scholarly journals Targeting transcriptional coregulator OCA-B/Pou2af1 blocks activated autoreactive T cells in the pancreas and type-1 diabetes

2020 ◽  
Author(s):  
Heejoo Kim ◽  
Jelena Perovanovic ◽  
Arvind Shakya ◽  
Zuolian Shen ◽  
Cody N. German ◽  
...  

AbstractThe transcriptional coregulator OCA-B promotes expression of T cell target genes in cases of repeated antigen exposure, a necessary feature of autoimmunity. We hypothesized that T cell-specific OCA-B deletion and pharmacologic OCA-B inhibition would protect mice from autoimmune diabetes. We developed an Ocab conditional allele and backcrossed it onto a diabetes-prone NOD/ShiLtJ strain background. T cell-specific OCA-B loss protected mice from spontaneous disease. Protection was associated with large reductions in islet CD8+ T cell receptor specificities associated with diabetes pathogenesis. CD4+ clones associated with diabetes were present, but associated with anergic phenotypes. The protective effect of OCA-B loss was recapitulated using autoantigen-specific NY8.3 mice, but diminished in monoclonal models specific to artificial or neoantigens. Rationally-designed membrane-penetrating OCA-B peptide inhibitors normalized glucose levels, and reduced T cell infiltration and proinflammatory cytokine expression in newly-diabetic NOD mice. Together, the results indicate that OCA-B is a potent autoimmune regulator and a promising target for pharmacologic inhibition.~40-word summary statement for the online JEM table of contents and alertsKim and colleagues show that OCA-B in T cells is essential for the generation of type-1 diabetes. OCA-B loss leaves the pancreatic lymph nodes largely undisturbed, but associates autoreactive CD4+ T cells in the pancreas with anergy while deleting potentially autoreactive CD8+ T cells.SummaryKim et al. show that loss or inhibition of OCA-B in T cells protects mice from type-1 diabetes.

2020 ◽  
Vol 218 (3) ◽  
Author(s):  
Heejoo Kim ◽  
Jelena Perovanovic ◽  
Arvind Shakya ◽  
Zuolian Shen ◽  
Cody N. German ◽  
...  

The transcriptional coregulator OCA-B promotes expression of T cell target genes in cases of repeated antigen exposure, a necessary feature of autoimmunity. We hypothesized that T cell–specific OCA-B deletion and pharmacologic OCA-B inhibition would protect mice from autoimmune diabetes. We developed an Ocab conditional allele and backcrossed it onto a diabetes-prone NOD/ShiLtJ strain background. T cell–specific OCA-B loss protected mice from spontaneous disease. Protection was associated with large reductions in islet CD8+ T cell receptor specificities associated with diabetes pathogenesis. CD4+ clones associated with diabetes were present but associated with anergic phenotypes. The protective effect of OCA-B loss was recapitulated using autoantigen-specific NY8.3 mice but diminished in monoclonal models specific to artificial or neoantigens. Rationally designed membrane-penetrating OCA-B peptide inhibitors normalized glucose levels and reduced T cell infiltration and proinflammatory cytokine expression in newly diabetic NOD mice. Together, the results indicate that OCA-B is a potent autoimmune regulator and a promising target for pharmacologic inhibition.


2021 ◽  
Vol 12 ◽  
Author(s):  
Maki Nakayama ◽  
Aaron W. Michels

T cell receptors (TCRs) are unique markers that define antigen specificity for a given T cell. With the evolution of sequencing and computational analysis technologies, TCRs are now prime candidates for the development of next-generation non-cell based T cell biomarkers, which provide a surrogate measure to assess the presence of antigen-specific T cells. Type 1 diabetes (T1D), the immune-mediated form of diabetes, is a prototypical organ specific autoimmune disease in which T cells play a pivotal role in targeting pancreatic insulin-producing beta cells. While the disease is now predictable by measuring autoantibodies in the peripheral blood directed to beta cell proteins, there is an urgent need to develop T cell markers that recapitulate T cell activity in the pancreas and can be a measure of disease activity. This review focuses on the potential and challenges of developing TCR biomarkers for T1D. We summarize current knowledge about TCR repertoires and clonotypes specific for T1D and discuss challenges that are unique for autoimmune diabetes. Ultimately, the integration of large TCR datasets produced from individuals with and without T1D along with computational ‘big data’ analysis will facilitate the development of TCRs as potentially powerful biomarkers in the development of T1D.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mengjun Zhang ◽  
Yuanqiang Wang ◽  
Xiangqian Li ◽  
Gang Meng ◽  
Xiaoling Chen ◽  
...  

