Immune Checkpoint Restoration as a Therapeutic Strategy to Halt Diabetes-Driven Atherosclerosis

Diabetic atherosclerosis results from the interplay between metabolic dysfunction and immune dysregulation and remains the major cause of mortality in patients with diabetes mellitus (DM) worldwide. Emerging evidence indicates that impaired immune checkpoint signaling, particularly through the PD-1/PD-L1 and CTLA-4 pathways, contributes to the chronic vascular inflammation characteristic of diabetic cardiovascular disease. These checkpoints normally help maintain vascular homeostasis by limiting proatherogenic immune responses. In type 2 diabetes (T2D), which accounts for 90-95% of cases, chronic hyperglycemia downregulates checkpoint expression in both immune effector cells and the vascular endothelium. In type 1 diabetes (T1D), autoimmune-mediated checkpoint failure within the pancreatic islets extends to the vascular tissues, creating an early cardiovascular risk through overlapping but distinct mechanisms. The loss of checkpoint regulation amplifies Th1 and Th17 responses while impairing regulatory T cell function and accelerating plaque formation and destabilization. Observations from cancer patients receiving checkpoint inhibitors, who exhibit increased cardiovascular events, further highlight the importance of these pathways in vascular integrity. Restoring checkpoint signaling through targeted interventions, combined with biomarker-driven stratification and personalized immune profiling, may provide new strategies for preventing or slowing atherosclerotic progression in patients with diabetes.