IFN-α Induces Heterogenous ROS Production in Human β-Cells

Type 1 diabetes (T1D) is a multifactorial disease involving genetic and environmental factors, including viral infection. We investigated the impact of interferon alpha (IFN-), a cytokine produced during the immune response to viral infection or the presence of un-edited endogenous double-stranded RNAs, on human {beta}-cell physiology. Intravital microscopy on transplanted human islets using a {beta}-cell-selective reactive oxygen species (ROS) biosensor (RIP1-GRX1-roGFP2), revealed a subset of human {beta}-cells that acutely produce ROS in response to IFN-. Comparison to Integrated Islet Distribution Program (IIDP) phenotypic data revealed that healthier donors had more ROS accumulating cells. In vitro IFN- treatment of human islets similarly elicited a heterogenous increase in superoxide production that originated in the mitochondria. To determine the unique molecular signature predisposing cells to IFN- stimulated ROS production, we flow sorted human islets treated with IFN-. RNA sequencing identified genes involved in inflammatory and immune response in the ROS-producing cells. Comparison with single cell RNA-Seq datasets available through the Human Pancreas Analysis Program (HPAP) showed that genes upregulated in ROS-producing cells are enriched in control {beta}-cells rather than T1D donors. Combined, these data suggest that IFN- stimulates mitochondrial ROS production in healthy human {beta}-cells, potentially predicting a more efficient antiviral response.