Autoreactive CD8+ T cells play an indispensable key role in the destruction of pancreatic islet β-cells and the initiation of type 1 diabetes (T1D). Insulin is an essential β-cell autoantigen in T1D. An HLA-A*0201-restricted epitope of insulin A chain (mInsA2-10) is an immunodominant ligand for autoreactive CD8+ T cells in NOD.β2mnull.HHD mice. Altered peptide ligands (APLs) carrying amino acid substitutions at T cell receptor (TCR) contact positions within an epitope are potential to modulate autoimmune responses via triggering altered TCR signaling. Here, we used a molecular simulation strategy to guide the generation of APL candidates by substitution of L-amino acids with D-amino acids at potential TCR contact residues (positions 4 and 6) of mInsA2-10, named mInsA2-10DQ4 and mInsA2-10DC6, respectively. We found that administration of mInsA2-10DQ4, but not DC6, significantly suppressed the development of T1D in NOD.β2mnull.HHD mice. Mechanistically, treatment with mInsA2-10DQ4 not only notably eliminated mInsA2-10 autoreactive CD8+ T cell responses but also prevented the infiltration of CD4+ T and CD8+ T cells, as well as the inflammatory responses in the pancreas of NOD.β2mnull.HHD mice. This study provides a new strategy for the development of APL vaccines for T1D prevention.


2021 ◽  
Vol 12 ◽  
Author(s):  
Laurie G. Landry ◽  
Amanda M. Anderson ◽  
Holger A. Russ ◽  
Liping Yu ◽  
Sally C. Kent ◽  
...  

Proinsulin is an abundant protein that is selectively expressed by pancreatic beta cells and has been a focus for development of antigen-specific immunotherapies for type 1 diabetes (T1D). In this study, we sought to comprehensively evaluate reactivity to preproinsulin by CD4 T cells originally isolated from pancreatic islets of organ donors having T1D. We analyzed 187 T cell receptor (TCR) clonotypes expressed by CD4 T cells obtained from six T1D donors and determined their response to 99 truncated preproinsulin peptide pools, in the presence of autologous B cells. We identified 14 TCR clonotypes from four out of the six donors that responded to preproinsulin peptides. Epitopes were found across all of proinsulin (insulin B-chain, C-peptide, and A-chain) including four hot spot regions containing peptides commonly targeted by TCR clonotypes derived from multiple T1D donors. Of importance, these hot spots overlap with peptide regions to which CD4 T cell responses have previously been detected in the peripheral blood of T1D patients. The 14 TCR clonotypes recognized proinsulin peptides presented by various HLA class II molecules, but there was a trend for dominant restriction with HLA-DQ, especially T1D risk alleles DQ8, DQ2, and DQ8-trans. The characteristics of the tri-molecular complex including proinsulin peptide, HLA-DQ molecule, and TCR derived from CD4 T cells in islets, provides an essential basis for developing antigen-specific biomarkers as well as immunotherapies.


PLoS ONE ◽  
2014 ◽  
Vol 9 (11) ◽  
pp. e112467 ◽  
Author(s):  
Joanna Kern ◽  
Robert Drutel ◽  
Silvia Leanhart ◽  
Marek Bogacz ◽  
Rafal Pacholczyk

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Cailin Yu ◽  
Jeremy C. Burns ◽  
William H. Robinson ◽  
Paul J. Utz ◽  
Peggy P. Ho ◽  
...  

Type 1 diabetes is an autoimmune disease in which insulin-producing pancreatic isletβcells are the target of self-reactive B and T cells. T cells reactive with epitopes derived from insulin and/or IGRP are critical for the initiation and maintenance of disease, but T cells reactive with other islet antigens likely have an essential role in disease progression. We sought to identify candidate CD8+T cell epitopes that are pathogenic in type 1 diabetes. Proteins that elicit autoantibodies in human type 1 diabetes were analyzed by predictive algorithms for candidate epitopes. Using several different tolerizing regimes using synthetic peptides, two new predicted tolerogenic CD8+T cell epitopes were identified in the murine homolog of the major human islet autoantigen zinc transporter ZnT8 (aa 158–166 and 282–290) and one in a non-βcell protein, dopamineβ-hydroxylase (aa 233–241). Tolerizing vaccination of NOD mice with a cDNA plasmid expressing full-length proinsulin prevented diabetes, whereas plasmids encoding ZnT8 and DβH did not. However, tolerizing vaccination of NOD mice with the proinsulin plasmid in combination with plasmids expressing ZnT8 and DβH decreased insulitis and enhanced prevention of disease compared to vaccination with the plasmid encoding proinsulin alone.


