Beta cell-specific CD8⁺ T cells maintain stem cell memory-associated epigenetic programs during type 1 diabetes.

Area of Science:

• Immunology
• Endocrinology
• Epigenetics

Background:

• Type 1 diabetes (T1D) is characterized by autoimmune destruction of pancreatic beta cells.
• CD8+ T cells targeting beta cells persist despite continuous antigen exposure, suggesting unique survival mechanisms.

Purpose of the Study:

• To investigate the epigenetic basis for the long-lived nature of beta cell-specific CD8+ T cells in T1D.
• To establish and utilize a DNA methylation-based multipotency index for assessing T cell differentiation states.

Main Methods:

• Development of a DNA methylation-based T cell multipotency index.
• Single-cell assay for transposase-accessible chromatin using sequencing (scTFA-seq).
• Analysis of CD8+ T cell distribution and epigenetic profiles in murine lymphoid and pancreatic tissues.

Main Results:

• Beta cell-specific CD8+ T cells exhibit a stem-like epigenetic multipotency score.
• Individual T cells display a mix of naive and effector epigenetic programs.
• T cells from lymphoid tissue retain greater epigenetic plasticity than those from the pancreas.

Conclusions:

• Epigenetic multipotency contributes to the longevity of autoreactive CD8+ T cells in T1D.
• The multipotency index is a valuable tool for studying CD8+ T cell differentiation in T1D.
• Understanding T cell plasticity is crucial for developing T1D immunotherapies.