T helper 17 cells and interleukin-17 immunity in type 1 diabetes: From pathophysiology to targeted immunotherapies

Type 1 diabetes (T1D) is a chronic organ-specific autoimmune disorder characterized by a progressive loss of the insulin-secreting pancreatic beta cells, which ultimately results in insulinopenia, hyperglycemia and lifelong need for exogenous insulin therapy. In the pathophysiological landscape of T1D, T helper 17 cells (Th17 cells) and their hallmark cytokine, interleukin (IL)-17, play pivotal roles from disease onset to disease progression. In this narrative mini-review, we discuss the dynamic interplay between Th17 cells and IL-17 in the context of T1D, providing insights into the underlying immunologic mechanisms contributing to the IL-17-immunity-mediated pancreatic beta-cell destruction. Furthermore, we summarized the main animal and clinical studies that investigated Th17- and IL-17-targeted interventions as promising immunotherapies able to alter the natural history of T1D.