2003 ◽  
Vol 198 (7) ◽  
pp. 1103-1106 ◽  
Author(s):  
Irina Apostolou ◽  
Zhenyue Hao ◽  
Klaus Rajewsky ◽  
Harald von Boehmer

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.


2020 ◽  
Author(s):  
Ada Admin ◽  
Terri C. Thayer ◽  
Joanne Davies ◽  
James A. Pearson ◽  
Stephanie J. Hanna ◽  
...  

Lymph node stromal cells (LNSC) are essential for providing and maintaining peripheral self-tolerance of potentially autoreactive cells. In type 1 diabetes, proinsulin-specific CD8<sup>+</sup>T-cells, escaping central and peripheral tolerance, contribute to beta-cell destruction. Using G9Cα<sup>-/-</sup>CD8<sup>+</sup>T-cells specific for proinsulin, we studied the mechanisms by which LNSC regulate low-avidity autoreactive cells in the nonobese diabetic (NOD) mouse model of type 1 diabetes. Whereas MHC-matched NOD-LNSC significantly reduced G9Cα<sup>-/-</sup>CD8<sup>+</sup>T-cell cytotoxicity and DC-induced proliferation, they failed to sufficiently regulate T-cells stimulated by anti-CD3/CD28. In contrast, non-MHC matched, control C57BL/6 mouse LNSC suppressed T-cell receptor engagement by anti-CD3/CD28 via MHC-independent mechanisms. This C57BL/6-LNSC suppression was maintained even after removal of the LNSC, demonstrating a direct effect of LNSC on T-cells, modifying antigen sensitivity and effector function. Thus, our results suggest that a loss of NOD-LNSC MHC-independent suppressive mechanisms may contribute to diabetes development.


2020 ◽  
Author(s):  
Ada Admin ◽  
Fernanda M. C. Sodré ◽  
Samal Bissenova ◽  
Ylke Bruggeman ◽  
Ronak Tilvawala ◽  
...  

Protein citrullination plays a role in several autoimmune diseases. Its involvement in murine and human type 1 diabetes has recently been recognized through the discovery of antibodies and T-cell reactivity against citrullinated peptides. In the current study, we demonstrate that systemic inhibition of peptidylarginine deiminases (PADs), the enzymes mediating citrullination, through BB-Cl-amidine treatment, prevents diabetes development in NOD mice. This prevention was associated with reduced levels of citrullination in the pancreas, decreased circulating autoantibody titers against citrullinated GRP78 and reduced spontaneous NETosis of bone marrow-derived neutrophils. Moreover, BB-Cl-amidine treatment induced a shift from Th1 to Th2 cytokines in the serum and an increase in the frequency of regulatory T cells in the blood and spleen. In the pancreas, BB-Cl-amidine treatment preserved insulin production and was associated with a less destructive immune infiltrate, characterized by reduced frequencies of effector memory CD4<sup>+</sup> T cells and a modest reduction in the frequency of IFNγ-producing CD4<sup>+</sup> and CD8<sup>+</sup> T cells. Our results point to a role of citrullination in the pathogenesis of autoimmune diabetes, with PAD inhibition leading to disease prevention through modulation of immune pathways. These findings provide insight in the potential of PAD inhibition for treating autoimmune diseases like type 1 diabetes.


2020 ◽  
Author(s):  
Ada Admin ◽  
Andrew P. Trembath ◽  
Kelsey L. Krausz ◽  
Neekun Sharma ◽  
Ivan C. Gerling ◽  
...  

NKG2D is implicated in autoimmune diabetes. However, the role of this receptor in diabetes pathogenesis is unclear owing to conflicting results with studies involving global inhibition of NKG2D signaling. We found that NKG2D and its ligands are present in human pancreata, with expression of NKG2D and its ligands increased in the islets of patients with type 1 diabetes. To directly assess the role of NKG2D in the pancreas, we generated NOD mice that express an NKG2D ligand in b-islet cells. Diabetes was reduced in these mice. The reduction corresponded with a decrease in the effector to central memory CD8<sup>+</sup> T cell ratio. Further, NKG2D signaling during in vitro activation of both mouse and human CD8+ T cells resulted in an increased number of central memory CD8<sup>+</sup> T cells and diabetes protection by central memory CD8<sup>+</sup> T cells in vivo. Taken together, these studies demonstrate that there is a protective role for central memory CD8<sup>+</sup> T cells in autoimmune diabetes and that this protection is enhanced with NKG2D signaling. These findings stress the importance of anatomical location when determining the role NKG2D signaling plays, as well as when developing therapeutic strategies targeting this pathway, in type 1 diabetes development.


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