Chronic CD4+ T-Cell Activation and Depletion in Human Immunodeficiency Virus Type 1 Infection: Type I Interferon-Mediated Disruption of T-Cell Dynamics

2007 ◽  
Vol 82 (4) ◽  
pp. 1870-1883 ◽  
Author(s):  
Ahmad R. Sedaghat ◽  
Jennifer German ◽  
Tanya M. Teslovich ◽  
Joseph Cofrancesco ◽  
Chunfa C. Jie ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Type I Interferon ◽  
Type I ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The mechanism of CD4+ T-cell depletion during chronic human immunodeficiency virus type 1 (HIV-1) infection remains unknown. Many studies suggest a significant role for chronic CD4+ T-cell activation. We assumed that the pathogenic process of excessive CD4+ T-cell activation would be reflected in the transcriptional profiles of activated CD4+ T cells. Here we demonstrate that the transcriptional programs of in vivo-activated CD4+ T cells from untreated HIV-positive (HIV+) individuals are clearly different from those of activated CD4+ T cells from HIV-negative (HIV−) individuals. We observed a dramatic up-regulation of cell cycle-associated and interferon-stimulated transcripts in activated CD4+ T cells of untreated HIV+ individuals. Furthermore, we find an enrichment of proliferative and type I interferon-responsive transcription factor binding sites in the promoters of genes that are differentially expressed in activated CD4+ T cells of untreated HIV+ individuals compared to those of HIV− individuals. We confirm these findings by examination of in vivo-activated CD4+ T cells. Taken together, these results suggest that activated CD4+ T cells from untreated HIV+ individuals are in a hyperproliferative state that is modulated by type I interferons. From these results, we propose a new model for CD4+ T-cell depletion during chronic HIV-1 infection.

scholarly journals Helminth Infection Can Reduce Insulitis and Type 1 Diabetes through CD25- and IL-10-Independent Mechanisms

2009 ◽  
Vol 77 (12) ◽  
pp. 5347-5358 ◽  
Author(s):  
Qian Liu ◽  
Krishnan Sundar ◽  
Pankaj K. Mishra ◽  
Gity Mousavi ◽  
Zhugong Liu ◽  
...  
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
Helminth Infection ◽  
Inflammatory Responses ◽  
Nod Mice ◽  
Interleukin 4 ◽  
Heligmosomoides Polygyrus ◽  
Nonobese Diabetic

ABSTRACT Parasitic helminth infection has been shown to modulate pathological inflammatory responses in allergy and autoimmune disease. The aim of this study was to examine the effects of infection with a helminth parasite, Heligmosomoides polygyrus, on type 1 diabetes (T1D) in nonobese diabetic (NOD) mice and to elucidate the mechanisms involved in this protection. H. polygyrus inoculation at 5 weeks of age protected NOD mice from T1D until 40 weeks of age and also inhibited the more aggressive cyclophosphamide-induced T1D. Moreover, H. polygyrus inoculation as late as 12 weeks of age reduced the onset of T1D in NOD mice. Following H. polygyrus inoculation of NOD mice, pancreatic insulitis was markedly inhibited. Interleukin-4 (IL-4), IL-10, and IL-13 expression and the frequency of CD4+ CD25+ FoxP3+ regulatory T cells were elevated in mesenteric and pancreatic lymph nodes. Depletion of CD4+ CD25+ T cells in vivo did not abrogate H. polygyrus-induced T1D protection, nor did anti-IL-10 receptor blocking antibody. These findings suggest that infection with H. polygyrus significantly inhibits T1D in NOD mice through CD25- and IL-10-independent mechanisms and also reduces the severity of T1D when administered late after the onset of insulitis.

scholarly journals A population of CD4+ T cells with a naïve phenotype stably polarized to the TH1 lineage

2020 ◽  
Author(s):  
Jonathan W. Lo ◽  
Maria Vila de Mucha ◽  
Luke B. Roberts ◽  
Natividad Garrido-Mesa ◽  
Arnulf Hertweck ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
T Cell Subsets ◽  
T Helper

AbstractT-bet is the lineage-specifying transcription factor for CD4+ T helper type 1 (TH1) cells. T-bet has also been found in other CD4+ T cell subsets, including TH17 cells and TREG, where it modulates their functional characteristics. However, we lack information on when and where T-bet is expressed during T cell differentiation and how this impacts T cell function. To address this, we traced the ontogeny of T-bet-expressing cells using a fluorescent fate-mapping mouse line. We demonstrate that T-bet is expressed in a subset of CD4+ T cells with naïve cell surface markers and that this novel cell population is phenotypically and functionally distinct from conventional naïve CD4+ T cells. These cells are also distinct from previously described populations of memory phenotype and stem cell-like T cells. Naïve-like T-bet-experienced cells are polarised to the TH1 lineage, predisposed to produce IFNγ upon cell activation, and resist repolarisation to other lineages in vitro and in vivo. These results demonstrate that lineage-specifying factors can function to polarise T cells in the absence of canonical markers of T cell activation and that this has an impact on the subsequent T helper response.

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