# Self-Reactive T Cell Development in Type 1 Diabetes

> **NIH NIH R01** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2020 · $381,250

## Abstract

Project Summary (Abstract):
Type I Diabetes (T1D) is an early onset autoimmune disease that culminates in the targeted destruction of insulin
producing  cells found within the pancreatic islets of Langerhans. The top two genetic susceptibility
determinants associated with development of Type 1 Diabetes are related to antigen presentation and antigen
availability (HLA and INS-VNTR). The identification of these and other susceptibility alleles highlight a potential
deficiency in central and peripheral tolerance to islets antigens. Therefore, studies focused on the fundamental
aspects of autoimmune T cell selection are crucial in identifying the key mechanisms that lead to the loss of
central tolerance. It is still unclear how the intracellular signaling and transcriptional profiles differ between T cells
selected on naturally expressed high affinity peptides (potential autoimmune antigens) versus low affinity
peptides (normal positive selection) during thymic development. The mechanisms behind loss of self-tolerance
appear to multifaceted and poorly understood. It is now evident that in addition to susceptibility alleles,
autoimmune diabetes is also associated with post-translationally modified epitopes that serve as neo-antigens
and aide in loss of self-tolerance. Pathogenic T cells that are specific for neo-antigens uniquely expressed in the
pancreas may escape thymic selection by a process known as ignorance. The Non-Obese Diabetic mouse
model offers an in vivo system to dissect the mechanisms of autoreactive T cell development in the thymus that
is not feasible in humans. Unlike systems build on model antigens, the NOD mouse offers a genetically
susceptible background where key target antigens undergo post-translational modification leading to
spontaneous diabetes development. Therefore, it is of high importance to study selection of autoimmune TCRs
that have spontaneously escaped negative selection in NOD mice. A limitation to such approach is the limited
number of available autoantigen-specific TCR transgenic NOD mice. This application capitalizes on our strengths
and experience in generating insulin specific TCR retrogenic mice as well as our in-depth knowledge of
thymocyte development and TCR signaling. The scope of this application will therefore be limited to, and focused
on, dissecting specific signaling mechanisms that allow thymic selection of autoimmune insulin and
chromogranin reactive Class-II restricted TCRs. In Aim 1 of the proposed work, we will use the InsB:9-23 TCR
contact mutant, p16A, to determine the cellular mechanisms for positive and negative selection of high and low
insulin reactive thymocytes. In Aim 2, we will determine the impact of early thymic antigen exposure in neonatal
mice on life-long tolerance to islet antigens. Information gathered from these studies may have a significant
impact on our understanding of how autoreactive T cells escape deletion and how antigen specific Treg
development occurs, leading to nov...

## Key facts

- **NIH application ID:** 9938567
- **Project number:** 5R01DK114456-04
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **Principal Investigator:** Matthew Bettini
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $381,250
- **Award type:** 5
- **Project period:** 2019-10-01 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9938567

## Citation

> US National Institutes of Health, RePORTER application 9938567, Self-Reactive T Cell Development in Type 1 Diabetes (5R01DK114456-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9938567. Licensed CC0.

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