Seminar | Extensive Characterization of Autoreactive CD8 T Cells in Type 1 Diabetes | Alice Weidman

To identify the rare subset of islet antigen-specific CD8 T cells implicated in type 1 diabetes (T1D) disease progression, we performed combinatorial dual-metal class I (HLA-A2) pooled-specificity tetramer staining of PBMCs from T1D subjects. We characterized the autoreactive CD8 T cells using an optimized 30-marker mass cytometry panel and compared their phenotype with total and virus-specific CD8 T cells. We used a variety of analysis approaches, including a method developed at Benaroya Research Institute customized for the characterization of a rare subset within a larger population. This method considers an intermediate number of phenotyping parameters. Using this new approach, we consistently found that virus-reactive cells exhibited a more memory- and exhausted-like phenotype, as expected. In contrast, autoreactive cells did not cluster tightly or vary significantly from total CD8 T cells, suggesting greater heterogeneity.