Unsupervised clustering reveals a unique Treg profile in slow progressors to type 1 diabetes

AbstractObjectiveTo profile CD4+ regulatory T cells (Tregs) in a well-characterised cohort of slow progressors to type 1 diabetes, individuals positive for multiple islet autoantibodies who remain diabetes-free for at least 10 years.Research Design and MethodsPeripheral blood samples were obtained from extreme slow progressor individuals (n=8), with up to 32 years follow-up, and age and gender-matched to healthy donors. One participant in this study was identified with a raised HbA1c at the time of assessment, and was individually evaluated in the data analysis. PBMCs were isolated, from donors, and to assess frequency, phenotype and function of Tregs, multi-parameter flow cytometry and T cell suppression assays were performed. Unsupervised clustering analysis, FlowSOM and CITRUS, was used to evaluate Treg phenotypes.ResultsTreg mediated suppression of CD4+ effector T cells, from slow progressors was significantly impaired, compared to healthy donors (P<0.05). Effector CD4 T cells, from slow progressors, were more responsive to Treg suppression, compared to healthy donors, demonstrated by increased suppression of CD25 expression on effector CD4 T cells (P<0.05). Unsupervised clustering on memory CD4 T cells, from slow progressors, showed an increased frequency of activated-memory CD4 Tregs associated with increased expression of GITR, compared to healthy donors (P<0.05). The participant with a raised HbA1c had a different Treg profile, compared to slow progressors and the matched controls.ConclusionsCD4+ Tregs from slow progressor individuals have a unique Treg signature. This report highlights the need for further study of Treg heterogeneity in individuals at-risk of developing type 1 diabetes.

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Activated but functionally impaired memory Tregs are expanded in slow progressors to type 1 diabetes

Diabetologia ◽

10.1007/s00125-021-05595-0 ◽

2021 ◽

Author(s):

Joanne Boldison ◽

Anna E. Long ◽

Rachel J. Aitken ◽

Isabel V. Wilson ◽

Clare Megson ◽

...

Keyword(s):

T Cells ◽

Type 1 Diabetes ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Unsupervised Clustering ◽

Autoimmune Response ◽

Peripheral Blood Mononuclear ◽

Slow Progressors ◽

Healthy Donors

Abstract Aims/hypothesis Slow progressors to type 1 diabetes are individuals positive for multiple pancreatic islet autoantibodies who have remained diabetes-free for at least 10 years; regulation of the autoimmune response is understudied in this group. Here, we profile CD4+ regulatory T cells (Tregs) in a small but well-characterised cohort of extreme slow progressors with a median age 43 (range 31–72 years), followed up for 18–32 years. Methods Peripheral blood samples were obtained from slow progressors (n = 8), age- and sex-matched to healthy donors. One participant in this study was identified with a raised HbA1c at the time of assessment and subsequently diagnosed with diabetes; this donor was individually evaluated in the analysis of the data. Peripheral blood mononuclear cells (PBMCs) were isolated, and to assess frequency, phenotype and function of Tregs in donors, multi-parameter flow cytometry and T cell suppression assays were performed. Unsupervised clustering analysis, using FlowSOM and CITRUS (cluster identification, characterization, and regression), was used to evaluate Treg phenotypes. Results Unsupervised clustering on memory CD4+ T cells from slow progressors showed an increased frequency of activated memory CD4+ Tregs, associated with increased expression of glucocorticoid-induced TNFR-related protein (GITR), compared with matched healthy donors. One participant with a raised HbA1c at the time of assessment had a different Treg profile compared with both slow progressors and matched controls. Functional assays demonstrated that Treg-mediated suppression of CD4+ effector T cells from slow progressors was significantly impaired, compared with healthy donors. However, effector CD4+ T cells from slow progressors were more responsive to Treg suppression compared with healthy donors, demonstrated by increased suppression of CD25 and CD134 expression on effector CD4+ T cells. Conclusions/interpretations We conclude that activated memory CD4+ Tregs from slow progressors are expanded and enriched for GITR expression, highlighting the need for further study of Treg heterogeneity in individuals at risk of developing type 1 diabetes. Graphical abstract

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Immunological characterisations of peripheral blood memory CD4+ T cells in children with type 1 diabetes, their non-diabetic siblings and age- and gender-matched unrelated healthy control children

10.14264/uql.2015.809 ◽

2015 ◽

Author(s):

Michael Lei Bian

Keyword(s):

T Cells ◽

Type 1 Diabetes ◽

Peripheral Blood ◽

Cd4 T Cells ◽

Age And Gender ◽

Healthy Control ◽

And Gender ◽

Memory Cd4 T Cells

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Faculty Opinions recommendation of Pathogenic CD4 T cells in type 1 diabetes recognize epitopes formed by peptide fusion.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726147425.793514725 ◽

2016 ◽

Author(s):

David Serreze

Keyword(s):

T Cells ◽

Type 1 Diabetes ◽

Cd4 T Cells

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Proinsulin-Reactive CD4 T Cells in the Islets of Type 1 Diabetes Organ Donors

Frontiers in Endocrinology ◽

10.3389/fendo.2021.622647 ◽

2021 ◽

Vol 12 ◽

Author(s):

Laurie G. Landry ◽

Amanda M. Anderson ◽

Holger A. Russ ◽

Liping Yu ◽

Sally C. Kent ◽

...

Keyword(s):

T Cells ◽

Type 1 Diabetes ◽

T Cell ◽

Cd4 T Cells ◽

Pancreatic Beta Cells ◽

Hot Spot ◽

Cell Receptor ◽

Organ Donors ◽

Hla Dq

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.

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