Single-cell transcriptomics and TCR repertoire sequencing of T cells of NOD mice

T cells primarily drive the autoimmune destruction of pancreatic beta cells in Type 1 diabetes (T1D). However, the profound yet uncharacterized diversity of the T cell populations in vivo has hindered obtaining a clear picture of the T cell changes that occur longitudinally as T1D onset happens. Here we profiled the transcriptome and TCR repertoire of T cells at single-cell resolution from longitudinally collected peripheral blood and islets of Non-Obese Diabetic (NOD) mice using single-cell RNA sequencing technology. We detected clonal expansion and characterized the transcriptional landscape of "islets-matching" T cell clones in the blood and "blood-matching" T cell clones in islets of diabetic NOD mice using the TCR as a molecular barcode. The clonally matching cells show enriched interferon-gamma response pathways than non-matching cells in blood and islets. In addition, we identified a set of transcriptional markers associated with the matching status of the T cell clones. This study provides a single-cell level transcriptome and TCR repertoire atlas of T cells in NOD mice. The results show that TCR and transcriptional signature can be used combinedly to develop biomarker panels for tracking and investigating islets infiltrating T cells. Paired single-cell RNA sequencing (scRNA-seq) and TCR repertoire sequencing on T cells collected from peripheral blood and pancreatic islets of NOD mice were conducted. Six paired islets and blood samples from diabetic mice and four blood samples from non-diabetic mice were used for single-cell RNA-seq and V(D)J repertoire sequencing.