Modeling human T-cell mediated beta cell destruction

Autoimmune destruction of pancreatic β cells underlies type 1 diabetes (T1D). To understand T-cell mediated immune impact on human pancreatic β cells, we combine β cell specific expression of a model antigen CD19 and anti-CD19 chimeric antigen receptor T (CAR-T) cells. Co-culturing CD19-expressing -like cells and CD19 CAR-T cells results in T-cell mediated β-like cell death with release of activated T cell cytokines. Transcriptome analysis of β-like cells and human islets treated with conditioned medium of the immune reaction identifies upregulation of immune reaction genes and the pyroptosis mediator GSDMD as well as its activator CASP4. Caspase-4-mediated cleaved GSDMD is detected in β-like cells under inflammation and endoplasmic reticulum (ER) stress conditions. Among the immune regulatory genes, PDL1 is one of the most upregulated, and PDL1 overexpression partially protects β-like cells in mice transplanted with human β cells. This experimental platform identifies potential mechanisms of β cell destruction and may allow testing therapeutic strategies. Examination of gene expression differences in primary human islets and human pluripostent stem cells differentiated beta-like cells under control or T cell conditioned medium condition.